diff pinion yoke spline

[tony 73]

I have a diff nugget in my challenger that I need to put in my roadrunner for a big trip on wednesday, problem is the pinion yokes are of different size. The RR is a large one ( Diff is a 4.33 that has a bad whine) , Challenger is a small one.  So want to swap yokes over, are the splines of the yokes going to be the same? Far as I can find there are only 2 sizes, 29 or 10. The nut sizes are the same at 1" 1/8.  I have a spare nugget (2.76, small yoke) and it's nut size is larger if this means anything.
 I am going to try removing the nuts tomorrow to see the splines but thought I would ask and see if I was wasting my time. Borrowing a rattle gun as 240 ft/lb is going to be tight.
  Any help much appreciated

[mopar jack]

you can get a u joint that adapts the small yoke to the large one.

[burdar]

If the nut sizes are the same, they should have the same spline count.

[1 Wild R/T]

If the nut sizes are the same, they should have the same spline count.

Yeah but the next question better be what is the case number on the pumpkins, cause a 489 has a crush sleeve unless it was rebuilt in the last ten years or so & had a crush sleeve eliminator added (very doubtful)

If you swap the yoke on a good 489 unit theres a good chance it won't be good much longer...

As mentioned you can get a U joint that adapts to the other yoke..  NAPA Pt# 347

[tony 73]

Thanks guys, I will look at the pumpkin no.s when I get home from work. Fingers crossed they they not 489. Saturday here so no chance of seeing if the Bearing shop can order one of those adapter u-joints. .
 Will keep you informed.

[tony 73]

Late for work now but the important stuff must be done. Pumpkin no.s are 7010742 (RR), 7010742 (Chal) . On the lower right hand corner of each number is another number. RR has 14 ,chal has 24. ??

[burdar]

Both are 742 cases.

[1 Wild R/T]

Yup, 742 swap away...  Should both be 10 spline yokes...

[tony 73]

Thanks again guys. Start on swap in the morning. Mopar guy here with a shop manual said the book says there maybe a collapsable spacer . Will keep you informed.

[1 Wild R/T]

742 does not use a collapsible spacer, bearing preload & pinion depth are both set with shims... Swap the yoke & torque the nut to 240 ft/lb..  BTW the yokes are pretty snug on the splines, you may need a puller...