2000 R1100S Clutch/Spline Failure

[spacewrench]

Looks like my luck ran out just after 77777 miles -- fortunately, only 200 yards from home, and downhill back to my garage.

I have one of the custom longer-spline input shafts made by an R1100S enthusiast, and a longer-spline clutch plate from BMW Boneyard, but somebody on the Pelican board suggested that a transmission that fails this way, is not permanently fixable (I guess there's an underlying alignment/similar problem that will gobble up my new splines too?)

I love my bike, and if I can get another 70k out of it, the repair would be worth it, but if I should swap the whole transmission while I'm back there, I might as well do that too.

I'm off to read through the many many repair stories around the Internet, but if anybody has recent info or is in the Portland Oregon area and wants to drink beer and kibbutz while I'm trying to take my bike apart, feel free to email!

[szurszewski]

Bummer - lucky sevens indeed!

 

I’m a coupe hours north of Portland these days, and I don’t have any useful skills or knowledge to help you out, BUT if you want an extra pair of hands to help take things apart or put them back together I’d be quite happy to ride down and bring my hands. Pretty flexible schedule - so the offer is good about any time. 
-josh

[dirtrider]

1 hour ago, spacewrench said:

Looks like my luck ran out just after 77777 miles -- fortunately, only 200 yards from home, and downhill back to my garage.

I have one of the custom longer-spline input shafts made by an R1100S enthusiast, and a longer-spline clutch plate from BMW Boneyard, but somebody on the Pelican board suggested that a transmission that fails this way, is not permanently fixable (I guess there's an underlying alignment/similar problem that will gobble up my new splines too?)

I love my bike, and if I can get another 70k out of it, the repair would be worth it, but if I should swap the whole transmission while I'm back there, I might as well do that too.

I'm off to read through the many many repair stories around the Internet, but if anybody has recent info or is in the Portland Oregon area and wants to drink beer and kibbutz while I'm trying to take my bike apart, feel free to email!

 

 

Afternoon spacewrench

 

As a rule when the BMW 1100/1150 6 speed bikes have a spline failure that usually points to an alignment issue (usually between the trans input shaft centerline & crankshaft centerline.

 

BUT, basic alignment issues usually show up much earlier than 77,000 miles. 

 

You really won't know much until you get your bike apart & look at/ measure things. 

 

You might (probably do) have a slight alignment problem but at 77,000 miles you might also have some rear main bearing wear therefore crankshaft lateral moment that is also effecting your trans input shaft to crankshaft alignment.   

 

If your new (longer spline) input shaft is properly made & the spline area is properly hardened  & your longer clutch hub is properly made & properly hardened, AND the input shaft splines get along with the clutch hub splines (material wise & surface treatment wise) then you should get at least another 70,000+ miles from your clutch spline interface.

 

Now if you have a lot of rear main bearing wear then all bets are off until the excess rear crankshaft movement is repaired. 

 

 

[spacewrench]

36 minutes ago, dirtrider said:

You might (probably do) have a slight alignment problem but at 77,000 miles you might also have some rear main bearing wear therefore crankshaft lateral moment that is also effecting your trans input shaft to crankshaft alignment.   

 

Thanks, DR!  A few questions if you don't mind:

* Is the typical alignment problem angular (shaft centerlines not parallel) or displacement (centerlines parallel, but separated a little bit)?

* Is it possible to adjust the alignment somehow?  I've read tales of people making slightly displaced pins?

* Can you measure the rear main bearing play when the clutch & transmission are out of the way?

I thought the transmission just bolted on, so I don't understand how you can look inside to check the alignment, nor how you would change it even if you were able to figure out that it's angled or displaced (or both). It seems like if you're stuck measuring things while the two parts are separated, it'll be impossible to get measurements accurate enough to know that you need to shim one side of the transmission by 0.002" or move the whole thing diagonally 0.003".  But I could be underestimating the measuring ability of a good machinist, or overestimating the necessary accuracy for this application.  (For all I know, if you're within 0.1" and ±2˚, that's close enough!)

[dirtrider]

Evening  

 

* Is the typical alignment problem angular (shaft centerlines not parallel) or displacement (centerlines parallel, but separated a little bit)?--- It could be both but it is very difficult to measure or change the angular. About all you can do is measure the offset then try to correct the offset using homemade  (off-setting) locating pins.  

