Old rearend pinion seal question.

I replaced the pinion seal on a '56 Cad rear today. Pretty much used this method found in another thread...

So it all went back together & the pinion is leaking just sitting on the garage floor. Does this mean the front pinion bearing is bad??? Or did I miss something?

Thanks.
-r

 

Was your yoke groved?

 

nope. Looked perfect to me.

 

This reminds me of the dumbest leak that I have just repaired- I just replaced the pinion seal on an Australian Ford, and the bloody thing still leaked. On close inspection with a flashlight I found the oil was leaking up past the SPLINE and behind the nut and washer- and I cleaned the spline and put some goop (silicone I think) which cured it. I have since found that this is a common leak on certain types of Jap trucks.

 

Tightening the yoke with an air gun 'til it don't move no more ??????

 

I have been told not to use an impact on a pinion nut when the gears are still meshed. That puts a lot of unneeded force on the gears.

 

If it had a bad bearing and you put a new seal on it, It shouldn't leak just sitting. The seal would support the pinion to a point. I would have to agree with 36 Roadster that you have EP90 running out the spline. All of this would apply provided you didn't screw up the new seal when you installed it and yoke was in good shape.

 

I can relate...havin the same problem in my 56 chevy,even tried two different seals..............

 

i put a new seal in mine last week and gm recomended that you put a bead of sealent around the seal, don't leak!!......yet...

 

Make sure it isn't over-full with fluid. Fill level is most likely to the bottom of the fill hole. I sometimes see guys pump fluid in until its gushing out and then hurry up to put the plug back in. Having that extra fluid probably does more harm than good and if the level is higher than the lowest point of the pinion seal it will most likely leak.

 

If that diff uses a crush collar for the bearing preload you should "NEVER" use the impact gun to retighten it! Bearing failure will be certain. That however will not cause it to drip from there right after the seal was replaced. Be certain that the right seal was used and that it fit properly around the seal lip mating surface on the yoke.