Annual Service and Cam Alignment

Andy "The Cam Chain tensioner is on the non drive side of a chain run and has nothing to do with maintaining proper cam position."

Andy then why do we need to put a repeatable tension on the cam chain with the cam chain tension tool to adjust the cams?

I have 11 or so of these under my belt including my new 17 GS, and soon a 18 GS (12) my ridding friend allows me to chase.

Seeing cam position sensors off, and cams off in new low mile bikes leads me to believe this is a original manufacturer error. I do not think we will ever wear our cams out of time.

Again the 88K RT was dead on so if wear was the issue it should (maybe) have shown on that bike.

I do appreciate everyone's thoughts on this as I just cant seem to figure it out other than manufacturer setup errors.

I love hearing well thought out reply's and this it where I learn stuff. Thank you for being patient and for your thoughts. Keep them coming.

I think the missing point here is chain pitch. The distance between the centers of the rollers. Chain wear between the drive ( crankshaft ) and driven ( camshaft ) is not made correct by the tensioner. It cannot change chain length. All the chain tensioners do is keep the slack in the chain from slapping back and forth. Tensioners are on the return side of the process. Cam chains are not known to stretch much. They live in an oil bath environment and actually have little load on them. I cannot see chain stretch as a factor in cam alignment in a bike without high mileage. Don't know what that mileage might be, but few are there yet is my guess.

Thank you Terry! You hit the nail right on the head.

What affect the cam timing, when the chain starts to wear, is the fact that the PITCH between rollers would have increased, which means that the relationship between the tooth of the drive gear to the tooth of the driven gear has changed, from the longer chain length. Clearly, Lee didn't get this!

As long as the chain tensioner is working as designed, the added slack will not affect anything (to do with the timing).

.........

 

Andy then why do we need to put a repeatable tension on the cam chain with the cam chain tension tool to adjust the cams?

 

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I love hearing well thought out reply's and this it where I learn stuff. Thank you for being patient and for your thoughts. Keep them coming.

Ahhhh.....I was waiting for somebody to pose this question! Let me turn that around on you, and ask you why BMW made that requirement? Actually, why that SPECIFIC loading and not something more, or less?

I will tell you my answer at the end.

Andy "The Cam Chain tensioner is on the non drive side of a chain run and has nothing to do with maintaining proper cam position."

 

Andy then why do we need to put a repeatable tension on the cam chain with the cam chain tension tool to adjust the cams?.

Because when you are performing maintenance, there is no engine oil pressure to load the tensioner.

We want to load the chain run to establish the full length of the chain to get the correct relationship between the crankshaft and the camshaft.

This issue never came into play before, because we could not check or adjust the cam timing. Now we have access to checking and adjusting it...we worry about it!

Now we have access to checking and adjusting it...we worry about it!

Exactly. Made me laugh out loud.

The only reason the cam chain tensioner is needed to check cam alignment is to remove slack from the drive side of chain. This simulates running conditions where the crankshaft gear pulls on the chain and the cam gear resists turning. Without this tension, you could move the cam gears back and forth with no movement of the crankshaft.

Yes, oil pressure keeps the tensioner loaded while operating. The special tool simulates this while checking alignment.

One thing good about these adjustable cam gears. You could actually correct for cam chain stretch if that was ever an issue.

The only reason the cam chain tensioner is needed to check cam alignment is to remove slack from the drive side of chain. This simulates running conditions where the crankshaft gear pulls on the chain and the cam gear resists turning. Without this tension, you could move the cam gears back and forth with no movement of the crankshaft.

Yes.

Yes, oil pressure keeps the tensioner loaded while operating. The special tool simulates this while checking alignment.

Yes

One thing good about these adjustable cam gears. You could actually correct for cam chain stretch if that was ever an issue.

Yes

A very handy calculator for use with torque wrenches and extensions of various sizes and shapes. Just click on whatever setup you have and go from there.

http://www.fordservicecontent.com/renderers/torquewrench/wrench_formula_main_en.asp

PadG

Ahh man you always pick on me

I would assume nothing more then a reference or point of measure.

I hate (not really) when you ask me questions I am not sure of the answer of

Being able to adjust them makes me wonder how they were from factory over the years.

What I find so strange is it is a "infinity" adjustment meaning you could turn them all you want as long as the cam lobe jig goes on in the right orientation to the cam lobes. I would always look for a wedge or key sytem but not here. I guess no other way to do them.

