7260 U-Joints virses 7290

[kycarnut]

I have the 7260 U-Joints in my car right now from factory but recently my aftermarket (read junk manufactured over sea's) pinion yoke broke and I dropped the driveshaft at 80 mph. Now I have to buy a new driveshaft and when you call these out of town machine shops they want me to upgrade to the 7290 U-Joints but I can have a local shop cut me a new tube and reuse my old ends for a lot less dough . Is it worth the money to upgrade to the bigger joints or will it really make any difference. I trust the opinions of my fellow members on this site because you guys have always been a big help and right on the money.

[Ghoste]

How much torque are you putting to the ground and how do you use the car?  Personally, I would do the upgrade because it is relatively inexpensive but if you are running something like a 318 through an automatic or jsut using the car as cruise night sort of car then the smaller joints are plenty strong enough.

[Chatt69chgr]

BB car, use the 7290's.  SB car, 7260's probably OK. 

[firefighter3931]

recently my aftermarket (read junk manufactured over sea's) pinion yoke broke and I dropped the driveshaft at 80 mph.   

Dang...that must have been exciting !    Any damage to the floorpans ?

I can have a local shop cut me a new tube and reuse my old ends for a lot less dough .

If the ends are good that's the route i would go unless you're racing with slicks every weekend. A quality Spicer u-joint is pretty togh and i know some that race with them. Mancini carries the Spicer 7260 joints for less than $20 a piece.

When you replace the yoke try and get a good quality forged piece that uses u-bolts instead of straps. If you can only find a 7290 pinion yoke that's forged buy it and the spicer 7260 to 7290 conversion u-joint. You will need to know the spline count on your pinion to order the correct yoke....there are two : 10 & 29 spline.


Ron

[kycarnut]

I guess it would have helped if I told you my setup . I'm running an older Summit crate engine that came straight from DCC it is a 360 Magnum advertised to have 390 HP @ 5300 RPM and 420 Ft.-Lbs of torque at 4400 RPM. I do plan on changing over to a 440 later on, as soon as, this economy picks up for us middle class folks but even at that it will be a mild build. I don't race this car. All I really do is go to a few car shows and get out on nice days and cruise. . Now I'm not going to say I don't like to spin the tires off at a redlight now and again just to keep the rice burners in check  or go down the interstate well above the posted limit but I don't abuse my car. By the way it was quit interesting when the shaft poped out but THANK GOD above no one was hurt and the damage even though heart breaking to me was minimal to the floor pans. See my car is what I like to call a semi-surviver though the motor and trans has been changed everything else is original down to the 40+ year old paint and carpet . Thanks again for everyone's help and please keep the comments coming.

[HPP]

You are probably fine with some good quality 7260s.

I used to drag race a built 360 in a 3200# car, launching at 4500 rpm with slicks.  I broke the cheap, chain store joint, but once I switched over to spicers, never had any more trouble.

[firefighter3931]

You are probably fine with some good quality 7260s.

I used to drag race a built 360 in a 3200# car, launching at 4500 rpm with slicks.  I broke the cheap, chain store joint, but once I switched over to spicers, never had any more trouble.

The 7260 spicer joints are fine.  At this point you just need to determine what the spline count is on your pinion gear and proceed. I'm assuming that you have an 83/4 3rd member in your car, correct ? If that's the case, then you need to know what centersection you have and what the spline count on your pinion shaft is. The 489 housing uses a collapsable crush sleeve to set pinion load which requires special consideration when installing the yoke.

At this point we need to know what you have back there. 



Ron

[kycarnut]

I have a 741 case with 3.55 Gears  Thanks Greg