The local driveshaft shop has said they can't build the driveshaft I need due to tube sizing problems. I think is was more complicated than he wanted to deal with. I'm considering building my own and having a local machine shop balance it.

The Solstice was a IRS with a CV joint at the transmission and a guibo at the rear axle. The B210 had a slip yoke in the transmission and a flange at the axle. I need to know how much movement is required in the slip joint of a driveshaft on a stick axle car. Figure race car with minimal suspension travel. The joints will be pretty straight at ride height. 

So I ordered a Solstice driveshaft. I also have the B210 driveshaft. I can figure out how to marry them together straight and get them balanced. The problem is a lack of slip joint in the middle since both ends of the new shaft will be flanged. 

The CV joint on the Solstice shaft has 1.5"-2" of travel on the splines. Is that enough movement to survive 24 hours or do I need to put a slip joint in the middle of the shaft? 

Yes I know how dangerous driveshafts can be. Yes there will be several driveshaft hoops to keep the carnage contained should it come apart. Thank you for your concern. 

1988RedT2
1988RedT2 MegaDork
7/31/20 4:09 p.m.

Sounds like trigonometry.    Can you draw a diagram with dimensions?

stafford1500
stafford1500 GRM+ Memberand Dork
7/31/20 4:20 p.m.

Sounds like an easy answer would be to get two get two tube that slip fit on each other and a zip tie. temporarily attach said tube to the trans and rear end. Run the suspension thru its paces and that will tell you if the CV plunge is enough or not. You are looking for max clearance between the zip tie on the small tube and the end of the large tube.

If the clearance is less than the plunge on the CV then you can set it up with the CV just off its limit to account for any bushing flex.

In reply to 1988RedT2 :

I'm sure it's a fairly simple formula that I don't know. 

It looks like there will be another issue. Using a CV on one end and a u joint on the other will introduce a lot of vibration. U joints don't rotate at a constant velocity. CV joints do. 

So, moving on to plan C. 

 

stafford1500
stafford1500 GRM+ Memberand Dork
7/31/20 4:25 p.m.
Toyman01 (Moderately Supportive Dude) said:

In reply to 1988RedT2 :

I'm sure it's a fairly simple formula that I don't know. 

It looks like there will be another issue. Using a CV on one end and a u joint on the other will introduce a lot of vibration. U joints don't rotate at a constant velocity. CV joints do. 

So, moving on to plan C. 

 

so TWO CVs???

You got the lathes to make the adapters

In reply to stafford1500 :

This is the direction I am leaning. I can order another used Solstice driveshaft for about $90. Then all I need is an adapter for the CV joint to the axle drive flange. 

The other option is $$$ and I would still have to build an adapter for the axle flange. 

Ranger50
Ranger50 UltimaDork
7/31/20 4:42 p.m.

Typical stationary trans and movable solid axle wants at least 1-1.5" sticking out past the output seal after being bottomed out. So you are looking at at least towards 3/4" of movement.

This may not be helpful at all.

I put a 5 speed in a stock height 69 Nova. To measure to have the driveshaft made, the shop told me to bottom the yoke out, then pull it out 3/4", and measure to the diff.  Like I say, doubtfully helpful

 

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
7/31/20 6:06 p.m.

It entirely depends on the vehicle.  Think about a lifted short wheelbase jeep compared to a Cadillac.  The first one has sharp angles, short shafts, and a ton of suspension travel.  The second one has next to zero angles, a super long shaft, and only a few inches of travel.

In most cars that I set up, I bottom the slip yoke, then pull it out 3/4" to measure for the shaft.  I never made a shaft for an off-roader, but many of them use a slip joint on a 2-piece shaft where they have plenty of room to make a 12" slip joint.

If you have questions about yours, why not try it out.  Pull the springs and run the axle through its travel with a stick to simulate the shaft.  Drop the axle the whole way and measure from the output shaft to the stick.  Then jack it up to the bumpstops and measure again.  If you get a 7/8" difference, cut that in half (7/16") and add 1/4" (4/16") for a safety margin.  In that example, I would set bottom the yoke and pull it out 11/16"

One end is designed, machined and ready for welding. 

The adapter for the rear axle is also built.

Hope to complete the machining for the other end tomorrow and weld it all up by Thursday. Then it's off to be balanced. 

 

Strizzo
Strizzo PowerDork
9/1/20 8:51 a.m.
Toyman01 (Moderately Supportive Dude) said:

In reply to 1988RedT2 :

I'm sure it's a fairly simple formula that I don't know. 

It looks like there will be another issue. Using a CV on one end and a u joint on the other will introduce a lot of vibration. U joints don't rotate at a constant velocity. CV joints do. 

So, moving on to plan C. 

 

You would think so but as long as the u-joint end is kept fairly straight, you'll be fine. Lots of suvs and trucks use the one cv/one u joint setup. Nissan did it in the Xterra and you'd only get vibes if you lifted with an add a leaf, if you used lift shackles the u joint stayed in line with the driveshaft and didn't cause problems. Even then it was only a slight vibration at like 28mph

Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
9/1/20 9:42 a.m.

Ford explorers have the slip joint in the middle of the driveshaft, and both ends fixed. 

Perhaps if needed you could use the center section from there?

I'm going to be using CV joints at both ends so I should be good to go. If it survives the Lemons 24 hour race in 2 weeks I'll call it a success. I did build two driveshaft hoops out of 1/8 x 2 flat bar. If anything fails they will keep the carnage under the floor pan.

Both ends machined, assembled and welded. The welds aren't the prettiest in the world but they'll hold. Total run out less than .003. Should be good enough. 

Today was spent figuring out how to keep the shaft straight while I welded the ends in the tube. 

With a big enough lathe, a dial indicator, a steady rest and enough time, it can be done. 

I'll get the tube cut and it all welded together tomorrow afternoon when I have a little help. It's going to be a case of tack it, check it and straighten. Then heavy tacks and check and straighten again. Then weld it and check it again. 

I'm calling this one a success. It appears to be running straight and true with no discernable vibration up to 3000-4000 rpms. 

 

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