Dang U-bolts!

[Vinny]

Be sure you get the type with the knurled flattened portion in the middle of the U

Without that you will crush the housing tube. Also the torque is 45 lbs not 100, not that feels about right.

Look in the FSM to verify the number but I'm 98% sure.

EXACTLY! Leave the impact gun stored away.

 

[MILO]

I use a hot wrench on u-bolt nuts

 

[mopower440]

PLEASE tell us where you got the flat top ones. Did they have the cross hatch on the flats? Thanks.

I just bought a set from mancini last week and yes they do have the cross hatch on the flats. Look identical to the originals.

 

[matthon]

PLEASE tell us where you got the flat top ones. Did they have the cross hatch on the flats?

They pop up on ebay from time to time.
Yes.

 

[harrisonm]

Because they don't know. How many guys do you see on here asking why something effed up and they don't even have a service manual? They don't know, so they assume and end up in trouble.

And service manuals are free. I had never touched a 4 speed before, but with a Factory Service manual and a How To article from a Mopar Muscle Magazine, I rebuilt the used 4 speed I bought when converting from an automatic. I have used my manual a lot.

 

[Oldiron440]

I would not reuse the ubolts again even if you can cut or split the nuts. The threads are rusted and when you run die over them a good amount of the threads will be made of rust.

 

[RustyRatRod]

I find it hilarious also all this arguing about flat VS round U bolts. Here's a shocker. Mopar Performance offered U bolts. Factory Chrysler high performance parts. In their racing parts catalogs. For decades. They still offer them. Mancini sells them. Guess what? They're ROUND!

 

[matthon]

I'm in the process of changing all the bolts in my car to flat.

 

[Woody500]

Tighten the nuts back up, and chase the threads with a die- that'll get fifty years of rust, gunk and undercoating off of them.
Then lube the nuts up real good and run 'em off.

A lot of times you can burn the rust off with an acytelene torch and they'll come off easier.

Then use a penetrating oil, I use Sea Foam now, liquid works better than spray, for some reason. I take a can like you'd pour in gas tank, drill a small hole in lid & put a red plastic spray tube in lid(tight fit) & then have a drip can.

Don't bother with PB Blaster or similar oils, they are NFG! Old School K&W Knock 'er Loose was the best & company was sold & they made it a PB Blaster clone that is crap!

Heat nuts thru many cycles, oiling when cooled enough you get no smoke. Then start back & forth small amounts & keep oiling heating oiling. Takes a while but is doable.

 

[cudamark]

I would not reuse the ubolts again even if you can cut or split the nuts. The threads are rusted and when you run die over them a good amount of the threads will be made of rust.

Maybe in the rust belt. Not an issue around here. Either they hold torque or they won't. Never seen one fail and cause a problem.

 

[CudaJason]

rather than spending big bucks on a set of u bolts from a restoration place, i have been getting them from U Bolts Direct. They are made in the USA with US steel for their U bolts. you can get them in what ever size and length you need and all the nuts and thick hardened washers with them. I used a set swapping the rear in my 66 Barracuda this year and it was about 55 dollars for the set shipped to my door. worked perfect.

U-Bolts, Center Bolts, Hardware and More | Uboltsdirect.com

 

[YY1]

Nut splitter saves a lot of time and should not damage the threads.

Torch could take hardening out.

If the factory nuts were "lock-nuts" how long did it take to get them all the way up those U bolts?

I believe the flats and knurling are to help prevent slipping. Full round ones tend to slip back and forth until tight.

I've never had a U bolt nut back off and have never used lock nuts.

If you're concerned, use a jam nut.

 

[cosgig]

Since they have such a low torque requirement, I can’t see the tube being crushed. I would assume the danger is only when they are over torqued, or installed with an impact wrench. Also the reason why the original nuts were swedged to keep them tight. Over tightening also stretches the soft cold rolled steel, which is also the function of tightening the nuts.

 

[str12-340]

Think for just a moment as to what happens if a 50-60 year old U-bolt, that has taken 1/4 of all the load of every jounce at the rear wheels for that long, snaps, putting all the load in the other one which may then fail. Look under your car and figure out the fall out...Just sayin'.

 

[RustyRatRod]

Think for just a moment as to what happens if a 50-60 year old U-bolt, that has taken 1/4 of all the load of every jounce at the rear wheels for that long, snaps, putting all the load in the other one which may then fail. Look under your car and figure out the fall out...Just sayin'.

Like this.