Axle identification.

[Vernon]

Hi again 

Looking to check the identity of the XJ’s rear axle.  It had a replacement one fitted in May 2011 and as you can see on the invoice it was done in Scotland!  So an expensive holiday………

 

But it does not specify axle type - it looks like a Dana 35 and the tag has cleaned up a bit but I’m going to have to have another go at it as a few numerals are still unclear.

 

See pic.

 

And yes, I too think I need a new filler cap - reusing the old one was not a good idea.

 

But main question is “how do I read the ID Tag?  -  I assume LS on the end of the top row of numbers is Limited Slip.

 

But what do the other numerals mean?.

 

Many thanks in advance once again

[UKTJ]

Certainly the wrong shape for a Dana 44, so I agree it looks like it is a Dana 35.

[V]

It's a Dana 35. They were the only axles on XJ Cherokees that had ABS. Non-ABS XJ Cherokees usually had the stronger Chrysler 8.25".

 

The Dana 35 was originally designed by AMC. I believe Chrysler sold the design to Dana when they acquired AMC. Ford have since used it as a front axle in various forms and it's actually an improvement over the D30 common in a lot of Jeeps.

 

I wonder if the problem your Jeep had in Scotland could have been resolved with new pinion bearings. A lot of car mechanics don't know how to change them or set the gears up properly. Swapping an entire axle is a simpler fix for wear for them. The D35 often weeps lube from the stock diff cover bung. If the level drops substantially there is insufficient oil supply to the pinion bearings and they wear out. The rubber filler bung should be replaced with a new one at every fill but rarely is. The long term fix is an after-market diff cover with a conventional screw in plug. Alternatively, modifying the existing steel cover by welding an O2 sensor boss into it and using a 20mm O2 hex-head plug with a copper washer to seal it should do the trick and you only need to replace the copper washer when it weeps.

 

[V]

The first part of the 2nd line of the tag is the gear ratio. It is not clear on this one but it looks like '3.73'.

[Vernon]

Brilliant V and UKTJ - many thanks.  I like the O2 sensor conversion.  That’s now on the list.

 

Do the numerals equate to age of manufacture?  
 

Am I correct in assuming LS is Limited Slip?

 

MANY THANKS for the info on the gear ratio V - I will check this against that for the front axle!!  . I did want to make sure they were the same BEFORE I use 4WD this winter .

 

Thanks again guys.

[UKTJ]

1 hour ago, Vernon said:

Brilliant V and UKTJ - many thanks.  I like the O2 sensor conversion.  That’s now on the list.

 

Do the numerals equate to age of manufacture?  
 

Am I correct in assuming LS is Limited Slip?

 

MANY THANKS for the info on the gear ratio V - I will check this against that for the front axle!!  . I did want to make sure they were the same BEFORE I use 4WD this winter .

 

Thanks again guys.

The axle was second hand when fitted, eleven years ago.  Chance of the clutch pack on the LSD being any good is IMHO very low.

[Vernon]

Agreed, it’s on my list!  There are some excellent YouTube videos on replacing the clutch packs.  
And it was watch one of these where it was mentioned that differing axles can have differing ratios and the resulting consequences re wind up - that I thought I really had better check out exactly was was put on as a replacement axle!!

I’ve used LSD lube anyway, but not got round to jacking her up to check how the wheels spin.

[V]

I don't know what the standard axle ratio(s) where for the diesel XJ across all of the model years. The petrol 2.5L was 4.11, the 4.0L was 3.55 . The diff cover and tag could be from the original axle or the donor's axle. You should check that the gear ratio in the front axle is identical to the ratio in the rear axle before selecting 4wd on the road.

