8 3/4 U-bolt question

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VintageRacer67

VintageRacer67

1967 Dart GT 318/Auto
Joined
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Hello FABO. I just purchased used shock plates and U-bolts for a 8 3/4 rear from a member here. I have a quick question. I received 2 which are flat at the top of the “U” and two that are not. I know on my 7 1/4 rear, all the U bolts looked the same (flat on top). Will these work for the 8 3/4? Or are two of U bolts incorrect?
Thanks FABO!

F43468AF-5C16-4360-B65A-7DAB38BC8911.jpeg
 
The OEM are flat on the top with x's on the under side for extra side hold I believe. The others are after market from a spring shop. They will all work just look different. put one of each on either side and no one will know . use the OEM on the inside so you don't notice the aftermarket style.
 
VintageRacer67 said:
. I received 2 which are flat at the top of the “U” and two that are not
Click to expand...
DO NOT use the non flattened ones.

The flats distribute the point load of the U bolt over a larger area.

You WILL crush the housing tube.

This is crush, NOT wear

16269856056996023466014490960590.jpg

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also, many folks get super excited about torqueing them down and they crank 'em. Tighten them in a crossing pattern, snugging them up as you go. Maybe 20 ft. lbs, then go to about 40-45 lbs. You only want about 45 ft lbs max.
 
Dana67Dart said:
DO NOT use the non flattened ones.

The flats distribute the point load of the U bolt over a larger area.

You WILL crush the housing tube.

This is crush NOT wear

View attachment 1715894213
Click to expand...

Yeah, that was my first thought when I saw them. Obviously, it would have been cheaper to produce them round, but Chrysler decided to make them flat for a reason. To spread the surface area out so it wouldn’t damage the housing tube. Thanks for confirming what I was worried about.

I guess I will junk these and try to find 2 more OEM ones. I should have just ordered new ones from the start. Lesson learned.
 
Dana67Dart said:
DO NOT use the non flattened ones.

The flats distribute the point load of the U bolt over a larger area.

You WILL crush the housing tube.

This is crush, NOT wear

View attachment 1715894213
View attachment 1715894214
Click to expand...
Wow must have been installed with a 3/4 impact. The calvert cal track kit comes with round u bolts. I never squashed a housing like that . Lift kits for trucks also round u bolts. Someone either over tightened them or they came out of the Dukes of Hazzard's General Lee bridge jump car

196.JPG


199.JPG
 
Oldmanmopar said:
Wow must have been installed with a 3/4 impact. The calvert cal track kit comes with round u bolts. I never squashed a housing like that . Lift kits for trucks also round u bolts. Someone either over tightened them or they came out of the Dukes of Hazzard's General Lee bridge jump car

View attachment 1715894226

View attachment 1715894227
Click to expand...

Okay. Maybe the round ones will be fine. Maybe not. If I can find 2 more OEM ones for a decent price, I’ll get them and use them just to be safe. The price I paid was worth the shock plates alone, so I’m good either way.
 
VintageRacer67 said:
Okay. Maybe the round ones will be fine. Maybe not. If I can find 2 more OEM ones for a decent price, I’ll get them and use them just to be safe. The price I paid was worth the shock plates alone, so I’m good either way.
Click to expand...
I've used both no issues.
 
Oldmanmopar said:
Someone either over tightened them or they came out of the Dukes of Hazzard's General Lee bridge jump car
Click to expand...
I bought the housing from photos, I did not know it was even possible.

But even in the FSM it cautions about over tightening. The tubes are rolled steel to form a tube, then further pressed / stamped / forged to form all the shapes needed.

Unlike a Dana 60 or the 7 1/4 with relatively thick wall tubing pressed / tach welded into a cast center.
 
The round ones will be fine. Almost every manufacturer uses the round ones. Even on camper trailers and every other trailer out there. I do agree the flat ones will distribute the clamping force over a wider area. Kim
 
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