On my swingarm dragster my driveshaft u-joint is 3 1/2 inches from trans seal which put the yoke which has some of it cut off and is a 1/4 inch from going all the way through the bushing. My question is if I buy a longer yoke which I think would be about 1 to 1 1/2 inch longer would that be a problem? To me that u-joint being 3 1/2 inches away from seal seems too far away. What are y'all's opinion? Thanks for anyone's time.

The yokes come too long for a dragster and need to be shortened. Maybe I don’t understand your question but if you buy a standard size yoke it’s not going to fit, the yoke and driveshaft assembly will be too long.

Have you recently changed to a different transmission or anything else for the matter? I measured mine its measures about 3 inches from the seal to the u joint.

jeff the yoke wont go in but so far no matter what,check that distance first.it also sounds like the bottom heims need to be lengthened slightly

I have been fighting this car from the time I got it. So I pulled everything apart. The swingarm bar was hitting the pinion support when hit with a launch or a big bump down track. I was killing timing at launch that tightened 60's also tightened extension setting. But on occasion at worst time I would get out of shape and slide around. So to keep it from hitting I lengthened the heims in back. Longer wheelbase by a half inch. I never liked the way the driveshaft look as I thought it was too much of yoke barrel visible. Now I measured and the yoke only goes in tail housing a little bit as it likes a quarter of an inch going through the bushing. The u-joint is 3 and a 1/2 inch out away from seal on housing. My yoke has been cut off so my question was if I buy a yoke that has all of its length and not cut off and it goes all the way through the bushing and the joint is 3 and 1/2 is that a problem ? I'm thinking U-joint should be about an inch from seal to stabilize the joint but I have no experience with swing arms or 4- links for that matter. Thanks for all responces

My opinion my driveshaft is too short so I thought about buying a yoke with full length to go through bushing but not bottom out.. U-joint will still be 3 and 1/2 inch away from the seal at back of transmission.

the tailshaft cover will not let the shaft go in far ,undo ujoints and physically push shaft in and check travel.i dont think its a problem on the distance if you have full engagement and the pinion angle is right.measure it from yoke to yoke

Your yoke should be almost all in, maybe quarter to 3/8 of a inch of travel, so you can buy a yoke but it needs to be cut to fit.

Jeff,
Not sure what chassis you have but on my
race tech they recommend 1/4-3/8" at ride height. That is from bottoming out in the trans.

Without seeing your car sounds like your pinion angle is way off perhaps someone put the bolts back in the wrong holes in the rear end housing.

Rusty my shorty cover does not have a lip in it. But I'm just going to buy a longer driveshaft as peace of mind and get yoke to go through bearing at least an 3/4 inch and get u-joint about 1 and 1/4 inch away from seal of trans cover. First instinct usually right. But thought if someone had ran one with 3 and 1/2 inch out then I might try that. Thanks to all and if anyone has any suggestions I welcome all replys

Coop 5140. I have pinion angle at 2.8 down. I hope what I found and have done fixes it cause I struggled all last year. Hope this driveshaft problem is the last thing for a long while. Thanks

Rs72z. Thank you I would think the u-joint would be more stable like that and less likely to bind.

I think you need to be about .5

Coop5140 about .5 through bushing or yoke from bottoming out against housing seal?

I watched a video of a swingarm suspension working and doesn't move much in and out till it shuts down and then it looked like it had more movement. Not sure how much but looked that way.

Jeff,
What chassis do you have?
Best bet is call builder and talk with them. They can help and make sure all your base settings are where they should be before you start spending money.
Make sure ride height and pinion angle is right.

Rs72z. I have talked to them and have had used their setting and changed trying to get it to go down the track but finally found out why it wouldn't with the swingarm bar hitting left side of pinion bearing support. That's why I lengthened wheelbase to make it clear. Now that should be good now just getting driveshaft fixed for the extended wheelbase. I have scaled car and have a good setting just won't be able to test till a track opens near me. Not going to spend a lot just lengthen driveshaft get it set in trans correct and hopefully problems solved. Racing -- Change one thing change it all. HaHa Thanks for your replys.

Not going to spend a lot just lengthen driveshaft get it set in trans correct and hopefully problems solved. Racing
i missed something,thought you said the yoke was a 1/4 from tranny,indicating shaft already built.1/4 is not leaving room for float in .doesnt need a lot more but some.i will measure mine in a little and let you know

quote:

Originally posted by smokinjeff:
On my swingarm dragster my driveshaft u-joint is 3 1/2 inches from trans seal which put the yoke which has some of it cut off and is a 1/4 inch from going all the way through the bushing. My question is if I buy a longer yoke which I think would be about 1 to 1 1/2 inch longer would that be a problem? To me that u-joint being 3 1/2 inches away from seal seems too far away. What are y'all's opinion? Thanks for anyone's time.

The drive shaft needs to be as long as possible to get full support at the trans, especially with shorty glides but not to long that it will bottom out on the trans or too long so it can't be removed. That length is not hard to figure out. But shorty glides don't have a lot of room for the yoke to slide in. Dan Page Race Cars has his own rear bearing housing for shorty glides, it uses two roller bearing back to back to correct this problem. So it your considering a new driveshaft, this would be the time to get one of his rear housing!