[1971455HO]

Ordered new stock springs from Eaton. Removed RH spring. Discovered only 1 U-bolt and two boots fastening bottom plate to leafs....Is this correct, or should there be two? Install kit came with four. Mine only had one per side.

[Sirrotica]

Originally Posted by 1971455HO

Ordered new stock springs from Eaton. Removed RH spring. Discovered only 1 U-bolt and two boots fastening bottom plate to leafs....Is this correct, or should there be two? Install kit came with four. Mine only had one per side.

From GM they came with one U bolt per side and 2 T bolts, it was probably someone's idea to save a few cents per car over using 2 full size U bolts. Yes you can pitch the T bolts, and use 2 U bolts per side as your vendor has sent you.

I've run a good many F bodies over the years from street cars to autocross cars, and dirt track cars. I've used both the T bolts with one U bolt, and the double U bolt configuration, never saw any advantage of one configuration over the other in handling, or performance.

[1971455HO]

Thank you sir. I'll put it back like it was. Appreciate it.

[Formulabruce]

The T bolts are used on the " inside" . These are stronger than the Ubolts and there were slightly longer ones used on cars with rear anti sway bars. For many many years after production the longer T bolts were available new.
Make sure you use 4 leaf spring set and the shock plate should be flat against the perch with isolators installed.
Originally the lower Isolators had metal rings in them to help keep center pin nut centered at all times. This type, which is longer than first gen, is getting hard to find.
PS, Save those springs and mark which side they came from. There is a 90% chance the new ones will be over arched, especially if you ordered anything over 115 lb. Rating.
Install spring horizontal bolts loose till you have car weighted, or you may have a hi rise look you don't want.

[1971455HO]

Thanks Bruce, great info as always. I'm keeping my originals anyway. Just in case the new ones aren't any better than the 50 year old ones. Got tell all ya'll, I've been doing all this by myself. Dang, these things get heavy after a while of wrestling with them. I was still 20 years old when this car was built. Time took it toll on both of us . The car has held up pretty good, can't make that same statement about me. But I'm hanging in there.

One more question, I put anti-seize on the rubber bushing
on the shackle end of these new springs + on the inside of both of the sway bar rubber. At the spring plate & the strut support. Am I wrong for doing that? I can't think it would do any thing but improve the function of both the spring & sway bar.
Thanks again

[Formulabruce]

I use waterproof grease ( marine) on those parts. Anti size is suspended in oil, so should be ok

[1971455HO]

Thanks Bruce, I appreciate your help.

[JUDGE3]

curious how those new leaf springs turned out and if you measured the free arch prior to install?

[1971455HO]

I replaced them because I thought they had sagged til the shocks were bottomed out. Every time I went over a pretty good bump it was like it hit solid with no give at all. I was wrong. What I discovered was when my car was put back together it was put together dry...no grease or anti-seize on anything. It couldn't move. Dry rubber to dry steel. Everything was tightened up to the max. I think it was just locked down and couldn't move. I may not understand just how it is supposed to be, but I put anti-seize on all the points I thought it should rotate at. The results are still unclear to me. It rides well and handles correctly but is still harsh on the rear. Maybe I don't remember just how harsh it was 42 years ago.

As for measuring the free arch. I did. The new ones from Eaton were only 3/16" if that, higher than my originals. Made me think I spent nearly $800.00 and a lot of work for nothing. The final height is within a 1/16" of where it was before I started. I tightened the rear shackles with the weight of the car until they were tight to the frame rail. I tightened the leaf spring end of the shackle until it compressed the rubber inserts even with the spring width. It was snug but still was rotatable. All rubber contacts were lubricated. I'm all ears if someone has any pointers they know about installing rear suspension. I'm going on 72 now. This stuff is heavier than I remember

[Formulabruce]

One thing often overlooked that you are dealing with is the fact that Many f body rear suspensions just don't move.
I am using bearings from now on, and have already done a couple. Del~a~Lum bearings from Global west alow the rear to move more and actually "Be" a suspension. I bead blasted mine and painted black. Greasable, and you can use with a gas shock which is faster and more responsive to and bumps.
Originally the rear springs were tightened at about a 30* degree angle down . Referring to front eye bolt. This really bound up the rear.
Look up global west del a lum bearings firebird. The videos Doug has are very good. It is some work, but worth it.

[1971455HO]

Thanks Bruce. had this car a long time. I remember when i got it, it had a set of hooker headers on it and they would scrape every time I was on a road that had abrupt rises and dips. Somebody had put coil overs on the rear shocks, I guess to pick it up a little so it had a rake on it. I don't know. But the rear never bounced...just the front. thanks for your input.

[JUDGE3]

Yours worked out great sounds like.

As it turned out, I thought mine were originals. but they were 5 leaf. learned from forumulabruce 5 leafs never were used. so after looking, the mounts had the bend and all. I straightened the mounts out nice and flat.

so I had nothing to measure off of. but it turned out well, I had my new 4 leafs re arched based on the rear quarter to top of tire measurement for a very reasonable price at $50 a side and it turned out just right.

I had seen where the old originals can be rearched to be like new?

I believe i'll check into those del a lum bearings. I went with the kyb gr2 gas shocks. supposedly a smoother ride.

I recall my 1980 new trans am. no, these cars were not easy on the bumps.

[4dblnkldude]

Thank you! I am doing this same job right now. I am going to get the eatons!