Bar's Leaks: Axle & Differential Gear Repair

[glcaines]

Has anyone used Bar's Leaks: Axle & Differential Gear Repair for differential seal leaks? A friend of mine runs a garage and he said that he has had very good luck with this product sealing pinion seals in differentials. He had no idea whether it was good for repair of noisy differentials as advertised but was suspicious that it wouldn't do anything. However, he said that it had helped re-seal leaking pinion seals on several differentials he had worked on, but only if the leaks were minor. He said for it to work you had to put 5 - 6 oz in the differential and not to overfill. He said that it doesn't work fast and that it takes a few weeks and several hundred miles before the leaks stop. He said that it made old hard seals pliable again and caused slight swelling in the seals. I'm always suspicious of snake oil type remedies, but who knows?

[Hambone]

Never heard of it, probably contains some of the same stuff in high mileage oil and other leak stop sealants, if it does stop the leak, I feel it would be temporary, the diff seals are not hard to change.

[rickf]

These leak repair products all work the same way and you pretty much nailed it with saying the seals swelled up. What you friend is not telling you is that the seal will now wear quickly and then shrink back down and leak profusely after a short period. It is a bit disconcerting to hear that a shop owner would be promoting and using these things. That said, Bars Leaks radiator repair DOES work extremely well in sealing radiator leaks. That said, the leak is NOT fixed, it is just sealed temporarily. It can pop open at any time. The difference between Bars Leaks radiator and the Seal stuff is that the radiator sealer plugs a hole in a metal substrate where the seal fixer swells the seal. The metal never changes but the seal shrink back down.

Bottom line, It might do the job for a short period but plan on replacing ALL of the seals after using it since it will ruin any good seals too.
As far as noise, Yea, oatmeal or sawdust work just fine. I have found both in many cars I have checked out.
Disclaimer: That is a dishonest way of making a noisy transmission or differential quiet for a sale!

[m3a1]

...and noisy differentials are kind the hallmark of 151s.

[glcaines]

I agree that using that stuff is most likely not the best idea and I don't intend to use it. In addition, the more I drive the A2, the less lube is leaking. I mean significantly less leaking. I am routinely checking the level in the differential, so that isn't an issue. I'm wondering if the warm lube is perhaps reconditioning the seals which were likely all dried out due to the length of time in storage without any lube present. An interesting conundrum since I don't want leaking seals, but on the other hand I don't want to replace them if the problem is going away, perhaps permanently. The other issue is that my NOS seals I purchased are almost as old as the date on the rebuilt differential, although the new seals were sealed in a plastic bag keeping oxygen away.

[halftracknut]

Hold off on all the diff fixes ....at 72 years old you can't hear the d=m= thing anyway...

[rickf]

Amen to that.

[m3a1]

It's a good thing they didn't have M151s in WWII. If you had been, you'd be driving down the street with the diffs howling and all the kids playing in the back yard and all the women hanging out their laundry would assume they were under attack by dive-bombing Stukas. Everybody would be running for cover.