Infamous Differential Leak
#1
Infamous Differential Leak
First allow me to apologize for my participation (or lack of) as of late. I love this forum but I've been completely consumed by my work so far this year.
Tuesday was a great day. Perfect day up here, and decided to take a nice cruise, and visit my father (a good 90 minute drive). Car drove like a dream there and back. But the next day my father informs me that I've left a small spot in his drive way. Definitely not motor oil, but definitely some sort of lubricant.
So when I finished work I took a look under the cat to see if there was any new drops. I found quite a bit more than a few drops on the pavement between my rear wheels. Looking at the underside of the car it looks pretty wet in the driver side, and there's some burnt oil on the that sides tailpipe as well. Seems to me like the output seal on that side is leaking and the spinning axle is just flinging it everywhere.
I've decided I'm not going to attempt to move it. I called my indi to get an idea of the repair cost. He started off by telling me a few things I already knew. (That the differentials were defective and recalled. There's an updated version available, and would require me to change several other things too.) where he lost me was when he told me that he COULD just reseal that output, but he would treat it as a customer diagnosed and ordered job and would not guarantee his work, claiming that simply resealing it would have me back to a leaky diff in no time.
Rewind a few months ago, at my last oil change. This indi recommended that I get new brake pads. When I told him that I do work such as that myself, he claimed that I wouldn't be able to on this car, without the electronic equipment to switch the car into service mode. I'm very confident I had read a detailed instruction on this forum explaining how I can, in fact, change the rear brakes myself. So I've been on the fence about this indi since then. But he did suggest I try to get the local jaguar dealer a try, since it's such low mileage (30,000).
Thoughts? Is it time for a new indi? Has anyone gotten an indi mechanic to guarantee his work when resealing their diff? Unfortunately, a new diff is not really an option right now.
Tuesday was a great day. Perfect day up here, and decided to take a nice cruise, and visit my father (a good 90 minute drive). Car drove like a dream there and back. But the next day my father informs me that I've left a small spot in his drive way. Definitely not motor oil, but definitely some sort of lubricant.
So when I finished work I took a look under the cat to see if there was any new drops. I found quite a bit more than a few drops on the pavement between my rear wheels. Looking at the underside of the car it looks pretty wet in the driver side, and there's some burnt oil on the that sides tailpipe as well. Seems to me like the output seal on that side is leaking and the spinning axle is just flinging it everywhere.
I've decided I'm not going to attempt to move it. I called my indi to get an idea of the repair cost. He started off by telling me a few things I already knew. (That the differentials were defective and recalled. There's an updated version available, and would require me to change several other things too.) where he lost me was when he told me that he COULD just reseal that output, but he would treat it as a customer diagnosed and ordered job and would not guarantee his work, claiming that simply resealing it would have me back to a leaky diff in no time.
Rewind a few months ago, at my last oil change. This indi recommended that I get new brake pads. When I told him that I do work such as that myself, he claimed that I wouldn't be able to on this car, without the electronic equipment to switch the car into service mode. I'm very confident I had read a detailed instruction on this forum explaining how I can, in fact, change the rear brakes myself. So I've been on the fence about this indi since then. But he did suggest I try to get the local jaguar dealer a try, since it's such low mileage (30,000).
Thoughts? Is it time for a new indi? Has anyone gotten an indi mechanic to guarantee his work when resealing their diff? Unfortunately, a new diff is not really an option right now.
Last edited by Canard; 06-25-2015 at 09:15 PM.
#2
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#5
If the seal is worn out then fitting a new seal will fix it. If the stub axle running in the seal is scored then fitting a new seal won't fix it. Only by taking out the old seal can you tell which it is.
Either way you have to pull out the old seal so you might as well have that done.
If a new diff is required you need new drive shafts which is why it is so expensive to R&R the diffs on this model year.
As for the "electronics" on the rear brakes that is the electronic hand brake (EPB) as fitted to a number of current cars such as Audi. Your mechanic is referring to the hazard associated with working on the rear brakes with power still available to the EPB. There is a service mode which disables the EPB while you work on the car. If you choose to work on the rear brakes without using this mode it is possible to lose a finger or two if the EPB activates, not likely but possible. Also, the rear brake pistons need screwing back in, not just pushing back in, to retract the automatic hand brake adjuster. You really need a specialized tool to do this easily.
Either way you have to pull out the old seal so you might as well have that done.
If a new diff is required you need new drive shafts which is why it is so expensive to R&R the diffs on this model year.
