Rear Pinion Seal Replacement Mess up

[PFFlier]

Well, I thought I had the procedure down.  Saw a couple videos  and also had done it on my F150 before so I went for it.  Now I'm ready to put the new pinion seal in and put the pinion flange nut on and finally found out that I was supposed to measure the torque required to remove the nut, but I didn't.  So I'm wondering if I can set the preload to 4 to 8 inch pounds (with tires and drums off) by applying whatever torque that requires  and call it good.  Any ideas?  BTW this is a 1991 PF with LSD.

[Frenchy]

1991 with an LSD should be Disc in the rear with in hat drum parking break. You might be able to do it with tires on the ground, but I havent done many like this. If have to you can call a local drivetrain shop to help. You can also remoce the diff fairly easily. Just remove the wheels and breaks, then you can slide the axles out enough to pull the diff.

[Slartibartfast]

I haven't dug into this on mine, but I had a look at the service manual, and it looks like it's easier than you think it is--assuming you've got the H233B, which AFAIK all 4WD V6 Pathfinders do. PD-16 in the '90 service manual says that all you have to do to change the pinion oil seal on an H233B is remove the flange nut, remove the flange, replace the oil seal, grease the oil seal, reinstall the flange, and torque the nut to between 145 and 210 lb/f--and that's an acceptable range, not an adjustment. Pinion bearing preload and pinion height are set using shims.

 

There are specs (in inch pounds) for how hard the assembly should be to turn, to make sure you didn't screw something up after an overhaul.  If you haven't done an overhaul, these tests should not be necessary. I don't see anything about measuring the loosening torque.

 

The H190 and C200 rear ends (only used in 2WD and/or four cylinder applications AFAIK) use collapsible spacers (crush sleeves) to set the pinion bearing preload. The manual says you can't replace the pinion oil seal on those without overhauling the whole thing. 

 

You can download the '90 manual from cardiagn.com or the '94/'95 manual from Nicoclub. Both are free. If you want to talk to someone who knows more about the H233B than the rest of us combined, try @hawairish. 

[PFFlier]

Thanks for the replies and clearing that up about mine having the H233B without crush washers.  What a relief.  I notice it doesn't say in the instruction but do you recommend using a little RTV on the inner 1/2" of the yoke splines to keep oil from seeping through?  That's pretty common on other vehicles.

[Slartibartfast]

Yeah, it's weird that the manual doesn't show doing that. They show using a puller to get the flange off, maybe they thought the splines were tight enough that it wasn't necessary? I doubt a light coat would hurt anything, though I would wipe off any excess that squeezes out before putting the nut back on. 

 

And yeah, I hadn't looked that up before, and now I'm relieved that I don't have an H190 or C200! What a PITA to replace one oil seal.

[hawairish]

3 hours ago, PFFlier said:

Thanks for the replies and clearing that up about mine having the H233B without crush washers.  What a relief.  I notice it doesn't say in the instruction but do you recommend using a little RTV on the inner 1/2" of the yoke splines to keep oil from seeping through?  That's pretty common on other vehicles.

 

Just replied to your PM.  Summing up here for anyone else, RTV/sealant use isn't spec'd anywhere except the fill and drain plugs, but consider it optional.  It is common on other diffs, as you noted, and won't hurt anything and may actually be recommended depending on the nature of the leak (if one).  I usually just apply a little diff oil to the seal before tapping it in, and the same on the flange splines.

 

I wouldn't worry about preload much here.  Expanding on what Slartifbartfast mentioned, preload and pinion depth are set with a thick spacers/shims as opposed to a stack of thin shims.  At the factory, they change a spacer to dial things in, and that spacer doesn't distort like stack of shims might, nor does it collapse like spacers on the other diffs mentioned.  So, provided you torque the pinion nut to spec, you'll most likely be in the original preload ball park.  The numbers Slart provided appear accurate for WD21, though I find it interesting they're much higher than newer H233B diffs (mine is 109-144 ft-lbs).  I usually target the midpoint.

