Need instruction changing out differential/rear end 69 RR

[godfatherofchry]

good for you frank,just put the center section on the jack you get under the car and let the wife operate the jack you might have to show her how.if not gooooood wife.jack it up and you can usually push it and tip it so to catch top bolt let jack down just a little and let it fall in to place..while pushing a little..and it wont be long before your race ready.......Artie ps.the posey additive try not to get it on you if its like what I have used It smells like hell.no worse than that poop ya! thats it....LOL

 

[frank]

Problem with universal size

Artie
Came up with a problem…….need your help
At the end of the differential where the drive shaft fits into is bigger than the new differential. The old one measures 3 7/8, the new differential end (where the universal fits into) measures 3 2/8. Do you need me to send some pictures?
How do I resolve this……………
Thanks

 

[frank]

Artie
Came up with a problem…….need your help
At the end of the differential where the drive shaft fits into is bigger than the new differential. The old one measures 3 7/8, the new differential end (where the universal fits into) measures 3 2/8. Do you need me to send some pictures?
How do I resolve this……………
Thanks

 

[ply64post]

u-joints

Artie
Came up with a problem…….need your help
At the end of the differential where the drive shaft fits into is bigger than the new differential. The old one measures 3 7/8, the new differential end (where the universal fits into) measures 3 2/8. Do you need me to send some pictures?
How do I resolve this……………
Thanks

Frank

This problem can be taken care of with a combination u-joint.
Mopar uses 2 different size joints 2 1/8 and 2 5/8 [measured from snap ring to snapring]
precision u joint part number is 347
neapco u joint number is 2-0527

These u joints will take care of your problem and i'm sure these can
be cross to other brand u joints.

Jeff

Also don't forget your speedo gear will need changed.
http://www.mymopar.com/index.php?pid=112

 

[Cranky]

Yup, you have a different yoke on the rear. As for help getting the chunk in...years past, I rolled it up on my chest once I was under the car and used my body as a jack. This was before I had a good floor jack! Now I put the chunk on the jack saddle and roll it under the car from the rear and once it's high enough, I then crawl under and put it in place. Heck with man handling 80lbs while under a car! On the thrust pin...if it's nearly as large as the axles, you have the cone type SureGrip. One more thing about these. It was a two piece spline setup (side gear and clutch cone x 2, one set on each side) that most miss when working on these and if the splines are not reassembled in alignment, your axle will not go in. It that happens, let us know and we'll help you with that. DO NOT for any reason try to seat the axles by using the bolts on the bearing retainer plates to pull them in. You'll only mess up the retainers.

 

[godfatherofchry]

Frank

This problem can be taken care of with a combination u-joint.
Mopar uses 2 different size joints 2 1/8 and 2 5/8 [measured from snap ring to snapring]
precision u joint part number is 347
neapco u joint number is 2-0527

These u joints will take care of your problem and i'm sure these can
be cross to other brand u joints.

Jeff

Also don't forget your speedo gear will need changed.
http://www.mymopar.com/index.php?pid=112

X2 heres your part #s and all frank,your lerning hang in there your getting her.............Artie:icon_thumright:

 

[godfatherofchry]

Yup, you have a different yoke on the rear. As for help getting the chunk in...years past, I rolled it up on my chest once I was under the car and used my body as a jack. This was before I had a good floor jack! Now I put the chunk on the jack saddle and roll it under the car from the rear and once it's high enough, I then crawl under and put it in place. Heck with man handling 80lbs while under a car! On the thrust pin...if it's nearly as large as the axles, you have the cone type SureGrip. One more thing about these. It was a two piece spline setup (side gear and clutch cone x 2, one set on each side) that most miss when working on these and if the splines are not reassembled in alignment, your axle will not go in. It that happens, let us know and we'll help you with that. DO NOT for any reason try to seat the axles by using the bolts on the bearing retainer plates to pull them in. You'll only mess up the retainers.

X2 here also.:icon_thumright::icon_thumright:.......Artie

 

[frank]

Univeral Joint Problem, need your input

Artie
Need your input…….the new differential axle Pinion that’s on the 3.23 differential is too small for the universal joint. Can I take the one off the differential I just took out and put it on the 3.23 differential so the universal joint fits?
If so is it just an easy change-out….or do I need to do anything special?
Also, the differential that I took out (which I thought was a 3.91) is a 4.11; no wonder the RR was screaming at 65mph.
Thanks

 

[frank]

photo

On the left is the 4.11 (old differential) on the right is the 3.23 (new one), my question is ….the 2 parts I have circled can I inter-change them?

 

[ply64post]

u joints

Artie
Need your input…….the new differential axle Pinion that’s on the 3.23 differential is too small for the universal joint. Can I take the one off the differential I just took out and put it on the 3.23 differential so the universal joint fits?
If so is it just an easy change-out….or do I need to do anything special?
Also, the differential that I took out (which I thought was a 3.91) is a 4.11; no wonder the RR was screaming at 65mph.
Thanks

Frank

This problem can be taken care of with a combination u-joint.
Mopar uses 2 different size joints 2 1/8 and 2 5/8 [measured from snap ring to snapring]
precision u joint part number is 347
neapco u joint number is 2-0527

These u joints will take care of your problem and i'm sure these can
be cross to other brand u joints.

