Rear end binding frame off?

[Brian K.]

Okay, I just installed my rear suspension on my restored frame (no body on the frame). After I installed the rear spring (the last thing I did) I can only get a 1/4 turn out of the rear end, prior too this everything turned freely. My question is this because of the angle on the suspension since the trailing arms are hanging (frame is on jack stands) and maybe the half shafts are hitting (I don't see any place where their hitting)? Is this normal?

[Russ S.]

Re: Rear end binding frame off?

Do you have the shocks installed? If not the trailing arms will be at their utmost travel which could possibly cause the u joints to bind.

[Brian K.]

Re: Rear end binding frame off?

I installed the shocks (new delco's) before the rear spring, I saved the spring for last. It's just weird that nothing was binding until the spring was installed, but that spring does really pull down on the trailing arms. So if their is a problem I want to address it now.

[Donald H.]

Re: Rear end binding frame off?

I recently finished the chassis on my 66. I did have binding like you describe, but I was very concerned with the stress on all the rear suspension with no body on. I was especially concerned with how the strut rod were twisted by the force if the spring. I used ratchet straps to pull the spring and trailing arms up to a more normal level. You might try this and see if you still have binding.

[Larry M.]

Re: Rear end binding frame off?

I installed the shocks (new delco's) before the rear spring, I saved the spring for last. It's just weird that nothing was binding until the spring was installed, but that spring does really pull down on the trailing arms. So if their is a problem I want to address it now.

Bair's indicates that many of today's rear shocks are too long and allow the rear suspension too much travel..........such that the half-shafts can bind. This may be your problem. Per their information, for 1963-1982 cars, the MAXIMUM distance (fully extended) for rear shocks center to center mounting points is 14-1/4 inches.

Check what you have installed. They indicate this excessive travel will create issues and will void their trailing arm rebuild warranty.

Larry

[Brian K.]

Re: Rear end binding frame off?

Hi Don, yes I noticed the strut rods have a slight twist, when you pulled the suspension to more of a ride height did this solve your binding problem? I plan on taking the frame off jack stands today and putting it on car dollies to move around.

[Brian K.]

Re: Rear end binding frame off?

Thanks Larry, I'll check the shocks travel.

[John H.]

Re: Rear end binding frame off?

Thanks Larry, I'll check the shocks travel.

Brian -

No need to check shock length/travel - your half-shaft U-joints are binding due to the rear suspension being in full rebound due to not having any weight on the rear of the chassis. Jack up the trailing arm on each side far enough to insert a 5/8" socket between the bottom of the trailing arm and the bottom of the clearance slot for the trailing arm in the frame, and the half-shaft binding will disappear.

[Larry M.]

Re: Rear end binding frame off?

Brian -

No need to check shock length/travel - your half-shaft U-joints are binding due to the rear suspension being in full rebound due to not having any weight on the rear of the chassis. Jack up the trailing arm on each side far enough to insert a 5/8" socket between the bottom of the trailing arm and the bottom of the clearance slot for the trailing arm in the frame, and the half-shaft binding will disappear.

I don't disagree with JohnZ's advice..................but if the shocks have too long a travel, the half-shafts can still bind if the car becomes slightly airborne from road bumps and dips at highway speed. Plus if you jack up the rear later for any work you still have the issue unless you do as John says each time.

I know I checked the rear shocks per Bair's advice and my new (but very old stock) Delco ones were fine. I also did not experience half-shaft binding when car was later raised again for other work.

FWIW.

Larry

[Brian K.]

Re: Rear end binding frame off?

Thanks John, and that a good idea about the socket.

[Donald H.]

Re: Rear end binding frame off?

I recently finished the chassis on my 66. I did have binding like you describe, but I was very concerned with the stress on all the rear suspension with no body on. I was especially concerned with how the strut rod were twisted by the force if the spring. I used ratchet straps to pull the spring and trailing arms up to a more normal level. You might try this and see if you still have binding.

Mine didn't exactly bind but would not roll smoothly until I pulled the trailing arms up with the straps.