 

* Is it possible to adjust the alignment somehow?  I've read tales of people making slightly displaced pins?-- You can make offset pins, or machine the trans end of the pin smaller then make up offset locator bushings. Or machine the trans side of the pins smaller, then align the trans front cover to the crankshaft centerline, then fill the space between the smaller pin & trans case hole with Devcon.

 

* Can you measure the rear main bearing play when the clutch & transmission are out of the way?-- Yes, pretty easy, just rig up a dial indicator on the block with the stinger on the crankshaft then push  left & right on the rear of crankshaft. They usually were in the lateral direction more than the vertical as that is the major piston firing loading direction. 

 

I thought the transmission just bolted on, so I don't understand how you can look inside to check the alignment, nor how you would change it even if you were able to figure out that it's angled or displaced (or both). It seems like if you're stuck measuring things while the two parts are separated, it'll be impossible to get measurements accurate enough to know that you need to shim one side of the transmission by 0.002" or move the whole thing diagonally 0.003".  But I could be underestimating the measuring ability of a good machinist, or overestimating the necessary accuracy for this application.  (For all I know, if you're within 0.1" and ±2˚, that's close enough!)--- Wow, with 0.1 (one hundred thousandths of an inch)  it probably wouldn't last 500 miles. In an old BMW service bulletin on the old K bikes they said that anything over 0.25mm (little over .009") will cause excess spline wear.

 

You can't measure the alignment with the trans on the engine but once the transmission is removed you can unbolt the front transmission housing  then bolt that (bare housing) back on the engine, then make an extension that bolts to a crankshaft bolt hole, run that extension up through the center of the front  housing bearing hole, then mount a small dial indicator on that extension. Then just turn the crankshaft & measure the run-out, as that will show any straight offset misalignment (won't show angular offset though). 

[spacewrench]

55 minutes ago, dirtrider said:

You can't measure the alignment with the trans on the engine but once the transmission is removed you can unbolt the front transmission housing  then bolt that (bare housing) back on the engine, then make an extension that bolts to a crankshaft bolt hole, run that extension up through the center of the front  housing bearing hole, then mount a small dial indicator on that extension. Then just turn the crankshaft & measure the run-out, as that will show any straight offset misalignment (won't show angular offset though). 

 

D'oh!  That tip is totally worth the price of admission here!  I wouldn't'a thought of it -- I probably would have just replaced the input shaft, reassembled the transmission and tried to put it back on.  I'll stop midway through and try to figure out the alignment when I can look through the inside of the front housing, before the guts are back in it.

 

Thanks!

[dirtrider]

12 hours ago, spacewrench said:

 

D'oh!  That tip is totally worth the price of admission here!  I wouldn't'a thought of it -- I probably would have just replaced the input shaft, reassembled the transmission and tried to put it back on.  I'll stop midway through and try to figure out the alignment when I can look through the inside of the front housing, before the guts are back in it.

 

Thanks!

 

Morning spacewrench

 

A couple  of thoughts-- Do verify rear main bearing wear (lateral movement)  before doing the alignment check using the trans front cover as rear main bearing wear can/will effect what you measure for trans to engine misalignment.  

 

If you have any (even slight) rear main bearing wear then remove the engine spark plugs before rotating the crankshaft for the trans to engine alignment check as cylinder compression will move the crankshaft back & forth during rotation. 

 

 

[nrp]

The engine rear main bearing wear is  from the engine-transmission radial alignment error.  i call it radial misalignment and the axis of the bearing wear can be in any direction.  The main bearing wears i have seen have been mostly oriented in a vertical direction, and so was the measured error.  

 

There is probably no spline wear contribution from moderate angular misalignment.  If you wish, it is easily verified using the swepted dial indicator in the flywheel and again on the transmission input shaft. But it isn't really very likely based on typical manufacturing processes.  Besides there is a flex plate between the clutch disk and the spline hub.  There is  no radial error accommodation built into anything, though. 

 

Radial misalignment on the other hand is VERY hard to control to sufficient accuracy to minimize spline wear.   My guess is that anything more than .003 in TIR  ()total indicated Run out) will cause premature wear.  I'd guess you have maybe on the order of.006 inch total radial error to give the life you experienced.   And that's my absolute wildest guess based on 50 years of engineering  (lawyers sell advice whereas engineers are simply flattered to be asked!)

