Pinion nut torque Diff rebuild
 

Hi
I have just rebuilt my diff. I have changed the bearings, seal but could not get new pinion shims so used the old ones. There were 3 shims on the pinion.

I am having a real problem torquing down the pinion nut. I have watched the video on amazon cars which is helpful. It gives a torque value of 280 to 300 newton meters (nm). The facebook group gave me figures from the haynes manual of 220 to 240 nm I believe.

The issue is that when I torque the nut to 130 nm which is the maximum my torque bar goes to the pinion is so tight that I can no longer turn it by hand. If I torque it to 280 or 300nm it will be so much tighter it may ruin the bearing. From my understanding you should be able to turn the pinion by hand and using feel, feel if there is too much or too little play but it should turn by hand.

Has anyone done this job before? I would be grateful for some guidance please as I don't understand how the haynes manual and other sources quote such high torque settings.

Thanks

Can you use a jack to torque it? Not sure how you would measure that though if your torque bar only goes to 130nm.

You would need a thicker shim then... the nut torque shouldn't be used to "adjust " the force used to turn the pinion.. just do it up to the correct torque... and use thicker shims until the turning torque is correct with the nut torqued to the correct figure. ( 200-220 Lb/Ft ) I suspect you have grossly overtightened the nut however...

The torque is ft lb not Nm. Should be 220 to 240 ft lb.

Link to the service manuals.

Not sure I understand what using a thicker shim will achieve.

Will it stop the bearing in the pinion being pulled forward into the bearing housing so stop the bearing becoming too tight?

I have three shims now on the pinion shaft which is how the diff was before I disassembled it.

What I need to understand is, if the pinion is too tight and wont move by hand at a torque value of 130 nm surely it needs to be less tight. At a torque of 100nm the pinion moves nicely by hand and there is no play so surely if it is now torqued to a higher value of 280nm it will destroy the bearing no?

The correct SI Engineering term is Lb/Ft (mass/distance)
Think about it..you don't say m/n do you ( distance/mass)

I know there seems to be major confusion out there in recent years about this even professionals like Barum engines make this mistake for example, then everyone thinks they are using the correct terms from hearsay and use that expression themselves. but they aren't correct..

Think of it as a foot long wrench and you put a force of 100 Lbs on the end you can visualise that..

The wrong way, a 1 Lb weight on a 100ft wrench....

Understand your issue here ! :-) not only do you have a torque setting that is suppose to be 220ft lbs = 300 nms to tighten of which you don't have a torque wrench to get to 300nms to , But also seem to be crimping the parts inside the axle too tight when you try and get to the recommended torque ! As you have changed the bearings I would have thought that the new bearings are slightly bigger than the old ones due to wear, have you tried taking spacers out and see if you can torque to a greater amount with less spacers ?
surely your just torquing up the nut to the threaded apart on the pinion ?

Paul

Torque equals force x distance same as moment. It's not force/distance.

indeed, The / wasn't supposed to be divided by, more a separator.

I should have used a dash -

ENV / Spicer diff pinion backlash.
 

While on the subject of differentials does anyone have an idea of the correct pinion rotational backlash of these two types used on the 544/early Amazon. I have the green Volvo manual on differentials but I cannot see any reference to this backlash measurement. My diff. backlash measured at the circumference on the pinion seems excessive at 8 to 10 mm. This is the amount I can turn the prop back and too by hand from under the car. Thanks.