Transmission & engine oil replacement for 2003 R1150RT

I have recently got a 2003 R1150RT from a very good friend of mine who has been a member since 2003 and speaks highly about this site. So could someone please advice me what is the most suitable transmission oil I should use for this bike keep in mind this bike very high mileage. I will also be replacing all fluids but starting with transmission and engine oil. For the engine I will be using Amsoil 20W50 for motorcycle - any input you can provide would be much appreciated.

Charles

I have recently got a 2003 R1150RT from a very good friend of mine who has been a member since 2003 and speaks highly about this site. So could someone please advice me what is the most suitable transmission oil I should use for this bike keep in mind this bike very high mileage. I will also be replacing all fluids but starting with transmission and engine oil. For the engine I will be using Amsoil 20W50 for motorcycle - any input you can provide would be much appreciated.

Morning Charles

That is a very easy question to answer-- use the gear oil that shifts the best. Problem is: that isn't the same for all 1150 6 speed transmissions.

There is/was a lot of variance in the old BMW 6 speeds with some liking thinner or multi-weight gear oil & others liking thicker single weight gear oil.

The thing to keep in mind is that most freshly changed gear oil works pretty good for a short time, it's after 1000 miles or so after the gear oil shears that they start shifting with more difficulty.

The one gear oil that seemed to work best (or pretty good anyhow) in the largest number of BMW 1150 6 speeds was the Mobil-1 75w140 but that isn't a given.

So basically pick a gear oil & try it, then give it a couple of thousand miles to evaluate it's shift qualities. If you are happy then keep using that gear oil, if not then try something different for the next gear oil change.

I had a number of 1150 6 speed bikes & one shifted best for the longest using Castrol SAF-XO (difficult to find in the US) but most did pretty good with Mobil-1 75w90 or Mobil-1 75w140. Royal Purple 75w140 also showed some promise but it seemed to shear & degrade quickly.

Bottom line here: what worked in mine or in others might not work as good in yours-- pick one & try it, if it works for more than a couple of thousand miles then stick with it. If it doesn't work long term then try something else.

For the engine, Mobil 1 15W-50 is hard to beat. It's easy to find, and the 5-qt jug should be under $23 at Walmart.

As DR says, "whatever shifts best". I have been using AMSOIL synthetic gear oil for the past few changes, and it's very good, but I can't honestly say it's better than anything else I have tried, including Mobil 1 75W-140 gear lube.

Oil change intervals are a topic almost as hotly debated as brands. I change the engine oil @ 5000 mile intervals (about once a year at my pace), and transmission FD oil at 10,000 mile intervals, mainly because 5000 and 10,000 are easy numbers to remember. The transmission and FD don't take all that much oil, and at 121,000 miles, I'd rather change more frequently than recommended in hopes of spotting a developing problem sooner than later. So far, both have been amazingly clean.

I don't know if he is still making them, but in the past, RealShelby has offered a hand-crafted Final Drive Minder, which I consider to be one of the most cost-effective farkles available. With it, I can quickly check the FD for unusual metal deposits without draining the oil. Looks good, works well, and is worth whatever is the current price.

Amsoil severe gear 75.140 trans 75.90 final drive.

I have a question along these lines, what are folks using to get the trans oil to drain out and not get all over the bike? Do I really need the special tool?

Afternoon Toast

Lots of ways to do it but my favorite is to first break the drain plug loose (just loose not out). Then slide a piece of plastic pipe over the drain area, then reach in through the center of that pipe with a long extension & remove the drain plug.

I usually drain with the bike on the center stand with a piece of wood under the L/H center stand foot so the oil runs out & away from the bike.

Nice, thanks for your input DR!

Evening Toast

OR, you can just cut a milk jug to look like this & stuff it in there (again lean bike to the right slightly)

It's the bike lean to the right that keeps the mess away.

I just use a toilet paper roll insert. It has worked well for many years and then I just throw it away so no oily storage issues of the funnels.