 

I have (and still can) made offset alignment pins, but I gave my travelling kludged indicator mag base to the local Airhead guys.  The end ball also fell off my cheap ($20) dial indicator.

 

It's probably best to find a different transmission and housing.  I don't think you can' expect substantially more life with simply a longer spline engagement.

[Jim Moore]

1 hour ago, nrp said:

It's probably best to find a different transmission and housing.  I don't think you can' expect substantially more life with simply a longer spline engagement.

 

There are some guys who have done pretty well with longer spline engagement.  Someone on the R1100S board. A guy out in Cali. Name escapes me.

[spacewrench]

I got a longer-spline input shaft from Reto Camenisch up in Canada, and a longer-splined-hub clutch disc from Beemer Boneyard.  Guys on another board pointed me to a couple of articles by Largiader (I think at Virginia Motorrad?)  If I understand correctly, a big part of the problem may be that the R11100S input shaft doesn't extend past where the clutch disc webbing connects to the splined hub.  So when you load up the disc by engaging the clutch, you're applying twist to the hub past the end of the splined shaft.  Which causes it to rock a little bit and wear down the splines.  (He doesn't exactly say that, it's just my interpretation of his pictures and description.)

[dirtrider]

11 hours ago, spacewrench said:

I got a longer-spline input shaft from Reto Camenisch up in Canada, and a longer-splined-hub clutch disc from Beemer Boneyard.  Guys on another board pointed me to a couple of articles by Largiader (I think at Virginia Motorrad?)  If I understand correctly, a big part of the problem may be that the R11100S input shaft doesn't extend past where the clutch disc webbing connects to the splined hub.  So when you load up the disc by engaging the clutch, you're applying twist to the hub past the end of the splined shaft.  Which causes it to rock a little bit and wear down the splines.  (He doesn't exactly say that, it's just my interpretation of his pictures and description.)

 

 

 

Morning spacewrench

 

Correct, your trans input shaft does not extend all the way through the clutch disk splines. I'm not really sure why, might be something BMW did on purpose or there could be  valid reason that it was designed or built that way.

 

If that short spline shaft to disk engagement was the reason for the spline failures then WHY didn't all BMW 1100/1150 6 speed motorcycles fail their splines?  Some failed as early as 20,000 miles & others went full life of the motorcycle to well over 150,000 miles, same short spline engagement.

 

I owned (2) "from new" BMW 1150RT 6 speed motorcycles, one failed the splines very early & the other one is still going on the original clutch splines & has  been ridden  to all US states except Hawaii & most of lower Canada (both motorcycles had the same short spline engagement). 

 

In any case BMW never changed the design or build over the entire run of the BMW 11XX 6 speed motorcycles. With all the clutch spline failures on the 11XX 6 speed motorcycles if the short spline engagement was  the  root-cause issue then why didn't BMW change the engagement depth in the later 1150 6 speed models? Early on BMW required all the dealers to send back the failed spline & clutch parts from warranty repaired spline failures so they definitely knew about the short spline engagement & I'm sure they did a failure analysis on the parts sent back. 

 

To my engineering mind spline failure is due to poor alignment not due to spline engagement depth, period. 

 

On the few  "failed spline" 1150 6 speed motorcycles  that I have checked the trans to engine alignment on  all have shown to be out of alignment (they were "low mileage at failure" motorcycles though) . But after correct  (best possible) alignment & new spline shaft / clutch disk install  I am not aware of a second failure on those bikes (but a few of those 1150 bikes have moved on to a number of new owners so I have lost track of  them long ago) 

 

 

 

 

 

 

[spacewrench]

3 hours ago, dirtrider said:

 

If that short spline shaft to disk engagement was the reason for the spline failures then WHY didn't all BMW 1100/1150 6 speed motorcycles fail their splines?

[...]

On the few  "failed spline" 1150 6 speed motorcycles  that I have checked the trans to engine alignment on  all have shown to be out of alignment (they were "low mileage at failure" motorcycles though) . But after correct  (best possible) alignment & new spline shaft / clutch disk install  I am not aware of a second failure on those bikes (but a few of those 1150 bikes have moved on to a number of new owners so I have lost track of  them long ago)

I dunno...

(Actually, I'm an electrical engineer, but definitely not a mechanical engineer!)

 

As a lawyer, I'd cynically guess that the reason for no change over the run is liability -- if they made (only) that minor change and the failure rate dropped, sue-happy Americans would have had a field day with them, same as people are doing to Apple over the iPhone batteries.  They'd have had to make bigger changes, and maybe the product line wasn't worth the engineering investment.

