Packard Forum Index » Post-War (1946-54)

I'm getting a little frustrated - I've replaced my differential pinion seal for the third time and gear oil is still draining out of the case. I worked very carefully the last time (again) to drive the seal in properly, and used very fine emery cloth to debur all the surfaces it might touch.

Is there something else going on here that causes these seals to fail? When I got the car the case was dry, and that seal (when I bought it) also leaked.

I've had the same problem.n If your car is high mileage and hasn't had particularly good maintenance it may have a worn ring around the pinion shaft. If it has worn too much the new seal can't make contact properly with the pinion shaft and will let fluid leak.
You can either replace the pinion shaft or have a sleeve machined and pressed in place on the old pinion shaft.

Or have it metal sprayed, then machined to the right diameter.

I recently had my pinion yoke "speedi-sleeved" due to wear in the pinion seal area. The comment was common wear due to dirt getting in this area. It was done at a driveshaft shop when I was having the yoke converted for a different u-joint. The cost was nominal, under $50 (25 or 30 if I recall), and was done as matter of routine good workmanship, no technical analysis required.

Was it done "on the car"? This is all new to me.

No. The yoke is unbolted from the pinion shaft prior to being able to remove the pinion seal. The outside of the pinion yoke (also referred by some as the U-joint yoke) rides against the inside of the pinion seal. I am by no means an expert on 49's, or mechanical repairs, but I suspect the procedure is the same on your 49? On my car, it was a matter of separating the u-joint from the differential (at the pinion/ujoint yoke), unbolting the yoke (big wrench, mind the torque position) and sliding it out/off. Take yoke to driveshaft shop, and if possible with the new pinion seal (so they can verify dimensions for a good seal). They will then order and apply a speedi-sleeve (really nice metal band). Pay at the front and return home to do it all backwards/over again. And the price of this armchair quarterbacking? Let the forum know how this worked out - I for one would like to know the source of your pinion seals. I have been told a second hand rumor about the quality/fit from one of the large Packard suppliers selling a "new manufacture", and the report was not what I wanted to hear, so indeed, this is a "real" question that needs comment. Nearly everybody I know fights pinion seal leaks...

Aside from whatever you do with the seal, you probably won't be able to find a new crush sleeve for the pinion bearing preload. So assuming the rear end was quiet to begin with, I'd suggest measuring EXACTLY the number of thread turns to get the pinion nut off, and replacing it in precisely the same position to maintain the previous bearing preload.

Fackmaster wrote, "I have been told a second hand rumor about the quality/fit from one of the large Packard suppliers selling a "new manufacture",



I just replaced the pinion seal on my 51. Can I ask who the supplier is that sold the questionable seal to you. Please email me if you don't think it's proper to respond here.

Thanks,

Of course I would not name names until I had something from personal experience to say, but I definitely am fishing to know sources for GOOD pinion seals. 311926

G'day all, With the Australian Dollar at US 95 cents it is going to be easy to spend two cents here.
With the pinion seal leak; Packard went to a neoprene seal in the 26th Series ( 1953) and prior to this they were generally a leather/ felt arrangement which you had to soak for about a week prior to fitment. If you installed a leather seal without soaking it will leak for a few months until it soaks up enough oil all around to swell the seal. You should also check that your axle housing vent is free to rotate. These often get stuck, clog up and pressurise the diff with a predictable result.
I sense from Owen and Flackmaster's threads that there may still be some avoidance of the Packard torqueing requirements for diff UJ's ( and gearbox UJ's). I must admit that it is a leap of faith to set a pinion crush sleeve preload to 5 ft/lbs and in the next paragraph TORQUE THE SAME NUT TO 300 FT/LBS ( 200 FT/LBS for the 22nd Series). I would not recommend, except as a last resort, a method of measuring the number of threads and trying to duplicate this. I have to ask my Dentist how many original teeth I have left so I generally opt for the Packard recomended procedure. Although i must add that given the number of miles which we drive, a defect would probably arise long after we have departed this veil.
With a few minor exceptions (involving the R6 overdrive and maybe a few others) the crush sleeve only involves the setting during assembly of new bearings and sleeve on a bench. If the procedure involves the replacement of a pinion seal only, the bearing pre-load is already set with the crushed sleeve AND THE SPECIFIED YOKE NUT TORQUE, and the recommended torque of 200 or 300 ft/lbs should be applied. A pic of the fixture needed to restrain the yoke is shown on Vol 22 No 1 Page 4. of the Packard Service letters on this site ( thanks to Bigkev and PG)
The "mystery torque" occurs as the crushable sleeve is not further tensioned because the UJ flange bottoms on the inside shoulder of the pinion shaft. Thus the additional 295 ft/lbs ( or 195 for the 22 series) only serves to torque up the UJ flange, not the crushable spacer. This is very necessary as many of the engines generate over 300ft/lbs torque and when multiplied by a lower gear could create a vibration at the diff, should the UJ flange bot be securely tensioned. best regards Peter Toet