Jeff

Also don't forget your speedo gear will need changed.
http://www.mymopar.com/index.php?pid=112

 

[godfatherofchry]

Frank, Read the above post's I wouldn't change the yoke it would be easier to change the ujont.and besides you don't wont to take the chance of changing the pinion depth? then you will have a noisy rear.just set that one on the shelf you my wont to put it back in sum day.or I'm sure it will be easy to sell.if its been untouched..........Artie

 

[frank]

u-joint change

If I change the u-joint smaller will it fit into the drive shaft end? The universal already in the driveshaft is a lot bigger and won’t fit into the snap-ring on the 3.23. Do they make one that has 2 sizes ends one end that fits the drive shaft and the other into the universal?

On the measurementing the snap-ring is it inside the snap-ring or outside.

Thanks,

 

[godfatherofchry]

Frank

This problem can be taken care of with a combination u-joint.
Mopar uses 2 different size joints 2 1/8 and 2 5/8 [measured from snap ring to snapring]
precision u joint part number is 347
neapco u joint number is 2-0527

These u joints will take care of your problem and i'm sure these can
be cross to other brand u joints.

Jeff

Also don't forget your speedo gear will need changed.
http://www.mymopar.com/index.php?pid=112

frank did you read this.the ujoint has both sizes one large and one small.it will go in your shaft.mybe im mising what your tring to say.let me know and will get you going................Artie

 

[Cranky]

Artie
Need your input…….the new differential axle Pinion that’s on the 3.23 differential is too small for the universal joint. Can I take the one off the differential I just took out and put it on the 3.23 differential so the universal joint fits?
If so is it just an easy change-out….or do I need to do anything special?
Also, the differential that I took out (which I thought was a 3.91) is a 4.11; no wonder the RR was screaming at 65mph.
Thanks

What is the case number of the new chunk? If it's the 89, you have to deal with the possibility of crushing the crush sleeve more than it needs to be and that will put too much preload on the pinion bearings. I've done it many times but I've been working on rear ends for a long time. Anyways, there are 4 different yokes for the modern times...you just found 2. The other 2 are made up with different spline count but both are the same size yokes. There are only 2 u-joint sizes and but both come with different splines. If they are not the 89 cases, you can pull the nuts and washers off and check the spline count. They will require an impact gun tho....and the adapter U-joint isn't a bad idea either but I think they have became kinda pricy.

Frank, Read the above post's I wouldn't change the yoke it would be easier to change the ujont.and besides you don't wont to take the chance of changing the pinion depth? then you will have a noisy rear.just set that one on the shelf you my wont to put it back in sum day.or I'm sure it will be easy to sell.if its been untouched..........Artie

Changing yokes will not bother pinion depth. Pinion depth is set with the rear bearing. Bearing preload is set with either a crush sleeve (89 case) or shims (41 and 42 cases).

 

[frank]

Artie and Jeff

I think it comes down to vocabulary and comprehension of the parts. Having said that; is the measurement made from inside the snap-ring or from end to end. If it’s measuring inside the universal joint the 3.23 I have measures
2 1/8 if measured outside it’s comes out to be 2 7/8.

Which one of the suggestions that Jeff made should I get?


precision u joint part number is 347
neapco u joint number is 2-0527

 

[frank]

Thanks Guys

I just placed the order with Summit it should be here in about 3 days...I'll keep you posted.

Can't thank you both enough for all your help...........

Precision Universal Joint 347 - Precision U-Joints


Universal Joint, Detroit 7260 to Detroit 7290 Style Conversion, Greasable, Steel, Each

 

[Jim's Maxie]

What is the case number of the new chunk? If it's the 89, you have to deal with the possibility of crushing the crush sleeve more than it needs to be and that will put too much preload on the pinion bearings. I've done it many times but I've been working on rear ends for a long time. Anyways, there are 4 different yokes for the modern times...you just found 2. The other 2 are made up with different spline count but both are the same size yokes. There are only 2 u-joint sizes and but both come with different splines. If they are not the 89 cases, you can pull the nuts and washers off and check the spline count. They will require an impact gun tho....and the adapter U-joint isn't a bad idea either but I think they have became kinda pricy.

Changing yokes will not bother pinion depth. Pinion depth is set with the rear bearing. Bearing preload is set with either a crush sleeve (89 case) or shims (41 and 42 cases).

Changing yokes will affect preload,even if torqued to specs,no two yokes are identical in length,a few thousands will affect preload.

 

[Cranky]

Changing yokes will affect preload,even if torqued to specs,no two yokes are identical in length,a few thousands will affect preload.

On a 41 or a 42 case, how does the yoke affect preload when the shims are behind the the front bearing? Also, on the 89, how would the yoke affect the preload when a crush sleeve isn't crushed any further than it was in the first place? The yoke can be a mile longer and it won't affect the preload.....think about it....

 

[ply64post]

u joints

I think it comes down to vocabulary and comprehension of the parts. Having said that; is the measurement made from inside the snap-ring or from end to end. If it’s measuring inside the universal joint the 3.23 I have measures
2 1/8 if measured outside it’s comes out to be 2 7/8.

Which one of the suggestions that Jeff made should I get?


precision u joint part number is 347
neapco u joint number is 2-0527

Frank

Real sorry for the confusion I could of explained about the combination u joint
a little better.
The measurements are at the snapring grooves 2 1/8 and 2 5/8,
the u joint will save you alot of hassle.

Jeff

 

[FridayGt]

Thank you all for all of this info. It will help me out a lot when I get around to saving up for a higher (numerically) ratio posi for my runner again.