Just seems odd four bolts running through four gears it all that holds the motor in time.

when you start talking about the center(or not) of a chain pin, or link or whatever you call that individual cog, and then take into account where that is falling into the center(or not) of the sprocket that is taking some small amounts of change into account.

I still say this is manufacture error.

I also say yes something new to worry about and fuss over, but IMHO it needs looked at.

The cam position sensor being off does make a 16 GS start hard. Once set it starts off first touch of the button. Just had that conversation the other day and the gentleman is adamant it was a huge difference.

Still having fun and hope to do more this Summer. It is interesting to me and it only takes a few more min once you are in for a valve check so no big deal to do.

You are getting paranoid, Lee!

The amount of tension that you need to apply, before doing your measurement or adjustment, should be enough to remove all of the slack PLUS some more to make the chain really taut. When chain drive is used for timing, as they often are, you have to make sure that the chain system is always rigid - that is zero slack and very taut. Unladen chain tends to "belly" even on the drive side, when the driven gear is relatively unloaded. When is the driven gear unloaded? Well, the position when you are making your check or valve adjustment is it! TDC on the compression stroke, when all valves are closed, which means that none of the cams are in contact with any valve stems, ergo no load on the cam gear! This is also true for when the engine is running. The hydraulic tensioner needs to provide the same force to take out the slack PLUS to make the chain rigid, since the loading of the cam gear will vary as the cams makes and breaks contact with the valve stems.

As to the bikes that you had found the cam timing to be off, I am sure that you recall me making the statement in your original thread, in the other forum, that obviously BMW have issues in their assembly line. I don't recall the stat that you had accumulate, but isn't it true that you had found problems mainly with the '14 and '15 boxers, and not with the newer ones? I hope so, because that would mean that BMW had found and eliminated the problem on the assembly line!

One other thought. This is the very first engine that I have heard of that has adjustability built in for setting the cam timing! Are there others out there?

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One other thought. This is the very first engine that I have heard of that has adjustability built in for setting the cam timing! Are there others out there?

Morning PadG

Sure, some multi-cam automotive engines but closer to home is the BMW camhead engine.

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One other thought. This is the very first engine that I have heard of that has adjustability built in for setting the cam timing! Are there others out there?

 

Morning PadG

 

Sure, some multi-cam automotive engines but closer to home is the BMW camhead engine.

 

The UJM dual cam motors can be. There was someone out there making slotted cam sprockets that allowed for a range of cam timing overlap degrees to be set. You could slot the sprocket hole yourself with a Dremel tool, but it would be ugly to do it that way. Basically slotted sprockets allowed you to tailor between high HP peaky or less HP with broader torque. That was some while ago and with the compression ratios they use today I would be real cautious about messing with cam timing too much or risk smacking a valve into a piston crown.

This is a very interesting conversation. Love the insight

Here's a question for the sages: IF the can timing is off by a gnats a$$ on my ‘16RT (whether caused during manufacturing assembly, new chain break-in, WHATEVER) — will my dealer do a check/adjust using these special BMW TOOLS when doing the routine valve adjust service? And once properly adjusted, would this procedure EVER be required again?? EVER??

In other words, is this a “set once and forget” procedure??

Inquiring minds want to know before buying these tools. I do all my own service but if adjustment is only needed once, it would be a good reason to have the dealer it, save the space in my toolbox, and more $$ to spend on tires.

There is a huge thread on this issue at adventure rider. I haven't looked in quite awhile but it seems like I remember reading that it is now a check at 6000 miles. Don't think there are instances where it had to be done again but I have slept since reading the thread!

My GS is going in for a headlight issue and recall next week and I am going to speak with Matt about the cam alignment check.

Good morning DR!

I didn't know that the camhead has the same adjustability! I was curious from the perspective of stock powerplants, and not mods. Would you know if the cam timing can be adjusted/set with BMW's inline 4s and 6s? The feature is what I would have expected to find for the S100RR, say!

There is a huge thread on this issue at adventure rider. I haven't looked in quite awhile but it seems like I remember reading that it is now a check at 6000 miles. Don't think there are instances where it had to be done again but I have slept since reading the thread!

 

My GS is going in for a headlight issue and recall next week and I am going to speak with Matt about the cam alignment check.

That was where all this started indeed, a few years back. 2014 or 15? I had read all of the conversations about it back then.

