Exhaust Alignment

[GonzoBard]

The gearbox and engine have recently gone back into my car. After a few hundred miles the exhaust has started to knock on the bodywork (standard hockey-stick design). I've tried adjusting the height of the exhaust relative to the tinware to increase the distance but the exhaust is still knocking, mainly under idle. Can I adjust the engine height such that it lowers slightly to increase exhaust clearance? I can see no other way of adjusting the exhaust relative to the engine but I'm not sure what height the engine should sit at.

[SeanP]

What year car?
Asking as the engine mounts changed in 1968 from the 911 type to the rubber blocks

[GonzoBard]

Sorry, it's a '66.

[GonzoBard]

Having thought about it the exhaust hasn't been knocking for the first couple of hundred miles since the engine has gone back in. Consequently I've checked the engine mount bolts and have tightened a couple which may have slackened. So not sure what tolerance there is to lower the engine. The exhaust is only a few mm from the body, which seems too close.

[SeanP]

Check the gearbox mounts haven’t come lose

[GonzoBard]

OK, thanks, will do. The mounting plate that sits in front of the main engine mount looks slightly out of alignment, high on the tailpipe side, suggesting something has twisted.

[SeanP]

That doesn’t seem right. The engine should eit level on the mounts.
Check the gearbox mounts.
Are all of the engine mounts new?

[GonzoBard]

Good call Sean, I have an off-side broken gearbox mount. Bolt missing, rubber mount shot. With the gearbox jacked into the correct position, exhaust no-where near the bodywork. I know which drive it must have failed on, I've done about 40 miles since, I hope nothing else has been damaged. Given one mount has failed I shall replace both. Looks like a reasonable job - with the back end up on ramps / axle stands I assume access should be reasonable and there should be no alignment problems? Thanks.

[SeanP]

Just as a caution check the gear selector connector and the accelerator push rod connectors for any damage.

Gearbox mounts pretty easy to change out, just remember to support the gearbox when doing it, also remember to reconnect the earth mount it’s surprising how many forget it’s there. I normally use axle stands under the torsion tube and a trolley jack to support the gearbox