TR6 Differential

[Jeff-C]

Hi Guys,

 

Has anyone taken on the task of overhauling their TR6 diff?

 

My TR has done 138000 miles and I'm a bit anxious about the diff. When I engage reverse and start to move I often get a clunk from the back axle which I suspect is the taking up of the slack. Propshaft is in good order as I've replaced bearings etc not many miles ago.

 

I believe you need certain special tools for the job, has anyone got these for hire or borrow?

 

Are there any pictures/drawings so that I could make some tools for the job?

 

Any advice gratefully received.

 

Thanks

Jeff

[cubehopper]

Hi Jeff,

There are quite detailed instructions in the brown book on stripping/rebuilding the diff.

 

Not too sure about how many specialist tools are involved,although spreaders are needed to remove the crownwheel/pinion

assembly from the housing, a dti to check for run out,and bearing pullers.

Hope this is a help.

Dave

[Jeff-C]

Thanks Dave,

 

I'm not familiar with the 'Brown Book' can you explain?

 

Thanks

Jeff

[Chris Mitchell]

Thanks Dave,

 

I'm not familiar with the 'Brown Book' can you explain?

 

Thanks

Jeff

 

 

Hi Jeff

 

I am not familiar with the Brown Book either?? Was lokking through the Haynes maual last night and that has a great section that shows and expalains how to rebuild the diff in great detail..

 

Before you go to the trouble of overhaulin the diff, have you checked the diff mounts?? I have recently bought a 6 that had a real clunk at the rear and it was the was the mounts not the diff itself

 

Cheers

Chris

[wheeler]

Hi Jeff

 

The 'Brown Book' is the 'Triumph TR6 Repair Operations Manual' You can download a pdf version here http://www.vitessesteve.co.uk/Servicemanuals.htm

 

I have just lived though a clunk from the diff saga see here http://www.tr-register.co.uk/forums/index.php?showtopic=28341 turned out to be knackered UJs.

 

Have a close look at these before ripping the diff apart.

 

Cheers

 

Bill

[Jeff-C]

Thankyou gents for your help.

 

I'll have a look at the car tomorrow and check out the UJ's - but I don't think that is the problem.

 

Cheers

Jeff

[rpurchon]

if your diff is not whining.you dont need to mess with the pinnion and crown wheel.

i wouldnt bother replacing the bearings if its not whining.new bearing probably worse than old.

to get rid of all the backlash,its the play in the planet gears.

you can replace the 2 small bronze cup shaped thrust washers.these will have worn.

they have their original size stamped on the back.

and there are 2 more larger thrust washers usualy delrin/hard plastic.

you dont need any special tools [spreaders] big screw driver will prize it out.

 

richard

[Stag powered]

if your diff is not whining.you dont need to mess with the pinnion and crown wheel.

i wouldnt bother replacing the bearings if its not whining.new bearing probably worse than old.

to get rid of all the backlash,its the play in the planet gears.

you can replace the 2 small bronze cup shaped thrust washers.these will have worn.

they have their original size stamped on the back.

and there are 2 more larger thrust washers usualy delrin/hard plastic.

you dont need any special tools [spreaders] big screw driver will prize it out.

 

richard

 

My diff has about 250,000 miles on it now and it is still on its original bearings, but I have had to replace these bronze thrust washers twice, and they need doing again.

If they are badly worn, the number stamping will have worn off, but the unworn bit in the middle can be measured for thickness and new ones purchased to suit

Neil

[rpurchon]

My diff has about 250,000 miles on it now and it is still on its original bearings, but I have had to replace these bronze thrust washers twice, and they need doing again.

If they are badly worn, the number stamping will have worn off, but the unworn bit in the middle can be measured for thickness and new ones purchased to suit

Neil

 

must have been lucky with mine.still had numbers on.65" thou i think

moss list loads of sizes,but they only stock a few sizes.

richard

[Jeff-C]

Many thanks for all your guidance gents

 

Jeff

[RobinTR6]

I have a similar problem, ie no whining but a slight clonk on engagement from stop in forward and reverse. The UJ's have all been replaced and the pins and bushes are all fine. Can someone identify the thrust washers for me , perhaps from the Moss catalogue so I can see what I'm looking for. In addition is this a difficult fix. Presumably you need to undo the half shafts to the back wheels .....

 

Thanks

Robin

[rpurchon]

I have a similar problem, ie no whining but a slight clonk on engagement from stop in forward and reverse. The UJ's have all been replaced and the pins and bushes are all fine. Can someone identify the thrust washers for me , perhaps from the Moss catalogue so I can see what I'm looking for. In addition is this a difficult fix. Presumably you need to undo the half shafts to the back wheels .....

