My rear differential has had numerous problems. The main seal had to be replaced twice do to a leak and the drivers side output shaft seal had to be replaced. Now my car has developed the known "Rear End Whine".

I had the drivers side output shaft seal replaced less than 4,000 miles ago and about 1,000 miles ago is when the "whine" showed up. I decided to check the level of fluid in the diff, so I parked on a level surface and removed the fill plug. The second I got the fill plug off, grayish black fluid started pouring out. From what I've read, these diffs are full right when the get to the fill plug. How my diff got filled past the plug is beyond me and why it looks so bad so fast is also a mystery.

My questions are: 1. how do I remove all the old fluid without removing the rear seal, and 2. has anyone ever used a differential additive in any of their cars (Jag or other) to help quite a noise?

Of course I wish I had a warranty to cover the work, but I don't, and I don't have the $4,000 laying around to have the differential replace.

 

If the fluid was hot from recent driving, it could easily have expanded above the fill plug's hole. That's probably what happened....

What color should your recently-filled fluid have been if it was in pristine condition?

I think your best approach for tackling this issue would be to siphon out as much of the current fluid as you can and replace it with a high-quality synthetic. I don't know what the Jaguar specs call for, but since you're beyond your warranty period, you can choose your own fluid. I would research fluids thoroughly before deciding which one to go with....

Keep us posted on what you decide to use and how your differential performs. I wonder if the internal break-up of metallic parts inside your differential is the reason your current fluid appears so black. Did a Jaguar dealer do your previous seal work? Did anyone offer you any feedback on the condition of the components they were able to see?

 

Hey Jon, you're probably right about the fluid expanding. The car had only been sitting a couple of hours since I drove it last.

Since all of the fluid was "supposedly" replaced when Jaguar did the last repair, I kinda expected it to be more of the goldish color. It looked more like it had 100,000 miles on it instead of 4,000 .

The last time they worked on the diff, they didn't give me any indication of any wear issues.

I'm doing tons of research to try to find anything that will help reduce the "whine". The factory calls for 75W140 Synthetic, but I'm thinking of going with 85W140. Maybe a Lucas or Royal Purple brand.

I'm hoping to get some feed back and direction from the members.

 

I'm interested in this topic because I have less than year of warranty left and I have the same car as you.

The part about the seals going bad quickly multiple times is curious.

You're going to have to seperate the cover to get a complete change of fluid.
If it's grayish then there might be a lot of suspended metal bit's in the oil.

Try getting a bit of a sample in a glass and look at it with a bright light and a magnifying glass. You could try a magnet as well.

If there are metallic bits in the oil and the seals keep going out I just wonder if the case has been manufactured out of alignment specs and these things are eating themselves up. I read on here that they have made some kind of a change and no longer supply the older version.

Honestly, I don't think an additive is going to help. They do make additives for the limtied slip clutch plates but this isn't a limited slip diff so there's no benefit from that.

There must be a reason why you're having repeated failures. If jag fixed it and it failed again I'd press pretty hard to get a replacement. Don't give up.

Keep us posted.

Bob S.

 

There's info about the diff & propshaft etc changes in JTB00053v2.pdf I posted a while back, if that helps at all.

 

Hey jagV8, I saw it and printed it off. Thank you for posting that.


Since that's the same TSB that will cost around $4,000 outside of warranty, I'm trying to find cheap or easier alternatives. I'm going to look into changing out the "axle housing bushing" that's mentioned in the report, as well as a better differential fluid. The “ahb” is only around $50. I have to figure out where it goes and how much work will be involved.

 

$4000 is rather off-putting!

Does yours have the driveshaft with the "swage" (diameter reduction, if I read the TSB right)?

 

After dropping some friends off at the airport yesterday afternoon in our S-Type, I pulled onto the freeway and accelerated to get up to speed. The audio system was turned off. Under acceleration, I heard a quick "whirr" coming from the rear of the car that lasted less than a quarter of a second. Everything else was normal - no jolt, no vibration, no loss of power. Just a quick "whirr" under acceleration. Had the audio system been on, I would not have heard the noise. I immediately thought "Oh no, it's an early sign of impending differential problems." I hope I'm wrong. I plan to drive the car a bit more over the next few days with the sound system off to see if I continue to hear this noise....

