14 Bff Seal Issues

[JEBSR]

I took a 14bff out of a 1008 (I believe) hardly any wear on anything showed 6600 miles and looks about right by the wear. Anyway I put a disc brake conversion on it and changed the hub seals since the kit supplied new ones. After a couple of miles I had oil running down my tires. I did check the part numbers at that point and they were different but once a crossover was done on the numbers it was the correct replacement. Changed the seals again and they held a day or two and that was it. The vent tube is not clogged, there is not up down/side to side play in the axle, housing not worn and hub is tight. Have litterly replaced hundreds of these over the year (other axles mainly) what the hell am I missing?????

 

[tarussell]

How was the seal surface on the spindle ? It might be in need of a "speedi-sleeve" .
One othe rthought is are you getting the seal in without it being distorted - common cause of new seal leak issues.

Tom

 

[JEBSR]

Spindle was perfect, even used a seal installer on the last set to make sure seat depth was the same and not cocked or bent. Not sure what's going on. Even checked to see if cucv was differant but it's the same according to the parts store.

 

[tarussell]

Hmmmm, How about the seal itself ? Is the spring still around the rubber lip ? I don't mean to sound like I am over simplfying things but it seems like you have done everything right and the spring missing might be the cause .
Does the replacement seal look cheap ? Might try a higher quality double lip double wall seal if so .

Tom

 

[JEBSR]

Please over simplify because I am obviously missing something. Spring is still in tact, and both sides are leaking. That is why I thought it was the vent clogged but it wasn't. They do look like a cheap seal, Maybe I should try a differant parts place and seal brand. Thanks for any input.

 

[tarussell]

Make sure your parts person double checks this number because I am going from memory of a National seal part # 2081 for most every GM 14FF rear axle that fit our style trucks.
If the parts house does not have a better seal than go to a industrial bearing and seal place. Give them that seal number or the dimensions and they should be able to fix you up with several higher quality seals.

One last though - is the lube way , way over filled ? I always raise one tube up higher and fill so that the wheel bearings ride in a bath of oil and have never had any issues with leaks but it could be over filled so much that it causes more pressure than the seal can handle .

I would try the better seal first and than see what happens .

Tom

 

[JEBSR]

It isn't over full as far as above the plug, However one thing that I did do to this axle that I haven't done before is to spin it to get my angle correct for a cv shaft. Since the oil plug is in front of the axle tubes and I rotated the front of the axle upward it would make since that the oil level once filled to the fill hole would be higher and also closer to the axle tubes and over-running.

Does this make since or have I just been smoking too much crack today?

 

[tarussell]

Easy on the crack pipe ! Ha,ha - It makes sense.

I would think you are getting plenty of lube in the diff since it is getting to the hubs.

Tom

 

[JEBSR]

Does anyone know if tilting the pinion up several degrees could cause this problem?? If so is there a fix, underfill (scary) or just deal with a leak

 

[mouse]

Plenty of folks running a 14bff with the pinion clocked up with no issues, including me. I would suspect the seals, or install since they both leak.

 

[dyeager535]

Did you rub the seals down with lube before install?

Made the mistake of not doing that on a 10 bolt yoke install, started leaking within the day.

And I concur that plenty of folks are running the diff with way more fluid than was ever intended without leaks, so I don't think that's your problem.

 

[JEBSR]

yea used 80/90 first set, grease on the 2nd and repeated on the third. guessing its just inferior seals

 

[hero]

Is it possible that if you put the seal in backwards that it would leak? From what I remember it wouldn't be THAT hard to get it mixed around and put the seal in backwards.

 

[Leadfoot]

I took a 14bff out of a 1008 (I believe) hardly any wear on anything showed 6600 miles and looks about right by the wear. Anyway I put a disc brake conversion on it and changed the hub seals since the kit supplied new ones. After a couple of miles I had oil running down my tires. I did check the part numbers at that point and they were different but once a crossover was done on the numbers it was the correct replacement. Changed the seals again and they held a day or two and that was it. The vent tube is not clogged, there is not up down/side to side play in the axle, housing not worn and hub is tight. Have litterly replaced hundreds of these over the year (other axles mainly) what the hell am I missing?????

Well it sounds as if they are poor seals, or there is a problem with the spindles that you are not seeing. Also, how do you know the vent, tube, and breather are not clogged?

The last thing is are you sure it's the hub seals and not the axle seals that are leaking. I have had axle seals leak on a 14FF and just ASSumed the leaks were from the hub seal....