simonjrwinter Posted April 23, 2016 Report Share Posted April 23, 2016 Right, had my diff rebuilt twice ( yes it did need it second time) and it's installed back in my car. It's STILL whining....ok, not as bad as before, it's not a diff issue now rather a noise transmission issue. The ONLY thing that's different about the diff is that it's now mounted with poly bushes rather than the rubber ones that came off. I can only assume these are what is transmitting the mechanical noise to the chassis/body as I've been all over it looking to where it may be touching. I can't put the old ones back 'cos the dog pinched them and chewed them up. So, I'm going to buy some original rubber mounts. I know there have been "issues" with some of the rubber mounts from some suppliers so I want to buy the best, can anyone recommend a good supplier? Quote Link to post Share on other sites
Andy Clarke Posted April 23, 2016 Report Share Posted April 23, 2016 I fitted some "poly bush" diff mountings sourced from a well known London based shop and the noise from the diff area was almost unbearable. Luckily I live quite close to Chris Witor, so before I scrapped the diff, I popped round for a chat and discovered that there are several different types of poly bush, with varying degrees of hardness. I ended up buying a set of the softest ones available from him and, hey presto, total silence (from that area at least) Andy. Quote Link to post Share on other sites
simonjrwinter Posted April 23, 2016 Author Report Share Posted April 23, 2016 I bought superpro I've been on their website and while there are fast road-comfort bushed for the front mounts, there is only one hardness for the rear Simon Quote Link to post Share on other sites
TriumphV8 Posted April 23, 2016 Report Share Posted April 23, 2016 Thats why I go for the BMW diff: No play, no noise and bulletproof and also goes easy on the driveshafts. Maybe worth a thought if the next steps dont cure the probs. Quote Link to post Share on other sites
Steves_TR6 Posted April 23, 2016 Report Share Posted April 23, 2016 I had the same experience on my last 6, fitted blue polybushes and the whining noise was very annoying on the motorway. Current car has yellow polly front and rubber rear, I think this was done by racetorations, and is quiet. When I rebuilt the diff I replaced the rubber with new rubber ones from tr_bitz I think ( bought at the Triumph/mg parts day so can't recall for certain) and all still quiet. I'd like to fit a set of the racetorations 'cups' to the rubber bushes to control in 'enthusiastic' driving but haven't in three years so far..... Steve Quote Link to post Share on other sites
Schnippel Posted April 23, 2016 Report Share Posted April 23, 2016 Helloit does not matter whether rubber or poly .The differential must run quietly .Does it not.Then there is an error .Best wishesRalf Quote Link to post Share on other sites
jogger321 Posted April 24, 2016 Report Share Posted April 24, 2016 Right, had my diff rebuilt twice ( yes it did need it second time) and it's installed back in my car. It's STILL whining....ok, not as bad as before, it's not a diff issue now rather a noise transmission issue. The ONLY thing that's different about the diff is that it's now mounted with poly bushes rather than the rubber ones that came off. I can only assume these are what is transmitting the mechanical noise to the chassis/body as I've been all over it looking to where it may be touching. I can't put the old ones back 'cos the dog pinched them and chewed them up. So, I'm going to buy some original rubber mounts. I know there have been "issues" with some of the rubber mounts from some suppliers so I want to buy the best, can anyone recommend a good supplier? I'm in the process of removing my diff in order to replace leaking seals as part of recommissioning my tr6.. I read all the posts I could find on hear about Diff rubber/polybush mounts. The rest of the car is going poly but I did decide in the end to rubber mount the diff & have purchased rubber mounts from that well known London based shop. Some people say poly on the diff mounts causes a hell of a lot of resonance through the chassis..others say it doesn't and also a lot of people say its a noisy old TR6 with 1950's type engineering so don't worry about it! Quote Link to post Share on other sites
simonjrwinter Posted April 24, 2016 Author Report Share Posted April 24, 2016 If my experience is representative of the change from rubber to poly, I'd say Rubber is better. It seems for some people ( maybe using softer poly) it's fine, but the noise will drive you nuts. Of course the real test for me will be when I re-fit rubber bushes....... Quote Link to post Share on other sites
simonjrwinter Posted April 24, 2016 Author Report Share Posted April 24, 2016 Hello it does not matter whether rubber or poly . The differential must run quietly . Does it not. Then there is an error . Best wishes Ralf No, any mechanical unit will make some sort of mechanical noise, that's why engines, gearboxes and diffs are rubber mounted so they DON'T transmit the mechanical noise to the car chassis/body. Quote Link to post Share on other sites
simonjrwinter Posted April 24, 2016 Author Report Share Posted April 24, 2016 Can anyone recommend which rubber mounts are best/won't fall apart? Quote Link to post Share on other sites
RonA Posted April 24, 2016 Report Share Posted April 24, 2016 (edited) I changed from all rubber bushes to blue poly bushes on the front and rubber bushes on the rear, there is noticeably more noise and harshness, I can live with it at present but I think I'll change back next winter. Edited April 24, 2016 by RonA Quote Link to post Share on other sites
