U-joint for a bastard combination

[a70duster]

Hello all, I'm temporarily using a mystery driveshaft. The yoke is for a 727 trans and I'm fitting it to an 8 3/4" rear diff. The length is correct BUT the u-joint caps are too small to correctly fit in the 8 3/4 pinion yoke.

I'd need a u-joint with different cap sizes.

Thanks

 

[66Valiant528]

7260 to 7290 conversion joint?

 

[66Valiant528]

2 1/8 snap ring to snap ring one way 2 5/8 the other way

 

[rbkt65]

jump joint from big to small or what ever is precision 347

 

[a70duster]

Thanks that should be the solution. I can do some measurement to confirm.

 

[Vaanth]

More information on the combination universal joints for the 7260 and 7290 sizes:

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7260 and 7290 are not part numbers, but are series reference numbers from the Detroit division of Chrysler, for the smaller and larger cross and roller universal joints commonly used in the propeller shaft, or drive shaft, of most rear wheel drive Chrysler passenger cars and light trucks from the late 1950s into the 1990s.

7260 and 7290 Universal Joint Sizing

Dimension measurement information for the 7260 and 7290 universal joints is listed in the following.

The following image shows the sizing at the driveshaft yoke:

7260 and 7290 yoke and universal joint sizing detail:

7260 Distance between retaining rings	G	2.125"
7260 Cap Outside Diameter	D	1.078"

7290 Distance between retaining rings	G	2.625"
7290 Cap Outside Diameter	D	1.125"

7260 and 7290 Combination Universal Joint

To mate yokes of different sizes,a combination universal joint with both 7260 and 7290 dimensions is available.

The combination universal joint yoke dimensions are shown in the following:

7260 Distance between retaining rings	G1	2.125"
7260 Cap Outside Diameter	D1	1.078"
7290 Distance between retaining rings	G2	2.625"
7290 Cap Outside Diameter	D2	1.125"

7260/7290 Combination Universal Joints Part Numbers​

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	Now part of SKF
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

 

[a70duster]

Thanks everyone - I got it figured out.

 

[pauly]

Just curious-do these run true and not vibrate even with the offset on one side?

 

[a70duster]

Just curious-do these run true and not vibrate even with the offset on one side?

Hi, so if you mean the entire drive train being offset it really doesn't matter. Here is an example with my '72 Duster. The yellow mark is a plumb-line from the center of the crankshaft. If you zoom in to the center of the picture, the nut/stud is the plumb-line of the output of the transmission. You can see they line up with the pinion gear of the differental.

To your question - yes these cars run true and don't vibrate. Vibration is something out of balance.

 

[pauly]

Thanks @a70duster. I know the whole drivetrain is offset just wondered in the driveshaft with conversion joints

 

[a70duster]

Ok, you meant the u-joint. Plenty of Mopar utilize this and they seem fine. The u-joint isn't offset, there are just different lengths for the endcaps.

 

[ragtopfury]

Just curious-do these run true and not vibrate even with the offset on one side?

The conversion joint still centers the shaft to the yoke. The joint is still symmetrical.