 

As an engineer (on the Internet, anyway) I'd guess that rider technique and/or conditions are significant.  Besides, a fair number of people never ride their bikes more than 5-10k -- I still see R1100Ss for sale with shockingly low mileage.  So maybe BMW figured they could roll the dice on the number of people who'd ride their bikes hard, vs. the ones who ride their bikes to Starbuck's for the club meeting.  And by the time everyone was seeing failures, it'd be 20 years later and only mad dogs and Englishmen would still be riding these.

 

I wish I knew whether my bike had had a previous failure.  I bought it from a guy who claimed to have worked at a dealer, and he said it was a one or two-owner bike from a couple who were good customers of the dealership.  If so, it was probably maintained adequately.  If this is the second failure, then they must have reassembled it out of alignment, or there's some other problem.  Or maybe I ride it differently than they did (but I only put on 10-12k of the 77k miles, over a year and a half or so).

 

Anyway, I've got the parts, and I know that I should try to line things up accurately, so I'm pretty optimistic that I'll be able to ride this bike for a long time.

[dirtrider]

Morning spacewrench

 

As a lawyer, I'd cynically guess that the reason for no change over the run is liability -- if they made (only) that minor change and the failure rate dropped, sue-happy Americans would have had a field day with them, same as people are doing to Apple over the iPhone batteries.  They'd have had to make bigger changes, and maybe the product line wasn't worth the engineering investment.

 

This doesn't seem to hold much water as BMW made a significant change in late 2003/2004 by going to a twin spark engine that significantly lowered the surging complaint rate (we didn't hear of much of any suing for the previous single spark surging problems)  When the twin spark was released would have been a prefect time to phase in a  running clutch/spline area change. 

 

Or when BMW changed out the final drive crown bearing from a 17 ball to a 19 ball to try to prevent cronic crown bearing failure.  

 

Or on the 1150 bikes when  BMW changed the I-ABS  system to a rear brake shutdown at stop & larger rear master cylinder to  compensate for not enough rear reserve (no retrofits with this).  

 

Same on the BMW 1200 bikes when BMW upsized the rear pinion bearing due to a high failure rate (didn't hear of any suing there either), or later in the  1200 run when BMW phased in a more robust drive shaft due to early shaft failures. 

 

Anyway, I've got the parts, and I know that I should try to line things up accurately, so I'm pretty optimistic that I'll be able to ride this bike for a long time.

 

Definitely try to measure the alignment & get it closer,  if you find it off more than a few thousandths then correct it.  (just don't let rear main bearing wear skew your measurement data).

 

If you find your trans to engine alignment off more than about .003"- .005" then you have probably found the reason for your failed splines.   

 

 

 

[AndyS]

I really think a new gearbox is the way to go. Trying to engineer a solution is very long winded. A new / replacement transmission off a newer bike sounds much more like the cure.

You already have been down the extended contact route, which may have deferred the issue, but didn't fix it. When you have the correct unit, you do not need an extended hub as the OEM items work just fine.

[Lowndes]

There was some discussion a while back, of a "warped clutch basket" being a possible cause of spline failure.   The warpage possibly caused by crated bikes being handled roughly (or dropped, as in landed abruptly) in transit.  Any warpage would be easy to see and measure thru the starter hole.

[dirtrider]

8 hours ago, Lowndes said:

There was some discussion a while back, of a "warped clutch basket" being a possible cause of spline failure.   The warpage possibly caused by crated bikes being handled roughly (or dropped, as in landed abruptly) in transit.  Any warpage would be easy to see and measure thru the starter hole.

 

Morning  Lowndes

 

When you say "warped clutch basket"  are you referring to the 'Clutch Housing' (basically the flywheel?

 

If so then I don't see how a person could see or measure any warpage through the starter hole.

 

The clutch housing is made up of stamped parts with only the contact areas for the pressure plate &  housing cover machined flat with machined  precise positions. All the other areas are pretty crude with no precision areas.

 

The  pressure plate floats on those springy leaf's & the clutch cover is cast then precision  machined only at the cutch  disk face, pins,  & at the contact points to the clutch housing. 

 

Once taken apart then a dial indicator could be set up to indicate on the precision machined pads of the clutch housing but with it still assembled I just can't see how to get any useful run-out data on any of the clutch parts. 

