8.75 Yoke Question

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stevedart

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I am having a problem getting a proper u joint for my 8.75 yoke. My problem is that I purchased a 489 4.10 chunk and want to link it to my 7290 drive shaft. The measurements of the yoke are 2.091" between the ends and 1.06" diameter. I purchased a 7920 to 7260 combination u joint and that did not fit the diameter. Then I purchased a 7290 to 1310 u joint. It fits but there is no room for any type of clip. I have attached some pictures. I also need straps which did not come with the chunk. What type of straps should I use? I realize strength of the small joint is an issue but I want to see if the 489 chunk is worth spending money on the large yoke. Hopefully someone can help solve my issue.
Thanks
Steve

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I guess I did not ask the question properly. Does anyone know what yoke I have with the above dimensions.
Thanks
 
I was in a similar predicament and ended up with a small yoke (7260?) on the rear........the measurements were all funky when I looked online but the 7260 was "right" with my stock driveshaft....the 7290 is the bigger one.

For straps/bolts, I just picked up a couple "help" kits from Pep Boys.
 
I just crawled under my car and took the same measurement as you have posted and they are identical. I am running a 8 3/4 489 posi with a 7260 yoke and drive shaft. I would guess you need the 7260/7290 conversion joint. Are you sure you got the right one the first time?
 
I thought the same. When I purchased the 7260 to 7290 and tried to put it in it did not fit. The diameter of the u joint would not seat properly, it was too big. Therefore I bought the 7290 to 1310 and now I have the clip problem. Do you think the moroso 85850 girdle would do the job to keep the u joint in place.

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The 7260 to 7290
7260 series portion measures
All 4 bearing caps are 1.078 inch diameter with inside "C" Clips to lock the cap in place.
The span between the yoke inner surfaces where the "C" Clips lock in is 2.125 inches
As my above pictures show space between is 2.09 and diameter which is not in the picture is 1.06
 
Don't use those moroso u joint girdles.

If the driveshaft/rear ever goes to an extreme angle, those girdles make a mess of the u-joint/shaft/yoke. Use the factory style stuff would be my suggestion.

That yoke isn't a 1300 series, they use a tab/clip on the outside to locate the cup. That yoke has no locating tabe.

The inside spread you have is pretty close to the 7260 sizing, 2 1/8" IIRC or about 2.125". Get rid of the paint and take a clean measurement would be my suggestion. The paint is giving you short readings. That's a 7260 yoke, IMHO.

Here's the measurement from the napa site
Bearing Dimensions : Diameters 1.078 " & 1.128 "
Contents : 1 U-Joint, 4 Lock Rings, 1 Grease Fitting
Driveline Series Combined : Detroit 7260 x Detroit 7290
Fitment Dimension : 2.12 " & 2.62 " Between Yoke Ears
Grease Fitting Location : Between Trunions
 
Thanks
Maybe that is the problem.
I will clean off the paint and remeasure.
 
Thanks Crackedback
You were exactly right. The yoke was painted with thick engine paint. Once sanded off the measurements were right on for the 7260 yoke.
Again thanks for the help I really appreciate it.
 
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