Drive shaft question.

[crotchss]

Nope.



Yup.

Guess I missed that, I read it too quickly

 

[ttype]

if your DS is still in the car "with" the 7.5", look to see what kind of "free length" there is between your transmission's rear seal to end of machined surface on yoke... the seal will leave a tell-tale guide/mark of free length left.(shiny vs brushed finish) IIRC, there's about 1"(+/-) difference between the two housings. there are almost as many tolerence differences as there are pinion housings out there. factor in some core shift too...

if you're left with 1/8" difference after your figuring, there isn't a lot of "oops" room left (like bouncing on your parking pin, backing your car on a downslope counts too... hey! few have never bounced there cars on their parking pins, some have done it once, others haven't the foggiest they're even doing that...you might not have, but your significant other never gives it a thought...)

err on the side of caution! i had a driveshaft shortened for me by Pat's Driveline service for a 700r4 swap. it appeared there was a lot of yoke left sticking out of the transmission (what could i have known? my first driveshaft shortening for a swap)
years later, feeling a little skeptical about using that driveshaft for an even bigger powerplant, pull the pin on an upgrade. get explained (by the shop's order form!) how to measure DS length, do that as per "their" procedure, have a super duper mondo strength DS made up, stress relieved(whole nine yards), have it shipped in, open the box, compare it to the one i was skeptical of, and they were practically identical(length) except in one area.

spline engagement. the new yoke(supplied) had a pile more yoke contact on the output shaft. it felt way more snug on the output shaft as well(think of valve stem guide wear and (maybe?) where odd hard to pinpoint vibrations originate...) wuddya mean? there's brand spankin new u-joints on it

hope this helps

it was a trans shop that did my swap the first time btw. it had a 7.5" rear. after "I" measured for the new one according to instructions for the upgrade 8.5" they were the same length. i'm in pontiacGP's boat with do the most you can to your abilities. the driveshaft shop you deal with has "explicit instructions" regarding how to measure for a new driveshaft. Pat's Driveline made mine according to the guy who measured mine. i do much nicer work than i can hire it seems, but that's me. i'd much rather work at the job i get paid well at, than work on my own cars, after i pay a shop to do what i could've done in the first place. that's the way the world is heading these days though. i will absolutely not attempt rebuilding a transmission at any cost. but i'll install a great rebuilt one without a pile of rework afterwards. gather your parts, and do the most you can to your abilities, and your pocketbook will thank you.

 

[ttype]

Just read on several sites, 3/4 inch to 1 inch sticking out is reasonable ballpark figure for stick-out. If you were to take this driveshaft and stick it into the trans another inch, there wouldn' t be much "oops" room left. This is the new and improved driveshaft for the 8.5".

 

[KYMalibu]

Is this Dave hester from storage wars.. lol. Yeepp

Now that's funny ! But yeah good questions !