Driveshaft leak

[McClare]

My rear differential has a leak where the driveshaft goes into it. I looked through my Haynes manual and it tells me how to take the d-shaft out and it looks pretty easy. I'm guessing that there's some sort of seal there that needs to be replaced. My question is that when I take the d-shaft out, is all the gear oil going to spill out all over the place? Are there any other precautions I should take? Looks like a pretty simple job to me.

[Joe Jeep]

If the rear diff is leaking from the driveshaft side, it sounds like you pinion oil seal is leaking. This is an oil seal with a spring that keeps the seal on the pinion yoke. If this is the case, you have to drop the drive shaft and break loose the nut holding the yoke to the diff (impact wrench). Then you can remove the seal and install the new one. That is if this is what is leaking. At least, this is what I did when my rear diff was leaking from the driveshast side.

[87manche]

www.madxj.com

 

 

there's a guide to doing the pinion seals on the D30 and D35 there.

Be careful not to cruch the crush sleeve.

I did mine, I tightened to 180 ft lbs. It was fine for over a year, until I grenaded the ring and pinion. 34's and a detroit was just too much for the little guy.

[Oizarod115]

the pinion nut is going to be TIGHT. its torqued somewhere in the hundreds of ft/lbs and that was yyeaaars ago.

 

I'm sure someone will chime in with the correct specs for tightening her back up. but you're going to have to have an impact

[87manche]

the pinion nut is going to be TIGHT. its torqued somewhere in the hundreds of ft/lbs and that was yyeaaars ago.

 

I'm sure someone will chime in with the correct specs for tightening her back up. but you're going to have to have an impact

 

spec is somewhere in the 200 ft lb range, but that's for a new gear install, and crushing the crush sleeve.

 

Like I said, 180 ft lbs gave me no problems, and the bearings looked good in the rear end when I inspected after the ring gear exploded.

[mjeff87]

I shouldn't mention this, but I'm gonna.... ;)

 

I replaced the pinion seal on my D35 a couple years ago, and just spun the nut back on with an impact until there was no play in the pinion, and it's been o.k. since. In fact, that axle is currently riding under Jerry's MJ at the moment.

 

But by all means, listen to the group and torque it properly. I'm guessing I just got lucky.

 

Jeff

[jeepthing07]

to torque it properly you have to pull the axleshafts/carrier out and mesure the preload on the bearings with a inch pound torque wrench.

 

if you scribe a mark on the nut and on the pinion and tightned it back (lining the marks up) and went a little tighter (like 1/4 turn or something) it should be fine and you can save yourself alot of work.

[Eagle]

Actually, to torque it properly you have to start with a new crush sleeve ... every time.

 

In real life, that's not what they do even at Jeep dealerships. The torque required to crush a new sleeve to get the correct preload is generally in excess of 300 foot-pounds. So the techs reuse the old sleeve and torque it to something less than a value that will cause it to crush further, but which WILL keep things nice and tight. Around 250 foot-pounds is what my tech friend told me. My torque wrench only goes up to 150, so if/when I get to do a pinion seal, I'll be shopping for a new torque wrench.

[jeepthing07]

you can replace it without useing a new crush sleeve but to do it the proper way you still need a $80 inch pound torque wrench. The FSM says to remove the axleshafts/carrier and get a baseline reading on the preload with a torque wench. so if it ends up taking 40 inch pounds to turn it you write it down and install the new seal and re-torque useing the 40 inch pounds and adding 5 inch pounds to it so it would be 45 inch pounds.

 

i don't remember who told me about scribing a line on the pinion and nut. and when tighting it back up to retighten it to that mark and going another 1/4 turn but they said it worked fine... i never tried it but it seems like the simplest way to do it without special tools and tearing the axle down

 

My friend's pinion seal is leaking on his YJ and he said the dealer wanted $130 to replace it. so he wanted me to do it and i told him no.. lol. its not really hard its just involved. i'm tired of working on other peoples junk

[87manche]

to torque it properly you have to pull the axleshafts/carrier out and mesure the preload on the bearings with a inch pound torque wrench.

 

if you scribe a mark on the nut and on the pinion and tightned it back (lining the marks up) and went a little tighter (like 1/4 turn or something) it should be fine and you can save yourself alot of work.

that's basically what I did, and ended up about 180 ft lbs.