 

 

[AndyS]

I assumed Lowndes meant the gearbox bell housing.

 

[nrp]

If I was in a meeting in the warranty & service dept of BMW & the topic is why all the spline failures on R1XXX bikes,  This would be  my first guess:

 

There is obviously an accuracy problem in the finished clutch bell housing.  Why?  Either the raw bell housing casting is being randomly distorted as it is clamped in the machining center (most certainly a numerically controlled outfit), or the raw casting is so flimsy that it distorts easily afterwards.  Numerical machining centers are inherently very accurate - certainly sufficient for this application.  

 

But I'm inclined to think that the design of the casting is inherently flimsy since there is a major cut out for the starter which interrupts the needed stiffness of the flange on the engine side. 

 

Just maybe the manufacturer doesn't understand the problem.  And as a company man (which I'm sure not!) - the cost of a wide ranging warranty fix would suggest we'd just tough it out & nobody in this room say anything.

 

 

[dirtrider]

21 hours ago, nrp said:

If I was in a meeting in the warranty & service dept of BMW & the topic is why all the spline failures on R1XXX bikes,  This would be  my first guess:

 

There is obviously an accuracy problem in the finished clutch bell housing.  Why?  Either the raw bell housing casting is being randomly distorted as it is clamped in the machining center (most certainly a numerically controlled outfit), or the raw casting is so flimsy that it distorts easily afterwards.  Numerical machining centers are inherently very accurate - certainly sufficient for this application.  

 

But I'm inclined to think that the design of the casting is inherently flimsy since there is a major cut out for the starter which interrupts the needed stiffness of the flange on the engine side. 

 

Just maybe the manufacturer doesn't understand the problem.  And as a company man (which I'm sure not!) - the cost of a wide ranging warranty fix would suggest we'd just tough it out & nobody in this room say anything.

 

 

 

Afternoon NRP

 

There has been talk (at least between some of us old BMW riders) that warped, bent front transmission  housing cover (front transmission case housing) is/was causing the spline misalignment. 

 

We haven't talked much about it lately but early on there seemed to be  a LOT more reports of failed splines on U.S. 1150 bikes than the very few failed spline reports from European 1150 motorcycles. 

 

A friend worked as a tec at a BMW dealer so would occasionally  uncrate new 1150 BMW motorcycles, according to him the early 1150 motorcycles came crated with no front wheel & a wood support under the mid bike area. Supposedly later in the 1150 run the shipping crate supporting (chalking) was changed. He didn't uncrate a lot of motorcycles as  he was a tec & they had personal for the uncrating  job if available. I couldn't ever get him to fully explain the shipping crate support change as he didn't retain a vivid  memory of crating arrangement. 

 

In any case, at one time we were convinced that  the possibility of a crate being dropped during shipment (into/out of a ships hold, during rail shipping,  or from loading or unloading on trucks, or even harsh fork lift treatment  could be bending the rather fragile   front transmission  housing cover due to the mid bike shipping crate supporting. 

 

We never confirmed anything, just some engineering talk over a beer & trying to understand the mis-alignment issue. 

 

Years ago I was at a BMW dealer & actually saw them drop a crated motorcycle out of a delivery truck when unloading it (I have no idea what model was in the crate but it sure wouldn't have done that thing any good)

 

There is a very high probability that any out of spec parts would have been identified & corrected pretty darn quickly by BMW as soon as warranty spline failure reports started tricking in. There is also a very good chance that BMW would have added a secondary parts inspection & verification process for the trans front housing parts once that area was identified as a problem area.     (manufacturing wise, I can see a short run of out-of-spec parts but  I can't see that run of bad parts continuing for  years).

 

The thing that has me somewhat baffled is there were few to no 1100 5 speed spline failures & the 1100 5 speed bikes had close to the same starter opening & rather fragile transmission front cover. (something changed with the 1150 6 speed, but what?) -- crating, shipping, parts quality control, design deficiency,  material change, ???????). Lots of speculation on the problem being short spline shaft engagement but that doesn't fit with all the 1150 6 speed bikes that go full duty life with no spline issues.

 

I put a new clutch in a 2003 1150RT last summer (had 97,000 miles on it & had same owner from new) & the splines looked like new. Even the clutch disk was OK on thickness & spline integrity, a leaky slave cylinder soaked the disk with brake fluid so that  was the reason for the new clutch.

