TR2/3/3A Castellated nut on the pinion

[jfarris]

I'm in the process of replacing a very bad diff seal. That nut is really tight.
Before I mess something up, is the nut right hand or left hand thread - I'm assuming normal right hand?
Help!
Thanks!

 

[Sarastro]

It's right handed. And, yes, it's tight. The spec is 85-100 lb ft. You should be able to remove it with a breaker bar.

 

[bobhustead]

Unless you arte going to replace bearings, torque specs are not useful for reasembly due to wear on the bearing/cup. Mark the nut and pinion before you break it (MANUALLY) and count the turns to remove it. Replace with the same number of turns to the marks.
Bob

 

[CJD]

Normally you’ll tighten 1/2 flat past your mark

 

[poolboy]

There could be a 'collapsible' spacer previoulsy set for the bearings preload that's involved, Jim..that's why you'd need to replace that nut pretty much as deep as it came off the pinion shaft. If you have the collapsible spacer and you overdo it you'll change the bearing 'preload'.

 

[sp53]

Yes that is one tight mama--- if you lose your place with counting the turns, what you are trying to achieve is the same as setting a front well bearing kinda, but this time you are getting the nut tight in a way that it takes 100lbs of torque to hold it with a cotter key, yet the bearing (which looks like a wheel bearing and race) spins free with a small drag, so you set the clearance with shims. I always get dyslexic here, but you add shims and it is looser.??? I think there are 3 maybe 4 shims.

Get the car up high enough so you can move and still have leverage to tighten 100lbs on a nut and feel some drag at the yoke. You will feel the drag and it does not have to be much----just a fuzz, but I think the number like 7lb drag holding force “something”

steve

 

[Geo Hahn]

I vaguely recall someone (here on BCF?) with a set-up for measuring the drag. It was an arm of some specific length (one foot would be handy) to which weight was added on the end. They had a particular drag in mind and added weight until the arm moved to see what they had.

 

[titanic]

I vaguely recall someone (here on BCF?) with a set-up for measuring the drag. It was an arm of some specific length (one foot would be handy) to which weight was added on the end. They had a particular drag in mind and added weight until the arm moved to see what they had.

I have done that. With a 12" arm the weight should be (from memory) 1.25-1.5 lb, this equals the 15-18 inch lb spec. Also, the preload is measured without the oil seal or ring gear installed.
Berry

 

[jfarris]

Finished the job with no damage to parts or animals. There were no shims behind the flange, only a large washer between the nut and flange. I was able to mark and count turns off and back on. when I got to 85ft lbs of torque, I was 1/2 a slot short of getting the cotter pin in, so that worked well. I was able to hold the flange by putting two bolts in it with a large pin punch wedged between them and the bottom of the car. I remember similarly using a piece of angle iron with holes in it bolted to the diff in my TR6 to torque the flange.
Thanks for the helps and hint, this forum is great!

 

[bobhustead]

Gland it worked out. I usually hold the flange with a large Stillson wrench.
Bob