Pinion seal leak?

[Fran Blacker]

I guess you measure the diameter of that vs the one in there now. I'd check the vent and see if someone else has ideas over the next few days, I'm sure there will be some. You can't put the old yoke in you probably wouldn't have the right pinion preload.

 

[66 bel]

OK thanks for all the help

 

[MOPOWER871]

maybe the seal got damaged when first installed? you said the ring and pinion is new so there's slim chance that the seal surface is worn. I would contact the builder, if hes reputable like you stated he should stand behind his work and fix it. and if that vent tube looks gacky, pull that vent tube and clean it out with some carb cleaner and reinstall. good luck

 

[miller]

Just a couple things, might be worth checking. You say the yoke is new, and you still have the old one.
The shaft end (that fits through the seal) on the old yoke, get a measurement of the diameter. Compare that with the new yoke, PLUS measure the new yoke to be sure it's not out-of-round.
Second, be sure the seal is the right part number. If it is, with the yoke in hand, fit the seal onto the shaft...should have a lightly snug fit. Also make sure the seal is installed in the correct direction.
Since it only seems to leak sitting still, could be looking at out-of-round somewhere.

 

[Fran Blacker]

Checked a yoke I have for diameter 1.875" where the seal rides and .0005 to .001 out of round. Used calipers so the out of round maybe a little more but not much. Miller's thought of out of round was a good one service manual didn't have a spec. If you have to change yokes you will have to retest/reset pinion preload. I guess that means a trip to the guy who set it up.

 

[5.7 hemi]

Go to Napa and get a speedy sleeve or medi sleeve, forget the exact name, but it goes on your yoke and gives the seal a new area to ride on and you won't have anymore leaks.

 

[RJRENTON]

Gentlemen,
The speedy sleeve comes with an install tool, which is removed AFTER the sleeve is installed. Be careful when installing the sleeve as it is quite thin fragile. Make sure the ID of the sleeve is clean and grease or oil free as well as OD or the component thar it fits over. I use the Locktite cleaning compound on boyh the OD and ID surfaces and a little loctite sealant as well to insure a leak free installation. Follow the speedy sleeve installation instructions...take your time and you will be fine.
Bob Renton

 

[Fran Blacker]

Gentlemen,
The speedy sleeve comes with an install tool, which is removed AFTER the sleeve is installed. Be careful when installing the sleeve as it is quite thin fragile. Make sure the ID of the sleeve is clean and grease or oil free as well as OD or the component thar it fits over. I use the Locktite cleaning compound on boyh the OD and ID surfaces and a little loctite sealant as well to insure a leak free installation. Follow the speedy sleeve installation instructions...take your time and you will be fine.
Bob Renton

The only thing speedy sleeve may not cure is a severe out of round yoke seal area where it rides on the seal, but would help?

 

[RJRENTON]

If an out of round condition exists it could be tued up... turned on a lathe, but be careful not to remove too much material....just a "skin cut". The determining factor is not to exceed 0.003" TIR total. If more than that, replace the yoke.
Explore different seal configurations....single lip, double lip, undersized ID, all with garter a spring to hold the sealing contact surface tighter to the rotating part I've done this numerous times in industry. There are volumes of sealing dimension to peruse.....by different suppliers....Chicago Rawhide, johns-mansville, john crane, etc.
Bob Renton

 

[5.7 hemi]

If I were you, and the yoke was out of round or scored deeply where the seal rides, I'd get a new yoke and seal and be done with it.

 

[Auto Teach]

If I were you, and the yoke was out of round or scored deeply where the seal rides, I'd get a new yoke and seal and be done with it.

The 742 takes a specific seal if I recall. It is more of a leather style seal.The last one I put in a diff.I setup was around $30.00.

 

[Fran Blacker]

The 742 takes a specific seal if I recall. It is more of a leather style seal.The last one I put in a diff.I setup was around $30.00.

Doctor Diff does list a different seal for 742 housing. 741 and 489 same seal. wonder why? or don't ask. Good to know I have one leaking.

 

[5.7 hemi]

It's different than the 741 or 489 case, no biggie as Dr. Diff, aka Cass has them. Change the yoke and seal and move on to other stuff on the car.

 

[Fran Blacker]

It's different than the 741 or 489 case, no biggie as Dr. Diff, aka Cass has them. Change the yoke and seal and move on to other stuff on the car.

Change yokes? What about pinion preload, take your chances?

 

[5.7 hemi]

The 742 uses shims, no worry about preload.