I just had my driveshaft shortened slightly and now it looks a little too short. It's a good 2.5 fingers. There is no weight in the car. It is stripped. This pic is with the weight on the axle. Do you think with the rest of car installed I should gain about another 1/2" in towards the tranny?

http://i55.photobucket.com/albums/g136/Caman355/MVC-001F-34.jpg

That does look way too short. You can see where the seal use to ride, that looks about right. Not sure if more weight will gain you enough though.

Ya, I think they hosed it up. Before I couldn't even get the driveshaft in so I had them take 1.25" off. Bad part is that was about 3 months ago.

About 1" of free travel is all you need.

you want the d/s to bottom out into the trans, with enough room to get the u-joint cups into the yoke at the same time...(the u-joint square to the d/s)that gives you about 3/4 of an inch when the straps are installed...where you`re at, you`ll prolly break tailshaft housings at a hard launch due to undue bearing leverage, and at the least get a vibration...sorry...

you took too much off driveshaft length. that far out of tranny will tear rear bushing up than kill tranny and yolk.driveshaft should measure middle of u-joint to middle of u-joint 49 7/8

Yikes....to answer your question.......unless your car has a 8" lift kit on it, you will gain very little with more weight. The weight will push the rear end down...not forward. That's a vibration nightmare in the waiting.

Thanks guys for the responses. That was alot of money wasted.

you want the d/s to bottom out into the trans, with enough room to get the u-joint cups into the yoke at the same time...(the u-joint square to the d/s)that gives you about 3/4 of an inch when the straps are installed...What he said.

However, with the rear axle off the ground and suspension unloaded, support the car by stands on the frame, you don'want the d/s to jam itself into the trans, it needs alittle clearance. As the weight is removed, the rear axle comes forward.

If you want to gain some length without retubing your shaft I have a sugestion for you. Your current trans. yoke is a spicer part # 2-3-4911X which has a narrow operating angle. By switching to a spicer part # 2-3-6081X which has a deeper operating angle you will gain 1/2 inch in length. This will also help with any leak that you could develop with your original trans. yoke because based on the picture it does look alittle rough where the seal will ride. Even if you rebalance the shaft after installing the new trans. yoke it should still be cheaper then having it retubed.
Robert

Dennis, maybe I missed it but why did you shorten the shaft?
The rule I followed for measuring for my new shaft was with the requirement of never having more than 1/4" cup to yoke clearance. And that's a LOT.

Dennis, maybe I missed it but why did you shorten the shaft?
The rule I followed for measuring for my new shaft was with the requirement of never having more than 1/4" cup to yoke clearance. And that's a LOT.

I don't understand cup to yoke. I thought the 1" at the tranny slip measure was the correct measure. Would mind explaining the clearance you are referring to? Is it the measurement from the rear end yoke to the universal joint 'cup' when placing the driveshaft in the rear end yoke?

Thanks!

In a perfect situation you want that trans. yoke to ride 3/4 of a inch from being bottomed out with the car sitting level on the ground. If you were 1/4 inch more or less than this it wouldn't be earth shattering but I wouldn't go past this point. 1/4 inch from bottomed out is asking for trouble. The last thing you need to have happen is to bottom that yoke out against the tail housing.
Robert

Dennis, maybe I missed it but why did you shorten the shaft?
The rule I followed for measuring for my new shaft was with the requirement of never having more than 1/4" cup to yoke clearance. And that's a LOT.

I originally couldn't get the driveshaft into the yoke on the diff. So by taking an inch off the length I would have about 3/4" of travel once it was installed. I know I wasn't this far off on my measurement.

Robert, is that a pretty common part your referring to? The spicer # 2-3-6081X

yes it is a common part. click below to purchase.
http://www.shaftmasters.com/store/index.php?main_page=advanced_search_result&search_in_description=1&keyword=2-3-6081

Oh man! Sorry men, I missed your questions.
I followed the instructions for measuring as posted by Inland Empire. http://www.iedls.com/measure.html
Let me try to improve on that lame measuring instruction I posted;
Try to have the car level. (close is OK) The instructions from IE want end of trany shaft (no yoke) to face of diff yoke. The idea is so as to have no more than 1/4" of clearance with the new shaft. ie; install the trany yoke all the way. The U joints should be no further than a 1/4" from the coupling on the diff. It's OK to have less. In fact, jockeying the cups by turning the diff is OK. I'm not sure that 'bind' is even possible. But call the experts.
Kinda purdy,, huh?
http://epitomesrebuild.com/images/236.JPG