Replace gearbox support bushes

[Rockape]

Another question on those gearbox support bushes.

 

Bough new ones from Rimmers using original part number - they are a couple of mm longer than the ones currently fitted - would that be due to compression of the existing ones and the new ones are correctly sized. 
 

or - is this dimension difference going to give me grief?

 

second - I have started to unscrew the bush - and have jack under the gearbox - but it seems to me that I am going to have to raise the rear of the engine and gearbox assembly quite a lot to be able to start the thread into the casing. And as I increase load on the jack - the whole of the front of the car is starting to lift 

 

Any advice  greatfully accepted before I do something stoopid……

 

mark

[Rockape]

Update - block of wood and a long lever appears to give me quite a bit of relative movement between the gearbox and the chassis - would that do it ?

[Pete Lewis]

no doubt these bushes collapse under the weight and efforts from the gearbox 

i would not worry about those few mm 

keep the old ones as some new stuff is made of unspecified rubber and much rubber parts are very inferior,   might look ok 

but life in use can be very poor   there are many posts on hear about after market rubber failing   

the mount is some what generic and probably used in a variety of places 

the orig would have a harness spec so they do the job , what you get on copies from china is ...well its rubber 

sorry about that but the learning curve is take care and keep an eye on them 

Pete

 

[Pete Lewis]

you may find you cant lift it enough to unscrew the mount from the rear extension hsg. you need about 20 mm 

you may need  to remove the support bracket which is just as much a faf 

so give it a lift and see   its some years since i did one 

its one of those 10minute jobs that might take an hour 

Pete

[Rockape]

19 hours ago, Pete Lewis said:

you may need  to remove the support bracket which is just as much a faf 

so give it a lift and see   its some years since i did one 

its one of those 10minute jobs that might take an hour 

Pete

A faff. ? I’ll say… the bracket is on top of the chassis members as can be seen in the photo .So same issue - getting clearance for the bushing bolts - I guess a combination of removing support bracket bolts to allow lateral movement, a trolley jack under the gearbox and a lever under the UJ and I might get enough space…….

 

sigh…..

[johny]

I'll be very surprised if you cant change the mounts by jacking the gearbox although I would do it with a trolley jack rather than levering with bits of wood...

[Wagger]

I disconnected the propshaft to do mine, then the rear of the box will lift easily with a jack under it.  Mark the flanges first. Also check clearance between radiator and fan, plus don't strain hoses. Took 20 mins max.

[Stratton Jimmer]

I last did this job about 1982 on a girlfriend's GT6 Mk2 non OD. I did as Wagger did and disconnected the propshaft. I seem to remember that there was a bit of a difference between the length of the rubber on the new and old bushes but the old ones were starting to break up.

[Rockape]

Well - thats that job jobbed. Found the root cause of the right hand bush being distorted (and a pig to get out) - the “U” bracket on which the bushes sit was off square.  It was further forward on the RHS by about 8mm. 
 

But that’s what the slots are for in the support plate I guess. Loosened the bolts, gentle tap with a rubber mallet on the “U” bracket and everything lines up nicely…..

 

thanks for the suggestions regarding marking the prop shaft and jacking/supporting the g/box. This helped.