Dan, that's just not right! Do you have a 9" in your truck? I'd say your driveshaft is at least an inch and a half too short. I checked the travel limit on mine, both before and after smacking the cup. It bottoms 3/4 - 1" from the yoke. With weight on the rear axle at rest, the seal surface is 1/2" - 5/8" from bottomed. I can take a picture if you want?

 

Everything on the truck is stock. Obviously, either the engine/tranny is too far forward or the rear end is too far back. Since the engine mounts haven't moved I think the problem has to do with the rear springs. I started to think there was a problem when I installed the parking brake cables. They were stretched much too tight between the rear backing plates and the mechanism under the rear cross member. The original springs fell apart when I took them off so I bought replacement springs. I compared them to the originals before I installed them and thought they matched up well. I guess I'll have to go back and take a closer look.

 

Your engine/trans is in the right place, it's in the rear mount properly. How long is your driveshaft, center-to-center?

 

Although I myself have never done it I heard the later 1970s G.M. is the same U joint as Ford, of the 1950s.

Take the old one your original to Napa and if you get a good parts man they will get you one. Thats the issue now a days a good parts man is getting hard to find.

I went into a local parts store waited in line for about 15 minutes to get to the parts counter, once I got there I gave the kid behind the counter the info of the part needed. I needed a 54 inch V Belt X 1/2 inch, well he said they don't sell them like that he had to know what it was for. By this time after waiting in line for 15 minutes I came up against this guy.

He wanted a story I gave him one he must have looked through 6 books trying to find some thing tha didn't exist. I did try to help him out in the first place, but this guy seemed to know all there was, sort of a self proclaimed pro.

So I went over to the appliance dept., and there it was exactly the size i needed, it only lasted the 150 mile trip that I needed it for but it did work. The following Monday I went to a place that sells bearings & Belts, got exactly what I needed with just the measurement info.

 

Yes, 5-star, it's the Powerglide yoke that is the same spline and u-joint but has a longer snout; see here: https://www.ford-trucks.com/forums/1...l#post12123232

Here's how mine is sitting. The red arrow is the furthest it will go in. You can see the oil ring from the seal. This is with the wheels on the ground, fully assembled truck.

 

The driveshaft measures 63" center to center. I checked all of the dimensions on the new springs vs. the original springs and they appear to be identical. The only thing I can think of that would explain the yoke being so far out is that the new springs are pretty stiff and won't flex until I get the weight of the body back on the frame. As you can see below, right now the front hanger of the rear springs is back almost as far as it will go.

 

That is the rear spring hanger, but if I am correct in seeing the differential, you have it at the front of the spring? That is likely the problem. Here is my left side spring assembled. My springs aren't new but they are plenty stiff.

 

Is it possible that your springs are reversed....front to back? I don't remember if the center pin is actually in the center of the spring or offset?
Even with no weight on the chassis, the yoke should not pull out that far...

Edit; I am slow at typing.....as Ross said, you have the spring hangers in the wrong position. No biggie....

 

On second look, the frame hangers are the same, just the shackle itself is in the wrong place......or maybe I just need more coffee???????????

 

I think you're right, Scott, the shackle just needs to move to the rear. I wouldn't have thought they are the same, but it looks like the frame brackets are the same. Unfortunately, it means pulling the pins out again, should be able to leave the axle connected. BTW notice how the pinion appears to be pointed down in his picture.

 

Ross, you're exactly right. I guess when I put it back together I should have referred to my notes from 2 years ago when I took it apart.

Feeling kind of dumb right now but at least I won't make that mistake again. Thanks for your help.

 

The springs being reversed was one of the first things I checked but it appears that the center pin is dead center. Anyway, I guess now I know what my project for this afternoon will be. It should't be too hard to switch things around but I not looking forward to it since it's already 90 degrees and very humid at 11:00 am.

 

Moved the hangers to the rear mounts of the rear springs and things are looking much better up at the transmission.

Thanks again guys for pointing out the obvious.

 

That was easy, eh? That kind of work is so easy when the parts are new, no dirt and corrosion to deal with, and the bed out of the way.

 

Yeah, it only took about two hours last night. The biggest problem was fighting off the mosquitos. I had planned to do it Sunday afternoon but a boy from town who's parents we know was running in the Olympics (steeplechase) so we joined friends to watch a broadcast of the race at the high school auditorium. He didn't win but it was a lot of fun to cheer him on.