[hawairish]

6 minutes ago, Slartibartfast said:

Yeah, it's weird that the manual doesn't show doing that. They show using a puller to get the flange off, maybe they thought the splines were tight enough that it wasn't necessary? I doubt a light coat would hurt anything, though I would wipe off any excess that squeezes out before putting the nut back on. 

 

And yeah, I hadn't looked that up before, and now I'm relieved that I don't have an H190 or C200! What a PITA to replace one oil seal.

 

Funny thing is that when I rebuilt my D44 earlier this year, I felt like I needed a puller because the flange was RTV'd to the splines.  I dislike working with RTV, but that's what manual called for.  Dialing that axle in sucked.

 

And yeah, dealing with crush sleeves seems like a pain.  I've fortunately not had to deal with it.  I'm also surprised that the R200 lacks a crush sleeve.  It uses a fat spacer instead with "adjustable" spacers.  By adjustable, I mean buying spacers that you can no longer get from Nissan, a.k.a. not adjustable.

[PFFlier]

When I went to clean up the yoke I noticed the surface where the oil seal rides had a groove cut in it.  I worked on it with crocus cloth but couldn't get rid of it so I ordered speedi sleeve for it.  Never used one before, looks like you can use the same sized oil seal. Shipping goes slow this time of year, especially with all the snow (here in northwest. So now I wait....

Edited December 22, 2022 by PFFlier
Fix typos and clarification.

[hawairish]

Got a pic?

[PFFlier]

Here's the picture of the groove in the yoke:

[Slartibartfast]

Can you catch a fingernail on the groove?

 

I did wonder about that when I saw the list of shims in the manual. What do you do about that when you re-gear these? 

 

Weird that the torque spec changed. Maybe they changed the thread pitch?

Edited December 22, 2022 by Slartibartfast

[PFFlier]

Can definitely catch a fingernail in the groove.  It only measured .002" less in diameter which is .001" deep per side.  Not sure if micrometer is getting to the bottom of the groove all the way.  I hope the speedi sleeve works.

[hawairish]

4 hours ago, Slartibartfast said:

I did wonder about that when I saw the list of shims in the manual. What do you do about that when you re-gear these? 

 

Weird that the torque spec changed. Maybe they changed the thread pitch?

 

That's the problem, unfortunately...if you re-gear, you have to hope that the current spacers are too short so that you can add a shim to it.  Otherwise can only shave it down and then maybe shim up if needed, or replace with shims.  Best option has been to get the whole diff (R200, or H233B 3rd member) since it'll already be set up for the gears in it.  For the H233B swap on my Frontier, I needed to move the R&P set to another housing with ABS on the snout and lucked out the existing spacers kept in within spec.  I don't think I'll be as lucky if I ever get around to putting the 5.13s into the R50.

 

Nissan did actually change the thread size of the pinion, but it went to the size we run now.  The older 3rds that had 9 bolt holes to mount and 10mm bolts on the carrier had pinions with smaller shafts and nut threads.  Learned that the hard way on the Frontier swap when trying to get 3.9s from an 87 D21 to work in a 93 axle.  But, later W/D21 and everything up to 04 are the same size.  Same pinion nut and bearings between WD21 and R50, too.  Silly Nissan.

 

3 hours ago, PFFlier said:

Can definitely catch a fingernail in the groove.  It only measured .002" less in diameter which is .001" deep per side.  Not sure if micrometer is getting to the bottom of the groove all the way.  I hope the speedi sleeve works.

 

That's an odd score line, but I wouldn't sweat it if the seal clears it.  How did the old seal look, and was it leaking?

[PFFlier]

Yes, it was leaking,  which is what started this whole project.  You could see where dirt was stuck to the oil flung on the floor aboveand the exhaust as well as all over the front of the diff.  I figured the groove was from the inside lip of the seal.