 

Thanks

Robin

 

items 47 are bronze and 49[plastic] in moss catalogue.you will have to take the diff out to get at it.

and now just to throw some petrol on the fire,

with so little bronze in the diff there no excuse for not using superior GL5 oil.

richard

[RobinTR6]

Richard

 

many thanks, I'll now investigate further.

 

Regards

Robin

[Jersey Royal]

items 47 are bronze and 49[plastic] in moss catalogue.you will have to take the diff out to get at it.

and now just to throw some petrol on the fire,

with so little bronze in the diff there no excuse for not using superior GL5 oil.

richard

 

 

 

I have just ftted a reconditioned diff. I ordered new nylocs and had Moss send me 2 l of a "suitable"

Diff oil. They sent me Penrite Hypoid Ep80w 90, which i now note is a Gl5

 

http://www.penriteoil.com.au/pis_pdfs/Hypoid%2080W-90%20OCT%202010.pdf

 

So is it realy considered ok to use in the diff, or should i be looking for a Gl4

 

Cheers

Guy

Edited May 9, 2011 by Jersey Royal

[Jersey Royal]

I have just ftted a reconditioned diff. I ordered new nylocs and had Moss send me 2 l of a "suitable"

Diff oil. They sent me Penrite Hypoid Ep80w 90, which i now note is a Gl5

 

http://www.penriteoil.com.au/pis_pdfs/Hypoid%2080W-90%20OCT%202010.pdf

 

So is it realy considered ok to use in the diff, or should i be looking for a Gl4

 

Cheers

Guy

 

 

I sent an e mail of to Moss technical dept asking for clarification.

 

and this is the reply.

 

Guy,

 

Yes, the oil recommendation it is correct.

 

There are bronze washers in the diff. But, the diff needs the extra

protection that a gearbox doesn't. It has to do with shearing forces.

 

 

 

Regards,

Russell Scott

Moss Europe Ltd

 

Cheers

Guy

[88V8]

Yes, the oil recommendation it is correct.

 

There are bronze washers in the diff. But, the diff needs the extra

protection that a gearbox doesn't. It has to do with shearing forces.

 

Regards,

Russell Scott

Moss Europe Ltd

 

GL5 has more EP additives, and is good for gears with shearing forces (hypoid) and shock loads (straight-cut such as planets). Normally, GL5 is prohibited for older cars because its sulphur, phosphorous or chlorine EP additives are agressive to yellow metal, but I have seen comment that this does not apply to new-generation GL5 oils. In that case, we would indeed be better off with GL5 in the diff.

 

I would want to receive specific clearance from the oil company before changing over, but I assume Moss have had some specific information on this.

 

Ivor

[Alec Pringle]

Having now seen what has come out of three TR diffs that contained GL5, and a fourth that may have been GL5, then I remain unconvinced - more shiny particles than I'm accustomed to seeing in old GL4 diff oil.

 

Then again, for 40 years I've stuck to a policy of changing Triumph gearbox and diff oils every 36K miles or 3 years, whichever comes sooner, and I've yet to wear out a gearbox or diff to the reconditioning stage. That may of course be entirely coincidental.

 

I'm sure current GL4 spec is a whole lot better than anything we were using in the 70s and 80s, when I could take IRS diffs round the clock without them batting an eyelid . . . .

 

Cheers,

 

Alec

[Jersey Royal]

GL5 has more EP additives, and is good for gears with shearing forces (hypoid) and shock loads (straight-cut such as planets). Normally, GL5 is prohibited for older cars because its sulphur, phosphorous or chlorine EP additives are agressive to yellow metal, but I have seen comment that this does not apply to new-generation GL5 oils. In that case, we would indeed be better off with GL5 in the diff.

 

I would want to receive specific clearance from the oil company before changing over, but I assume Moss have had some specific information on this.

 

Ivor

 

So i asked the Technical dept at Penrite themselves about there Hypoid 80w-90 GL5

 

Guy,

 

Come and do my job! Correct on all points:

 

Previous GL-5 formulations contained sulphur and phosphorous in a slightly different form which attacked and pitted copper and bronze components when they got above 70 deg C -which happened locally when the fluid film was squeezed between the gears.

 

So, my guess is that your TR6 -my brother had a yellow one in 1971! -used to use a GL-4 product to lower the sulphur / phosphorous level and avoid this problem on its bronze washers / bushes. Also, another question is "is it a true hypoid, or are the gears spiral bevel?" -which is a slightly less onerous application.

 

The really, really, good news is this product: http://www.penriteoil.com.au/pis_pdfs/Hypoid%2080W-90%20OCT%202010.pdf -a modern GL-5 formulation for hypoid diffs that doesn't attack yellow metals.

 

Best regards,

 

Martin.

 

Martin Gough

Sales and Operations Manager

Penrite Oil Company UK and Forest Lubricants UK Ltd

 

 

So there it is, i feel a lot happier now

 

Cheers

Guy

[johnny250]

Nice one Guy...and a job offer too!

 

john