leaking differential seal

[nickd]

My front differential seal is leaking, the seal (part# 18 on figure 79 20p)
is on the front side of the differential on the front axle. The oil is getting slung by the companion flange dirt deflector and further sprayed by the fan and spraying oil every where. Has anyone changed this seal? It looks easy from the exploded diagram.

 

[JRBAMATEX]

I've been changing seals like crazy lately. I changed the same seal this weekend, only it was the input shaft for the first rear axle. The one behind the T-case. It's a snap and will be even easier for you because you don't have to take off a drive shaft. Just slip out the cotter pin securing the companion flange nut. Then remove the companion flange nut. You may have to find a way to keep the drive from turning since you likely will not have the front diff engaged. Maybe slide a piece of flat stock through the U-joint on the other side and let it catch on the ground to keep the shaft from turning. Then take the nut off. I think it's a 1 1/2" socket you'll need. Figure on getting out the 3/4 in drive socket set. Once you have the nut off the companion flange will slide right out. Next you need a 5/8 socket to remove the seal housing. Take out all those bolts and "carefully" remove the housing. It doesn't have paper or synthetic gaskets. It has steel shims that you will be reusing if you are careful. Once you get the housing off "carefully remove the shims and soak them in mineral spirits or something like that. Whatever you have will work (gas, paint thinner, etc.) Then go pop out the old seal. Best if you have a large socket that fits nicely around the seal for knocking the old one out and for setting the new one. I don't have such a socket so I just use a block of wood and be very careful when I set the new one back into the housing. One thing to remember is that it is best if the housing is as clean as you can get it. Also it doesn't hurt to put some silicone. (I use permatex ultra blue) on the inside of the housing where the new seal will set. (Extra sealing). Once you have the new seal pressed into the housing set that aside. Then go back to your shims they should be ripe for cleaning. Take a rag and clean them up to dry and just metal. No old silicone. Then lay them on some news paper and lightly spay on some spray gasket. I use copper based spray gasket. When you put the shims back on make absolutely sure that you put them on right. There are two holes close together on one part of the shims. One of those holes is for a bolt to go through. The other one lets oil pass through the little oiling channel that you will see on the back side of the seal housing. Make sure you have this set correctly. I don't think it will let you bolt it up if it's not right but just in case make sure. Anyway, once you have the housing and the shims back on the diff and torqued down real good. (Don't strip the bolts but pull them down about as tight as you can with a 3/8 drive socket). Then grease the splines on the through shaft and put a little grease on the rubber edges of the seal and slip the companion flange back on. Tighten up the companion flange 1 1/2" nut as tight as you can safely and still leave the hole exposed for the cotter pin. Put the cotter pin back in. Drive it some and then check your diff gear oil level top it off if need be.

Good luck,

 

[gringeltaube]

diff. seal replacement

Whow, Jrbamatex! That's what I call a detailed step by step explanation. Nothing could go wrong that way!

Just let me suggest a few additional tricks:

Have you ever tried to replace the seal without removing the seal housing? It is possible, sometimes with a small pry bar, if not just insert some self tapping screws to pull it out.

Have you noticed that the housings are deep enough for 2 seals? Just put some synthetic grease (water resistant) in between them and forget them for years!

Whenever I had to re-adjust bearing end play/preload by removing/replacing shims I just cleaned them with paint thinner, installed them DRY and torqued housing retaining bolts, than use Loctite 290 ( the self penetrating, very liquid green stuff) for sealing around and between shims. It works well!

It is safe to have a 2 ft piece of heavy flat iron directly bolted to the flange to prevent it from rotate when tightening the 1.5” nut.

Just my 2 ½ cents.
Gerhard

 

[davemccoull]

Diff seals

I agree with the Master, the seals can be changed without unbolting the seal housing, don,t forget to drop oil level though!
I have done this job many times.
Dave.

 

[nickd]

Thanks guys for the quick responses! Anyone have the part number for the seal ?I will evaluate replacing the seal without removing the housing first

 

[cranetruck]

Great job describing the procedure guys, nothing beats hearing it from the experienced!

These seals are important if you plan on fording waters more than 2 ft deep, I found out that those particular seals on my front axle were leaking after installing the pressurization system on my deuce. A hissing noise from the low pressure air made the leaks obvious.

 

[ken]

When these seals fail it's usally because the pinion bearings are bad!. That lets the pinion shaft waller around instead of running true. This lets gear lube pass between the seal and the flange. Iv'e changed about 20 sets of these bearings on the fire trucks. You will need a bearing seperator and a way to press or warm up the new bearing to install it on the shaft. I use the bar b q pit. I have the commerical bearing #'s and seal #'s at home. Trucks with the sprag T-case are the worst ones. They usally tear up the center axle ones first.

 

[davemccoull]

Diff seals

I get the seals from local bearing stockist
80mm O.D. x60mm I.D. x 10mm wide i use two of these, i think the stock size is 15mm wide. Also check bearings whilst doing job!.

 

[JRBAMATEX]

You know now that you mention it you could do these seals without pulling the housing. Also, I really like the idea of putting in two seals. There actually is enough of a lip left to get another one in behind the first one. It would then be a "Super Seal". I am going to try this as I still need to do some more of my diff's.

 

[devilman96]

PLEASE SEE THE CORRECTION TO SEAL SIZES ON

http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=5023

Cool... I've been searching for those sizes!!!

The above seal mentioned by davemccoull is listed by CR in 2 different seal types...

23442 is a single lipped 60X80X10 (ID X OD X W)

The second listing is 23438 which is a double lipped seal 60X80X10.

If you are installing these in pairs DO NOT PUT BOTH IN THE SAME DIRECTION!!! Install the first seal using PN 23438 OR PN 23442 and install the second (outer) seal using PN 23442 ONLY installing it BACKWARDS with a little grease between them. This will allow the outer seal to act as a dust wipe and prevent the shaft from being eaten up!

I would never recommend using PN 23438 in a 2 seal application, being that it is double lipped you end up with 4 seal surfaces ganged up together and you can not face them in opposite directions as needed, the lips will crush and bind... Shaft wear, shaft wear, shaft wear!!!

If you wish to install a single seal rather than using the above mentioned seals in pairs the closest part number (found to date) is a CR 23443 60X80X13MM which is a single lip seal.

Keep posting the PN's and or sizes to things as you find them... I have an XML file that is growing by the day with civilian cross reference part numbers and suppliers.

 

[nickd]

I removed the old seal today the part number on it as A-1201-U-515 is this a good number fro crossreferencing the correct seal?

 

[devilman96]

Please see the correction to the seal size on http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=5023