 

All cars make more and different noises as they get older. Hopefully that's the case for yours. A diff that's actually failing is very noticable. I've had to fix a couple of them as well as 5 speed boxes.

I'm not familiar enough with this car as yet and since I got it at 14.5K miles it wasn't a new car but seems pretty tight. The example I drove at 50K seemed about the same but that was only a 20 minute test drive.

You know in the Italian car world when a car gets older and makes more noises we just open the windows more often. It muffles at lot of those impending doom thoughs.

You could always upgrade to a STR. They whine and you like it!

Bob S.

 

I'm not sure. I'll be crawling under her today to take a look.

 

Jon, did it do it while changing gears? My trans used to do that until the dealer re-did the trans fluid and added an additive.

 

I'm not sure if the gears were changing at the time I heard the "whirr". I'll keep listening and report back with more details if I hear it again....

 

Iluvmy05STR,

Tell me more about the transmission fluid additive that your dealer used to silence your whirring noise. What is the part number of the additive? Is there a TSB published on this issue? Did they explain to you what causes the noise, why the additive silences it, and whether there is any potential damage to the transmission in the future?

I heard the noise again yesterday morning while under acceleration between 15 mph and 25 mph. Just as before, it only lasted for about a quarter of a second and there is no noticeable degradation in transmission performance. But I'm concerned that this is an early sign of potential future ZF problems....

 

Hey Jon,

The Jag Dealership didn't give me any indication if it would cause any problems down the road but I could definitely tell a difference after they worked on it. Besides the noise, I had a severe "lurch". I had the work done while it was still under warranty. They didn't mention any TSB on it. I'm not exactly sure what additive they put in the transmission. I was told the "whirl" was coming from the trans fluid slipping or pushing through the transmission. The additive is to keep this from happening.

_______________

I emailed Royal Purple to see what they would say about using a different differential fluid with an additive. Below is their reply. I may try to use the 85W-140 and see what happens.

A 75W-140 and a 85W-140 will be approximately the same viscosity at operating temperature (~210 deg. F). However, at lower temperatures the 85W-140 becomes much more viscous than the 75W-140. We are not sure how viscosity sensitive the Jaguar differentials are, so I cannot give a confident answer as to whether or not a 85W-140 will help the noise. If the noise is only when the vehicle is cold, maybe. If the noise is only, or primarily, after the vehicle is warmed up, probably not.

What fluid are you using currently? Viscosity is not the only thing that can effect operating noise and smoothness. Often, the RP formulation will aid in quieting operation even when you use the same viscosity fluid, assuming there is no actual damage.


Thanks for considering Royal Purple and have a great day!


Best Regards,

Christopher Barker

 

You can see the lurch was addressed via item B, as usual for the 6HP26 lurch. You'll surely have seen many posts about this here.

 

Yeah, all my trans issues where addressed and fixed about 1.5 years ago. Now it's the freakin best transmission someone could ask for. Silky smooth and always in the perfect gear.

 

Lmao!!

 

There is a TSB (JTB00070) that supposedly addresses the quick whirring noise (also described as a "chirp" or "bark") emitted by the ZF on occasion during upshifts and downshifts (I've only heard it during upshifts). It involves draining about a litre of ZF Fluid and adding about a litre of "super lubricant" to the transmission pan. I'm trying to find out what that "super lubricant" is, and also get a part number for it. This stuff supposedly helps to keep the clutch packs from sticking and making the noise. It addresses only the noise, not any harsh shifting (or "the lurch") that some of you may be experiencing....

If anyone has additional information or personal experience with having this specific TSB done to their car, please enlighten us....

 

I posted the TSB a while back. It lists the part #
It's here: https://www.jaguarforums.com/forum/s...t=29047&page=2

Note: this is not about the subject of this thread (the diff). It's about the ZF transmission.

 

Thanks. I'll check it out....