489 with 1350 Replacement

[mrbone]

So, I'm switching Chunks to go from 3.55 to 3.90's..
Of course when I upgraded last year I added 1350 yoke to my 741 with 3.55's.

Now I need to replace the yoke on my 489 chunk.
If I understand this new process..

Mark the threads & nut.
Remove nut.
(Replace seal while I'm in there).
Replace with new 1350 yoke & original crush sleeve.
Re-install original nut.
Tighten with Loctite to previous marks plus, 1/8 a turn.

Do I have a proper grasp of things?
THANKS!

 

[493 Mike]

I would recommend adding a .010" shim on the front end of the crush sleeve and crush it a little more, following FSM procedure. I've done so many I can feel the correct preload pinion drag. You do not want excessive preload on the pinion bearings and specs vary depending on used or new bearings.
Mike

 

[Dipstick]

Marking the threads and nut is only useful when reusing the same yoke. Since the new yoke might have different depth dimensions, the original position of the nut is irrelevant.

 

[hunt2elk]

Measure how many inch pounds it takes to turn the pinion before you take the nut off. Tightened it up the same after swapping.

 

[mrbone]

Found the shim under the yoke gouged and in sad condition. New shims weren’t exactly the same size but I use them and tightened it down as near as I could to the previous torque. Just wanted to give an update.
Don't like the color I painted the chunk- thought it would be darker.

 

[john-9]

the shim you found under the yoke has nothing to do with pinion bearing preload - it is factory installed washer so the yoke does not gouge into the bearing when you tighten down the yoke to establish bearing preload on the crush collar between the front and rear pinion bearing -- to add shim to the top of the crush collar you have to remove the small bearing under the yoke .

 

[mrbone]

Oh, thanks for the heads up!

 

[mrbone]

By the way, here’s an easy way to negotiate the nut. Special tool I welded to hold the Yoke.
You can use it while the chunk is on the car also.