BMW Gearbox mounting - Forum Archive

peterux 1 Jan 2006, 8:10pm

Here's a quick question to anyone online tonight.

Yesterday, I fitted my engine and gearbox :biggrin:

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

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 1 Jan 2006, 9:58pm

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 2 Jan 2006, 11:43am

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 2 Jan 2006, 5:51pm

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 :eusa_drool:

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

GreatOldOne 2 Jan 2006, 8:29pm

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

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

peterux 2 Jan 2006, 10:05pm

Thanks GreatOldOne!
Have you ordered your chassis?

That makes 4 BMW builds :eusa_dance:

There must be more :confused:

MartinClan 3 Jan 2006, 10:23pm

Gearbox mount

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 4 Jan 2006, 1:44pm

peterux wrote:

Thanks GreatOldOne!
Have you ordered your chassis?

That makes 4 BMW builds :eusa_dance:

There must be more :confused:

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 4 Jan 2006, 11:01pm

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 5 Jan 2006, 11:48pm

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 ! :biggrin:

I hope this helps all other builders out there,

regards

Peter