Driveshaft length issues.

[Bobs 67Camaro]

I am currently installing a LS3/6L80e into my 67 Camaro. I have also done a Speedtech track time package. I hope to have it running in a few weeks!

I ordered a driveshaft from Strange Engineering (through quick performance). I provided a measurement from the face of the splined shaft on the tranny to the center of the rear u joint (at ride height--which is nearly horz). I also provided a measurement from the face of the seal on the tranny to the center of the rear u joint. The seal actually hangs out further than the splined tail shaft (apparently the splined shaft typically sticks out beyond the seal--on most trannies). The seal hangs out 3/16" beyond the face of the shaft.

When I installed the driveshaft, it seemed to be a little too short--so I decided to take a few measurements:

At ride height, I could unbolt the rear u-joint, and slide the driveshaft forward an addition 2.125" before the yoke bottomed out on the splined shaft (I have been told this should be around 1.5").

I also measured the amount of sleeved area at ride height. It appears that the yoke is sleeved onto the tail shaft 1 to 1.125" at ride height. Is this enough?



Does anyone know if 1-1.125" enough? Considering my driveshaft is nearly horz, and the rear coil over/torque arm system does not move as much as the original system, perhaps this is enough?

Thank you for your help!
Bobby

[andrewb70]

Bobby,

It sounds like the driveshaft that was made is too short. As you noted, if the output shaft of the transmission and the pinion yoke are in-line with eachother at rest, that would be the longest that the driveshaft needs to be. Any movement of the rear end, up or down, would actually pull the yoke out of the transmission. For this reason, when I order my driveshaft, I always provide a u-joint center to center dimension with the yoke positioned where I want it in my transmission. Also remember that we build our cars with rather firm suspension. This greatly limits the amount that the rear end actually moves around. Some pictures would help.

Andrew

[The WidowMaker]

At ride height, I could unbolt the rear u-joint, and slide the driveshaft forward an addition 2.125" before the yoke bottomed out on the splined shaft (I have been told this should be around 1.5").

this needs to be 3/4 - 1". im at 1.125" and dennys says that i "should" be fine. mine was a screw up in measuring without the pinion yoke fully seated.

[Bobs 67Camaro]

Sounds like I am quite a bit short. I did not know if 1" sleeve was enough.

I will call strange engineering tomorrow morning and see what they think.

Thank you for your help!

[Bobs 67Camaro]

Here are some pictures:
The one showing the slip yoke removed has (2) red lines 1.125" apart. The line closer to the U-joint represents where the rubber seal is when the driveshaft is installed and at ride height. The red line further away from the u-joint represents where the seal is when the splined tail shaft begins sleeving into the yoke.

[Bobs 67Camaro]

<a href="http://s1122.photobucket.com/albums/l529/rbfox1/?action=view&amp;current=mail-2.jpg" target="_blank"><img src="http://i1122.photobucket.com/albums/l529/rbfox1/mail-2.jpg" border="0" alt="Photobucket"></a>

[Bobs 67Camaro]

http://i1122.photobucket.com/albums/...ox1/mail-2.jpg

[Bobs 67Camaro]

[The WidowMaker]

use some thinner and remove those marks. put the ds in and mark it at ride height at the seal. then unbolt the rear u-joint and slide it all the way in and mark again. measure the difference between those two lines. thats the only number that really matters. id check with the ds supplier and see what they say.

[John Wright]

May end up needing a longer yoke so you can bottom it out inside the tranny...pull it out 1" and measure c/c of the u-joints...to get the length correct and still have enough engagement on the output shaft.

[Bobs 67Camaro]

I did end up getting a yoke which was 1.5" longer. I got it from Quick Performance in Iowa (seems to work well).

THank you for the suggestions!

[John Wright]

Glad you were able to get it worked out.....now go and enjoy that thing!

[John Wright]

BTW, this is a "booted" rear output seal. The standard seals do not have that extra material out past the lip of the seal.



I tried to replace the seal on my Silverado this past week and found that the booted seal was harder to find locally without going to the dealer.