Differential Pinion Shims, Oil Seal and Such

[Correus]

Hello Everyone!

I’m in need of some serious help in regard to the differential pinion oil seal and such.

So many weird questions have popped up but I’ll try to keep them as few as possible. I’m in no way shape or form a mechanic so please bear with me as I try to explain the issues/problems.

The Rover in question is a 1963 SIIa 88.

Vehicle serial # 24406929A

Engine serial # 25140728C

Gearbox serial # 2514664B

The Green Bible’s parts book says that the differential style is for the front and rear Rover axles suffix A-G. That's plain and simple and easy to understand.

Question #1 –
There are some parts within the differential that are different based on the suffix. For example, if you need to replace the differential pinion inner bearing you order one number for suffix "A" and another for suffix "B" onwards. Since the differential is part of the drive train it would make sense, at least to me, that you use the suffix code associated with the gearbox - in my case that would be "B". Is this correct?

Currently I'm working on the swivel balls and hubs but am waiting for some parts to arrive before finishing them. I figured I could go ahead and get started on replacing the oil seals and such on the differentials. When the rear differential end plate/oil seal retainer/mud shield assy unit (part #236547) came off, the pinion inner bearing came off with it.

Attached to the outer side of the bearing (the end facing the drive shaft) was a washer. This washer has two different designations; thrust washer (part #231242 suffix “A”) or differential Spacer (part # 539745 suffix “B” onwards). Attached to the inner facing side of the bearing were the remains of various sized shims. Several of the shims are so worn there are even holes in them and some of the shims disintegrated into pieces. Some of these pieces are so thin they become almost invisible when you look at them from the side! The stack of shims is somewhere between 1/8 - 1/4 inches tall and there are 7 in various shapes of “intact” and 2 or 3 in pieces.

http://i97.photobucket.com/albums/l236/Correus/20150126_135057_resized_1.jpg


Question #2 –
Is it possible to buy a set of assorted shims like you can for the swivel ball Railko? All I'm finding are individual shims from a couple of suppliers and the prices are around $1.30 - $7.95 for each shim and one of them is even $19.00! It seems like someone would sell a set since you have to play with the pinion in order to figure out how many you need like; just like you have to do with the Railko ones.


Question #3, #4 & #4a –
In regard to the pinion shims… The manual talks about a "pre-load" of 7-12 pounds in regard to the pinion and the shims. Was there a part that created the "pre-load"? There is a part in the exploded parts view in the parts book; it’s listed as 502248 suffix "A" NLS (it could be 602248 - smudged printing), was this the "pre-load" part? If so, it could still be attached to that stack of washers - there appears to be a thicker one on them.

http://i97.photobucket.com/albums/l236/Correus/20150127_193501_resizedB.jpg

http://i97.photobucket.com/albums/l236/Correus/PinionParts3.jpg

The following photo shows how the parts off my Rover match the post "Suffix A" diagram. However, I'm wondering if the shim closest to the differential planetary gears (the biggest shim) is actually the missing mystery shim 502248 suffix "A".

http://i97.photobucket.com/albums/l236/Correus/Land-Rover-Series-II-IIA-III-Drivetrain-Differential-Schematicc.jpg

There was a metal clad oil seal inside the differential end plate/oil seal retainer/mud shield assy unit with "275124" stamped on it. I could not find that number associated with LR but I did one with Volvo. The original part number for the seal is 217507 but the replacement is FRC4586. The replacement part looks nothing like the original and isn't as thick either. It appears that the thrust washer/differential spacer rides up against the oil seal. Since the original oil seal is covered with metal it appears that the thrust washer/differential spacer didn’t damage the seal. This leads me to my next question.

http://i97.photobucket.com/albums/l236/Correus/20150126_175415_resizedA.jpg

Question #5 & #6 –
The new seal is covered in rubber and the lip end faces the pinion inner bearing and the thrust washer/differential spacer would be shoved up against it. Since the lip end is the hollow end, and it’s made of rubber, what keeps the thrust washer/differential spacer from chewing the new oil seal up? Is there a better oil seal I should be looking at? I haven’t found a metal clad oil seal available for my differential type. AB has one that looks to be the same size as the metal clad one but it is also covered in rubber - Item: 65 (Same Fit As Part # FRC4586 )

http://i97.photobucket.com/albums/l236/Correus/FRC4586-Topa.jpg

http://i97.photobucket.com/albums/l236/Correus/Item65SameFitAsPartFRC4586.jpg

Question #7 & #8 –
As to that thrust washer/differential spacer…the one that came out with the bearing is a little thicker than a quarter. The replacement part for “suffix A” is 231242 and I haven’t been able to find a picture of it. The one for “suffix B onwards” is 539745 and is a LOT thicker. This is one of the reasons I asked about the suffixes at the beginning. Which part should be used? If part #539745 is the correct one how will the extra length/thickness affect the pinion and all the other parts on it? Something of note - John Craddock Ltd says the part didn't start to be used until 1965.

