InjectedSS

OK Heres the deal, I can't quite figure out if I need to cut my DS down or not. It fits just fine but I think that the yoke is too long and it's too close to the end of the tailshaft in my T56. Take a look at the pics below and you will see what Im talking about.

PIC01
PIC02
PIC03
PIC04

What your seeing is EXACTLY how my driveshaft sits when it's completly bolted into the car. You will see the little black mark on the end of the tailshaft. Thats how far up my yoke comes into the tranny Is this going to be acceptable or not? The guy at the driveline shop said it would be fine since I have enough room in THIS PIC But Im not so sure on his knowledge for T56's. Doesn't seem like enough to me and Im thinking I should cut my yoke down about an inch.

ALSO if you take a look at THIS PIC you will see that mine measures 44 1/4"s and my drive shaft now From the CENTER of the rear u-joint to the tip of the yoke measures 47"s So Im thinking too long

Any Ideas

Z-Attitude

Why don't you just remove the rear u-joint caps and see how far in you can slide the yoke into the tranny. It should go a little, if so you are fine. Since the rear end and the tranny are coupled with a steel frame they are not going to change distance from each other. Later>>>>>

InjectedSS

LOL Dude did you not even look at the pics?? I already know how far the driveshaft goes into the tail shaft. It's explained all right there in the above pics

And about the rear end and tranny not changing distance from each other is where I think your wrong. I have heard many stories about guys launching and the driveshaft goes up into the transmission and smacks against the seal and then can cause the tailshaft to snap.. So this is my concern!

simple

i thought i read in an old thread that Fred or Rich said, that 3/4 of an inch is what you want to allow for 'squat' i guess you'd call it on hard launches!
seems to me like you're dead on the money at .75xx of an inch
i could be wrong but i'm pretty sure thats what one of them said!

InjectedSS

Yea but there are different types of yokes. 3/4" just isn't some number set in stone to use on every single yoke out there. Think of it like this. My yoke could be 6 inches long and still stick out 3/4" from the tail shaft! BUT someone elses yoke could be 5" and stick out 3/4". BUT if you think about it, the 6" shaft would still be UP INSIDE the tailshaft MORE than the 5" yoke would. See what Im saying

simple

gotcha....
what kind of yoke do you have and what can we compare it to?
what length is the stock yoke?

InjectedSS

Well mine is the stock legth yoke but that's not saying much cause I have seen more than one sized stock length yoke As a matter of fact I have TWO DIFFERENT stock steel camaro driveshafts in my garage right now and they are both different sized yokes. BUT they are the EXACT same OVERALL length

simple

since you're digi cam equipped, is it possible for you to take some pics (the same way) with the other shaft and mark that one also?
in those pics in your first post, is that of a stock steel shaft?

InjectedSS

Yes I will line up the shafts tomorrow and grab some pics.. BUT the other shaft that has a shorter yoke and longer shaft WILL NOT go into place. There just ISN'T enough room. But the one that I have in there has a LONGER YOKE and a shorter length shaft so in turn it allows me to slide the yoke into the tranny further so I can then slide the rear u-joint into the pinion yoke. Where's the other shaft just bottoms out in the tailshaft before I can even get the rear u-joint in. See what Im sayin?

Injuneer

The measurement you are after isn't how far the yoke "sticks out" of the driveshaft. Its how much can the yoke be pushed into the tailshaft housing from its "normal" position, before it "bottoms out". The correct method is to set the car at normal ride height, remove the rear u-joint caps and slide the DS into the tranny. Stock clearance is typically 1/2". High power applications should be closer to 1".

The engine can move on the mounts, assuming you don't have solid mounts or plates. As the rear height of the car moves up and down, the axle rotates around the LCA front pivots, causing the DS to need to lengthen and shorten. And if you are using anything other than solid rod-ends on the LCA's, the axle will move forward relative to the body, on launch as the bushings compress. And the axle will move backwards on a hard stop for the same reason. That's why the slip yoke is there.

InjectedSS

OK Im lost :blah: What do you mean when you say "Before it bottoms out" Before What bottoms out??? Are we talking about before the tip of the yoke bottoms out at the end of the tail shaft?? Cause that's what Im talking about. Or am I looking at the wrong thing here?

Did you look at the pics Fred?? You see what I am hunting at? Am I just heading in the wrong direction as for what Im looking for? Are you talking about when the tailshaft bottoms out INSIDE the pinion yoke? Cause I thought I was supposed to be looking at when the TIP of the yoke bottoms out into the tailshaft. If that makes any sense?? Like I thought that the prob was that the VERY TIP of the toke can push FORWARD INSIDE the tailshaft and hit the seal that's INSIDE the tranny

OK here is where I think Im on a different page than you Fred. Take a look at THIS PIC you will see that in the YELLOW is what I was concerned on. Where Im trying to get the TIP of the yoke as far away from the end of the tailshaft! BUT what I think your talking about is in the RED where your saying that I should be concerned with getting the end of the tailshaft as far away from the bottom of the yoke.. Is that correct??

Injuneer

Yes, I looked at the pictures. Appeared that all you were doing was pointing out that when the slider was pushed onto the output shaft a certain distance, about 3/4" of the slider was still out of the tailshaft hounsing under some unclear condition.

It doesn't matter why it bottoms out.... if the inside/bottom of the slider hits the end of the shaft, or the front end of the slider is smashed into the seal.... either way, you don't want it to happen. So you put the shaft in, set the car at ride height, and then loosen the caps and slide the DS forward. If it slides about 3/4" to 1" into the tailshaft before it bottoms out (hits something), it is fine. If it is 1/2" or less, it is too long. If it slides in more than 1" it may be too short.

InjectedSS

AHHHHHHHH OK It's all making sense now

So BOTH situations are important! Meaning that having the tail shaft bottom out inside the yoke, AND having the yoke climb into the tranny too much! I gotchya

Well in that case then, if you look at THIS PIC you will see I have roughly 3/4" of an inch play! So that should be fine then eh...

See I was getting confused cause with the stock rear the shaft stuck out more, so as you said above there was MORE than 1" of play in there... But my buddy at the driveline shop was trying to explain that most of the time the manufacturers do that on purpose so that there is plenty of slack... Guess he was right

Injuneer

No... you have 3/4" of the slider outside the tailshaft housing. How much farther can it be pushed in before it stops moving? That is what you need to know.

InjectedSS

Oh yea, good question I guess I will have to check it tomorrow then.. So I should be able to slide the driveshaft with the way it sits now, 3/4" MORE into the tail shaft without it hitting? I will check tomorrow