 

 

 

 

 

 

 

[nrp]

The original pictures at sporttouring.com of my run out measuring rig were from a local R1100RT.  The host dumped the pictures after a few years and I had no backup. 

 

I tore my 2000 R1100RT apart shortly thereafter only to find perfect splines, but was struck by the flex possibilities of the bell housing. 

 

I agree it is a mystery why this problem won't go away.  Some simple tests would have been in order. 

 

The alignment errors I have seen or been privy to (only a couple) have all been the same direction, which would suggest maybe a drop?.  I am concerned though that the use of normal mag base fixturing for a dial test indicator may flex enough to give a gravity-induced error, or like you have pointed out, the rear crank bearing clearance may make an observer wonder just where is the engine centerline.

Edited March 9, 2020 by nrp

[Jim Moore]

14 hours ago, dirtrider said:

The thing that has me somewhat baffled is there were few to no 1100 5 speed spline failures & the 1100 5 speed bikes had close to the same starter opening & rather fragile transmission front cover. 

Hi DR,

 

There were plenty of 'em. There are dozens of threads on the R1100S board at Pelican parts.

[dirtrider]

2 hours ago, Jim Moore said:

Hi DR,

 

There were plenty of 'em. There are dozens of threads on the R1100S board at Pelican parts.

 

Morning Jim

 

How many of those R1100S bikes with spline failures were 6 speed bikes? 

 

I have seen a couple & heard of some others but they were all 1100S 6 speed spline failures. 

 

 

 

 

[Jim Moore]

2 hours ago, dirtrider said:

 

Morning Jim

 

How many of those R1100S bikes with spline failures were 6 speed bikes? 

 

I have seen a couple & heard of some others but they were all 1100S 6 speed spline failures. 

 

 

 

 

Nevermind. You were saying R1100 5 speed, I was reading R1100S. Sorry.

[nrp]

FWIW - I had a classic transmission input spline failure in my lil 1975 R90/6 about 25 years ago, before Forums etc.  It doesn't get ridden much anymore & I can redo the anti-seize on the spline so easily.  But I  know that when the engine-transmission bolts are loosened, there is a lot of breathing between the E-T interface.  But I can't figure out how to measure the amount and direction of the obvious radial error since it really is a blind assembly.

[dirtrider]

11 minutes ago, nrp said:

FWIW - I had a classic transmission input spline failure in my lil 1975 R90/6 about 25 years ago, before Forums etc.  It doesn't get ridden much anymore & I can redo the anti-seize on the spline so easily.  But I  know that when the engine-transmission bolts are loosened, there is a lot of breathing between the E-T interface.  But I can't figure out how to measure the amount and direction of the obvious radial error since it really is a blind assembly.

 

Afternoon NRP

 

Back in the day  (airhead) we used to mount the transmission, then with the engine idling   loosen the bolts very slightly & keep working the clutch with the engine idling. The thought was to allow the transmission to self center on the engine's rotating crankshaft instant center.  Once trans movement (dancing on the bolts) settled down we would re-tighten the bolts. 

 

Not sure how much it really helped but we felt better for doing it & myself & none of my fellow riders had any spline issues after doing that.  

 

I have had the same thoughts on the BMW 1150 6 speed failed-spline bikes (never went past the thought stage though) , remove the trans alignment pins, then machine the pin end that goes into the trans front housing about .030" smaller OD, then re-assemble the trans to engine (with new parts).

 

Then, do the running engine/allow trans to self center, then tighten the bolts when the dancing stops. Then either fill the trans front housing pin holes (between machined pins & trans front cover) with Devcon , or just make up  offset bushings to adapt the smaller pin OD to the larger trans front housing hole ID to lock the transmission in place.

 

My one big concern on the 1150 6 speed is that the transmission is so  much heavier that it might not self center due to the heavy weight. 

 

Was just a thought anyhow___

 

  

[SmokinRZ]

I bought a 99 R1100GS (5 spd transmission) a few years back and the previous owner had replaced the transmission at 60K due to input shaft failure.  The replacement transmission was making noise so I pulled it at 80K miles and the input shaft was absolutely perfect.  No wear and still had the machining marks on the top of the splines.  That makes me think the flaw was either the transmission case or an improperly hardened input shaft.  The 5 spd transmission in the 1100 is not know for input shaft failures.