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On this I still disagree even with alloy cups.

 

You disagree with me???? Such a surprise ????????

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Marc r. The above is just genial banter Between enthusiasts I am sure. Ntc is doing the Yorkshire thing by getting his point across in as few words as possible, M comes from Glasgow I think.

 

I can equate to the conversation having lived in SW France for 7 years and trying to understand the accent here you have to be tuned in to it it isn't Parisienne French!!!

 

It's made my day!

I like this forum .... :rolleyes:

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I am with GT6M that some CWPs can not be set properly. Some of them change

play depending at what position it is measured. Put the cage in a lathe to check for

out of round conditions but the problem was in the crown wheel. Some can be set properly

on the load side and than the other side does not fit perfect. Such axles are quiet when

accelerating but if you depress the pedal the noise starts.....

 

That is one reason why we talk about noise. It can only be transferred what has

been created before. Fiddeling with softer rubber helps to reduce the noise but

does not cure the problem itself. That is the reason why some claim benefit of

other rubbers (they have a noisy diff) and others do not face that problem that much

(axle is more quiet). Some modern axles like BMW do not make noise

at all and they are absolutely free of play, too.

 

If a CWP is not set properly it starts with noise when offset is small but does not affect lifetime and

still withstands the power but gets louder with every step away from the prefect setup and when set seriously

bad it will fail sooner or later. Had a diff at a friends Sunbeam Lotus that failed after only 1000 Km!

The only thing that was done wrong was to change the cage to LSD and did wrong distance of crown wheel!

 

From all that reasons I decided to work on a BMW diff that also allows to use

longer CV drive shafts. That helps to keep things sound because the TR6

has the disadvantage that the axle bottoms under hard acceleration. This

bends the drive shafts and large angles in the joints they do not like. Longer

drive shafts need smaller bending angles. Universal joints fail pretty fast under

these conditions but CV-joints do not like large angles, too.

 

So BMW is a good idea if you want complete silence and a reliable drive train.

No lost wheels, no wining, no wear in drive shafts, no vibration, no play........

Edited by TriumphV8
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Correct way is as per the 2 pictures from Sean and the 1st / Left picture from Simon, on top of it make sense at a mechanical point of view and it is coherent with the typical drawing available on the Triumph ROM "section #51/ Rear axel" and Spare parts catalogues.

 

Regards

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Phew

Mine is fitted properly :P

IMG_0936_zpsgtfzw79l.jpg

...... My old diff used to wine more then the Duchess :ph34r::lol::lol::lol:

it was fitted with old rubber mounts, replaced buy blue poly bushes, no noise at all now, Happy bunny

Edited by Clarkey
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Hello,

I'd like to chime in on this 'Diff whine' topic please, however mines perhaps more of a 'low rumble' at times. I've tried a few things, buts its starting to puzzle me. So things I've tried:

  • yes its got oil in, looks clean.
  • have receipt from PO for recent rebuild of diff with new CW & P. In 2008, around 12k miles since. (from Coventry Axles from memory, to confirm would have to dig out paperwork)
  • As diff was thought good, I've had main propshaft refurbished (2 new UJ's, 1 new yoke, new central spline and re-balanced)
  • replaced the two rear splined driveshafts (new 'dog-bone' units, then installed with new UJ's all round)

but still the noise persists, so I'm turning my attention back at the diff again.

Had a local friendly transmission place (who rebuilt my gearbox and O/D) ride in the car to assess. Their thought - doesn't seem to be serious, too low a noise for CW & P setup, either sticky UJ in new driveshafts (but nothing changed when they were replaced) or possibly a bearing just starting to go in the diff - keep driving and keep listening...!

 

The low rumble is only really evident at speed. typically 65-70mph or above. Its heard, but also felt through the seat bases.

It is load dependent. accelerate hard or fully coast and the rumble is really there. feather the throttle at a cruise a 'sweet spot' can be found.

Also noticed hot (thin) oil makes it worse. After a 1.5hr motorway cruise I thought it was deteriorating, but after 1hr lazy lunch and cool down it was quieter again for a while, then got louder further in the journey. When hot and louder I can notice some rumbles down around 40-50mph when coasting.

One anecdotal observation. When rear wheels are up, spinning one wheel it would rather spin the main propshaft and gearbox output that the other wheel in reverse (which I believe is more typical). No the brakes don't bind. Putting the box in a gear to lock the propshaft, it will turn the other wheel in reverse but it then feels bit stiff & 'notchy' rather than smooth. Red herrings or indications of trouble..? (its a standard and not limited slip diff as far as I know!)

 

So would appreciate peoples view on this. Has any one come across this sort of behaviour before? Likely causes/ solutions?

Can Triumph diffs be quiet in operation? - seen many comment here about noises, or lots of slack, etc.

Cheers,

James.

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If you want a diff and axle fully free of play and noise you need to swap to a BMW diff.

