8 3/4 rear end leak question

[longgone]

Just put in a new 3.91 gears in my cuda rear end (8 3/4 suregrip), did the whole master kit with seals and such too from randy's.

Drove it some and my front seal where the yoke goes in is dripping a drop a minute or so.  What are the likely causes?
Bad new seal?  Seal not put in properly?  Yoke worn?
What are my best next steps?  I want to make sure I have all the right parts to fix it before I start on it again.

I'm no mechanic pro just a eager person willing to get his hands dirty.  I did have help from a good mechanic putting the ring/pinion in and the unit together though.

Thanks
Blueglow

[Chryco Psycho]

could be a bad seal as made or hurt when installed , or if the yolk was worn or damaged it can leak oil past as well , is it a 489 & does it have the crush sleeve , if so I would seriously think before disturbing the yolk , possibly contact Randys & see what they want you to do with it assuming there is a warranty

[longgone]

Its a 742 casing rear end.  Any further advice with that info added?  Your da man Chryco!
Blueglow

[Moparal]

If everything was new and you feel it was installed propper. Then you could think on the line of the gear oil is foaming up, possibly over filled and the vent is not letting out air which can cause a leak from too much pressure inside the housing. The vent is on the axle tube, which I am sure your aware of but can be damaged. If you happened to over fill the axle with oil from being on the wrong level when filling. It could be over filled. Was the car level or just the back end up in the air when you filled the unit? Did you put in the propper amount or fill it up till it leaked out the filler hole? I've seen this happen before. But it is possible that you have a groove worn in the yoke, or installed the seal and nicked it. Or a piece of crud was on the yoke you didnt notice when you installed it. Or even possibly the wrong seal....Keep us posted.

[longgone]

All those are great tips!  I'm gonna go see my mechanice Monday or so and put it on the lift and see if we can't figure it out.  He nor I are realy mopar experts so all these years of mopar experience here helps a lot.
Thanks
Blueglow

[Chryco Psycho]

the 742 did not uyse a crush sleeve so I would center punch the nut & pinion so you car retighten to the same point & undo the nut , remove the yolk & change the seal if nothing Al suggested works