Good morning DR!

 

I didn't know that the camhead has the same adjustability! I was curious from the perspective of stock powerplants, and not mods. Would you know if the cam timing can be adjusted/set with BMW's inline 4s and 6s? The feature is what I would have expected to find for the S100RR, say!

Morning PadG

The 1000RR uses 3 bolt cam gear positioning (so non adjustable) & the 1600 uses cam gear locating dowels (so non adjustable).

Way back even Harley used a press-on cam driven gear (no key, pin, or bolt locating control) so it was adjustable. Not easily as the cam had to be removed (very easy to do) then the gear pressed off then pressed back on in a slightly different clocking (we used to do that on the Harley Evo's to gain performance in certain operating windows especially if larger pistons were installed).

The new BMW 1200 WC cam adjustability is probably as good as any as it easily allows (precise) cam-train initial setting at factory level, covers up any machining mis-tolerances, allows very close cam timing even if the cylinder heights, head gasket thicknesses, or cylinder head machining is slightly off, & allows a slight change in cam timing at a later date if it is needed to meet new emission standards, or even easily allows new model cam updates using all the same drive/driven parts.

Seems simple enough-- set once at initial assembly, re-check/re-set at about 6K (give or take) to account for early life wear-in, then good to go for life of engine.

Good morning DR!

 

I didn't know that the camhead has the same adjustability! I was curious from the perspective of stock powerplants, and not mods. Would you know if the cam timing can be adjusted/set with BMW's inline 4s and 6s? The feature is what I would have expected to find for the S100RR, say!

 

Morning PadG

 

 

The 1000RR uses 3 bolt cam gear positioning (so non adjustable) & the 1600 uses cam gear locating dowels (so non adjustable).

 

 

 

 

 

 

Hi Dirtrider,

Actually the S1000 series including my S1000XR do have cam timing adjustment capibility. When I got my XR I purchased the cam timing tools for it like the tools I purchased for the wetheads. The concept is the same but the methods and tools are different. The S1000 engines do use a TDC tool, cam chain tensioner tool, Cam alignment tool and a cam socket wrench to accomplish this task. The driven cam sprockets have slotted bolt holes to adjust positions.

Seems like the normal cam chain stretch should be checked and the cams adjusted if necessary during the normal 18K valve check service intervals.

This procedure can be found in the BMW Repair DVD for S models K4x. section, 11 30 501 Adjusting ignition timing (cylinder-head cover removed)

Good morning DR!

 

I didn't know that the camhead has the same adjustability! I was curious from the perspective of stock powerplants, and not mods. Would you know if the cam timing can be adjusted/set with BMW's inline 4s and 6s? The feature is what I would have expected to find for the S100RR, say!

 

Morning PadG

 

 

The 1000RR uses 3 bolt cam gear positioning (so non adjustable) & the 1600 uses cam gear locating dowels (so non adjustable).

 

 

 

 

 

 

 

 

Hi Dirtrider,

 

Actually the S1000 series including my S1000XR do have cam timing adjustment capibility. When I got my XR I purchased the cam timing tools for it like the tools I purchased for the wetheads. The concept is the same but the methods and tools are different. The S1000 engines do use a TDC tool, cam chain tensioner tool, Cam alignment tool and a cam socket wrench to accomplish this task. The driven cam sprockets have slotted bolt holes to adjust positions.

 

Seems like the normal cam chain stretch should be checked and the cams adjusted if necessary during the normal 18K valve check service intervals.

 

This procedure can be found in the BMW Repair DVD for S models K4x. section, 11 30 501 Adjusting ignition timing (cylinder-head cover removed)

Thanks Mudman

I see that in the manual now that you pointed it out. I didn't realize those sprockets were slotted under the screw heads.

Hi Dirtrider,

I thank you for all the useful information you have shared over the years. I have learned much from your postings. I just wanted to share what I learned from ownership of the S1000XR.

I appreciate and look forward to your postings.

Thank you gentlemen! The fact that the 1000RR power plant has this adjustability feature makes sense to me, since it is a high-strung and highly tuned engine, and would be more sensitive to small variations. DR, how is the adjustment done on the camhead? It is surprising to me that the feature is on any of the boxers at all!

