8 3/4, 741 yoke/u-joint/seal interchange question - and moron award nominee...

[GrabberOrange69]

I recently purchased a 3.23 SureGrip to replace the 2.93 peg leg in my '65 Coronet. In a "rookie" move, I assumed since both housings were 2070741 housings, the yokes would be the same. In fact, the u-joint straps appear to interchange. Now that the PIG is in my housing, I realize the distance across one yoke is 3 1/4" while the other is 4". Solutions....

1) Can I swap the yokes, i.e. will they interchange? If I did, will I have to set pre-load and back lash again?

2) Is there a "swap" u-joint I could use?

3) Will I have to get a new yoke on the drive shaft to match the housing?

I have unscrewed myself from the ceiling, accepted my fate, and I'm ready to listen. Thanks in advance!

 

[5.7 hemi]

You can swap the yokes but onlu if they are both fine or course spline and then you will have to recheck the backlash.
Use a conversion u-joint, the easiest to do in your situation.
Dont mess with the drive shaft, unless ya want to spend some money on a new yoke and rebalance.

 

[Meep-Meep]

With a 741 housing the pinion bearing preload is set with shims so you can swap yokes without worrying about putting too much preload on the pinion bearings. The 489 case uses a crush sleeve and are sensitive to pinion nut torque. Go ahead and swap yokes but make sure you tighten that yoke good!

 

[69RUNR]

Use the conversion joint, NAPA sells them, a lot easier than swaping yokes.

 

[Cranky]

The 8-3/4" axle was offered with two size cross & roller style universal joint. These are referred to as the '7260' (2-1/8" yoke ID) and the '7290' (2-5/8" yoke ID). The cap diameter for the '7260' is 1.078". The cap diameter for the '7290' is 1.126".

There are four different yokes that have been used with the 8-3/4" axle for the '7260' and '7290' style universal joints. The '741'/'742' assemblies used a coarse spline (10 splines) drive pinion. The 489 used a fine spline (29 splines) yoke. Note: during the phase-in period of 69-71 for the '489' unit, there were several permutations of pinion size and yoke availability. 69-70 '489' units may be equipped with a coarse (10) spline pinion, particularly for the '7290'. There are two yokes for the '7260' and '7290' universal joints with fine (29) splines. Like Meep said, they take a good amount of torque but if you have the 489, you can crush the sleeve beyond it's intended crush when you tighten it back up and if that happens, the thing won't turn anymore. So, what rear are you working with?

 

[Photon440]

You can probably use something like this:
http://www.ebay.com/itm/PLYMOUTH-DO...Parts_Accessories&hash=item53f863a663&vxp=mtr

 

[GrabberOrange69]

Well, I bought the conversion u-joint - thanks 5.7 & 69RUNR & Photon. I'll put it in this weekend.

MeepMeep - good info; I thought the 741 was preshimmed without a crush sleave, nice to know I can change it if needed without removing the assembly.

Cranky - I have a 741 with the 7290 yoke; I have now discovered the original yoke was a 7260. The housing is a '65 273 b-body.