Best Penetrant to Remove Differential U-Bolts?

My u bolts are 5/8s grade 8 steel on my dart.

A semi truck shop made the for me custom for about 30 bucks each. I could tighten them untill my custom 9" collapses.

When the hot sticky slicks grab the road behind my 4.88 spool gear set i dont want to worry about my pinion pointing up, Shearing the pinion and sending my drive shaft into the car.

I can post some pics of a wrecked race car in our shop where this happened so... its not something i ever want to see again.


I wound never re use U bolts except maybe on a garden trailer...

Cope said:

My u bolts are 5/8s grade 8 steel on my dart.

A semi truck shop made the for me custom for about 30 bucks each. I could tighten them untill my custom 9" collapses.

When the hot sticky slicks grab the road behind my 4.88 spool gear set i dont want to worry about my pinion pointing up, Shearing the pinion and sending my drive shaft into the car.

I can post some pics of a wrecked race car in our shop where this happened so... its not something i ever want to see again.


I wound never re use U bolts except maybe on a garden trailer...

Click to expand...

Good advice. BUt I sure wouldn't over torque the u bolts. That will not allow the leaf springs to work properly.

Mine are torqued to what ever the manufacturer said when i bought them.

Im jist saying if i wanted to put the impact on the nut i think it would crush the 1/4" thick tube before the U bolt broke.

Cope said:

Mine are torqued to what ever the manufacturer said when i bought them.

Im jist saying if i wanted to put the impact on the nut i think it would crush the 1/4" thick tube before the U bolt broke.

Click to expand...

I get what you're saying.....but the manufacturer of those U bolts doesn't know that 45 LB FT is the designated torque spec for Mopar leaf springs. Over torquing them will result in the springs not working properly. They will bind and not allow the suspension to work.

I understand what you are saying but MY car is not a factory 318 car with 8" wheels.

It works for me and i dont have to worry about trying to use 1/4" U bolts to hold my axle.

I personally have had a drive shaft inside the car twice. The first time my buddy was lucky not to loose hos feet and the second time it let go when the axle twisted, pinion gear sheared off and it came in through the back seat. So its something i take seriously.

My drive shaf hoops are inch and a quarter by one twenty wall. I will never have the drive shaft inside my car ever again.

Over kill, yes.
Not worry about a 5 foot long chunk of metal inside the car spinning at a ridiculous speed.

Priceless.

Over-torquing the u-bolt will just stiffen the spring, won't it? Not ideal in a stock setting, but who drives a stock car anymore? Kinda like OE alignment specs for bias ply tires. LOL

UPDATE:

Not scientific, but I experimented with the only two products I could find and purchase at Autozone, which was Liquid Wrench and PB Blaster. I used LW on the two ubolts on the passenger side and PB on the driver's side. After several applications I knew it was going to be a battle, so I waited overnight.

Using a not too long 1/2 drive Craftsman breaker bar, I was able to break the four passenger side nuts (LW) loose without too much difficulty. Once loose, I used the box end of a 3/4" combination wrench to spin them off. Of course, because of the self-locking construction, one cannot spin the loose nuts off by hand. I was pleased but still sure there was always a black sheep to be found during any such undertaking.

On the driver's side (PB), I was able to loosen two nuts with the same breaker bar, but obviously with more torque than was required on the other side. The other two nuts (on the inside ubolt) would not budge and I was afraid of splitting the 3/4" deep socket that I had borrowed. I gingerly put a pipe on the breaker bar a couple of times, but did not use full force because I felt too much resistance. I gave up on the oily, foamy PB and switched over to LW applications. (seemed watery and looked to evaporate compared to the PB). I went to lunch.

Back from lunch, still no luck so the shop owner went home to find something we could use to heat up the two stubborn nuts. While waiting for him, and after more applications of LW (and maximum effort that I dared try) I felt the breaker bar move slightly while at the same time I heard a loud squeak/squeal. I got less than a full turn on that nut, squealing with each movement, when I found I was able to slide the ubolt (and accompanying lower shock mount plate) over toward the carrier enough where I could remove the differential without even having to loosen the fourth and final frozen nut. Relief at last and already past 4:00 PM.

You can try freeze off. It has worked for me several times. Next step the Smoke wrench and just replace. Over stressing any fastener related to suspension is deemed not worthy of any use afterwards IMO...

JW

I forgot about the heat and wax (paraffin) trick (no, not S & M kind).

How to Remove Stuck Nuts and Bolts - DSPORT Magazine

If you are removing rear to paint underside of car. Why not remove everything at once. Disconnect emergency brake cables, the brake line, front and rear spring hanger bolts and bottom shock bolts last and remove it all at once. Then no reason to mess with u bolts..just my .002...

We needed the leaf springs attached to raise and lower the vehicle while fabricating the "turn the vehicle 90 degrees on its side" type "rotisserie." With blocks of wood already under the frame in front of the leaf spring bolts (front), there is no room for a floor jack anywhere else. Foto is the sample the carpenter is using to follow this weekend to fabricate something similar for me.

that propane bottle torch isn't worth the time to light the flame let alone sit there long enough to see if it will generate enough heat, youll be there a LONG time if it even works at all, oxy acetylene is where its at.. or get one of those induction heating tools like a Mini Ductor....