littlejim Posted April 24, 2016 Report Share Posted April 24, 2016 (edited) Simon, dunno if it will help your situation, but my diff front seal looked OK. so it went back when I completed the refurb. On my first long trip, to the coast and back, it gave up the ghost about fifty miles from home and started leaving a trail for the next trip back. (beats bread crumbs hansel!) After the seal replacement I had a decent whine and was reluctant to do a diff re-adjustment, so I put some Nulon G-70 gearbox and diff treatment in. (fine teflon particles.) After a while it reduced the grinding noise quite a bit, - still can get a bit of noise on the overrun. Put more in each time I checked the diff oil level and got better each time. Not perfect, still a bit of overrun noise, but originally it whined all the time. Edited April 24, 2016 by littlejim Quote Link to post Share on other sites
mattyb Posted April 24, 2016 Report Share Posted April 24, 2016 (edited) On the fearsome, high powered Morris Minor ...... its fairly common to fit a combination of rubber and poly bushes (front tie rod in particular) Just a thought ? regards Matt Edited April 24, 2016 by mattyb Quote Link to post Share on other sites
DaveN Posted April 24, 2016 Report Share Posted April 24, 2016 How odd! I changed mine from rubber to blue poly because of noise and I'm very pleased with the results and lack of noise!! Go figure? :-) Quote Link to post Share on other sites
simonjrwinter Posted April 24, 2016 Author Report Share Posted April 24, 2016 How odd! I changed mine from rubber to blue poly because of noise and I'm very pleased with the results and lack of noise!! Go figure? :-) It's odd isn't it. LOTS of folk find no difference at all, and yet for some it's awful. No rhyme nor reason to it! Quote Link to post Share on other sites
DaveN Posted April 24, 2016 Report Share Posted April 24, 2016 It begs the question is there a difference between manufacturers and/or different batches of the same items? Quote Link to post Share on other sites
TriumphV8 Posted April 24, 2016 Report Share Posted April 24, 2016 It's odd isn't it. LOTS of folk find no difference at all, and yet for some it's awful. No rhyme nor reason to it! You can find answer in my earlier posts to the diffs: A diff still withstands the forces when slightly out of correct position but it starts making noise. If offset becomes to large CWP starts to eat each other. Two reasons might prevent our diffs from perfect setup: The mechanics dont spoil their time with shimming the CWP several times Nearby is close enough for them and maybe the CWP itself and the diff are not that precise. Several times I found it difficult to set the play because it varies with the position of the crown wheel. With such a bad part a fully quiet diff can not be established because at some positions the play is wrong. So people with a perfect set CWP can swap between all the rubbers and notice nearly no difference because there is no noise. As the noise increases the influence of softer rubbers becomes more and more important. But everybody should be aware that with a sweet diff mounting the symptoms maybe cured but not the cause of the noise. Its impressive to turn a BMW diff by hand, it has virtually no play and the feeling is not that toothed wheels are turned or ball bearings turn but a soft resistance like the casing has no CWP fitted. Only when turning the driveshaft flanges against each other the working inside the diff cage can be felt with a marbelling. Be aware that TR diff was made for 100BHP and with the Rover V8 it needs to be set very good otherwise it will not last long. Also temperature becomes a problem, I could measure oil temp in the range of 200 degrees C what is more than the limit and the rubber rings from the driveshaft flages fry at that temperature over the time. Quote Link to post Share on other sites
Clarkey Posted April 25, 2016 Report Share Posted April 25, 2016 Hi Simon I refitted my diff last year, I used blue polly from Chris witor, my old diff wined more than the Duchess ( ) I replaced the trailing arm bushes with polly as well, having run the diff in for around 50 miles of smooth steady driving, she is a s quiet as a mouse. Quote Link to post Share on other sites
roy53 Posted April 26, 2016 Report Share Posted April 26, 2016 Simon i have several used rubber mounts if you would like to try them ? ROY Quote Link to post Share on other sites
stephen cooper Posted April 26, 2016 Report Share Posted April 26, 2016 I also seem to have a resonance at about 60-70mph since poly bushes were fitted to my diff. Roy after Simon has replied If you have any good ones left I'd like to buy a set. Cheers Quote Link to post Share on other sites
Guest ntc Posted April 26, 2016 Report Share Posted April 26, 2016 (edited) There should be no noise simple unless using red mounts. Edited April 26, 2016 by ntc Quote Link to post Share on other sites
Graham Posted April 26, 2016 Report Share Posted April 26, 2016 Simon I have to,ask the obvious question, and my apologies if you have already discounted this, but it's not a rear drive shaft bearing moaning is it ? Many years ago I had a drone coming from the near side of the car and after I removed girlfriend at the time I tracked the noise down to a combination of rear wheel bearing and a hub about to part company with the trailing arm as the bearing flange had cracked...........just a thought as you would hope that having had the diff rebuilt twice that should have eliminated it as a source of the noise. ATB Graham Quote Link to post Share on other sites
simonjrwinter Posted April 26, 2016 Author Report Share Posted April 26, 2016 I hope not, I've just paid £1500 for CV driveshafts an hubs! Quote Link to post Share on other sites
Graham Posted April 26, 2016 Report Share Posted April 26, 2016 I hope not, I've just paid £1500 for CV driveshafts an hubs!Ah perhaps not then !ATB Graham Quote Link to post Share on other sites
Tom Fremont Posted April 26, 2016 Report Share Posted April 26, 2016 TRF supply fine original type rubber mounts; no noises and no issues after many years and miles. These are on my circa 150 BHP '250 which still has its original diff studs intact ( I don't abuse the privilege; gently shifting before giving it the WOT ). I would discourage anything but the softest bushings unless the diff studs/mounts have been reinforced. Cheers, Tom Quote Link to post Share on other sites
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