U Bolt size for BoB

[donkdonk]

I searched for this, and I looked again through most of the Bobbed threads, but I did not see this anywhere. I was wondering if there is a standard size for the u bolts needed when you use M105 springs? What size do I tell them when I have them made? Thanks

 

[100dollarman]

The springs are 2 1/2" wide. I used 5/8" stock, but some guys use 3/4". You need to figure out how long they will be considering if you are using any blocks, how thick your plates are, etc. A mock-up of the spring/axle combo is best so you can get an accurate measurement.

Here is a pic of how I did mine-

 

[donkdonk]

Did you lift the front of yours also?

 

[100dollarman]

Did you lift the front of yours also?

No lift in front- and no rubbing

 

[donkdonk]

You used the M105 springs correct? Is there a reason for not using the overload springs?

 

[100dollarman]

You used the M105 springs correct? Is there a reason for not using the overload springs?

I did use 105 springs- they are the same as front Deuce springs if you leave the overloads out. Heavy enough for any bob job.

 

[donkdonk]

So what is the reason for adding the lift blocks in the rear and not lifting the front?

 

[russ81]

It is illegal to drive a vehicle on the road that has lift blocks on the front.

 

[beaubeau]

I was wondering if anyone noticed any Axel Twist when using M105 springs, without the use of Torque rods. It may be OK if no amount of weight is carried, but with any weight there could be considerable twisting of axel and not so good on U-joints. Phil

 

[CCATLETT1984]

It is illegal to drive a vehicle on the road that has lift blocks on the front.

zero-rate springs (which bolt into the spring pack) are perfectly legal to use on the front of the vehicle. Since they cant spin out of the pack.

 

[100dollarman]

So what is the reason for adding the lift blocks in the rear and not lifting the front?

The reason I used the blocks was to level out the truck. The 105 spring hangers mount to the SIDE of the frame making it about 4" lower in the back. Front Deuce hangers put the spring directly UNDER the frame.

Another option is to weld a 4" spacer to the bottom of the frame and then mount the spring hangers to the side of that and using no block.

As far as spring wrap or twisting is concerned- I was concerned, but after trying it out in extreme offroad situations, I am convinced that it is fine to use the blocks. Not shown in my pic is the locators on the lower spring plate welded on after pic (3/4 x 3/4 L metal) that acts as a stop against the square axle on both sides so the springs, spacer, plates, u-bolts cant move. Also I ground grooves on that top plate to make a saddle for the u bolts to stay in.

Also- The trailer spring hangers have some pinion angle built into them- the front spring eye is higher than the rear.

Hope that helps!

Also- I may space the frame down on the next one instead of using blocks to see how that works.

 

[Offroadfabworks]

3/4" U-bolts