[dld]

I'm thinking that these plates are not supposed to be bent as showen in pics.

when disassembling car I could not see where these had been messed with . still had locking nuts and looked untouched.

[TA455HO]

Part number is 480909 and the NOS ones I've had as well as originals all seem a bit flatter through the middle. I can take pictures from another angle if you'd like but you can probably see these look flatter than yours.



Chad

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[Aus78Formula]

Yes, should be flat, are always out of shape. You'll need a press to have much luck.

[dld]

Originally Posted by Aus78Formula

Yes, should be flat, are always out of shape. You'll need a press to have much luck.

Yes I have one. just wanted to be sure. before I made a error.

is there a fix. for this or just let it ride

[Mace1971]

Yes, should be flat. Check with Dave at PTFB, he has heavy duty replacement plates out of heavier steel for the F Bodies.

[Formulabruce]

How these get 'bent"
1. The wrong springs. Putting the common 5 leaf replacement springs in a 4 leaf Pontiac spring perch, then crank away with the impact.
2. The repop spring rubbers top and bottom are too wide and too thick, and should be ground to fit so shock plate is tight against the axle perch, then crank away with the impact.
3. The "U" in the shock plate can make the "center bolt" in the spring, not even locate in the hole in the bent plate itself causing a unsafe condition.

[Aus78Formula]

Or just old, common even with cars with nothing done to them, and over the years guys have nipped them up thinking the gap should be closed up at the U-bolt/T-bolts.

[Formulabruce]

Originally Posted by Aus78Formula

Or just old, common even with cars with nothing done to them, and over the years guys have nipped them up thinking the gap should be closed up at the U-bolt/T-bolts.

There is ZERO GAP at the T bolts , U bolts and shock plate . When these cars were new there was Zero Gap. I could see rust maybe , or rubbers expanding, but I have parted out untouched cars and the plates still were flat and touching each other. Also, I set up the later 70's and 80-81 Birds at the dealership, did warranty and service on older ones. ..
Really shouldn't be a gap to "Nip up" , but I sure do understand the urge to do it, I see resto shops get it wrong a lot.

[Aus78Formula]

That's right, I mean the common issue is to crank it up to close, whatever the reason may be. Obviously when you can't compress anymore something else starts to pull in.

[dld]

Well the guy I got the car from said he did a little drag racing and the car appearing stock . I think was played with . No big deal now because I have car in a thousand peices.

Car did have all stock springs and rubber parts although worn and one leaf broken in the spring. Air shocks were added also.

I plan on a rest mod build and will be putting in the drop springs and maybe after market sway bar.

Reason for post was to here if was common and if I needed to address this in the build with a upgrade.

You guys have been very in lighting Thanks Don

[76TA462]

I am in the process of a front and rear suspension upgrade on my 76 TA. When I saw this thread I contacted some of the suppliers because I installed new OEM leaf spring plates a couple years ago, and using spec torque they curved/bent a bit. Everything worked out fine though, but all comes apart again for the new upgrade. I received responses this morning from two major suspension suppliers/manufacturers about my concern of re-using my OEM plates. I stated my use is street only, with a very strong 462. Responses were that this is common/normal for OEM plates and that if the bend is not excessive, I need not be concerned. One of the manufacturers stated that bending of the stock plate is the main reason people buy HD plates. I'm sitting on the fence at the moment.

[76TA462]

Update already!! The third suspension manufacturer I contacted stated it would be best to replace the leaf spring plate. I am going to play it safe :>)

[dld]

Originally Posted by Formulabruce

How these get 'bent"
1. The wrong springs. Putting the common 5 leaf replacement springs in a 4 leaf Pontiac spring perch, then crank away with the impact.
2. The repop spring rubbers top and bottom are too wide and too thick, and should be ground to fit so shock plate is tight against the axle perch, then crank away with the impact.
3. The "U" in the shock plate can make the "center bolt" in the spring, not even locate in the hole in the bent plate itself causing a unsafe condition.

Nice detail on your car. are there lock nuts on the u bolts

[NOT A TA]

Aftermarket PTFB plates below. They actually weigh less than stock plates but with the right angle don't bend when tightening the way the stock plates do. They also make them with tie down loops on them for strapping cars in a trailer. I have a set of each but can't find the pics of the ones with tow loop. Stock plates for resto type cars I just use a press to flatten them back out.

[Formulabruce]

Originally Posted by dld

Nice detail on your car. are there lock nuts on the u bolts

I think this pic is from BentWheel Bob's 1972 Formula455. Stock Ubolts and T bolts didnt have a locker as far as I recall.
I like to use small locking nuts on the Drop links to the rear anti sway bar though.

[Formulabruce]

Originally Posted by NOT A TA

I noticed you have a 5 leaf spring set in a 4 leaf perch. Getting stronger plates would be a good idea as you have done because your plate cannot touch the Axle perch as designed. Since there is a gap along side the ubolts in this set up I would agree on stronger plates to try to keep spring and centerbolt located and staying put. In this case your "ubolts" are your "Extended Spring Perch" from the axle. 5 leaf springs and oversize rubbers are the most common reasons for bent plates. If the shock plates are actually touching the Perch "Flat", they cannot bend when tightening. Looks like you have yours secure though !

[NOT A TA]

The pic above was during mock up, nothing is tight in the pic and I haven't decided on the final configuration as far as spring rubber, pinion angle shims, etc. The U-bolts are upgraded to 1/2" as well as also replacing the T-bolts with U-bolts. My build is different than almost everyone else who is doing restomod or pro touring type builds because it's a lot more road track "race car" oriented than most will build. As an example although you can see the anti-sway bar mounts I welded to the frame rails (started with an Esprit) where the T/A's had them I made mounts to attach the lower links to the axle tubes directly rather than the spring plates to help with aerodynamic things I've been working on. Moving the brackets up to the axle tubes leaves more space for the diffuser tunnels. The car will have a removable full splitter/under tray/rear diffuser from the front past the rear bumper for track use.

[dld]

used a press to bend back to straight. Took 8,000 lbs. to straighten cold.

may weld a brace on edge.

[dld]

Originally Posted by Formulabruce

I think this pic is from BentWheel Bob's 1972 Formula455. Stock Ubolts and T bolts didnt have a locker as far as I recall.
I like to use small locking nuts on the Drop links to the rear anti sway bar though.

not good focus. but here is pic of my car before tare down. note lock nuts in T-bolts

[73ta]

I replaced the T bolts with larger U bolts and welded gussets on my stock plates. No more bending.