1. Jack up the Jeep on four axle stands so that all four wheels are off the ground. You can do it one axle at a time with the transfer case in neutral if you only have two axle stands. Chock both sides of both wheels on the ground if you don't use four axle stands. A two post lift make it easy to dangle all four wheels in the air.
2. Put the transmission and transfer case in neutral.
3. Put a chalk mark, paint mark or sticky tape on the sidewall of one front tyre and one rear tyre to indicate a 12 O'clock position.
4. Now mark the propshafts so that you can identify roughly the degrees of rotation. You could attach a slip of paper around the tube with sticky tape suitably marked with either 4, 6 or 12 positions or use a paint pen or chalk marks on the tube.
5. The next bit is easier with a helper. Get under the Jeep and count how many times the front propshaft rotates when the helper rotates the marked front tyre one full turn.
6. Do the same for the rear propshaft and rear tyre.

The propshaft rotation count should be identical front and back. If they are not identical, remove the front propshaft until you can install matched gears. You will get three and a half rotations for 3.55 gears, three and three quarter rotations for 3.73 gears and just over four rotations for 4.11 gears.

[V]

You can test the LSD when doing the axle gear ratio verification. When rotating the tyre the other tyre should rotate in the same direction. If it rotates in the opposite direction it is either an open diff or a non-functional LSD.

[Vernon]

45 minutes ago, V said:

I don't know what the standard axle ratio(s) where for the diesel XJ across all of the model years. The petrol 2.5L was 4.11, the 4.0L was 3.55 . The diff cover and tag could be from the original axle or the donor's axle. You should check that the gear ratio in the front axle is identical to the ratio in the rear axle before selecting 4wd on the road.

1. Jack up the Jeep on four axle stands so that all four wheels are off the ground. You can do it one axle at a time with the transfer case in neutral if you only have two axle stands. Chock both sides of both wheels on the ground if you don't use four axle stands. A two post lift make it easy to dangle all four wheels in the air.
2. Put the transmission and transfer case in neutral.
3. Put a chalk mark, paint mark or sticky tape on the sidewall of one front tyre and one rear tyre to indicate a 12 O'clock position.
4. Now mark the propshafts so that you can identify roughly the degrees of rotation. You could attach a slip of paper around the tube with sticky tape suitably marked with either 4, 6 or 12 positions or use a paint pen or chalk marks on the tube.
5. The next bit is easier with a helper. Get under the Jeep and count how many times the front propshaft rotates when the helper rotates the marked front tyre one full turn.
6. Do the same for the rear propshaft and rear tyre.

The propshaft rotation count should be identical front and back. If they are not identical, remove the front propshaft until you can install matched gears. You will get three and a half rotations for 3.55 gears, three and three quarter rotations for 3.73 gears and just over four rotations for 4.11 gears.

many thanks - yes that test for the LSD was on the cards.  And checking out the rotations is now on the cards as well.

 

I was going to set her up on axle stands and mark front and back wheel rotations to check the wheel turns are the same.

 

which I’ll do anyway, but will now determine what axle gearing I have front and rear as well thanks to your excellent advice.

 

the LSD situation will get checked as well.

[Vernon]

Finally had the time and good weather to check things out.

 

First bit of good news - definitely an LSD fitted - jacked up rear and both wheels spin in same direction when I turn one.

 

I then let down one side and jacked up the front so I had both wheels on one side off the ground.  Neutral selected on gear and transfer box then carefully marked the propshafts after lining up the wheel valves to “TDC”.

 

Then turned each Wheel in turn one rotation and checked the marks on the propshafts.

 

Then Checked at three turns each and then six turns.

 

Happy to say at each check the marks on the propshafts were lined up spot on.

 

So at least I have two axles of the same ratios!!  Shame the garage that replaced the rear one back in 2011 could not have confirmed that on the invoice.

 

But after doing this - it occurred to me that there was no resistance to speak off when turning the rear wheel with the other rear wheel on the ground.

 

So am I right to assume the LSD plates are totally shot now?   I assumed if they were then the wheels would rotate in opposite directions?

 

Is there now just enough friction to cause the positive same direction turn when tested? - But not enough for a “functioning” LSD?

 

Any thoughts guys?