Thank you gentlemen! The fact that the 1000RR power plant has this adjustability feature makes sense to me, since it is a high-strung and highly tuned engine, and would be more sensitive to small variations. DR, how is the adjustment done on the camhead? It is surprising to me that the feature is on any of the boxers at all!

Afternoon Pad G

Very similar to the wethead. Crankshaft at TDC, cam chain tensioning tool to take slack out of chain, loosen cam sprocket bolts, use cam position locating/holding tool on cams, then re-torque cam bolts.

Did my riding friends 18 GS today. 905 miles. Great news for him everything was spot on. His valves measured out much better than mine.

L

Intake 12 14

Exhaust 36 36

R

Intake 14 14

Exhaust 36 36

I ran a fingernail on all cam lobes and no problems smooth on all cams.

So the Recap:

15 RT 12,000 miles, Left off real bad, right off also. Cam sensor on.

16 GS 12,000 miles, Right side off pretty well and left side off. Cam sensor way out. Adjusted

16 RT 6000 miles, Right dead on, Left off ever so slightly, Adjusted. Cam Position Sensor on.

16 RT 12,000 miles, Dead on both sides. Cam sensor on.

15 GSA 12,000 Miles, Dead on both sides. Cam sensor on.

14 RT 18,000 Miles , Dead on both sides. Cam sensors on.

14 RT 13,000 Miles, Dead on both sides. Cam sensor on.

15 RT 87,000 Miles, Dead on both sides. Cam sensor was off. Adjusted

16 GSA 1,688 Miles Right dead on. Left off ever so slightly, Adjusted. Cam Position Sensor on.

17 GS 56 Miles Dead on both sides Cam Position Sensor right on.

18 GS 905 Miles Dead on both sides Cam Position Sensor right on

I am thinking that they have gotten this right on the newer model years. I am sure the calls from dealers concerning cam timing probably sent them to the production floor to straiten it out. I am still checking them and will continue and since I do a valve check also it gives people data so when the valves are checked again they have a great reference point.

I got invited to Alexandria VA for a tech day hosted by Jim VonBaden who produces technical reference service DVD's for BMW's. I got to do a demo on checking cams. I used his bike.

Must have been 40-50 bikes there easy! What a great time and the scope of work that was done was amazing. Just about anything you needed done or wanted done could have been on the spot. Had three bikes in the garages, a Harley, KTM, and a BMW GS, one directly outside of the garage, and then Jim's bike to the left of the garages for the cam check. The door prizes were crazy. A GS-911, ezCAN's, and I won a set of full blown Skene P3 lights that can be programed to do just about anything! Hex, Beemer Bone Yard, Skene Lighting, and so many more vendors contributed door prizes that were out of this world.

What a great time!

Anyway the results.

A 2015 GS with 11,500 miles on it.

Both sides were off not a lot but off, and the cam position sensor was off. Only complaint was two push of button to start sometimes.

I put them in time and adjusted the cam position sensor

Valves matched the 6K check

So the Recap:

15 RT 12,000 miles, Left off real bad, right off also. Cam sensor on.

16 GS 12,000 miles, Right side off pretty well and left side off. Cam sensor way out. Adjusted

16 RT 6000 miles, Right dead on, Left off ever so slightly, Adjusted. Cam Position Sensor on.

16 RT 12,000 miles, Dead on both sides. Cam sensor on.

15 GSA 12,000 Miles, Dead on both sides. Cam sensor on.

14 RT 18,000 Miles , Dead on both sides. Cam sensors on.

14 RT 13,000 Miles, Dead on both sides. Cam sensor on.

15 RT 87,000 Miles, Dead on both sides. Cam sensor was off. Adjusted

16 GSA 1,688 Miles Right dead on. Left off ever so slightly, Adjusted. Cam Position Sensor on.

17.5 GS 56 Miles Dead on both sides Cam Position Sensor right on.

18 GS 905 Miles Dead on both sides Cam Position Sensor right on

15 GS 11,500 Miles Cam Timing off slightly both sides. Cam Position Sensor off a lot.

Looks to me still the older bikes need set while the newer 17 and 18 bikes are good. Like I say must be they got the production floor fixed.

I recently bit the bullet and purchased the tools for this job. I have a '16 RT with 30k miles. Bike started and ran without problems before and after service. Here are my results:

Left side dead on

Right side just a little tight but gage went on so I didn't adjust

Cam sensor off a tad (maybe 1/32") so I adjusted.

All valve clearances within spec