Anyway noise can be reduced with the TR parts that it is not noticed with top down.

 

To come closer without the experience from former repairs I would recommend to swap.

Just change the diff to another and look what changed.

If vibrations still persist:

If there are vibrations in the seat that rise with speed its more likely the propshaft.

If there is a rumble that starts with 80Km/h and gets a little less at higher speed and than

comes back with speed more rising its more wheel & driveshaft.

Be aware that I had a driveshaft/wheel arrangement that needed more than 100grams at

one wheel to get all balanced at the car with the Hofmann finishbalancer!

That was really a pain to drive at higher speeds!

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Jim, just cos there new bearings fitted, or were in 2008, dont mean they are OK

good test of a bearing is how much the inner /outer moves.

Butt, the condition of the inner races can only be seen by a real good clean and plenty of light

 

I had a car in that had a really noisey rumble / grumble, thought it were wheel bearing, but it wer,nt

it were diff side bearings, the case hardening breks doon, and the balls then go owa this ruff spot, and mek a noise an vibrtion

 

no saying it is this, but this is a possibility

 

BILD0118.jpg

 

BILD0121.jpg

 

M

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All,

Thanks for replies so far.

On the rear wheel bearings, well is a possibility, but in my experience when they go (on cars in general, not Triumph specific) you tend to have rumble across a large speed range and the pitch rises and falls with speed. Also often it changes when cornering one way or the other (as one of the races which has the rough surface on doesn't like the side loading)

I don't have this sort of behavior. this is generally quiet until fairly high speed (unless long journey and what I suspect is hot oil)

However I should admit that to deal with an advisory at MoT of a slack rear wheel bearing, offiside, while the rear shaft dog-bones were replaced, we took the opportunity to tighten up the 'slack rear bearing'. It only took 1/2 of a flat on the large nut if that to remove the slack. Just the minimum to remove the slack, was very aware not to pinch the bearing and was aware of the rear hub is not that robust.

 

GT6M - interesting comment on the diff side bearings - I wonder about those too. There is a little oil weep from one of them, which might be symptoms of some issues.

 

I guess one of the main views I'd like to canvas is - Do people concur its unlikely to let me down suddenly. I should have a gradual deterioration with plenty of warning to rectify before I'm left stuck at the side of the road. :(

 

As Andreas says, suppose a swap of a diff would be the best way to identify if it is the issue. However I don't have a spare to try... unless anyone could loan me one potentially.?!?! ;)

 

Cheers,

J.

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  • 3 months later...

Right,

Have driven the car for the first time since the diff was re-installed correctly....it still bloody whines.

Not on acceleration/deceleration but at a constant speed. I'm happy to live with a little whine, but this is really pretty loud.

Seems to be worse in 4th gear for some reason. Yes it IS the diff not gearbox.

I guess it'll be coming out AGAIN!

 

Simon

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What mounting bushes are you using and are you sure the casing is not touching anywhere especially on the rear shock absorber bridge?

Stuart.

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Have driven the car for the first time since the diff was re-installed correctly....it still bloody whines.

Not on acceleration/deceleration but at a constant speed. I'm happy to live with a little whine, but this is really pretty loud.

 

 

When the crownwheel/pinion is not set correct it starts with a little noise.

This is often the case when I do the refurbish, it can be heard but does not fail.

Its difficult to set a fully quiet diff and not necessary for good lifetime.

 

When its more out of correct setup its get louder and will not stand the power.

Especially the V8 needs a close to perfect setup because the diff size is at the

limit for that engine power. It was made for 100BHP in the TR4 but mine works

since the swap in 1980 and got some refurbish and the QUAIFE but never

broke or damaged a CWP.

 

So it must be removed quickly before the CWP starts to eat each other.

 

Difficult to judge but when the preload of the bearings is not correct the

CWP changes position under load and maybe under load it fits better

and the noise drops. Just an idea....

 

Anyway worth to strip the axle and paint the teeth and look how they engage

like it is shown in the typical pictures. After that I would test the preload of the crown wheel

just coarse by taking it out and feel if can be put back or if there is a preload to

spread the outer bearing rings preventing their refit. If you can fit it by hand its wrong.

 

Than I would measure the torque of the pinion wheel by fitting a steel arm

at the propshaft flange and feel the resistance to turn it. I have a steel arm

to mount and when it drops, its too loose, if it sticks to much preload. It

must be close to drop if you tip it with a finger.

 

Each more mile might spoil the CWP and they become expernsive these days.

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What mounting bushes are you using and are you sure the casing is not touching anywhere especially on the rear shock absorber bridge?

Stuart.

I thought that was the problem when I had the diff rubbers (polybushes) round the wrong way and it WAS touching then, I thought turning them the correct way round had meant it wasn't touching anywhere, however, I will now double check.

 

Simon

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