Pinion Seal Saga

[DonaldSmith]

On my DeSoto Suburban, I noticed that the pinion seal was leaking again. 

 

Back in 2013, I replaced the oil seal and installed a Speedi-Sleeve on the flange shaft, to correct a leaking condition.  I got the seal from the local auto parts store, as listed for the vehicle.  Only problem, the outer diameter was too small.  As I remember, I reduced the effective inside diameter of the housing by lining it with thin strips of stainless steel.   In addition, I used sealant around the outside of the seal housing.  But the sealant and lubricant did not get along, and the seal failed. 

 

I got a second seal, and used the first seal as a temporary oil-stop, to allow the second seal to be secured with JB Weld.  This has lasted seven or eight years.  (I didn't notice exactly when it began to leak again.)  

 

Last week I removed the flange.  The Speedi-Sleeve is still in good condition, a little shinier where the seal rubbed it, but no grooves.  The seal seemed to leak between the JB Weld and the housing.  

 

This time, I took a rough dimension of the housing diameter, and ordered a seal from Grainger, an industrial supply firm.  For the 1-3/4" shafts, they had a range of outer diameters.  I bought some cheap HF calipers, and measured the opening.  Right on for the seal I had ordered.  Now I just wait for the seal to be shipped to the local store. 

 

I think I will pump out the lubricant, to get the seal area clean.  I might even set the seal housing with a little sealant around the perimeter.  Any thoughts?  

 

   

[Sniper]

Use brake clean to clean off the housing where you want to use sealant. 

 

Been noticing a lot of parts listings are incorrect or incomplete.  Clutch release bearing on fluid drive vs non-fluid drive comes to mind.  All the listings show the non FD bearing only but do not say non-FD only, it is implied they are the same.

 

Bearing and seal numbers are usually universal across manufacturers, so if the old part has a number on it use that number to get a replacement, assuming the old part fit properly.

[Veemoney]

I just replaced a pinion seal on a 47 car Diff and it called for seal 663602 as stock and shows it was used for mopar cars 37-50. I used the newer style seal CR18880. Check your dimensions again to verify. 1.750 seems small for the ID. Below is the CR18880 spec.

Shaft Diameter	1.875 in
Outside Diameter	3.105 in
Width	0.500 in

 

You can drain some fluid, clean and add some sealant. Most newer seals have what looks like paint on the outside fit surface. This paint is actually a sealer but depending on your surface you can opt for more.

[DonaldSmith]

Thanks Veemony for the info on the seals coming with an outer sealant coating.  Actual verified measurements for my car are are 1-3/4" shaft and 3-3/8" opening.   Moral of the story, verify the dimensions before buying the part.

 

OK, I'm editing this.  3-3/16 instead of 3-3/8.   

Edited July 27, 2021 by DonaldSmith

[DonaldSmith]

Correction: Not 3-3/8", it's 3-3/16".  Measure twice; cut once.  (How do I edit my previous post?) 

[DJK]

Click on the 3 dots on the far right next to author.

[James_Douglas]

Don, Keep your eye on ebay. Every now and then a pinion flange with a perfect sealing surface comes along. Since the Suburban uses the larger rear that part is worthless to everyone else except the big Chrysler 8 long wheelbase guys.

 

I have tried new seal and NOS seals with a new flange and the thing still leaks a little no matter what!

 

James