Sprint gearbox mounting replaced - extremely noisy car!

[Galileo]

I have spent all day fitting a new gearbox mount (purchased from a major supplier) on my Sprint to cure the bad tramp on setting off. I was quite convinced this was the problem as all other bushes seemed okay but the gearbox one looked like black blancmange. So when I say all day, it's not because I'm slow, it's just that I've fitted the damn thing four times now!

IMG_20151004_135650.s.jpg (133.12 KiB) Viewed 2740 times

First test drive and the noise in the car was so loud I thought I've broken something and immediately backed up, and jacked it up to see what I'd stupidly done, but it all looked fine. Undid everything and double checked my work, let's face it, a gearbox mount is not seriously technical mechanics after all. Another test drive and yet again, sounded like the gearbox or engine was pressed against the body. Seemed more of gap N/S so undid everything and levered towards the middle and tightened everything back up, test drive, no change. Took it all off again and compared it with my spare gearbox, everything looked the same. Mount back on, still sounds like a bag of spanners.

Is this just because the mount is new? Do they wear off in time? I must confess I'm a little bit bored with it now, I've cured the tramp, but I would rather have it back then the racket the poor thing is making now. It's got dark and I've ran out of ideas, but what could I have done wrong?!

[Ron1966]

If you can post a picture up of the mount . I have known people put these in wrong that's not saying you have fitted wrong but members will have a better idea with a picture. That old mount was well past it.

[Carledo]

What he said^^^^^^^ !

It may have been that the old one was incorrectly fitted and the sogginess and wear concealed the error and now you have a new one it's shown up. The correct fit is a bit counter intuitive but a quick pic will let us decide!

Steve

[Galileo]

Well, as luck would have it I confidently took a picture after the first fit for my 'restro' thread so here we go:

IMG_20151004_150520.s.jpg (151.46 KiB) Viewed 2702 times

To fit the mount, I did these exact steps:

• Undid the centre nut a few turns
  Put a trolley jack under the gearbox and took the load
  Removed centre nut
  Undid the fuel and brake lines from their clip
  Removed the the four nuts holding the crossmember
  Removed the two nuts holding the gearbox mounting plate as I needed extra clearance
  Removed both bolts holding the existing rubber mount
  Cleaned everything up
  Reversed the above with the new mount

The only thing different about the new mount is that it is completely solid, my spare gearbox's one is only attached to the mount frame on the long sides, difficult to tell if this is the case with my old one, bit too mushy!

[Ron1966]

Looks correct to me . Picture a bit blurred but the mount is the correct way up and fitted down through the crossmember. Does the noise sound like the engine or transmission vibrating and making a droning noise because it is contact with the body or subframe .

[Magenta Auto Sprint]

could it be the centre bearing?
I also found on my old jeep that I got what I thought was tramping in reverse and it turned out to be worn spines on the propshaft.

[Galileo]

Not all of it's blurred (why am I thinking of Eric Morecambe and André Previn?!), slight issue with camera aperture settings and the light levels under a car, just consider it an 'arty' shot!

To answer the question, imagine you had bolted the gearbox directly to the body, that's what it sounds like. Yes my box whines quite a bit, mind you they probably did that from new, but when in straight through top you get all the engine, exhaust and a rotating noise and it's very LOUD!

I cannot get the mount to even move slightly when I try and twist the crossmember. So some research this morning seems to point to all of the mounts available today as being made in India/Thailand and work great in LDV Pilots, but not so good in a Sprint or TR7. To my surprise there is a heavy duty version, TKC2642 used in the TR8 and the diesel SD1, can't imagine how hard they must be.

Then I read this republished article from the US TWOA http://www.trdrivers.com/tr7_tr8_gearbox_mounts.html and ah, that explains quite a lot. Also see that the US suppliers version of the TKC1044 looks just like the original eg. http://britishpartsdirect.com/index.php ... ct_id=3213


Looks to me that the mount described and supplied as being compatible with a Sprint is just plain not fit for purpose. I'm thinking of three options now, modify the crossmember to take a different type of mount with the Ford Sierra a common suggestion, drill out some rubber from the supplied mount to try and get some flexibility into it and last of all use my spare gearbox's OEM mount which I'm loath to do as I can't yet guarantee a lack of oil contamination. I guess there is also the option of contacting a UK manufacturer like GMT Rubber to make the correct mount, but I'll let you know how that one goes when I get left a wodge of cash by a rich relative.

[tony g]

What a great article! Thanks for posting that. Its a shame that an American site has gone to the trouble of clearing that up and someone in this country couldnt do the same. It'll be Sierra for my replacement when needed.
I would send yours back for a refund if it were mine.

Tony

[James467]

Surely if this was the case with these mounts then we would have herd about it on the forum before?

[MIG Wielder]

The Lotus Elite S1 gearbox mount is the same as the Dolomite Sprint one. This is a piccy of one I removed from my Elite some years ago when I swapped the box.

lotuselite S1 mount.jpg (82.27 KiB) Viewed 2625 times

Yes, the rubber is quite soft and as you note the rubber is only connected on 2 sides (voided ?)

Try this supplier who is well know in the Lotus world.
http://www.sjsportscars.co.uk/index.php?mod=10
If you click on the camera icon you get an actual photo of the part. Note the one you want is the Series 1 gearbox mount.
If you would like to try my old Lotus mount first, ( as in the photo) drop me a P.M. and I'll get it in the post to you.
Good luck sorting it.
Tony.

[sprint95m]

Surely if this was the case with these mounts then we would have herd about it on the forum before?

It has been documented on here several times over the past few years.


Furthermore, I detailed an alternative mount which is readily available, better quality and reasonably cheap....
Ford Sierra type 9.




Ian.

[Galileo]

Separated at birth? Not really! The original Metzler bush is clearly voided as you say Tony (Mig Welder) and obviously very different in construction to the knock off copy. The original design looks to me to be one that allows for a very limited amount of twist with the rubber 'fingers' buffering against the inner metal bell, at all other times the bush allows the gearbox to 'float' but with no lateral movement, but a degree of fore and aft movement with the otherwise soft rubber insulating the body from the noise of the engine, gearbox and exhaust that is attached to it. The replacement bushes do not offer the same experience to me, but hey, I work in telecoms and networks, so what do I know?!

Original TKC1044 vs New.jpg (195.59 KiB) Viewed 2605 times

Good call with the Lotus Elite use of the same bush, I've seen that it's been used in a few applications, from a Dolomite to a minibus but not a sports car! I'll drop them an email and ask if their bush SJ075F0003 is voided and has a reasonably low shore rating. Failing that, I'm either going to order one from the US, or use a type 9 ford bush I have that was originally destined for my kit car, needs the top U channel angle grinding away and the crossmember hole enlarging but otherwise is a pretty good match, and I'm glad to see that I would not be a trailblazer as helpfully pointed out by Ian (Sprint95m).

Think what I will start to do is to search the forum first to see if anyone mentions having an issue before buying, or maybe we should have a do not buy list?

[Toledo Man]

This might help.

[James467]

Is it possible to mount the crossmember the wrong way round, thus maybe making it contact the exhaust where you can't see it?

Mines at the blasters so I can't check.

[Galileo]

I'm not sure tbh, but in my case the cross member is definitely the right way around.

I did intend removing the new bush and comparing the height etc with one of my OEM bushes, and maybe drilling out some material from the new bush to see what effect it would have, but the pesky weather got in the way, it hasn't stopped raining for long enough...