Gearbox, date of manufacture.

[Le singe]

I recently bought a 1998 R850 for spares, the bike was incomplete, I'm not even sure of the model! It has a 5-speed gearbox which works perfectly.
I removed the gearbox today to clean it up and found sealant around the end plate, which convinces me it has been re-built at some time.
According to the experts, later, (after '97), gearboxes are extremely reliable, so why has it been re-built?
There are numbers stamped on the top, RHS of the cluch housing, one of which is '1995', my 1100 is a '94 model and has '94' stamped in the same location on the clutch housing.
Is this just a coincidence, or are the gearboxes stamped with numbers which correspond to their date of manufacture?

 

[Rob Farmer]

What are the other date codes on the bike? The wheels, forks etc all have a date of manufacture cast in. It could be the bike was just laying about for a long time before being registered.

 

[Le singe]

There was only the engine, gearbox, alternator, etc, hence me not knowing what model it was.
I've searched all the usual sources, ie Phil Hawkin's BMW site, for a date from the engine number, but 850 info is thin on the ground.
Maxbmwmotorcycles site doesn't have any info at all on the 850s.
If necessary, I'll have to strip the 'box and have a look inside.

 

[Tsiklonaut]

I think the post '97 aren't "extremely reliable" indeed, BMW is known by their dodgy quality control often. But indeed, there may be user-bound fault there - you never know what attitude the bike was driven, and if the was ex-sportsbikes driver, he probably swiched the gears without the clutch - some drivers really are techincally stupid, they brake the bike themselves, and ask "why the fek it didn't work"?

There's also big probability it was ridden offroad w/o HardParts meaning the gearbox case was cracked and maybe the previous owner just replaced the whole gearbox.

There's dozens of reasons...

So maybe ask the previous owner first.

But on the build date from Micapeak GS page:

Production Year Notes:

1. Production for the new model year starts after the annual works holiday in August. The production model year runs from September to August e.g. model year 98 runs from September 97 to August 98.

However there is always a delay between production and registration. So not all bikes registered during that period are from that model year. For example some 98 models were registered during October 98 which falls within model year 99.


2. Individual changes are sometimes introduced piecemeal during a model year. This means that a particular bike may not necessarily have all the changes listed for its model year.

3. An individual bike may have pieces from a following production year retro-fitted by a dealer or owner.

 

[Rob Farmer]

BMW don't make gearboxes. They are made by Getrag. The same people who make them for Porshe, Jaguar, Audi and a shed load of other quality makes...Not sure how Skoda ended up in there

http://www.en.getrag.de/185/185


The blame for dodgy boxes shouldn't really be levelled at BMW. They went to the best in the market and got them to design and build the gearboxes. Mind it was Getrag who designed the Yam XS 750/850 gearboxes in the 70's AND the new mini gearbox...Doh!

 

[Le singe]

I now know it's an R850R, the alternator has 04/99 on it, hardly conclusive I realise.
I bought it from a salvage company, there was no front frame as the insurers
had insisted it was removed and destroyed, hence no registration papers.
The gearbox may not be rebuilt, but I cannot believe BMW would not wipe off excess sealant after the cover was fitted.
What comes out usually goes in as well, too much is very amateurish.....!

 

[Rob Farmer]

Was the sealant clear or white? I've just had a look at my Adventures. Theres a rubberish sealant visible on the joints and I know thats never been apart.

 

[Le singe]

Thanks for that Rob, it's rubbery and dark grey/black in colour. Definately not Hylomar!

 

[Le singe]

Up-date. I stripped the engine, (850), which came with the gearbox today, as I only want to keep the crankshaft from the bottom end.
The gasket cement/sealant which had aroused my suspicions about the gearbox, was the same on the engine. I'm certain that the engine has not been apart before.
Still don't quite understand why BMW deem it necessary to use so much on each joint though!
Speaking to the owner of our local garage, he tells me it's the same with modern cars, the assemblers seem to apply it like toothpaste!
I'll have to make sure I've half a dozen tubes ready for the next gearbox rebuild