1957 Pinion Seal

[Coupe]

The pinion seal on my '57 started leaking this spring.  I bought the seal and had a reliable shop replace it. It still leaks.  The mechanic said the breather must be plugged or there isn't one.  I can't find one.  I've had this car on the road for 17 years with no pinion leak until now.  I know later model cars have breathers on the rear axle.  If there is one where is it?

Thank you
Paul
CLC # 18899 

[1959Fleetwood]

Hello Paul,

The breatherhole is located at the upper backside of the axle housing.
Actually it is a small slot on the edge were the stamped steel cover is welded to the cast iron axle housing. I agree it is very difficult to see without a torch. Normally these slots don't plug up... The new seal can have a leak between the
seal chamber in the axle housing and the steel housing from the seal. Clean the whole edge, drive car around a few blocks and check if you see oil seeping through. I always mount a new seal with Permatex aviation type sealer or locktite.  The other possibility is that the yoke flange has a  groove from wear of the old hardened out seal,
A new seal will leak there because of damage to the seal lip. Yoke flangs can be repaired with a repair sleeve that you have to press over the yoke surface. SKF/ Timken part # is 99193. The 3rd possibility is overfilling the rear axle/differential. My interpretation is to keep the oil level a 1/4" below the filling plug to minimize leaking in unwanted places.
Hope this helps.

Matern Harmsel
CLC 15331

[Jay Friedman]

I can send a photo of the breather hole located at the upper backside of the axle housing, but I can't download it to this web site.  I can download it to a personal email, so if you'd like to see it, email me at jaysfriedman@yahoo.com and I'll send it to you.

[bgrutza]

If it comes to having to replace the seal I replaced my pinion seal with satisfactory results following the shop manual procedure. Retorquing the crush washer is critical.