Differential Oil Seals

[wheeler]

Hi All

 

I bought a secondhand TR6 diff on ebay a few months back to replace my existing one which has a lot of play/backlash. I have opened up the new one and everything looks fine and the diff has very little backlash. The unit when I received it was covered in oil but don't know if this was due to oil leaking out of the breather or the oil seals. Oil seals don't seem very expensive so I thought I would replace them. Instructions in the repair operations manual look fairly straight forward but before I proceed has anyone experience of replacing these seals? I would be grateful for any advice, tips etc.

 

I currently have the diff mounted with polyurethane front mountings, I do seem to get quite a lot of transmission noise, are rubber mountings any quieter? Are there any particular advantages/disadvantages of poly diff mountings over rubber?

 

Many thanks for your advice

 

Bill

[Bald Rick]

Hi All

 

I bought a secondhand TR6 diff on ebay a few months back to replace my existing one which has a lot of play/backlash. I have opened up the new one and everything looks fine and the diff has very little backlash. The unit when I received it was covered in oil but don't know if this was due to oil leaking out of the breather or the oil seals. Oil seals don't seem very expensive so I thought I would replace them. Instructions in the repair operations manual look fairly straight forward but before I proceed has anyone experience of replacing these seals? I would be grateful for any advice, tips etc.

 

I currently have the diff mounted with polyurethane front mountings, I do seem to get quite a lot of transmission noise, are rubber mountings any quieter? Are there any particular advantages/disadvantages of poly diff mountings over rubber?

 

Many thanks for your advice

 

Bill

 

Hi Bill

 

I fitted brand new rubber mountings when I had a rebuilt diff fitted recently and they failed in less than 250 miles. There was such a thumping from the back end I thought the diff pins had come adrift. When I took the mountings out I found the bond between the centre tube and the rubber had completely failed allowing the diff to thump up and down. No doubt I had a bad pair and was just unlucky as the previous mounts had been in place for years. However they are an inherantly bad design.

 

The polyurethane ones I have just fitted are designed so that they cannot fail in the same way as they do not rely on a chemical rubber to metal bond. Stick with the urethane ones even if they do transmit more noise!

 

Hope this helps

 

Tony

[jean]

It seems that this is a known problem with the repro rear diff silent blocks. You can overcome it by adding two thick hard rubber disks/washers under the block.

Ask Jon Ellison what happened to him at the occasion of the Silverstone weekend

 

P.S. Jon my congratulations for the fantastic race result .

[roulli]

A) Diff sealing:

 

I am also planning to replace the 3 sealings of the diff. According to the brown book everything appears to be pretty straight forward, but I learned from another TR forum, that one needs to pull off the flange of the axle, which in most cases will require a +10ton press. Like always, with tapered flanges & key, one must pay attention not to deform the flange...

Any experience shared here would be welcomed..

 

Rubber Diff mountings:

 

Jean, I can't see what you mean with "You can overcome it by adding two thick hard rubber disks/washers under the block"

Can you precise the description a bit.

Thanks in advance

 

Cheers

Patrick

[jerrytr5]

I replaced the output shaft seals on mine recently. Problem is you need to remove the bearings from the shaft first which I couldn't do with a puller. The first shop I took them to couldn't do them on a ten tonne press. The second shop managed it. I presume that using such high pressures means that the bearings cannot be re-used (well I wouldn't anyway) so add new bearings from a reputable supplier to your shopping list.

I never bothered doing the pinion as it was in good condition but as I recall some versions use a collapsible spacer which needs specialist equipment/knowledge to do properly.

Jerry

[Guest ron]

Patrick and Bill

I replaced these seals on my original diff years ago during restoration, I remember having a great deal of difficulty with the output ones getting the drive flanges off, I seem to recall the seal housings need to be removed at the same time.

The most likely seal to be leaking is the nose one, if it's the original it's an old fashioned leather one.

Mine turned out to be a waste of time as the diff was howling like a banshee when I put the car on the road, so I bought a recon one from TRBitz.

Ron

[Guest ron]

Could I add a bit of advice from industrial engineering experience which I have posted in the past on threads about splitting the rear hubs;

The best way to split a shallow taper is to apply pressure with a heavy duty non hydraulic puller [not an Auto shop Mickey Mouse one!] then belt the puller up the middle with a dead blow hammer, it will usually separate after a couple of belts, although this sounds crude it works well and is much less likely to do damage than pressing things off with a massive press.

Ron

[Eyetee]

The diff has been on the bench for quite a while, bought the 3 seals and cover gasget from TrEnterprises with the advice that its a simple matter of removing drive flanges and replacing seals. The Drive flanges are a little tricky to remove and a local engineer made a puller, simple design, plate, drill and a few nuts and bolts. Shall post a picture tomorrow if I remember camara.

[Eyetee]

Washed diff with gunk painted iron with rust eater

The bolt is 1" * 8" and is threaded through the plate

4 smaller bolts are m8

Tapered with a woodruf key, the seal is original metal and plastic which was past brittle.

Complicated seal part leather, put up a fight, dig to deep and risk striking baring beneath.

 

Tempted to drill and tap a sump plug but oil removed had done 70,000 miles, was 35 years old and still smelled like gear oil, if a little dirty so decided otherwise.

[Eyetee]

Going to use either hermatite or silicon on assemble.

[wheeler]

Many thanks Guys for the advice especially Eyetee for the great pictures, will let you know how I get on.

 

Again many thanks

 

Bill

[wheeler]

Finally got round to fitting the new oil seals in the new differential. A member of the Thames Valley group who is a blacksmith made me up a puller similar to Eyetee's. Scared the sh-t out of me when the flanges separated from the taper, one hell of a bang! No trouble getting the old diff out, a friend lent me his 'diff cradle' a wooden tray which allows you to balance the diff on the jack when lowering or raising. Even managed to change the diffs without removing the exhaust, just needs a bit of a tilt to poke the front bracket over the rear pipes. I have changed the poly bushes for rubber to try and reduce transmission noise, noted reports of poor bush life but am keeping fingers crossed. Went for a test drive yesterday, well pleased no more clonks.

 

Just one question how do you torque up the drive/prop shaft flange bolts? I could not get my torque wrench with socket on the flange nut/bolt heads, is there such a thing as an open ended or ring spanner torque wrench?

 

Many thanks for the advice and info.

 

Best regards

 

Bill