BMW Gearbox mounting

peterux · #1 1st January 2006, 19:10

Here's a quick question to anyone online tonight.

Yesterday, I fitted my engine and gearbox

Does anyone know what is the correct fixing height for the gearbox mounting?

Is there some way of linning the 'box up with the differentail, or should I wait until I have the propshaft.

Should the mounting bracket be level with the floor?

Any tips would be appreciated,

thanks Peter

Purple Ak · #2 1st January 2006, 20:58

Can't help alot I'm afraid . But the engine/ box should always be mounted down the centreline of a chassis. Props always take on an angle to the diff due to the offset of the pinion

Patrick · #3 2nd January 2006, 10:43

We didnt have a propshaft at the time of fitting the gearbox. So we placed the bracket so that the bends lines up with the bottom of the transmission tunnel.

We've since recieved the propshaft and it fits fine.

peterux · #4 2nd January 2006, 16:51

Thanks Patrick.

That's what I thought, but wondered if there was an ''official'' Marlin correct position?

I trial fitted the exhaust manifold and the old original exhaust pipe today.

I plan to adjust the position of the gearbox height until the pipe is parallel to the underside of the chassis.

good luck

Peter.

P.S. I wonder how many other BMW Sportster builders are there registered to this forum? I know there is you and Richard who have now overtaken me in my build, plus Martin Clan who seems to be just ahead of you guys? We are all buiding e30 models. Then there is a guy called Andy who is building an e36 but his website updates seem to have ceased. I met a guy at TotalKitcar day at Brands Hatch who was just odering his kit from Marlin and was planning to build an M3 version.hmmmmm

Perhaps any other builders could identify themselves and give us a quick summary of their state of build?

GreatOldOne · #5 2nd January 2006, 19:29

Well, I'm only just starting out. My Sportster is still decidedly e30 shaped, and currently dripping oil into a catchpan in my garage...

Hopefully this will be remidied shortly! (The e30ness and the leak)

peterux · #6 2nd January 2006, 21:05

Thanks GreatOldOne!
Have you ordered your chassis?

That makes 4 BMW builds

There must be more

MartinClan · #7 3rd January 2006, 21:23

I positioned my gearbox mount so that the exhaust runs parallel to the floor. You can then use a simple exhaust system with straight pipes and a TR6 silencer as I have done. (no expensive custom exhaust) I had to narrow the mount supplied by Marlin as it was about 4mm to wide to fit in the tunnel!

Robin

GreatOldOne · #8 4th January 2006, 12:44

Quote:

Originally Posted by peterux

Thanks GreatOldOne!
Have you ordered your chassis?

That makes 4 BMW builds

There must be more

No, I haven't ordered the chassis yet - Due to a distinct lack of space, I'm refurbing the engine and other parts first before getting the marlin bits in. I'm guessing it'll be in a few months time, as the engine will be stripped and rebuilt as part of the renewal of the beemer bits.

peterux · #9 4th January 2006, 22:01

To GreatOldOne:
good luck with your refurbishment!

To Martin,
I think we came to the same conclusion on alignment, however my bracket fits my tunnel perfectly.
Whilst serching for TR6 silencer boxes on ebay, i came across a pair of individual silencers, so plan to use these along with most of the original BM exhaust system.

best regards

Peter

peterux · #10 5th January 2006, 22:48

I dropped Mark at Marlin my question of gearbox alignment and this the 'official' answer............

Hi Peter

The correct angle for the engine to run can be gauged from the base of the
sump pan. It would always be best for the sump pan to run level but for a
few degrees of tilt towards the sump plug.

Attach the gearbox mounting to obtain this preferred position.

HNY

Mark

I'll be getting my spirit level out at the weekend !

I hope this helps all other builders out there,

regards

Peter