Jaguar diff pinion nut adjustment

Zedn · #1 (**permalink**) 11-17-2009, 02:30 AM

I just removed the pinion nut on my Jag XJ6 S3 diff in order to change the seal.

My problem is that i neglected to mark the location of the nut or count the turns to undo it.
Can anyone confirm if it will be ok just tighten until the backlash torqe is 25-30 In-lbs?

Thanks.
Liam

RICK LAKE · #2 (**permalink**) 11-17-2009, 02:55 AM

Zedn If you are using new bearings you need an air gun to set the bearings. Once you remove the play in the pinion shaft to the bearings get an inch torque wrench, you want 25 inch pounds of drag when turning the pinion ONLY. Keep tighening the nut until you get to this spec. Backlash is more done with the spacers on the carrier bearings to move it right and left. You are looking for the tooth contact to be in the middle of the carrier gear ring. Make sure you include any shims before mounting new bearings on the pinion or carrier. Rick L. Ps slow down and mark the parts next time big guy.

Zedn · #3 (**permalink**) 11-17-2009, 03:13 AM

Thanks for the reply,

I am just changing the seal as the bearings appear to be fine. I am worried about over crushing the crush sleeve.

I dont have a sensitive enough torque wrench so i will need to see if i can borrow / buy one.

When i said backlash torque, i meant the drag. I will do as you say and tighten to 25 in-lbs.

I have been doing some reading and it looks like if i do what you have said it should be fine provided i work slowly and dont over crush the sleeve.

Failure to mark was more a case of ignorance rather than rushing.

Cheers.
Liam

Rick Parker · #4 (**permalink**) 11-17-2009, 08:28 AM

As Rick was saying above this adjustment cannot be done if the ring gear is intact. The inch pound drag measurment is taken "BEFORE" the Ring Gear is put in place. You may have more work ahead of you than you anticipate.

tboneheller · #5 (**permalink**) 11-17-2009, 08:53 AM

The proper way to do it is to remove the carrier & the pinion so the crush sleeve can be replaced. That being said, most of my customers do not want to pay the extra money to have it done "correctly". If you install the pinion nut by hand or with an impact wrench set on low, you will be able to feel when your bearings bottom out on the crush sleeve. Don't over-tighten it. be sure to "stake" the pinion nut. Any noise that it makes will be covered by the side pipes.

Zedn · #6 (**permalink**) 11-17-2009, 12:17 PM

Quote:

The proper way to do it is to remove the carrier & the pinion so the crush sleeve can be replaced. That being said, most of my customers do not want to pay the extra money to have it done "correctly". If you install the pinion nut by hand or with an impact wrench set on low, you will be able to feel when your bearings bottom out on the crush sleeve. Don't over-tighten it. be sure to "stake" the pinion nut. Any noise that it makes will be covered by the side pipes.

It is my understanding that the crush sleeve is there to maintain the corect torque required to turn the flange. i.e it crushes as you tighten so that you can obtain the correct amount of friction. If the sleeve is not overcrushed and the correct torque can be obtained i see no reason why it should be replaced.

Correct me if i am wrong, but the only reason i can see to mark the assembly before removal is so you can get to a starting point without over crushing the sleeve and then tighten from there. I just need to be careful tightening.

BJ's Snake · #7 (**permalink**) 11-18-2009, 02:28 AM

Zedn,
It seems that you have all the answers so why don't you do what you think is best.

Cheers
BJ

Zedn · #8 (**permalink**) 11-18-2009, 03:07 AM

Quote:

It seems that you have all the answers

Thats cause i found the jag service procedure after posting which confirmed what i was asking. Sorry if it comes across as trying to be a "know it all".

RICK LAKE · #9 (**permalink**) 11-18-2009, 03:12 AM

Zedn Liam The crush sleeve is to help cortrol the bearing load on the pinion bearings and stop bearing crush. All you are doing is replacing the seal, OK.
Why is the seal leaking??? Is there a bearing problem? Too much play side to side, or in and out of the pinion? Is there a groove in the rearend yoke? Does the rearend have 100 K miles on it?
The crush sleeve controls the preload of the pinion bearings to not over tighten them. It keeps the bearing plates at the correct torque but lets the rollers in the bearing have no or little load on them all the time. Too loose, per wear out of the bearings, too tight burns them out or blueing.
Some people don't beleive in the crush collars and run solid spacers, I don't. I do think you need to look at a rear support cover for the Dana 44 when done. Cap walking with high HP motors or drag racing is a problem. Jag rear is only good for about 400 hp and 450 ft of torque for normal driving. This is with a 27 spline stub shaft. If you have more power, a 30 spline setup of the carrier would be a 27% stronger setup. I run this with a locker and support cover on the rear case. 9 years and no failures yet. I did have a setup problem with a stub bearing and it seized after 3 miles.
Tighen the nut until you feel a drag. no play in the pinion. Leave it there and road test, see if you feel or hear any whining sound from the rearend. Get a rubber hose and put it on the carrier and do steady speeds of 20,30,40,50.60,70 mph and then coast down. If there is no noise change or a whining on coast down you are ok. Make sure you have the correct amount of fluid in the housing. Good luck. Ps keep asking questions, try not to overthink the answers.

Zedn · #10 (**permalink**) 11-18-2009, 03:26 AM

Thanks Rick,

The diff is old and has been sitting for a long time out of the car. It was so filthy to begin with, and looked like all seals were leaking so i replaced pinion and output seals. There is no obvious play in the bearings and the diff seems to be fine. Its basically just that the seals are old.

Liam

tboneheller · #11 (**permalink**) 11-18-2009, 05:03 AM

If this rear end has been sitting around for a while, I would recommend taking it completely apart & see what you have. More than likely the parts inside the differential that were not covered by oil will show some signs of surface rust. If it were mine, I would replace every bearing & seal in it & never have to worry about it again.

David Kirkham · #12 (**permalink**) 11-18-2009, 08:15 AM

Gents,

The original Cobra differential didn't have a crush sleeve. (Not sure about his unit, I'd have to see it). The inner pinion race are shimmed to the correct depth and then the pinion flange is torqued down to something like 250 foot pounds (if I remember right, I can find the correct torque if anyone is interested).

David

Zedn · #13 (**permalink**) 11-18-2009, 12:22 PM

Hi all,

just to clarify, when i say crush sleave i am refering to part 2 on this diagram (pinion collapsible spacer)

CHANMADD · #14 (**permalink**) 11-18-2009, 03:40 PM

I ahve removed those nuts many times for replacing the seal. The crush washers purpose is to get the correct setup between the pinion and ring gear. If you have not distirbed the pinion just put the thing back together and tighten by hand untill it is tight...15 lbs ? at least do not tighten it so that it crushes the washer more. As long as there is no play on the nut and you get the split pin in nicely it will be just perfect.
John