Replaced broken 8.75 489, going from U-bolts to Straps

[flyamx]

OK full disclosure, I'm an AMC guy. Just happens that my '68 AMX has a Chrysler 8.75 489 sure grip 3.91 rear that I broke last year drag racing. Found a replacement 489 chunk on this forum a few weeks ago and installed a few hours ago. Everything was going well until it came time to hook up the driveshaft. My old 489 chunk has a 7260 Yoke with U-bolts. The new one has a 7260 Yoke with straps. The straps don't tighten near enough, u-joints will fall right out. U-joints are Spicer P051. I measured the U-joint cap and got 1-1/16".

So can anyone please tell me:

Is there a different U-joint size I now need for straps?

Also, why doesn't the yoke -w- straps have a lip on the end to hold the u-joint in place like the yoke with U-Bolts?

How can you tell if the driveshaft placement is correct without those yoke lips ensuring proper placement?

Finally I did find the following girdle @ Summit that is spec'd for a 1-1/16 U-joint. Wondering if this would solve my problem quickly?

http://www.summitracing.com/parts/mor-85850/overview/

Thanks, appreciate it.

 

[Sedanman]

There shouldn't be any difference in the u joint. My buddy used that same strap kit and all he did was drill out the holes and bolt it on without an issue.

 

[Supershafts]

You got some backyard wizardry crap there, AMC most likely had the 1310 end yoke
You should have replaced the same yoke you had.
you have pics of the old end yoke.

The girdle isn't helping you, and the p051 # is the cap for spicer which is a 1.063 diameter which is a 1310/1330 series cap

 

[Inertia]

Also, why doesn't the yoke -w- straps have a lip on the end to hold the u-joint in place like the yoke with U-Bolts?

How can you tell if the driveshaft placement is correct without those yoke lips ensuring proper placement?

Finally I did find the following girdle @ Summit that is spec'd for a 1-1/16 U-joint. Wondering if this would solve my problem quickly?

http://www.summitracing.com/parts/mor-85850/overview/

Thanks, appreciate it.

The mopar joints use the circlips on the caps, to centre the joint on the inside of the yoke..

 

[flyamx]

You got some backyard wizardry crap there, AMC most likely had the 1310 end yoke
You should have replaced the same yoke you had.
you have pics of the old end yoke.

The girdle isn't helping you, and the p051 # is the cap for spicer which is a 1.063 diameter which is a 1310/1330 series cap

Thanks.

I bought the car with the Chrysler 8.75 already in. I didn't know the new 489 had a different style yoke, never occurred to me. Truth is I've only seen the U-bolt style yoke, didn't know there were other styles.


Here's a link to pics of the yokes...the bottom 2.

http://theamcforum.com/forum/topic50109_post460840.html#460840

 

[flyamx]

The mopar joints use the circlips on the caps, to centre the joint on the inside of the yoke..

I'm familiar with circlips being used on the driveshaft u-joints but on the yoke u-joints is new to me. Anyone have any pics?

Thanks.

 

[Dartnut]

Oops!

 

[Dartnut]

Picture......

 

[flyamx]

Picture......

Thanks, but I still must be missing something. By looking at your pic I don't see anything that would prevent the U_joint cap from falling off like it is. I took some pics to illustrate what's happening:

 

[flyamx]

This is why I was thinking that the Moroso U-Joint Girdles 85850 would solve the problem:

 

[DoctorDiff]

Looks like you have a 1310 (external clip) driveshaft and a 7260 (internal clip) pinion yoke.

You need a 1310/7260 conversion U-joint.

 

[flyamx]

Looks like you have a 1310 (external clip) driveshaft and a 7260 (internal clip) pinion yoke.

You need a 1310/7260 conversion U-joint.

Thanks. Just to confirm, the girdle won't work? I'm asking 'cause I already ordered it from Summit but it hasn't shipped yet so I could cancel yet tonight.

 

[SGBARRACUDA]

Maybe I missed something in all the posts above. But why not change yoke from your old 489?

 

[flyamx]

Maybe I missed something in all the posts above. But why not change yoke from your old 489?

Well, I had suggested that to a third party (not on this thread) and he told me not to that because the whole crushed sleeve thing was a major hassle. Not knowing much about Mopar stuff I thought he knows more than I do. Now that the new chunk is in the car, would you still consider that a better option than new u-Joints?
Thanks.

