Driveshaft Balancing Recommendation?

[68/70Vette]

I havt a balanced driveshaft (C3) and I need to replace the yoke. It came with a 27 spline slip yoke and I need to replace it with a 31 spline. Seems to me I should have the drive shaft re-balanced since they are balanced with the slip yoke installed. Recommendations for a shop? I'd prefer a local LA shop, but anywhere in the US is ok. I've read that most driveshafts are balanced at 1000 rpm, but that it's best to ballance them at 3000 rpm or so.

Thanks

 

[mrvette]

I havt a balanced driveshaft (C3) and I need to replace the yoke. It came with a 27 spline slip yoke and I need to replace it with a 31 spline. Seems to me I should have the drive shaft re-balanced since they are balanced with the slip yoke installed. Recommendations for a shop? I'd prefer a local LA shop, but anywhere in the US is ok. I've read that most driveshafts are balanced at 1000 rpm, but that it's best to ballance them at 3000 rpm or so.

Thanks

I have changed yoke sizes often enough over the years and except for shortening the drive shaft I have never had to rebalance, however, you probably will need a cross joint that matches the larger yoke to the smaller shaft setup....common parts house in stock item.....

:thumbs:

 

[Twin_Turbo]

I would buy a conversion/bastard joint if needed and get a slip yoke w/ caps. No need to press that whole shebang back together, so much easier... easier also to take the DS off that way

31 splines, for a tremec conversion??

 

[SuperBuickGuy]

when you go to pick up the new joint, do take the driveshaft and new yoke with you.... I have a stack of u-joints from failed "I'm sure this is the one because that's what the book/computer says" or my favorite "I know it's just a bit smaller but it'll work!"

- I live miles from the store, and I've actually used parts from one on another with quite a bit of success.... that and, in an effort not to return, I've mixed and matched then felt it wasn't right to return the mismatched one that was left.

 

[68/70Vette]

I bought a Keisler TK0600 5 speed and included with the purchase was a balanced driveshaft. I ordered a drive shaft with 3150 U-Joints at both ends. When I went to install it, the sllip yoke wouldn't fit. I noticed the slip yoke was a 27 splin yoke, the Tremac output shaft was 31 spline. The Tremac output shaft was about 1.333 inches in diameter, the yoke that was delivered was considerable smaller in diameter. Keisler said they'd ship me the proper slip yoke and when I asked about balancing, they said it wouldn't be necesssary to rebalance the driveshaft. Rather than argue, I decided to just pay to have it rebalanced if necessary. So...I asked the question. Looks like Gene put in a vote that it doesn't need rebalancing.

Also, the 3150 yoke will probably require cutting a hole in the fiberglass tranny tunnel to fit. The diameter of the 3150 yoke's spin is just a little too bit for the stock tranny tunnel. The pinion gear (Tom's) has a 3150 billet yoke, so I thought I'd make the tranny yoke just as strong.

 

[larrywalk]

I believe you're talking about needing a 27 spline yoke for a 1350 u-joint - bear in mind that large 1350 u-joints are not required for the drive shaft but are used with the half shafts. The correct u-joint for the drive shaft should be a 1330 or a 1310, or a conversion u-joint, depending on the size of the yoke and drive shaft ends. By all means, get a slip yoke with removable straps or u-bolts, otherwise installation or removal will require either pulling the engine or rear end!

BTW, the torque through the drive shaft u-joints is less than half that being absorbed by the 1350 u-joints in the half shafts, so why bother to use 1350 u-joints in the drive shaft?

Lastly, I've never had to rebalance a drive shaft after swapping u-joints or yokes.

 

[68/70Vette]

I believe you're talking about needing a 27 spline yoke for a 1350 u-joint - bear in mind that large 1350 u-joints are not required for the drive shaft but are used with the half shafts. The correct u-joint for the drive shaft should be a 1330 or a 1310, or a conversion u-joint, depending on the size of the yoke and drive shaft ends. By all means, get a slip yoke with removable straps or u-bolts, otherwise installation or removal will require either pulling the engine or rear end!

BTW, the torque through the drive shaft u-joints is less than half that being absorbed by the 1350 u-joints in the half shafts, so why bother to use 1350 u-joints in the drive shaft?

Lastly, I've never had to rebalance a drive shaft after swapping u-joints or yokes.

Wish I would have read this a few months ago. I know have a driveshaft with all 3150's. Actually nothing wrong with a 3150 at the pinion yoke. How ever the 3150 at the tranny slip yoke is a little too big in diameter. Gonna have to cut a small (I think) hole in the tranny tunnel for the body to drop on the frame.

 

[larrywalk]

It's a 1350 u-joint not a 3150