pre-loading the engine/gearbox mounts

[Miraz]

I now have the correct engine brackets fitted, but still seem to have an issue with aligning them with the mounts.

 

If the gearbox mount is loosely bolted in place then the engine mounts seem to be about 12-14mm too far forward for the bolts in the brackets to engage.

 

The advice from Caterham is to slacken the bolts holding the brackets to the engine off until it is possible to engage the bolts in the rubber mounts, then tighten everything up again distorting the engine and gearbox mounts in the process.

 

This makes me a little uncomfortable - is it reasonable to expect the mounts to be loaded up this heavily? I expect that it will significantly increase the nvh transmitted to the chassis and/or shorten the life of the mounts.

 

Apparently this is not an unusual thing with SV's - they all do that sir!

 

Miraz

[ashaughnessy]

I don't know what "they all do" but this sounds dodgy. I think the brackets aren't the most long lasting thing anyway (just replace mine, they were cracked all round) and to pre-load them like this sounds bad. The rubbers don't last forever either. When I replaced my brackets and engine mounts recently, everything fitted like a glove, I didn't have to do any fiddling. This was on a live axle xflow.

Anthony

[Paul Turner]

I had a similar experience when I built my current 92 de-dion x-flow car and fitted it with a 4 speed sport gearbox. Caterham supplied an additional mount with the kit that slid between the lower tunnel chassis tubes and was secured by 2 small bolts, it could not move as the chassis tapers to the rear as did the mount. When the engine/gearbox were fitted the holes in the rubber mount were approx 15mm behind the holes in the chassis mount. Spoke to Caterham who sent another mount, easy to change fortunately, and this proved to be identical. Spoke to Caterham again and one of their technical staff suggested hitting the mount with a hammer and knocking it further back, a bit impossible when the chassis and mount both taper. At this point I ignored Caterhams expert advice and slotted the holes on the rubber mount and the chassis mount until the bolts fitted and used large diameter washers on the bolts for extra security. It ran like that for 3 years hillclimbing and sprinting with no problems. A similar solution with your car sounds possible although in reality should not be needed. My car now has a 5 speed box and there were no alignment problems when I fitted it.

[Miraz]

They've offered to remedy it at pbi on the basis that I get it into a driveable state first.

 

My current thinking is to see how much of a slot I can dremel into the gearbox mount in order to reduce the amount that I'm going to have to bend things.

 

Miraz