I'm confused. QDF3W Just appears to be one piece of the assembly. Don't I need the whole 9 yards here?

 

a few quick comments on this while i finish breakfast and get back to work. Tbirds is correct. the diff fluid nor the trans fluid is pink. I think you may have several issues. about the only thing pink in the car is the coolant, power steering fluid and thats it. That diff looks definitly leaking and am I the only dealer tech that reseals the diff output seals. NOOOO. If you indeed do have a scored shaft you need a new output shaft as it will just leak again. same with a bad shaft bearing. But both of these issues are unlikely. We replace diffs when theyre noisy/broken, not leaking. I can rebuild diffs but not at work, its just not $$$ or time wise. I am generally working on 10-16 cars a day at a time.
And PLEASE, that indie is FOS on the rear brakes. just push the park release button down to release the rear parking brake and leave the keys in the car. Its not going to activate when you replace pads. I do this all day and I have never lost a finger or had them activate .
Back to work

 

Hope you enjoyed your breakfast

@canard,

I've forgotten who else has posted in this thread, but Brutal
knows more about differentials than most on this forum, and
in particular Jaguar differentials. Well worth listening when
he speaks.

And pink is not diff lube.

 

I appreciate everyone's resourcefulness. This is a learning experience for me. The only RWD car I've ever owned, and my mechanical knowledge is usually acquired on the basis of "my car is broke, how am I going to fix it without giving my entire saving account to a mechanic?"

When we talk about installing a Quaife differential, we aren't talking the case and all, correct? We are actually talking about putting the new differential into the case I already have, with new bearing and seals?

Sorry I posted this before I noticed the new page of comments. The thing that has me worried is that the car is wet on the Rubber covering the driver sides output shaft and dry on the passenger side. A year ago I had a garage and a room mate with lots of tools; now i live in the city and use a communal parking garage. It's hard for me to investigate things unless I know exactly what I'm looking for.

 

Yes, Quaife supplies only the differential cage with its proprietary torque biasing helical cut differential gears. The main case, crown and pinion gears and various shafts, bearings and seals must be supplied by the owner.

LSD are now of very limited use since most of the benefit is now delivered by much cheaper purely electronic traction control relying on the abs brake pressure and software to control wheelspin. Even LSD are now electronically modulated and even then offer very little practical features for road driving.

The usual failure mode for these differentials is a side seal. Your symptoms of wet on one side and not the other is consistent with this. Replacing the seal is not particularly expensive but if the shaft has been scored then a new seal will not last long. Only taking the seal out can show a mechanic whether the shaft is scored or not. If scored then a full rebuild or replacement diff will be required. A used case and shafts etc ought to be available in North America because this type of diff was fitted to a number of cars over here, just the gearset may have to be switched over and that is likely in good shape.

 

I guess what I can't wrap my head around, is why two mechanics don't want to just fix the shaft/seal or bearing and seal? They seem to insist I get the updated Jag differential, and new drive shafts. Like I said, car still drives like a dream. It's definitely NOT broken.

And what might I expect either one of those jobs to cost in the US?

Lastly, it isn't leaking so bad that it's leaving spots in the ground again, just moistening the underbody, should I not risk driving it anywhere? And by anywhere I mean to the shop myself. I feel a shop owner may be more likely to take advantage of someone who's towed the vehicle in.

 

Go buy some fluid from the dealer, and one of those pumper things from AutoZone. You can empty the differential yourself, measure what comes out, measure the exact amount that is supposed to go in (it's not the kind you fill to top of the fill plug, it's an exact amount).

Then clean off the diff with brake cleaner so you can start fresh. Drive the car and watch for how much fluid is coming out. Then you can repeat the process (except you can reuse the fluid that comes out because it's fresh) over time to see how bad of a leak it is.

If it's not leaking a lot, you might be able to go years of just topping it off before you need to do anything super expensive.

 

Bear in mind the leak slows as the oil level drops. Driving with insufficient oil can ruin the gearset.

As long as the diff shaft isn't damaged a new seal should be around US$300 installed. A new bearing as well would be more.

If the diff shaft is scored then a used replacement is your only option as new ones are not made anymore. The new replacement part is larger and requires new axle shafts as well which is why it is do expensive to replace.

If you can't source a good used diff and the shaft is scored you may as well just keep refilling the old one until it whines or leaks so fast you can't keep up.

 

Well the last replacement seal only lasted 2 weeks. The mechanic claimed the bearing was the issue, but someone else mentioned here you can't possibly know that with removing the bearing. So please be patient with me as I ask specifically, a new bearing without replacing the differential IS an option? And if the shaft is scored a simple new shaft is not, the whole diff must be replaced?

The diff doesn't make any noise that I can tell. Car makes only a whisper of a noise at freeway speeds and even speeds higher than I'll admit.

 

I do not think a separate shaft is available. Your remedy is a used diff into which your undamaged parts can be transferred. The revised diff now fitted to these cars is significantly larger which means new axle shafts are required (the drive shafts attaching the rear wheels to the drivers in each side of the diff.

The usual mode of failure is seal failure scoring the shaft on one side. If the seal is renewed before the shaft is scored then all will be fine. Otherwise you need a replacement diff which ought to be available here. Try a Ford dealer.

No noise is good since that means the diff innards can be transferred to a suitably sized case provided the replacement diff has good axle shafts.

 

Has anyone looked at getting the damaged surfaces machined at a machine shop and sleaved if necessary?

 

Like an undersized bearing and seal?

If that were an option wouldn't fabricating the stub axle make more sense?