Hi, i will have my rear axle out to replace seal +++. But should i replace the clutchplates (LSD) at the same time and is it possible to do that without needing to setup/adjust the axle/pinion again?
I dont know if i need to replace them, it looks like there are working ok, its not any problem to have fun on snow :-) and when i jack up the car and turn one wheel the other turn the same way, is there some other things i can check to see if it is okey?

 

If your trans is in park, an open diff will turn the other wheel in the opposite direction. Likewise, with the trans in park, you shouldn't be able to turn either wheel with an LSD. Having said that, if the trans is in neutral, the other wheel will spin in the same direction.

I hope you set up the pinion bearing preload properly when you did the seal as this is CRITICAL!

Yes, you can replace the clutchplates without pulling the carrier assembly. You'll have to pull the planetary cross shaft, planetary gears, axle clips, slide the axles out enough to disengage the side gears, then pull the side gears out. The clutches are under the side gears. What activates the clutches is side loading from the planetary gears and the preload spring pack in the center. Be aware, the shims behind the planet gears are a PITA to reposition.

 

I haven't done the seal yet. I will follow the service manual. But why does the torque needed to rotate the shaft change on how correct the shaft nut are?

PINION SHAFT SEAL REPLACEMENT
REMOVAL
(1) Raise and support the vehicle.
(2) Mark the drive shaft yoke and pinion yoke for
installation alignment reference.
(3) Remove the drive shaft from the yoke.
(4) Rotate the pinion gear three or four times.
(5) Measure the amount of torque (in Newtonmeters
or inch-pounds) necessary to rotate the pinion
gear with a torque wrench. Note the torque for installation
reference. It must be known to properly
adjust the pinion gear bearing preload torque
after seal installation.
(6) Remove the pinion yoke nut and washer. Use
Remover C-452 and Wrench C-3281 to remove the
pinion yoke (Fig. 2).
(7) Mark the positions of the yoke and pinion gear
for installation alignment reference.
(8) Use Remover W-251 to remove the pinion gear
seal (Fig. 3).
INSTALLATION
(1) Apply a light coating of gear lubricant on the lip
of pinion seal. Install seal with Installer W-147-E and
Handle C-4171 (Fig. 4).
(2) Align the installation reference marks and install
yoke on the pinion gear with Installer W-162-D.
(3) Install a new nut on the pinion gear. Tighten
the nut only enough to remove the shaft end
play.
CAUTION: Exercise care during the bearing preload
torque adjustment. Do not over-tighten, or loosen
and then re-tighten the nut. Do not exceed the bearing
preload torque. The collapsible preload spacer
on the pinion shaft will have to be replaced. The
bearing preload torque will be re-adjusted afterward.
(4) Install a socket and inch-pound torque wrench
on the pinion nut.
(5) Rotate the shaft with the torque wrench and
note the torque.
The required preload is equal to the amount
at removal plus 0.56 NIm (5 in. lbs.).
(6) Use Flange Wrench C-3281 to retain the yoke
and shaft (Fig. 5). Tighten the shaft nut in very small
increments.
(7) Continue tightening the shaft nut in small increments
until the correct bearing preload torque is
attained.
(8) Align the installation reference marks and attach
the drive shaft to the yoke.
(9) Add API grade GL 5 hypoid gear lubricant to
the differential housing, if necessary.
(10) Lower the vehicle.

 

The amount of torque it takes to turn the pinion is what they measure for proper pre-load on the pinion bearings. They want you to measure the before spec so you can put it back into that spec +5 in/lbs. Too much torque would indicate the bearing pre load is too tight, not enough then pre load is too loose. If its too tight then it could burn up the bearings, too loose you will have play, noise and eventually lead to failure.

 

Please note that the torque required to turn the pinion is what is critical. The nut can require 200 ft/lbs to remove or reinstall, but to turn the pinion yoke must only be 18 to 25 in/lbs.

Let me be more simple. Jack up the rear end and remove the tires and brake calipers to remove their friction. Remove the driveshaft. Use an inch pound torque wrench to measure how much torque it takes to turn the pinion itself. It should be around 18 in/lbs. Mark the nut and yoke with a reference mark (yellow paint or something) so you can come close when you put it back together. Remove the large pinion nut. It's going to take a large pipe wrench or something to hold the yoke and an equally large wrench to remove the nut. You can use an impact wrench for removal, but DO NOT use one for reassembly. The top of the nut is pinched to make it an interference fit so no lock washer is needed. Pry out the old seal and install a new one.

Check the sealing surface of the yoke for a wear groove. If it is grooved, it should be replaced or the new seal won't last long. Reinstall the yoke and tighten the nut a few turns at a time until you can't slide the yoke in and out and your reference marks are coming together. Check your "torque-to-turn" with the in/lb wrench as you begin to align the reference marks, using the big wrench a little at a time. Your final "torque-to-turn" (pinion) should not be more than 5 in/lbs more than what you measured in the first place. Put your brake calipers and tires back on and driveshaft in. Done.

Yes, it's tedious, but it's nesessary so you don't burn up the pinion bearings.

In my time, I've seen rear ends explode on the dragstrip because this simple job wasn't done properly.

 

Thanx for info :-)

 

When i remove the wheels and brakes, i can easily turn the yoke/pinion with my hand (two fingers), its not any/much resistance at all, i dont have a torque wrench that go so low that its possible to measure the torque so i need to buy a smaller one. But should it be so litle resistance when turning the pinion/yoke? The smallest torque wrench i can see is down to 3nm and thats 26.55 in/lbs. I see that dave1123 wrote 18 in/lbs, So its corret that i need to find a tiny litle torqu wrench?

 

You need a beam style, or a dial type torque wrench to test the turning torque, a clicker ain't gonna work.

 

18-25 in/lbs! Way too tight for a model 35. For new bearings proper preload is 12-14 in/lbs and for used bearings it is 6-7 in/lbs. If you go 18-25 in/lbs you will smoke those bearings quick.

Miles

 

I think i will mark the nut and put it back in the same position. I cant find any tools that would measure so low torque.