Hiya.
Well it's taken me yonks to find what I've been looking for - but persistance paid off!
I knew I'd read on another forum a similar problem to this. Like most on here I'd be thinking propshaft - but have a read of the following. I've done a load of cutting and pasting. The thread is referring to Dolomite Sprints.
Here goes:
A friend of mine has a yellow dolomite sprint and has been at his wits end for 2 years with a really annoying vibration inside the cabin which occurs around 2000 rpm. Hess been to various garages, had clutches changed, prop shafts balanced, rubber mounts changed etc, you name it he's changed it! No one has been able to fix the problem until recently when we put out heads together. As a last resort we took the engine out, had the crank, flywheel, clutch, rods, pistons all dynamically balanced, rebuilt the engine and the problem still existed and he was moments away from selling the car. When he originally purchased the car the price was quite low and we believe the reason why was the problem was so difficult to detect and the owners had given up and passed the car onto him. When I looked at this problem logically I decided that the sound must be transmitting from the engine and gearbox to the car in some way and that it wouldn't matter if you had the roughest, shakiest engine on the planet, there's no way the the vibrations could actually get through to the car as bad as they do now. We checked all round the engine - nothing was touching, the engine wobbled about nicely in the bay and you could see the front engine mounts were displacing the vibration nicely but yet there was still this annoying vibration in the car. I said to my friend, it has to be a simple case of disconnecting things, one by one, until we find out what's causing the problem, I gave the example of if I was superman, and could hold the engine in place with no engine or gearbox mounts, exhaust or anything that could transmit sound or vibration, and engine the noise would have to stop as it would just be hovering there in limbo. We both laughed and agreed. We started by taking the 2 front engine mounts off and holding the engine over the engine bay with an engine crane but the noise still persisted inside the car. Before removing the exhaust, which we knew was going to be noisy, we dropped the gearbox mount and inspected it. It was in perfect condition - no splits or cracks or fouling of any metal and looked good condition, but when we started the engine the noise had miraculously gone - meaning the problem was the rear gearbox mount. We were frustrated because we couldn't see what was wrong with the mount. We decided to look underneath my car and take my gearbox mount off so we could physically compare the 2 and if necessary swap the 2 mounts over to see if the fault moved onto my car, but immediately when going underneath my car we noticed my gearbox wobbled up and down nicely as if it was nicely balanced on a spring and the rubber was nice and flexible, unlike the gearbox mount on his car. I would also like to add that we have had 2 replacement gearbox mounts on his car over the last few years up to this point so assumed this would not be the fault. It turns out that the gearbox mounts sold by Rimmer Brothers and the gearbox mounts that are sold currently by a seller on eBay are of a very hard rubber compound which doesn't have any give in it at all, so the purpose of this post is to ask you if your car is really noisy around the 2000rpm mark? If so have you purchased a new gearbox mount recently? If the answer's yes, inspect your rear gearbox box mount, this could well be the problem with your car. My friend loves driving his car and is going to keep it! I found an old gearbox mount I had knocking about and gave it to him, he is happy as a pig in S**t now!! happy days...Please post back if you have any input on this or if you have time to get under your car and bounce your gear box... does it just sit there and you have to really push hard to get it to flex or can you bounce it up and down with a finger??
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I had the same problem, I bought all new engine & gearbox mountings, the vibration was horrendous so I re-fitted a soggy old gearbox mount & the vibration dissapeared. The new re-manufactured mounts are far too hard.
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Hello all,
my original gearbox mount seemed rediculously worn, so I bought a new one from Rimmers. A good sturdy mount I thought. Having tightened up the nilock nut to what seemed a reasonable torque, I reversed the car off the drive to have my daughter say " we never had that noise before". Allowing the newness to wear off a bit has now resulted in a noisy front bearing on the gearbox. I was going to post a question on the correct torque for it as it doesn't seem to be mentioned anywhere. I am now resigned to removing the box and fitting a new bearing. Does anyone know of a decent mount supplier?
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I tried 2 new ones before re-fitting my old one. The first from Rimmers the second from Numpty.
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[The Sprint and TR7/8 5 speed share the same gearbox mounting rubber - forgot to mention that.]
What do you make of that then?
Shaun.
http://www.flickr.com/photos/12691409@N08/
