Stop Leak to fix front diffential seal leak

[lj4r]

Has anyone used Blue Devil Stop Leak to fix a seal leak on the front differential seal? I have used it on each of our four 4th Gen transfer case actuator seals. It worked great. Not sure if use in the differential would cause any issues. Had a shop change out the front left CV axle and they said that it was the case and that the leak would return, they quoted $4000 to replace the case. I am not sure that I trust them, the CV axle that they removed and replaced was the original. Odd to have a OEM case go bad. Although anything is possible. Thanks Phil

2016 4Runner SR5 Premium
83,000 miles

 

[Captain Spalding]

I’ve never used Blue Devil Stop Leak. I looked ar the instructions, which were brief and seem incomplete.

“Directions: BlueDevil Oil Stop Leak
1. Pour 1 bottle (8 oz.) into leaking component’s oil sump, or crank case.
Treats 4 to 6 quarts of motor oil.
2. Start engine or equipment and operate for 1 to 2 hours or until leak has
stopped (for extreme leaks up to 2 days drive time may be required).
Use this product for: pinion seals, gear cases, refillable shock absorbers, gear
boxes, axle seals, and gear differentials.”​

In the case of a differential are you supposed to remove 8 oz. of differential oil before adding the stop leak? And then what? Do you just leave it in? Or do you drain and refill?

I would be cautious about doing anything that would increase the viscosity of the differential oil for any more than a brief period. The synchronizers in the transfer case depend upon the diff oil not being heavier than specified.

 

[Jakeepoo3]

No f'ing way I'd use anything other than the proper gear oil. Did the leak come before or after the CV axle was replaced? If after the shop probably caused the leak replacing the axle incorrectly. If before it's probably just a bad or cockeyed dust seal and the shop is dumb. They should have replaced the seal while the axle was off.. The leak is only come from one side? I off-road hard and a lot. I've had that same drip caused by a slightly cockeyed dust seal after going hard. Had to remove axle and knock the seal back to it's proper position. The case is fine. 4000 grand wow might check another shop. Don't get screwed!

 

[lj4r]

with the transfer case actuator leaks, I put in about half a bottle, drove around for 30 miles or so and then drained and refilled with clean fluid. Leaving it too long could cause the seals to swell too much. I had my suspicions about the seal. They told me that they changed the seal when they changed the cv axle. Not sure if they did or not. The leak is pretty small, I just don't like having any drips. The truck overall is tough as nails! Phil

 

[Jakeepoo3]

with the transfer case actuator leaks, I put in about half a bottle, drove around for 30 miles or so and then drained and refilled with clean fluid. Leaving it too long could cause the seals to swell too much. I had my suspicions about the seal. They told me that they changed the seal when they changed the cv axle. Not sure if they did or not. The leak is pretty small, I just don't like having any drips. The truck overall is tough as nails! Phil

Where is the drip coming from? The front differential or the transfer case? Definitely tough as nails. If leak is coming from the differential it's going to drip from the CV axle on one side or the other. The transfer case would leak at the drive shaft seals most likely.

 

[lj4r]

leak is coming from the left side cv axle seal where the axle inserts into the differential case. Transfer case is dry as a bone. Rear differential is dry, transmission and motor are dry. Phil

 

[Jakeepoo3]

leak is coming from the left side cv axle seal where the axle inserts into the differential case. Transfer case is dry as a bone. Rear differential is dry, transmission and motor are dry. Phil

That's the same side they put the axle on right. The leak was there before replacement and it's still leaking or did the leak come after axle replacement. Either way you mentioned they installed a new dust seal also. Unless someone has taken your axle off and put a die grinder in the seals seat why would the case be bad. What was their explanation why the case is bad. If they actually did install a new dust seal they did it incorrectly or knocked it out of its proper position slamming in the new axle wrong. I would never let a"mechanic" work on my truck!! If I had to I would be all up in their grill watching every move haha

 

[CutthroatSlam]

Replace the seal, it’s not hard to do.

 

[Captain Spalding]

Replace the seal, it’s not hard to do.

Haha. Not hard to do.

As in an oil change is not hard to do?
Or as in a transfer case R&R is not hard to do?

 

[CutthroatSlam]

Haha. Not hard to do.

As in an oil change is not hard to do?
Or as in a transfer case R&R is not hard to do?

I’ve done both. I think most shy away from the work that involves taking apart or removing major components because they fear getting the vehicle back together. I always say it's easier to run and work on older, high mileage cars, when you have two. That way you have back-up transportation if you're running into issues getting the repair job back together.

 

[Rocko9999]

What was wrong with the case exactly? Seal mating surface was damaged? Bad casting? How bad is the leak?

 

[Whippersnapper02]

Stop leak is no good anywhere. Have the seal changed if you can't do it yourself.

 

[Golfpilot]

For DIY-instructions you can search for the "ECGS Bushing" or "Needlebearing replace" videos.
Because with the bushing installation it is recommended to replace this seal as well. It should be the same work steps, except not to replace the bearing but only the seal.

for example:
Toyota Needle Bearing Swap for ECGS Bushing- Clamshell Front Differential - YouTube
(removal of the axle before the seal time mark)

or further tips from the tacomas which should not be much different:
Easiest Way To Remove Tacoma Gen 3 CV Axle PLUS ECGS Bushing Install - YouTube
South Carolina BS thread under new MANAGEMENT and lives in SC | Page 5097 | Tacoma World

I'm not a car mechanic either, but i'm confident that i can replace the bearing and seal. I've already ordered the ECGS bushing AND a new seal, as a precaution because the axle on my 2019 TRD Offroad already has play.