Gearbox MUCH quieter.

[Howard722]

I agree!!-. The companies that enjoy our business need to up their game, they must know there is a problem.

[busheytrader]

Well, I think the preferred fix would be to unearth some original "new old stock" mounts and fit one, but this temporary fix is so cheap and easy to do - 20 Minutes. Would recommend using nylock nuts, and tightening them up enough to compress the bush by about a third. No movement only insulation.
I think a lengthy test drive, and then a double check that everything is still safe and secure would be in order.

I thought I'd give this a go and fitted 10mm thick polybush washers between the gearbox mount and chassis rails to quieten the screaming gearbox in 3rd and 5th. Albeit up on axle stands, the transmission noise at 70mph in 3rd and 5th is probably around 20% of what it was on the road a few months ago. I now have the following choice. I could fit another set of poly washers on the topside of the floor pan to prevent all direct contact between the gearbox mount and the chassis rail, or find the Volvo gearbox mount I bought earlier and make the necessary modifications to fit as per this thread. If this doesn't solve the noises and the gearbox is at fault I have a hopefully good secondhand item in the garage.

Looking back the noises started when I replaced the jellylike rubber gearbox mount several years ago but I didn't make the connection as I couldn't use the car for about 6 months afterwards. The replacement was as hard as granite but I was told it was an uprated TR8 item. I have another one which is probably even harder still. I told the supplier about the resultant gearbox noise but the immediate reply was that my gearbox must be f****d.

[Howard722]

I understand the idea here but what I don`t yet follow is how you/others are preventing the noise from transmitting through the bolts. There must surely be metal to metal edge contact here unless you `sleeve` the bolts somehow, similar to the remote gearshift isolation mounting set-up.
Could get complicated so methinks it`s time for the Volvo mount. Just to confirm-if it helps!-my rock hardo mount gave an excruciating noise and I couldn`t understand how changing the oil (had I put the new oil in ?) could give such a result until the penny dropped-doh!

[busheytrader]

Hi Howard,

I guess it's more a case of resonance than just the vibration passing through to the monocoque. Sleeving the bolts with a rubber material and fitting poly washers top and bottom would isolate the gearbox vibrations from the body shell but that's just replicating what the rubber gearbox mount should be doing in the first place! Your comments made me check the oil level in the gearbox just in case. It's full of Castrol Syntrans.

I'll see if I can apply the Volvo gearbox mount solution. If I can't find it in the garage I'll just have to order another. if one set of poly washers have drastically cut down the transmission noise then I'm hoping that a softer gearbox mount will solve the problem.

I had a quick google this morning and found a comprehensive thread on using the Volvo mount. I was after a few extra pics which this has. http://forum.triumphdolomite.co.uk/view ... 90&start=0

[littlepippin]

Put another polybush in today - between the bottom of the gearbox, and the round aluminium spacer part.

Whoa, even quieter and the whole car feels and sound so much better.....

All my concerns about worn out gearbox bearings GONE.

Still leaks oil like a seive ..... but who cares.....its a Triumph,

[busheytrader]

I can vouch for the Volvo gearbox mount rubber modification if the polybushes give out. My gearbox no longer sounds like it's going to explode, in fact there's no extra transmission noise over the original gearbox mount.




Just for fun I found the original 37 year old oil soaked jelly item in a garage tidy up this week. I regret changing it for the Solid mount which made me suspect the gearbox bearings had worn out. I now have 2 granite rubber mount paperweights sat next to a replacement LT77 gearbox that I never needed.


Here's the link to how I adapted the Volvo mount.
viewtopic.php?f=2&t=23518&p=239732&hilit=Volvo+mount#p239732

The wedge recently passed its MOT. The tester sees plenty of TR7's annually and looked over the mount as if it was a oem part.

Adam

[littlepippin]

Well done with the Volvo mount - its a great solution.
Still don't understand why the modern rubber is so hard - can the makers not obtain 70's rubber anymore ? Did it become extinct - or endangered ?

[busheytrader]

This is what it looks like from underneath. The original big pressing UKC2209 that fits underneath isn't compatible and was substituted by a 3mm thick washer. As I've said before I'm not an engineer and looked for a practical solution. My humble opinion is that unless your competing in motorsport the rubber mount will spend its life being compressed by the weight of the engine / gearbox combo unless the car rolls over. The forces acting in the opposite direction are pretty small by comparison and the washer should suffice. (I've always wondered why UKC2209 lower mounting plate is so large. If proved otherwise I have a sheet of 3mm steel that I can fabricate an alternative)


2 Down pipes from the V8 and a shortened SD1 propshaft.

I'd guess that the mount that BL / Triumph used to buy for their production line isnt used by any current manufacturer and the retailers have to buy it in limited production runs, hence the "made in India" sticker on the packet. I bought 2 from separate wedge specialists in the U.K. and the packaging looked the same. It's not just the rubber that's inferior, the shape of the internal metal parts is wrong as well according to the investigation by this guy on the dolomite forum and also the TWOA. He did the donkey work and since Dolomites and wedges share the same gearbox mount I adapted his research to fit mine. He deserves the applause.

These are the links to his posts.

http://forum.triumphdolomite.co.uk/view ... =4&t=29990

http://forum.triumphdolomite.co.uk/view ... hp?t=29836

There's also an excellent article on why these aftermarket reproduction mounts are cr4p on this link. Original research done by the TWOA on the TR Drivers Club website.

http://www.trdrivers.com/tr7_tr8_gearbox_mounts.html

As a side issue, I've had a few Dolly Sprints over the years pull alongside me at the lights etc thinking that their 22 extra bhp from their 8 extra valves will blow me away. My wedge still wears it TR7 stickers and looks stock apart from different alloys and a larger single exhaust pipe. Upshot is I have about 80 bhp more than them and a lot more torque from twice as many pistons so they have trouble keeping up with me.....

Adam