Rear end not centered!

[5t341tH]

Hello all. I have a question about my rear end not being centered to the frame. It’s about 7mm offset to the passenger (right) side. I measured the backplate to the frame and it’s off the same amount.  I’ve disconnected the axle from the leaf springs and tried Pushing it to get it centered but once I tighten everything down again, it goes back to where it was. Any way to get this centered? I do have lowering blocks but I don’t think it could affect anything right?  Thanks for reading

[banzai510(hainz)]

Lowering blocks have the hole on center center block?

i have the Belltech blocks and they have a counter sunk hole to locate the block on.

 

maybe the U bolt is bent .

[5t341tH]

30 minutes ago, banzai510(hainz) said:

Lowering blocks have the hole on center center block?

i have the Belltech blocks and they have a counter sunk hole to locate the block on.

 

maybe the U bolt is bent .

Yes the have the hole and the pin too. The U bolt would make the axle not centered?

[Jersey]

Take the blocks out of the equation to eliminate that as the cause. If you still come up with the 7mm offset...it’s not the blocks. The dowel (pins) will locate everything. Have someone drive it and follow behind to see if it tracks square. I can tell you my brother’s ‘79 standard cab is offset too, he has 3” blocks. He tracks square going down the road.  

[datzenmike]

 Then switch the blocks.

 

 

[Jersey]

46 minutes ago, 5t341tH said:

The U bolt would make the axle not centered?

It shouldn’t...Check the measurements from the backplates to the perches. 

[5t341tH]

How tight fitting should the pins be into the holes? The block can move around when placed onto the springs. I’ll take off the blocks and measure it again

[Jersey]

I’m sure there will be a variance in fitment, depending on the blocks. I’ve seen blocks with both: Tapered and non-tapered dowel pins. I was under mine today, I checked and even mine is shifted toward the passenger side a tad...Not to the degree that you’ve mentioned, but nevertheless...Was it lowered all ready or did you lower it? I believe, if there aren’t any drivability issues...I’d say, probably no affect. As for the blocks moving around on the leaf spring, I’ve seen blocks shift a little. When you put the blocks in, make sure both dowels are engaged. The leaf spring seat is pretty much centered on the bottom leaf, by way of the dowel bolt and the u bolts. 

 

 

Edited April 15, 2020 by Jersey

[5t341tH]

23 hours ago, Jersey said:

I’m sure there will be a variance in fitment, depending on the blocks. I’ve seen blocks with both: Tapered and non-tapered dowel pins. I was under mine today, I checked and even mine is shifted toward the passenger side a tad...Not to the degree that you’ve mentioned, but nevertheless...Was it lowered all ready or did you lower it? I believe, if there aren’t any drivability issues...I’d say, probably no affect. As for the blocks moving around on the leaf spring, I’ve seen blocks shift a little. When you put the blocks in, make sure both dowels are engaged. The leaf spring seat is pretty much centered on the bottom leaf, by way of the dowel bolt and the u bolts. 

 

 

Thanks. I will do some more measuring once I take off the blocks. I lowered it myself. I had this truck for many years. I started with 3” straight blocks and now I’m on 4” angled blocks

Edited April 16, 2020 by 5t341tH

[Stoffregen Motorsports]

I've seen some real garbage out there in the leaf spring lift/lowering block department. I've seen them made out of potmetal, seen them with broken off dowels, and even seen them with the two suraces unparallel with each other. If the machining is not done perfectly, ie - unparallel surfaces, I could totally see them shifting the axle to one side.

 

Also, you need to tighten the u-bolts evenly. If they are tightened un-evenly, that too could shift the axle to one side, just ever so slightly but the added distance caused by the lowering block will amplify that amount.

 

It's also possible that the truck was hit at some point and the leafs or frame could be bent. Rear truck frame sections are petty flimsy.

[Jersey]

2 hours ago, Stoffregen Motorsports said:

I've seen some real garbage out there in the leaf spring lift/lowering block department. I've seen them made out of potmetal, seen them with broken off dowels, and even seen them with the two suraces unparallel with each other. If the machining is not done perfectly, ie - unparallel surfaces, I could totally see them shifting the axle to one side.

 

Also, you need to tighten the u-bolts evenly. If they are tightened un-evenly, that too could shift the axle to one side, just ever so slightly but the added distance caused by the lowering block will amplify that amount.

 

It's also possible that the truck was hit at some point and the leafs or frame could be bent. Rear truck frame sections are petty flimsy.

When my brother bought his first 620, in ‘86, we went to look at it and the kid had used a 2X4 for the blocks. That was the first thing I fixed on that truck. That truck was the bane of my existence, I worked on that truck more than my own. I finally had to tell my brother, to either learn how to work on it, or get rid of it...Fortunately: He learned. As to whether this truck has been hit, causing this issue...I had that thought, too. 

[5t341tH]

Honestly I am trying to center it for looks. I have some wheels on there now that aren't sticking out past the fender evenly so I am trying to correct it. The truck drives fine. I will tackle this more when I have time. But since I've been sent back to work, I am out of it...for now

[wayno]

Try loosening the box mounts and pushing it over, if that does it you may have to adjust the cab to match the box also.