489 case

[rs1]

I have a 489 case with a small yoke and I have a large yoke from a 489 case can they bee swapped?

 

[Xcudame]

As long as both are the same splines. They came either 10 splines or 29 splines. At least the 741/742 8 3/4 rears did.

Also, the 489 case used a crush sleeve to set the pinion gear depth. If you crush that collar more, you'll mess up the gear mess. They sell a shim kit that you can replace the crush sleeve with. Just measure the length of the current crush sleeve in your 489 case and use the sleeve and shims to duplicate that length.

 

[Vaanth]

I have a 489 case with a small yoke and I have a large yoke from a 489 case can they bee swapped?

Yes, the yokes can be swapped, with some considerations.

As noted, most factory '489' differentials (full casting number 2881488 or 2881489) use the crush sleeve, which should be replaced and the crush reset when any parts replacement is performed. The yoke nut can be marked and the turns carefully counted when removed and if the depth of the replacement yoke is the same, the nut turns count and mark can be returned to the original setting, plus a slight bit more to just begin crush, which will usually put things back, yet with some risk. If anything changes in the setup though, it should be re-set up per the factory service manual. Also as noted the crush sleeve setup can be replaced when re-set up with a solid spacer/shim arrangement similar to the '741' and '742' differentials.

Most factory '489' differentials except some early units in 1969 and 1970 are 29 spline pinions. The 1-3/4" pinion ('742') also appeared in some '489' carriers during the 1969 - 1970 phase-in period. These units have 10 splines and the spacer/shim pinion setting. In general, 29 spline pinions use a 1-5/16" or 1-1/4" hex size nut and 10 spline pinions use a 1-1/8" hex size nut. Aftermarket '489' ring and pinion sets might use 10 splines or 29 spines and different nut hex sizes.

For some additional 8-3/4" axle information, refer to the following document, which is dated some, but still informative:

A Chrysler 8-3/4" Rear Axle Guide

I will eventually revise, correct, and update it...


As an alternative to swapping yokes, if it fits the need, a combination, or conversion, universal joint can be used. It is not an ideal solution, but an effective simple solution to combining the mismatched sizes. The following table lists aftermarket part numbers for the 7260/7290 (small/large) conversion universal joint:

7260/7290 Combination Universal Joints​

Brand	Numbers	Notes
Precision	347
Moog	347	Formerly Precision
Dana Spicer	25-3244X 5-3244X (old number) 5-527X (old number)
TRW	20226	Now Federal Mogul
ACDelco	45U0169
GMB	240-0369 215-1309
Meritor	CP527X	Formerly Rockwell
PTC	P347 360 (old number)
SKF	UJ347
Chicago Rawhide (CR)	UJ347
Neapco	2-0527
Mcquay-Norris	U527
Perfect Circle	527
Rockford	K527
Borg Warner	114527
Amgauge	114527
Allied Eastern Corporation (AEC)	360
Xact-fit	XF527
AAP	20527
NIKKO	G5369X
Neotek	20527DL
MotorMaster	3133-C
Northern Auto Systems	847733
NAPA	NUJ240-0369 UJ347 P347
GMB	240-0369

For more information about 7260 and 7290 universal joints, see the following:

Chrysler 7260 and 7290 Universal Joints

---

 

[Xcudame]

Thanks @Vaanth , you are more thorough than me! Much appreciated.

 

[rs1]

Thanks for the info