As for the "electronics" on the rear brakes that is the electronic hand brake (EPB) as fitted to a number of current cars such as Audi. Your mechanic is referring to the hazard associated with working on the rear brakes with power still available to the EPB. There is a service mode which disables the EPB while you work on the car. If you choose to work on the rear brakes without using this mode it is possible to lose a finger or two if the EPB activates, not likely but possible. Also, the rear brake pistons need screwing back in, not just pushing back in, to retract the automatic hand brake adjuster. You really need a specialized tool to do this easily.
#6
Having a friend of a friend come check it out before I get it towed anywhere. I'm just confused because the location makes it seem like it's coming from the diff, but the color of the liquid looks like tranny fluid. If you have a trans oil pan leak, does it leak into the plate covering the underbody, and roll toward the back of the car?
#7
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#12
Pink oil would be transmission fluid most likely although I've never seen ZF proprietary fluid, it may not be pink. Power steering fluid is not a likely candidate.
Differential oil should not be pink but should stink due to the additives required for high gear tooth pressures found in by point bevel gearsets.
#13
#14
Worst case scenario.
The leak was from the differential. The mechanic wanted to replace the differential. Unfortunately, I'm a lot leaner right now than when I bought the vehicle, so a reseal was my only option.
Also, mechanic said the bearing had play.
Also, mechanic said the bearing had play.
Last edited by Canard; 07-01-2015 at 08:40 PM.
#15
When it starts leaking again this link gives very useful info about what replacement to look for:
https://www.jaguarforums.com/forum/j...ntials-134733/
https://www.jaguarforums.com/forum/j...ntials-134733/
#17
Tbird, a reseal is already done and paid for, so I hope this is incorrect. I'll be keeping an eye out for leaks anyway, since no mechanic recommends resealing this diff.
I didn't like a few things when I picked her back up though. My mechanic said the bearing has a lot of play, and that's what ruined the seal, but does resealing a differential typically mean replacing the bearing as well? Secondly; with the information jagular gave above, I wanted to know what the stub axle looks like. He claimed the differential "isn't designed that way."
I didn't like a few things when I picked her back up though. My mechanic said the bearing has a lot of play, and that's what ruined the seal, but does resealing a differential typically mean replacing the bearing as well? Secondly; with the information jagular gave above, I wanted to know what the stub axle looks like. He claimed the differential "isn't designed that way."
#18
You won't see the bearing issue unless you pull the bearing out. The shaft scoring issue would have to be the part of the shaft the seal runs on to cause a leak.
Any bearing play would surely lead to noise from the differential.
The axle shaft comes out and the seal would be next. The bearing is behind the seal and would normally remain in place.
Here's an assembled diff with the axle shaft mounting drivers fitted:
jaguar gkn differential parts
http://www.scparts.co.uk/sc_en/engli...i-and-iii.html
Those plates part numbered 65 are the drivers attached to shafts inserted through the seals into the diff cage. This is a much older diff but the design principle should be the same.
Actually, this link from lower down, the "other" leaky diff thread, shows the thing in pictures:
http://www.jackstransmissions.com/pa...e-diff-install
Fitting a new seal would be the correct repair unless the bearing or shaft were worn. This was recently done on my '09 for example.
Any bearing play would surely lead to noise from the differential.
The axle shaft comes out and the seal would be next. The bearing is behind the seal and would normally remain in place.
Here's an assembled diff with the axle shaft mounting drivers fitted:
jaguar gkn differential parts
http://www.scparts.co.uk/sc_en/engli...i-and-iii.html
Those plates part numbered 65 are the drivers attached to shafts inserted through the seals into the diff cage. This is a much older diff but the design principle should be the same.
Actually, this link from lower down, the "other" leaky diff thread, shows the thing in pictures:
http://www.jackstransmissions.com/pa...e-diff-install
Fitting a new seal would be the correct repair unless the bearing or shaft were worn. This was recently done on my '09 for example.
Last edited by jagular; 07-03-2015 at 08:55 AM.
#19
Just got back from a family dinner, after parking the car I could smell something. Shines a light under there and can see some fresh fluid on my driver-side tail pipe. We're still leaking. I've either got a misdiagnosis (I'm not that lucky) or a differential that isn't going to be fixed with a seal.
Aren't there alternatives to the updated jaguar differential that requires so many new parts? Aftermarket differentials or even getting the differential I have refurbished?
Aren't there alternatives to the updated jaguar differential that requires so many new parts? Aftermarket differentials or even getting the differential I have refurbished?