http://i97.photobucket.com/albums/l236/Correus/20150127_124158_resizedB.jpg

http://i97.photobucket.com/albums/l236/Correus/DifferentialSpacerPart539745.jpg


So – can any of you help shed some light on these things?

Thanks for all of the help!

[SafeAirOne]

Question #1 –
There are some parts within the differential that are different based on the suffix. For example, if you need to replace the differential pinion inner bearing you order one number for suffix "A" and another for suffix "B" onwards. Since the differential is part of the drive train it would make sense, at least to me, that you use the suffix code associated with the gearbox - in my case that would be "B". Is this correct?



See: http://gunsandrovers.com/showthread.php?t=6460&p=67408&viewfull=1#post67408

[I Leak Oil]

The shims perform two functions. The inner bearing shim(s) goes behind the outer bearing race (cone) and is used to adjust the pinion depth. This depth is critical in the longevity and operation of the pinion and ring gear. Get it wrong and it will make noise and won't last very long.
The shims for the outer pinion bearing are there to take up the space between the inside (facing the pinion gear) face of the bearning's inner race and the shoulder of the pinion shaft. The shim pack is just slightly thinner than this gap, which is what will allow you to torque down the pinion nut and create the bearing preload. The thrust washer is what goes between the other side of that inner bearing race and the pinion nut.
If your shims are chewed up it means you either lost preload which allowed the inner race to move or the bearing heated up and spun on the shaft.

Bottom line is you definitely need the correct bearing and spacer that will match the pinion shaft. I'd recommend replacing both pinion bearings and probably the carrier bearings as well. Fools money spent if you don't, IMO

Forgot to add, like Mark said the thrust washer shouldn't ride on the seal. The only thing touching the seal should be the housing on the outside, and the sealing surface of the pinion yoke. Which reminds me. Take a look at the pinion yoke while it's out. If it has a groove in it you will need to replace it or sleeve it or your new seal will be useless.

[Herdsman2]

Did your ever find the answer to 5 and 6 above. I am in the middle of replacing the pinion seal myself and have the exact same issue. I assumed I received the wrong pinion seal until I saw your thread. Did you use the rubber seal? If so, how did it work? Does the lip side face the front of the vehicle or in toward the diff?

Thanks in advance for any assist. I was going to call Rovers North tomorrow to ask. The weather is so nice here, I hate to have "old bumpy" in pieces.

[Correus]

Heya Frank -

Sorry for the delay.

Nope, never did get an answer, not even from the dealers.

I went ahead and used the funny looking one. Large lipped side facing the diff and small funny looking side facing out. Be sure to use some joint compound when you insert it into the seal housing/holder.

[Herdsman2]

Thanks for the reply. Apparently the metal one isn't made anymore. That said, the folks at our host squared me away and I am ready to get her back together. The weather here today is going to hit the 80s, so a perfect night for reassembly.

Top Tip on the joint compound. Any particular brand you like, I have never used it before. I will have to stop at the auto store on the way home tonight.

[Correus]

Actually the metal one is still available. I found it on a vintage car parts web site out of the UK. The price was unbelievably high and didn't include the shipping. I think you would have to be nuts to buy it.

The other one - the one that looks like a solid black plastic version of the metal one - is still available in the UK as well. Some of the dealers here in the US have it - supposedly - but when I ordered it the other is what they sent. I guess it's being fazed out.

Anyway - I use Permatex Ultra Black.

http://www.permatex.com/products-2/product-categories/gasketing/gasket-makers/permatex-ultra-black-maximum-oil-resistance-rtv-silicone-gasket-maker-detail

It's going to be in the mid 80s here in south central KS. I'm going to be working on installing the new brakes on the front as well as installing new races and bearings on the front hubs.

Good luck and have fun!