 

[SGBARRACUDA]

That is an argument that will draw different answers on here. All I will tell you is I'm 58 and have removed and replaced a bunch of yokes on 489 cases that use the crush sleeve, for one reason or another(change a leaking pinion seal or change yokes from 7260 to 7290 or to a 1350 yoke. As long as you don't crush the sleeve more than it is from when you remove the original yoke you will be just fine. I also use a new pinion nut and red locktite when I install the different yokes.

 

[Inertia]

^^^ what he said,, only I'm 63, and use the old pinion nuts ....

 

[flyamx]

Well if I were a little less intimidated by changing the U-Joints, is this the correct 1310/7260 unit:

Moog Chassis Parts HMG319 - Moog U-Joints
Universal Joint, Detroit 7260 to Spicer 1310 Style Conversion, Steel, Greasable

Overview
Brand: Moog Chassis Parts
Manufacturer's Part Number: HMG319
Part Type: U-Joints
Product Line: Moog U-Joints
Summit Racing Part Number: MOG-319
Greasable: Yes
Solid: No
Universal Joint Style: Detroit 7260/Spicer 1310
Bearing Cap Style: 2 grooved, 2 plain
Bearing Cap Diameter (in) Axis 1: 1.078 in.
Width Including Clips (in) Axis 1: 2.125 in.
Bearing Cap Diameter (in) Axis 2: 1.063-1.064 in.
Width Including Clips (in) Axis 2: 3.218 in.
Universal Joint Material: Steel
Quantity: Sold individually.
Description: These Moog U-joints are precision-manufactured to exacting standards. They have forged and case-hardened alloy steel crosses and heat-treated needle bearings, cold-formed radial bearing cups for 360 degree lubrication distribution, superior-quality seals, and a grease fitting in the cross body for easy maintenance.

 

[DoctorDiff]

1. The 7260 Moroso caps won't fit the 1310 U-joint.

2. Your old yoke may or may not fit your new third-member because 489 castings used both 10 and 29 spline pinion stems.

3. I believe changing the yoke without replacing the crush sleeve is the primary cause of rearend failures.

 

[Dartnut]

The first pic in post #9 shows that the driveshaft end has external clips like G.M. products.
Chryslers have the internal clips that seat against the inside of the yoke. There are grooves near the bottom seal, and it looks like yours do not have them.
The pic i posted was of a Chrysler yoke.
I don't know if there is a u joint that would have both styles on it so you could make it work.......
You might have to change the end of the driveshaft yoke and use a Chrysler end to make it work.

 

[Dartnut]

Here is the conversion u joint in my car, you can barely see the clips on the first photo.
The driveshaft end is the small u joint and the rear yoke is the large end.
The second photo shows a side view, and the cap looks like it's too far out, but the internal snap ring is bottomed out on the inside of the shaft.
I have driven the car for a couple of hundred miles and have no vibrations and it still looks like this.

 

[67Dart273]

Mopar DID USE external clips for a couple/ three years on some applications. Don't know if it was 8 3/4 or only Dana. My recollection is a 67 GTX we junked, Dana axle. This was one HELL of a long time ago, in the early 70's

 

[flyamx]

Here is the conversion u joint in my car, you can barely see the clips on the first photo.
The driveshaft end is the small u joint and the rear yoke is the large end.
The second photo shows a side view, and the cap looks like it's too far out, but the internal snap ring is bottomed out on the inside of the shaft.
I have driven the car for a couple of hundred miles and have no vibrations and it still looks like this.

Wow, that looks really nice under there. Thanks for the pics. It takes me awhile but I think with the help I've received from all you guys we'll get it worked out. I'll keep updating on my progress.

Thanks again for all the help.

 

[flyamx]

Wow, that looks really nice under there. Thanks for the pics. It takes me awhile but I think with the help I've received from all you guys we'll get it worked out. I'll keep updating on my progress.

Thanks again for all the help.

Again, i know it's not a Mopar, but incase anyone is interested..(at least it ain't a Chevy)....

 

[Supershafts]

You want a 5-788x joint, just order that and be done.

The pic is making that end yoke look like a 7290, the 7260 end yoke doesn't taper out for the pin nut bore hole, if thats the case and it is 7290 you need a neapco # 2-0527 unless you find a nos 5-527x in spicer.

The easiest way to know if thats 7290 is to measure it from inside face to face if it's like 2-5/8" it's 7290 and you need the 2-0527 joint.

 

[Dartnut]

Wow, that looks really nice under there. Thanks for the pics. It takes me awhile but I think with the help I've received from all you guys we'll get it worked out. I'll keep updating on my progress.

Thanks again for all the help.

You're welcome.
Nice looking car BTW.