Rear blocks removed - alignment way off

[Dakar09]

Hey all,

I slipped out the rear block on my truck, dropped her down nicely in the rear. No changes to the front at all. I reused the original 4x4 u-bolts at the time (the weather popped into the upper 60s and I lost my mind, had to get under the truck). I torqued things down properly as best I could considering I couldn't get the deepest socket I had onto the nut, but the plan is to put 2wd u-bolts on. It took forever to get these delivered, but I have them now.

The locating pins aligned properly and snugged it all down. But now my alignment is off pretty bad. I had my wife drive behind me, she said it isn't crabbing (like a misaligned rear axle would). I can't imagine dropping the rear an inch would nerf the alignment that bad, if at all.

I'm going to put new wheels and tires on soon, and was going to have it aligned anyway. But I'll be swapping the u-bolts out before then.

Anything I should do to make sure everything is aligned with the leaf springs before I tighten everything down? I assumed if the dual pins were locating properly on the rear axle on both sides, it should be fine.

Or could Ford have set the alignment so poorly from the factory that this exaggerated it? I've had really bad tire wear on the stock HanPoops, but the truck always tracked straight. I just assumed it was my driving style mixed with uber soft tires.

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[Jmitchelltfo]

Get some quantifiable numbers. Pull a measuring tape out and measure from a set point on the frame to the axle right by the U bolts. Now pick the identical spots on the other side and you will see how far out you are, and you can slide it when you install your new U bolts. I "slid" mine 1/16" when I removed my rear blocks. I'm not sure how much slop there is, but I was able to adjust mine on the first attempt.

The easiest way is a trip to your local alignment shop and they can tell you........preferably after your new U bolts are installed.

 

[Dakar09]

I'll get the tape out when I put the new u-bolts in. Didn't want to get it aligned, put those in, and and then have to go back. I was hoping that since once side was still clamped down and the locating pins lined up, the rear axle would just go back in the right position. I've had to make these types of adjustments on classic cars I updated, but usually there's an adjustable panhard bar that makes that so much easier.

 

[FaaWrenchBndr]

Caster is the only thing that should be affected by the removal of those blocks. There’s just no way around that nothing else should be affected and rear alignment is not adjustable.

 

[Dakar09]

I imagine Ford just aligned the truck with the way the factory blocks were installed and it's off now due to my "non precision" work back there. I'll do some measurements with the new u-bolt install anyway but just have it re-aligned with the new rear height/axle position.

I did measure the wheel position in each wheel well, it was the same on both sides. So if anything is off, it's side to side.

Thanks, guys

 

[adyaro77]

I just went through this, but when I removed the OEM blocks and installed 2 in. blocks. In my situation we made sure to measure the axle per the shop manual to make sure that the rear axle was installed properly. My buddy uses a laser. After the alignment the shop told us that it was probably off to begin with. By us correcting the axle it kicked the front alignment off. They said they see it all the time.

 

[Dakar09]

I just went through this, but when I removed the OEM blocks and installed 2 in. blocks. In my situation we made sure to measure the axle per the shop manual to make sure that the rear axle was installed properly. My buddy uses a laser. After the alignment the shop told us that it was probably off to begin with. By us correcting the axle it kicked the front alignment off. They said they see it all the time.

Slightly wonky setup from the factory is on my mind, too. I was going to crack out the shop manual when I did the new u bolts and will look for their measurement method.

 

[Dakar09]

Interim update:

I managed to get the 2wd u-bolts on the driver's side (because stupid me only ordered one 4 pack of new nuts from Ford when I needed another one).

I tried to be lazy again, and I think this is where my issues came from. I jacked up that side and removed the wheel figuring it would all go back together easily. Nope. The alignment pins on the leaf spring were off from the axle slots. So I had to jack up the other side to get the wheel off the ground, which allowed me to move the axle slightly and get things to line up. Snugged it up then put her on the ground for final torque sequence (four different values under weight bearing).

Alignment is almost back to normal.

Few tips for those doing this:

Here are the differences between the 4wd and 2wd U-bolts. The latter allow you to get a proper socket and torque wrench on the nuts:

This bracket needs to come off to swap out the u-bolts (headlight leveler?):

There is some adjustability in the forward alighment slot, as it's much larger than the aft alignment pin:

I'll get to the other side when the nuts come in and will follow the same process of both wheels off the ground.

I'm also appalled at how bad the axle looks after less than one year on the road up here in New England...

 

[Jmitchelltfo]

Interim update:

I managed to get the 2wd u-bolts on the driver's side (because stupid me only ordered one 4 pack of new nuts from Ford when I needed another one).

I tried to be lazy again, and I think this is where my issues came from. I jacked up that side and removed the wheel figuring it would all go back together easily. Nope. The alignment pins on the leaf spring were off from the axle slots. So I had to jack up the other side to get the wheel off the ground, which allowed me to move the axle slightly and get things to line up. Snugged it up then put her on the ground for final torque sequence (four different values under weight bearing).

Alignment is almost back to normal.

Few tips for those doing this:

Here are the differences between the 4wd and 2wd U-bolts. The latter allow you to get a proper socket and torque wrench on the nuts:

This bracket needs to come off to swap out the u-bolts (headlight leveler?):

There is some adjustability in the forward alighment slot, as it's much larger than the aft alignment pin:

I'll get to the other side when the nuts come in and will follow the same process of both wheels off the ground.

I'm also appalled at how bad the axle looks after less than one year on the road up here in New England...

I have no clue if there is any more than 1/16” of adjustment. But that is how far I slid the passenger side of my axle after removing the rear blocks.

I got my rear axle to measure dead nuts straight on the first attempt by loosening every bolt and tapping a 4x4 block of wood with a 3 pound sledge. I might have been able to do it by hand, but I didn’t loosen the drivers side bolts very much.

 

[adyaro77]

I can tell you without any doubt between the two sides you can get up to a half inch of movement.

 

[Dakar09]

The locating hole in tbe axle for the more forward pin on the leaf spring is significantly larger than the pin. I'd say you get at least 1/4" movement in any direction because of that, but the rearward pin is a more snug fit. I would think that would help limit the gross movement of the axle. But it definitely doesn't fit like a glove.

This all tells me that Ford just "gets it close" on initial assembly and then aligns the front wheels to compensate.

 

[Larrymoe]

Did you remove the tires the first time you did this?

 

[Dakar09]

I didn't. I did it the lazy "easy" way as I saw a few guys do it. Remove the u-bolt nuts, jack up the leaf springs, remove blocks and drop it right back where it was. One side at a time. Funny thing is, the leaf spring pins went right back into positions with no mucking about, which is why the wacky alignment surprised me. Nothing should have moved by much.

 

[Larrymoe]

I wonder if mine is off then?

 

[Dakar09]

You removed the blocks? I knew rigjt away when I drove it. Wheel needs to be turned slightly to the left to track straight.

But from what I've read on this forum over the last year, Ford doesn't bat a thousand at aligning these properly from the factory anyway.

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