Diff input shaft nut

[bigcat1]

Hi, I'm in the process of replacing the differential input shaft seal which has been leaking badly for a little while. I'm not very far into the job and I'm unsure about the nut that holds the flange in place as it is not what I expected. I thought it would be a castellated nut with a split pin.
I think the seal was changed by a previous owner (at a garage) in about 1992.
I'm sure I've seen this kind of nut on more modern cars but not sure how to deal with it. I think its a kind of 'one time' locking nut. I'm not sure whether it can just be undone as is; or whether the 'tangs' need to be bent out to make it easier to remove? I've ordered a new nut which isnt castellated either but is the type with a flange similar to those type used to secure the brake disc to the hub.

If anyone has any wisdom or advice about these type of nuts I would be very grateful.

[piman]

Hello Bigcat1,

that nut looks like the type used on collapsible spacer differentials. However I didn't think that Jagurs of that era used collapsible spacers.
The reason being that if the nut is removed it needs to be replaced to teh same spot, usually done by marking the nut and the pinion suc that it can be refitted in the same alinment to your marks. Also the nunber of turns need to be carefully counted. This should, in theory give the same preload as it was originally set to.
If you can be sure that the preload is set by shimming, none of the above is necessary. That said preload is lost when a lot of miles pass due to bearing wear.If the differential is quiet then it should be fine?

Alec

[B87UL]

You should have no problem removing the nut as normal. It is only constructed with steel tabs because the normal locking nylon nuts are liable to melt under influence of heat.

The nut is not your problem, but repeating the bearing preload may be. It is important to be able to replicate the position of the nut and in that respect it may be wiser to use the old nut after slightly punching each tab before refitting. Whatever method is used you will need to accurately measure the nut position in relation to the end of the pinion shaft, and mark the nut in relation to the drive flange to replicate the correct bearing preload.

Be prepared to have the drive flange machined / polished around the track where the oil seal runs. Very importantly machine the drive flange face to ensure it is square to the propeller shaft and that the male to female fixtures couple without fouling. As long as only a few thousandths of an inch is removed it will not cause any issue. If the drive flange resists removal be careful to remove it with a block type puller to prevent distortion of the face.

Don’t forget to use sealer on the ten spline drive flange, excessive sealer will expel as the flange is refitted….don’t place sealer on the pinion shaft, or at least use a minimal amount. Also apply sealer around the outside of the new seal and use a block or old bearing to fit the new seal in position without distorting the metal seal outer carrier.

Norman

[bigcat1]

Thanks for your reply,
The car is a 1961 so who knows what might have happened in the last 59 years! The only clue I have is from 1992 when a former owner (Who kept extensive records-bless him) wrote: 'input shaft trouble' which was resolved by his local garage at a cost of £34. I have assumed that this was a replacement of the seal as even 28 years ago you wouldn't get a diff rebuilt for that kind of money!

I have just painted some marks on the nut and shaft to mark position, I need to get the car a bit higher up before I can use my breaker bar.

It will be interesting to see if there is a split pin drilling in the shaft. This would indicate to me that the diff is original and that the garage just put a new nut on when they did the seal.

Cheers

Brett

[bigcat1]

Thanks Norman,

I will take careful note of your comments. I know a firm that could do me some machining if required. Hopefully that won't be required but I'm always prepared for the worst case scenario!

Cheers

Brett

[B87UL]

Brett

More often than not pinion seal leakage is down to either bearing wear or a poor contact surface on the drive flange. Be prepared to stop and get your drive flange machined if needed or the seal will only leak again.

If, by any chance, the flange wear is too deep to machine out you can obtain refurbishment sleeves from SKF or Chicago Rawhide. The former has taken over the latter but some Chicago Rawhide ones may be around.

I notice you have painted marks on the adjacent parts, but I think you should take some accurate measurements of the nut face from the shaft end, with a vernier or depth micrometer. You need that depth position fairly accurately, within about 0.002 inch or the bearings will not be preloaded correctly and the contact position on the hypoid gears will alter. Either is likely to create noise.

Replacing the seal is easy, but you need to work to a fine tolerance otherwise you can be making a money pit problem.

Forgive me for explaining further but other members may not understand the problem.

In the case of the Jaguar the pinion is trying to thrust forward towards the gearbox during on throttle driving and reversing that movement on the overrun. Any bearing slackness will permit the pinion to shunt fore and aft and in any event some 160 plus ridges will form on the crown wheel teeth and about 52 ridges on the pinion, with normal wear. The more used the car, the deeper the ridges.

If during oil seal replacement the end wise position of the pinion alters, then the ridges will clash, ride on each other, and the axle will whine on power or overrun. Should the pinion bearings be left slacker than previous, expect the oil seal to leak again and the differential to become potentially history.

