I have a 9.25 from a truck, converted to fit my Satellite. I ripped the pinion yoke a couple days ago and was told the yokes are too small for the amount of power Im running, especially if Im spooled in my rear end (cornering) Does anyone run one of these and would it be wise to replace the whole thing or just the spool?

 

69 -

I'm running a 3.23 9 1/4 posi in the Charger rated around 525 HP, since c1980, with numerous runs under its belt. It's still in one piece. (In the interest of full disclosure, I've never run slicks - if that matter to you.)

I've heard that it wasn't considered a HP rear, but I've never had an issue.

Archer

 

Good to know, do you know what size u joint you have? I ripped that apart too, allegedly because it is too small to handle the output. I just want to know if Im going to be replacing parts every month if I keep the 9.25 or if my shops laziness is coming in to play again.(ex-shop)

Thanks Arch

 

Find you a rear yoke that can support a 1350 size u-joint and you won't have a problem. Try Randy's Ring and Pinion. I would also change out the driveshaft and front slip yoke to the same size.

 

69 -

Agree with changing both U joints, but the drive shaft is another story. If it appears intact, STRAIGHT , balanced and fits correctly, it probably fine. (Fits correctly is the tricky part, doing engine / rear swaps, it's too easy to get drive shaft that looks fine but is a little too short. Even a little too short can result in vibration an various speeds - don't ask me how I know that.)

Also, if you don't have at least one drive shaft loop, that's a good idea, just cheap insurance.

Archer

 

I would look at putting in a solid pinion spacer as it is the one weak link.

Something my son found: http://www.youtube.com/watch?v=eD0CEyapQK4

 

To go up on u-joint size the yokes on each end of the driveshaft needs to be replaced. I would never use those conversion type u-joints. I would rather spend the money on a new 3 1/2" driveshaft.

 

If you tore up the yoke the drive shaft is probably twisted anyway...
Have a new one made with the HD U-joints

 

Was the yoke the oringinal yoke? If it came out of a truck and the truck was beat on, then the yoke could have been cracked. Most of the time you don't see this happen as there are weaker parts in the drieline that could break first.

If it is a 73 and up axle, then an 8 3/4 yoke can be installed as well.

 

Ok, I have been looking for yokes, can only seem to find the two sizes to fit u joints 2760 & 2790. Reading if the drive shaft being short and causing the vibrations made me think, I have hijacker rear shocks which were on the car when I bought it and havnt replaced em yet, they leak out after a day, they are done, but if I fill em up with air would that in effect lengthen the distance between trans to diff? If I dont fill em up everyother day or so the ride is pretty bad.

 

Yep I checked to..with that rearend you are limited. You should have the 7290 u-joint size yoke already. If so get you a u-bolt type billet rear yoke. I tore the four quarter twenty bolts and straps off a factory yolk with my 440. I have a 3/8" u-bolt yoke now.

7290 series measures

• 3.625 inches wide in both directions
• All 4 bearing caps are 1.125 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 2.562 inches

 

Lost axles in similar fashion as u described. Thought is was joint or yoke related. It was too to much axle wrap from torque. We stuck a camera under there and watched under launch. It didn't seem bad but our launch was soft to keep slip down. The axle actually rotated up and bound causing the joint to bind on the 1-2 shift. 2600rpm stall and 400 to the rear wheel and a shift kit from Martin Saine. Not close to your power and since ours was clearly in the range of what the axle can handle we knew it had to be bind, flex or something else. Ours broke on the 1-2 shift and dropped the shaft. Thank God it had a loop. We used Calvert bar and no more issues. I would check for vertical axle rotation. Not sure how your car is set up but just wanted to throw this out for info purposes.

 

Good suggestion.

 

Thanks, this sounds scarry close to what happened...just leaving my house, shifting to second under soft load. Will be lookin into Calvert fo rthe fix, thanks

 

Now you can spend more money on that
2009 Super Charged Daughter.

 

Joining the thread a little late, but I picked up a 9 1/4 rear, was from a 72 or 73 Police Magnum. Dropped it right in, perfect fit, it's a 3.23 Suregrip and runs awesome. This was a stock option for the Cordoba, so I went with the equivalent for my year yoke and u-joint wise, believe it may be a conversion one, can't remember as it has been awhile.

 

With air shocks you could be changing the pinion angle when filled with air !! That would be something to check regardless..

 

Good point, I have air shocks as well, usually have them stiff, like the angle and the ride at that height. The pinion seems fine to me, but the rear was an option for my car but if it wasn't I would be more concerned.