Reading on the internet I get the impression that at least some outfits view 29 spline and 30 spline yokes/shafts behind a 727 or 833 as the same thing. Apparently this may have to do with a missing spline.

So what are the facts? Are there two separate yoke/output shaft combinations, one pair having 29 splines and the other pair having 30 splines or is this a confused matter referring to only one yoke/shaft combination in which there WERE 30 but one is missing?

And where do 7260 and 7290 fit into this?

Thanks

7290 is the large size u-joint
7260 ismore common on the A-body and is the smaller U-joint

-D.Idiot

29/30 spline is a matter of semantics. Technically 29 is correct because of the dead locator, but both are in fact, the same size,shape, etc..

_________________
Official Cookie and Mater Tormentor.

In the driveline business it is called 29 on 30. The 727 and 833OD have the same yoke for a splined output shaft. I always have large ujoints put on my driveshafts for good luck. The yokes are about $50 new, and I may have some laying around. They are getting mucy harder to find out of junkyards without being forced to buy the drivesshaft so I just started going with new.

rock
'64d100

Hmmm, suppose I found one lying in a ditch. I wouldn't know if it was large or small would I!

Thanks

PS. Never mind. I found the sizes on the internet.

I take it by "ujoints" you mean to include the yokes, I.E. 7290 everything?

Thanks

Ross,

oops, Yes I have the yokes put on. I put in the joints and I always use the big ones. I figure the ones made for 440's will be just the ticket for a hot little 225.

rock
'64d100

Big ones meaning 7290. OK as long as it fits the 833 (29/30 spline). That being up front.

Does that include the rear of the shaft too? So I'd need to put a big yoke on the rear end? (A lot easier to find than a weld yoke.)

Thanks

Rosskinder,

Look at ebay item 250302778390. It is by a guy named ujointmaster. I have bought a number of things from him and found him to be a straight shooter. If my driveshafts don't have the rear yoke for large ujoints, yes, I get them swapped. I use 489 case third members (gear sets) and mine always come wth that size pinon yoke as normal. If you have a 741 case you may need the adapter ujoint that lets you use a big yoke on one side and a small joint yoke on the other. The adapter ujoint has one side of each, in other words.

I use new yokes that slide onto the tranny for two reasons. Used ones often have a groove cut in them from a dried out rear main seal and you are doomed to leak if using it. Also they often have pitted rusty spots that even if you use crocus cloth to polish still will make a leak. New, no trouble.
rock
'64d100

741, 742, and 489 all can be had with either a big or small yoke. Make sure to ask by U-joint number because "big yoke" also covers the 1350 U-joint.

_________________
Official Cookie and Mater Tormentor.

I think you offered me a complete drive shaft. I think you are now putting me onto a slip yoke like you use.

But I don't find an obvious link between these two posts.

Do you have the complete drive shaft I think you mentioned you could supply? If so, how much?

Thanks

Hello Ross,

There is a connection...in this thread you were asking: "I take it by "ujoints" you mean to include the yokes, I.E. 7290 everything?" so I was pointing you to where you could get the slip on yoke and other information about slip on yokes. Ujointmaster is good to talk with and if you call him up or email him he gives useful info.

It seemed to me you were going to either have a driveshaft make up or rework one someone (Zilla?) offered you. I had responded to the outrageous price of $350 quoted you by saying I had a driveshaft I'd sell but cautioned it may cost you $50 or so to have a yoke put on it. I don't know what length you need to tell you if mine will fit exactly. If you take your existing assembly and measure from the back of the tranny case(not the output shaft) to the center of the ujoint yoke on your pinion in a straight line, it would immediately tell us if my shaft was too long or too short for you. You would then be able to decide if you wanted to contact the folks where I live and have one made from scratch, or have mine lengthened or shortened.

When you really get down to determining shaft length, you make sure your vehicle is on a level firm place. Take a slip on yoke and push it all the way into the tailhousing over the output shaft. Lube the yoke first! Pull it out 3/4 of an inch. Measure from the center of a ujoint hole back to the center of the ujoint hole at the pinion. That distance is the one driveshaft shops use to make up a shaft. I wouldn't want to sell you something you don't need, and while mine is new, you can literally make a driveshaft out of about any old one too, for about $125 to $150. While I would take $120 for mine, if it didn't fit you would have an added cost, but still a fine shaft. It may be useful to have on hand before you need one so once you know the exact length you may be able to have a cheap fix made locally to it, or with a little luck use it as is.

rock
'64d100

The word "everything" (above) explains why I was surprised when you specified one piece. Every place I go I look for "everything" - the whole enchelada at the front end of the drive shaft including some tube. (Such a kit would make my own drive shaft quickly usable. But when you said "everything" including the shaft I said "make me up a bill.")

So far I have a LOT of people saying "slip yoke" - not just you. Apparently slip yokes are available in huge quantities somewhere.
Oh. I thought you said it was already made up. That's why I said, "make me up a bill." Yeah, that's what they said at the shop here.
From the sound of things, your shop would be cheaper than mine.
If I ever get that drag link out of the way I'll put the trans in and measure. And if the length can be set for $50 as I think you said, I'd have that done at your shop.


Thanks

Ross,

What I am suggesting is regardless of drag length or replacing the tranny, just make a good faith measure of what you have now. Knowing what you have now, whether 55 or 25 inches is indicative of what you will have to do in the future. I have spare bells, blocks, and trannies and can always just bolt em all together and tell you how long back from the block the tailhousing of an 833 is. Come to think of it, I believe Dart270 posted a link to a tranny dimension diagram last year.

rock
'64d100

It appears that the measurement from the center of the rear joint to the end of the tranny cone is 55.5 inches.

That should work out to about 52 inches center-to-center of the joints (just guessing).

Even though that is a guess, would you mind telling me why the drive shaft for a 1970 Cuda big block with automatic would be about 5 inches shorter than that? Is a big block 5 inches longer than a /6?

Thanks