OME Lift and Shaft/Shackle Alignment

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Sparkman86

Sparkman86

Joined
Jan 12, 2018
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Location
Arlington, TX
I've seen this discussed a few times but it's always one or the other and not both. I installed a 2.5" OME medium spring lift on my 1969 40 and am having some issues with the rear drove shaft not fitting. I've read this can be a problem solved by cutting the shaft down to fit. However, my rear shackle angle is also nearly vertical when, from what I understand, it should be pointed toward the rear of the vehicle for a smoother ride. Cutting the drive shaft will not solve that.

Before I start cutting and modifying, is there something I'm missing? I have the body on the truck but it is empty (no seats, fuel tank, top). Would adding weight to the truck flatten the springs permanently or would they just perk back up when the weight is removed? I do not own a top so it will likely never be fully weighed down.

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I wouldn't do anything with the suspension until the vehicle is done. Looking at the pics, you can't even install a shock on the lower mount. Typically when you add a lift the driveshaft slip joint needs to be extended. A 2 1/2" lift shouldn't require any modifications. Have the frt springs been installed yet?
 
pb4ugo said:
Have the frt springs been installed yet?
Click to expand...
Front springs are on with the full engine weight on them and the drive shaft bolted right up. The shackle angle is similar to the rear.

pb4ugo said:
Looking at the pics, you can't even install a shock on the lower mount.
Click to expand...

Good catch. So are the springs expected to flatten out when loaded to allow the shocks to mount? Is there a "break-in" period that will settle them? The roll bar and seats don't weigh that much so I can't imagine they will make much of a difference.

20240602_151210.jpg
 
zerotreedelta said:
Is the '69 different from the '76 in terms of the shock mounts? On the 76, it's a plate that goes below the spring and puts the shock mount stud to the side. Things definitely will settle in, but that center part of the spring won't change much, so that shock stud looks...odd.
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Yeah a bit different mounting plate and shock mount style. These are the factory plates and axles from 1969. Looking at the disassembly pics though, the shock bolt isn't much different than what it is now. On closer look, I think I could mount a shock here without any issue.

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IMG_8378.JPG
 
IDK, I know nothing about OME suspensions. Maybe someone more knowledgeable on them will chime in. Your lift looks like it's higher than my 4" Skyjacker suspension lift. To me, it appears the springs have too much arch or the springs aren't long enuff or both. My guess, It's probably because you don't have any weight on the suspension.

@zerotreedelta, Yes, the shock mount is different than later models. IDK when it changed but my Oct 71(72 model) 40 had the mounts on the back of the spring perch also. On my 75, I change the mounting location from the spring plate to the spring perch too. I never cared for the shock mount to be on the spring plate which exposes it to trail rash.
 
Kinda figured the 69 was a different setup, but figured worth the check. :D

It does seem like you're sitting "high", based on your rear shackle - this is mine after it settled in, but I have a hardtop, and I think I did the light/normal springs in the 2-2.5" OME. As spring flattened and that shackle pushed back, the driveshaft angle/distance was better. Not fully apple-to-apples, but might shed some light/comparison.

PXL_20240815_163531203.MP.jpg
 
Are you 100% sure the leafs are installed in the right direction? I have 2.5 lift from redline and the center pin is not centered in the leaf pack. The longer side goes towards the end of the vehicle. Tips on installing the 2.5 Ultimate Lift Kit on FJ40 Land Cruiser - https://redlinelandcruisers.com/installing-2-5-ultimate-lift-kit-on-fj40/ for reference on mine.

This may or may not apply to yours, but I point this out because from that pic your shackle looks inverted. I would expect this to be angled the other side of 90* down do when it is compressed it pushes the shackle towards the rear. In my case, the center pin on the leafs are not centered. If yours is the same maybe they needs to be rotated 180* so the longer portion points towards the rear of the truck pushing the shackle outward and probably lowering your vehicle a bit.

the first pic shows my shackle angle -- compression pushes the leaf end towards the rear.
1723749211091.png


versus yours where the angle looks off ...
1723749245790.png
 
dkcrew said:
Are you 100% sure the leafs are installed in the right direction? I have 2.5 lift from redline and the center pin is not centered in the leaf pack. The longer side goes towards the end of the vehicle.

because from that pic your shackle looks inverted. I would expect this to be angled the other side of 90* down do when it is compressed it pushes the shackle towards the rear.
Click to expand...
Long side of spring toward the rear of vehicle with the arrows pointing toward the spring perches.

The shackle angle is exactly why I'm not ready to modify the driveshaft yet. It's angled the wrong way. I would expect that to change if the spring flattens out so maybe that's the only issue. Not enough weight in the rear to properly shape the springs.

20240815_145731.jpg
 
zerotreedelta said:
Kinda figured the 69 was a different setup, but figured worth the check. :D

It does seem like you're sitting "high", based on your rear shackle - this is mine after it settled in, but I have a hardtop, and I think I did the light/normal springs in the 2-2.5" OME. As spring flattened and that shackle pushed back, the driveshaft angle/distance was better. Not fully apple-to-apples, but might shed some light/comparison.
Click to expand...
This is good info. I'll load it down with some weight while I'm working on other things and see if that flattens the curve of the springs and brings things into alignment.
 
zerotreedelta said:
On the OME, the + goes forward - looks correct in the early photos.

I had a similar shackle angle with mine until the body went on, then it settled in.... perhaps the mediums are a little stiff for running no top and no extra bumper/etc?
Click to expand...
I hope not. Would hate to need new springs just because of that. I got medium because I may have a light camper trailer on the back and wanted to be able to accommodate. I think I'll load up some "artificial" weight in the bed and let it settle in for awhile before I do anything else.
 
jim land said:
Take a leaf out and get some anti inversion shackles
Click to expand...
I have some anti inversion that I may swap in, but I really like these Downey Toyotas and want to make them work if possible.

I hadn't considered taking out a leaf. If the spring arch doesn't settle down after having some weight in it for a while, I'll go that route. I'm sure there are plenty of posts about the best way to do that.

Thanks all for the help.
 
You might try a shorter shackle. You may get a little more vertical angle and it might flatten the spring a bit. When I was setting up my 75 frt end I had longer shackles which put my caster angle to the negative. I made some shorter 1's and got the caster to the plus side. I also got a better shackle angle. I shortened the rear a little too, but slightly longer than the frt.

I noticed your fronts look shorter.
 
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