will stock driveshaft work on a straight axle

[sonicsaleen]

will stock driveshaft work on a straight axle
Car has a Detroit locker on it.. I know the flange is different. Looks like they just take the flange off and the joints just bolt to the rear end.. Just want to make sure length and everything else is good. I dont usually mess around with straight axle cobras.

 

[ttk53]

yes when I swapped I just had to get a flange for the 1350 cobra drive shaft U joint.

Took SRA out of 97 gt and used my Drive-shaft
Put IRS in 97 gt and used his Drive-shaft.

 

[sonicsaleen]

looks like all i have to do is take the irs flange off the driveshaft end and bolts right to the u joint.

 

[blacksheep-1]

FWIW I measured a stick axle driveshaft and an IRS unit, the IRS is about 3/4 to 1 inch shorter (I forget exactly), apparently because the IRS unit does not move up and down like the stick axle. (The measure was from the yoke to the flange) now IMO it should still work since you are limiting the movement of the stick axle, I've used a stick axle aluminum shaft in an IRS unit and it barely..barely fit again, it worked because the IRS unit doesn't move up and down but it was tight. The point is, sort of run the suspension through it's arc when you are done to make sure it will all work. Chances are ,it will unless you are planning to ramp jump the car and your name is Joie Chitwood.

 

[shurur]

T45->SRA ==45.5" DS
T45->IRS == 44.5" DS
T56->IRS == 43.5" DS

So
best fit T56->SRA ==44.5" DS

I don't think the larger 1350 pinion flange is any longer than the 1330 flange (?)
so you should have plenty of play with the 43.5" Terminator DS.
.75" play is the general rule.

 

[Black Sex]

I used my stock DS on with a SRA. I just swapped the flange

 

[blacksheep-1]

I used my stock DS on with a SRA. I just swapped the flange

It will work, but you will probably give up some spline on the transmission yoke, in other words, it will be weaker.

 

[shurur]

It will work, but you will probably give up some spline on the transmission yoke, in other words, it will be weaker.

Meaning the more transmission output shaft spline that is not sheathed by a yoke is weakened and has more chance of shearing or twisting. (?)

And if the DS is so tight that it has to wedged in, and has no play, then it will wear the pinion bearings/transmission bearing(?)

I always thought that the DS play was for body flex, but was told it was needed for (torque?) windup...and don't get what that is really..

I have too much time on my hands....

 

[ctgreddy]

from what the op is describing sounds like the rear end has a completely different flange on it then factory ones. post a pic if you can, but you say you have to bolt the ujoint right to the flange on the rear which is now how fords usually are, that's a gm thing usually. If that's the case you may need a custom length driveshaft. or just get the flange on the rear end swapped out.

 

[sonicsaleen]

rear end doesnt have a flange. neither did the ds that was on the car. the u joint bolted right to the rear.

 

[myslowstang]

I used my stock DS when I did my SRA swap also

 

[Black Sex]

It will work, but you will probably give up some spline on the transmission yoke, in other words, it will be weaker.

Mine held up to 570rwhp quite well.

 

[blacksheep-1]

Mine held up to 570rwhp quite well.

OK,
I'm just saying it won't be as strong as the correct driveshaft because the yoke won't have all the contact necessary for the greatest strength. The big(er) issue with this , with the exception of the driveshaft falling out of the car, is that the trans mainshaft will " twist" and then you'll never get the right driveshaft yoke in.
I've owned a trans yoke that had a 1 spline shift and there's no way you're ever going to get a new yoke on that one. and now you're replacing the yoke and the mainshaft.

Meaning the more transmission output shaft spline that is not sheathed by a yoke is weakened and has more chance of shearing or twisting. (?)

And if the DS is so tight that it has to wedged in, and has no play, then it will wear the pinion bearings/transmission bearing(?)

I always thought that the DS play was for body flex, but was told it was needed for (torque?) windup...and don't get what that is really..

I have too much time on my hands....

#1 yes, as described above
#2 it could but there was about a 3/8 play, so I lived with it
#3 I think what they mean there is that the IRS is basically bolted to the subframe, it really can't move, it's part of the chassis now, the stick axle on the other hand does move quite a bit under launch and that driveshaft needs the extra length to keep all the parts together

Hope that explains it

BTW, here's an old school war story, back in the early 60s when we ran Oldsmobile rears in everything, we'd mark the axles with a stripe, when the stripe twisted 90 degrees, we'd change sides, wind it back to straight , then discard the axle at that point. I'm sure that driveshafts probably do the same thing, I refuse to mark some of these because I think it might scare me..lol