Pinion nut question

[72LB]

Had to replace the pinion seal in my 69 and can't find a nut locally anywhere so I have to re-use the nut. An old timer told me to use some loctite blue and don't over tighten. I need to get this truck back on the road, is there a torque spec I need to follow?

[Grumpy old man]

did you already remove the nut and seal?

[72LB]

yes

[Grumpy old man]

Before you remove them you have to mark the position of the nut then on reassembly you have to replace it back to the original position as closely as possible to try to match the original preload it had before . just tightening it back down can change pinion depth and thrash your rear, it's not as simple as remove and replace.

[Rich69shortfleet]

I was in the same situation a while back. I spoke with a highly experienced and highly regarded rear end guy and he said to simply torque the pinion nut to 150 lb/ft and be on my way. It takes a LOT more torque than 150 lb/ft to crush the crush sleeve so at 150 lb/ft you will not affect the crush sleeve or alter the pinion depth.

One thing that is VERY important is that you clean the threads on the nut and threads on the pinion. Make sure that any and all old threadlocker has been removed and that there are no nicks or damage to the threads. Then, using a quality high strength threadlocker reassemble and torque to 150 lb/ft. If you haven't done so, adding a touch of RTV to the splines on the yoke will help prevent a leak via the splines which can appear like a pinion seal leak in the future.

I have to stress, be sure to clean the threads very well. Leave no residue behind. Did I mention you need to clean the threads? Any remaining old threadlocker can wildly affect getting the proper preload via the torque setting. Don't forget to clean the threads.

I have had to do this three times over the years chasing a leaking pinion seal. I've had no problems with the rear end and it remains as quiet as when it was new. I have hauled and towed plenty with no issues so it is clear I got good advice and have not altered the pinion depth in any way.

[57taskforce]

Originally Posted by Rich69shortfleet

I was in the same situation a while back. I spoke with a highly experienced and highly regarded rear end guy and he said to simply torque the pinion nut to 150 lb/ft and be on my way. It takes a LOT more torque than 150 lb/ft to crush the crush sleeve so at 150 lb/ft you will not affect the crush sleeve or alter the pinion depth.

One thing that is VERY important is that you clean the threads on the nut and threads on the pinion. Make sure that any and all old threadlocker has been removed and that there are no nicks or damage to the threads. Then, using a quality high strength threadlocker reassemble and torque to 150 lb/ft. If you haven't done so, adding a touch of RTV to the splines on the yoke will help prevent a leak via the splines which can appear like a pinion seal leak in the future.

I have to stress, be sure to clean the threads very well. Leave no residue behind. Did I mention you need to clean the threads? Any remaining old threadlocker can wildly affect getting the proper preload via the torque setting. Don't forget to clean the threads.

I have had to do this three times over the years chasing a leaking pinion seal. I've had no problems with the rear end and it remains as quiet as when it was new. I have hauled and towed plenty with no issues so it is clear I got good advice and have not altered the pinion depth in any way.

This is how I’ve done a few as well. Never had one problem with bearing or gear wear doing it this way.

[Rich69shortfleet]

FYI, the torque required to begin to crush a crush sleeve is 225 lb/ft or more.

[RustyBucket]

Originally Posted by Rich69shortfleet

FYI, the torque required to begin to crush a crush sleeve is 225 lb/ft or more.

A friend of mine had a drive line shop and used an industrial sized 1" drive impact wrench to crush the new sleeves. He had a touch for just how many times to hit it. Said the sound changed as the sleeve began to crush. Then he would check the pre load w/an inch lb. torque wrench. One of those guys that made everything he worked on look easy. .... unlike ME

[slikside]

Sub'd.

[72LB]

Wow it didn't feel that tight when I took if off. I will clean the threads thoroughly, what about using loctite? Me thinks torquing the nut will be fun under the truck.

[Rich69shortfleet]

Loctite is fine as long as it is the high strength version. As far as torquing the nut, hopefully you have an effective parking brake. Applying the parking brake and leaving it in gear (wheels off the ground!) should be enough. And either a long torque wrench or a long helper handle. You need to get the truck as high as you can safely so you have as much room to swing the wrench as possible.

[72LB]

I have a yoke wrench so I should be ok.

[CastIron]

I've done it by marking the old nut and loctiting back in the same spot. I've also done a lot of them on rwd cars when I worked at a GM dealership. The proper procedure for those (it was a recall with specific instructions) was to just torque the nut. I don't remember exactly how tight it was though.

[Metaldoc]

I believe you need a new crush sleeve and torque till you have 10 inch pounds of drag on the torque wrench.

[Rich69shortfleet]

Originally Posted by 72LB

I have a yoke wrench so I should be ok.

Lucky duck!

Originally Posted by Metaldoc

I believe you need a new crush sleeve and torque till you have 10 inch pounds of drag on the torque wrench.

No, not at all if all you are doing is removing the pinion nut to replace the pinion seal. If you are replacing bearings or gears, yes, but not for just removing and replacing the pinion nut.

[72LB]

Originally Posted by Rich69shortfleet

Lucky duck!

Found it at a swap meet last year, I knew there was a reason I bought it.

[72LB]

Torqued it too 150 and it was fairly tight, ended up backing it off a tiny bit and it has around 10 to 12 inch lbs of drag to it.

[volksworld]

that 10 inch pounds would be for a pinion gear in a bare case...so if you have a diff , axles and drums there would be a hellava lot more drag....and i sincerely doubt the sleeve "uncrushes" when you backed the nut off

[72LB]

Thats with axles in it, was told to check the drag with tires and drums off.