Been absent a while but have been tearing into the rear end of the car, have switched from a Dana to a Salisbury 4HU, does anyone have a pinion torque value for checking rotational resistance ?

I have the values from the workshop manual showing old bearings a 20 to 25 inch pounds or new bearings 30 to 40 inch pounds - but it isn't clear if this is complete diff or pinion only.

I was under the impression that the diff I have has been refurbed, it is certainly dry and carrying most of its paint, it is far too hard to turn I think but I want a more definitive test - such as how much torque to rotate the pinion on a fully assembled differential (no drive shafts, discs or brakes - bare diff)

 

Pinion only. You're measuring the drag of the bearings on the pinion shaft only.

 

Thought that was the case - typical and of no value in diagnosis only assembly - because if I'm stripping I'm rebuilding, I am trying tro assess condition without stripping or further dismantlng - so I need a value from a complete but bare salisbury as in complete with output shafts but nothing else but in good order.

I'm not prepared to DIY the rebuild so if needed it will be expensive, I am out of time and patience on this 'weekend' project ...

Going to go with no rebuild, although stubborn at first the average on the diff is 6.5NM - around 58 inch pounds - if good pinion is 30 to 40 inch pounds then I am going to call the overall assembly good at 58 my original Dana was less.

 

I just had my IRS rebuilt(at a great expense).

Considering the amount of work required to get the diff out of the cage, I cant imagine installing an unconfirmed “good” unit.

There must be a way to test the thing before you put it all back together. In the US/Canada, the Dana is a breeze to have rebuillt, no special bits required.

 

I have pretty much done everything, the subframe is powder coated, both hubs are done as are the dog bones (also powder coated) new bearings / shims / spacers etc everywhere, drive shafts done (powder coated and spicers installed - no more grease shields), new disc's, calipers rebuilt with stainless pistons and handbrake mech's fully restored - so an absolute ton of work - then I get to the diff - seals are dry but there seems to be no way to really check the diff without stripping it and that is a ton of work to not replace bearings.

I hear ya on the it's a lot of work because it really is not to mention a chunk of spending that is pretty eye watering if I do the diff too. I've already passed £1k .... the diff will add that and then some again. So I have been scouring for a set of tests that can be done without tearing down, end float seems fine, backlash is borderline non existent. I really need to see the back of the heavy work this year, the way health is going time is running out so I want the car back on its wheels this year even if I farm some of the work out.

Now I'm really undecided .... take a chance or spend another crazy amount that may not be really necessary for the sake of piece of mind.

 

Take a chance Ben. It will be fine. If the seals are dry and all OK, backlash etc, it will be OK. Even if not, a new pinion seal can be installed easily, diff in car.

 

The diff is tight and dry, backlash is minimal though I wouldn't say none, decision made - it can go in as is - it is a huge expense for nothing more than peace of mind and the complete sub I bought has clearly had some TLC at some point - it sure wasn't a planned thing but a Salisbury came up and I took the opportunity - my Dana was quiet but one output shaft is damp and the universal concensus seems to be ditch the Dana, at least more seem to lean toward that. I believe Dana made the Salisbury internals too though, I did check with a few suppliers re parts availability and they confirmed that Dana's are challenging.

 

I’m going to admit my way of testing.
I load it into the car, take to the race track, dump the clutch at 5000+ rpm and see if I have one black tire streak or 2
I could get exact scientific numbers by measuring both tracks I suppose, but I haven’t. In fact it’s so rare for me to have to work on the differential, that I’ve only done it once. The first and only time I rebuilt the rear end.
In retrospect the rebuild really wasn’t needed. But I was being **** about a Junkyard purchase.

 

Btw, i have the correct spicer flange to adapt standard Dana pinion to a Salisbury unit.

not the one with U bolts, the one that looks just like factory but has the increased spline count.

new un-used if anyone is interested, bought it and didn't use it.

 

I resemble that remark ....

Now I need to check the PCD on the pinion flange .... does the standard Dana to Salisbury 'adapter' mean the prop shaft flanges are different ? - I hadn't thought of that ... may check the parts list

 

Ben
The prop shaft to diff pinion flange is identical regardless of diff.
If you want the full knowledge about DANAs in the XJS (about which there is loads of nonsense written) read this thread:
https://www.jaguarforums.com/forum/x...tified-229645/

The output shafts are the drivetrain connecting parts that are different between the Salisbury and the DANA, in as much as DANA outputs will not fit Salisburys and vice versa. But as long as your Salisbury has the output shafts on it, they will fit onto the axle driveshafts, which are identical regardless of diff make.

 

My salisbury is 100% complete - I actually read your pain some time ago and ths formed one of my reasonings for moving from the Dana.

 

Good plan the Salisbury is better (though not as good to drive as a Torsen unit in it would be!) and the output shafts easily rebuildable, diff in car, if needed.
I actually went through the original DANA which laste about 45,000 miles and went through a brand new one in about the same.

 

After seeing the innards of both a Salisbury and a Dana, I’d say the Dana has an edge. Higher spline counts on output shafts and pinion. Huge bearings on output too.

no drain plug is a pain and parts availability on some bearings is an issue.

Input flanges look different but both work fine with driveshaft.

the salisbury is much more common/easier to get parts for.

 

Whilst I'm not saying it will be all Miss Daisy I don't plan on any track days, I will keep the Dana around though will probably stand it on its nose and overfill with the appropriate oil and stick it under the bench along with the drive shafts that belong to it. I will likely sell the old subframe or donate it to a needy cause. Only one of my original hubs was serviceable - one was cracked.

 

Sorry, all my Jaguars go to the race track. Even the 1972 Sedan I just got. Of course the 4.2 original engine is going into my engine collection and I’ll slide one of my 5.3 V12’s in
Then out the back it will get a trailer hitch to pull the XJS RACE CAR to the track.
But no you don’t have to actually race it. You can do the same thing on any quiet safe street. Just let off the throttle before you break the speed limit.

 

Backlash shouldn't be zero, it's 0.006-.0.010" measured at the crown wheel. If you're comparing the pinion to the output shafts there will be some extra play in the output shafts. If it turns smoothly and the oil is clean ( i.e. not burnt and no metal particles) it's probably good.

 

Plans changed ...

Drained oil with a view to putting in nice clean oil and didn't care for what I found - some of what came out was more like jelly, there is a lot of black 'paste' in the bottom of the diff (didn't remove cover) and that was enough to trigger another 4 figure spend so the diff left on a pallet today for Simply Performance because I didn't feel inclined to mess with it. I think the bearings are fine but we shall see, I may put new friction plates in it anyhow.

Jaguar, the weekend job that overran - a little.



The oil in an old V12 sump that was spotless, not sure if the 'lumpy' bits came out well though - you can see some evidence of it in the centre where the pickup goes toward the edges.

 

Ben
I bet that there is nothing wrong with that diff! The oil looks perfectly OK! Far cheaper to takje the cover off, inspect the teeth, flush it and refill!
I do relate to the warm feeling one gets when a new part is fited though!

 

It has already left the building - a fool and his money they say - I do think you are correct and to be fair to Ben at Simply Performance he will put it on the bench, check it out and has said that they won't replace anything they don't need to - but they will make it look pretty - and I'm guessing reset all the preloads etc as they will be doing a strip and inspect.

The oil absolutely stinks but not burnt - I really can't stand the smell of gear oil - there is absolutely no forbidden glitter so I'm confident that the gear train and bearings are fine.

I do think you're correct Greg, the way my luck runs any decision that I make is usually the wrong one - so I end up second guessing myself all the time - .