Although the emphasis above is on replacing the parts as before, on known old or worn axles it is often beneficial to tighten the flange nut about 1/16th turn more than before to counteract for worn pinion bearings.

I hope the comments might be helpful, they come from a background of rebuilding over 600 R-R axles and years ago a fair quantity of Salisbury in Aston, and Alvis.

Norman

[bigcat1]

Many thanks for your further reply.
I'm very grateful for any information I can get. This is the kind of indepth knowledge that isn't available from a workshop manual. I shall certainly make some readings to try and ensure that the nut returns to its original position as closely as possible, bearing in mind your comment about potentially tightening the nut slightly more.
The axle doesn't appear to whine in any manner, although difficult to tell sometimes given the Moss gearbox!

[djpeters23140]

Hi, I am about to carry out the same job on my Daimler V8 250. What sealer would you recommend for the splines, also,
when I look to see what oil is in my garage I find half a can of 80w90 gl5, which makes me fear it has had the wrong oil in it. Does anyone know if there are any brass components in the V8 250 diff that I should be concerned about. I am going to flush it with gl4 prior to changing the seal. Thank you in advance,
Dave

[B87UL]

Dave

For the splines, in the past (now retired), I would have used Bondloc B609. I believe this may have been superseded by B641. The former was listed as a Sleeve and Bush retainer, the latter as a Bearing Retainer, both Anaerobic. You need more than just a sealer for that application to withstand slight movement and heat. Suggest you contact Bondloc direct. I have never experienced an axle leak with that product having used it in hundreds of axles. Usual disclaimers.

You would be better off using a GL4 EP80/90 Hypoid oil, than the later GL5. Forget about yellow metal damage, that problem only really existed in worm and wheel axles. The additive package in GL5 I seem to remember is about double that in GL4.

After working world wide on hypoid drives I have yet to see yellow metal damage be the cause of any axle component failure outside of a test lab. That sort of damage was caused by a high content of sulphur and only at extremely high temperatures, first detected in engine oils way before axles. It was cured by replacing the additive package back in the 50’s and reducing the Sulphur content. You will find any amount of owners telling you about yellow metal problems, outside of a test rig, ask them to show you how a bronze component failed and damaged an axle.

Rolls- Royce ran one of their B40 engines some 1400 hours at FULL throttle before they could detect Sulphur burn on the small end bronze bushes………and you are bothered about EP oil!!. That same company filled all post war yellow metal axles up to the 70’s with EP Oils, Gearboxes following from 1954, Jaguar also followed with EP oil in their all synchromesh gearboxes circa 1964.

For the record, my comments on yellow metal ver EP oils are first hand, I have read all the R-R test reports on oils including EP hypoid oils for the period 1950’s into the 1970’s.In addition I have seen the interiors of hundreds of hypoid axles with the usual failures. Even one driven none stop at high speed until the axle oil actually burst onto flames, bronze items still intact.

[djpeters23140]

Thanks for your time and all the interesting info. I've filled it with fresh oil to do a flush, will drain it after a run and change the seal with care and noting all the advice.
Thank you
Dave

[djpeters23140]

Norman, You mentioned using a block type puller, excuse my ignorance, how would this differ from a 3 legged puller, ie what would it look like.
Cheers
Dave

[B87UL]

Dave
A three legged puller is a torture instrument for bending drive flanges, designed especially to ensure the owner actually experiences drive line vibrations needing further ££££££ investigation and work.

A way to navigate around that potential extra expense is to use a steel circular block, with ground faces, of at least 0.500 inch thick but preferably about 1.00 inch thick and drilled to match the four drive flange holes. That block can both be drilled centrally and tapped to accept a central fine threaded large set screw to produce a block puller, or the block can be bolted to the flange for extra support before using a three leg puller. You will need to relieve the centre of the block on one side to prevent fouling of the pinion nut.

The flanges that have spine attachments will usually draw off quite easily but over the years they become distorted by constant withdrawals and a block puller is a good way to preserve what is left. On the other hand a tapered attachment especially in the order of 1:200, needs a block puller.

Industrial standards mean that the effort to make a block puller is worthwhile because the Mk 2 / S Type drive flange sizes suit many vehicles. If necessary the four attachment holes in the block can be elongated to suit a wider range of flanges.

If you do get stuck for parts, or shaft rebuilding try Bailey Morris, St Neots, Cambridgeshire, they are still OE manufactures for Jaguar. Usual Disclaimers.

[djpeters23140]

Job now done, used all advice given, it was an original leather seal fitted, I don't expect the replacement modern one will last as long. My only concern is I refilled the diff with 1 1/2 litres of oil which doesn't bring the level upto the filler point. I've always thought diffs were filled untill the oil spills out of the filler point. Does this mean the oil can not be topped up, only drained and filled with a known quantity.