5.5* Degree Negative Caster (1 Viewer)

[rrv333]

I'm a newbie to mud and the proud owner of a 89 FJ62. This my first post to mud. I recently installed one of Man-a-Fre's 4" OME lift kits with a shackle reversal. After finishing the lift, I hopped in the 62 and headed to my Dad's to weld it into place per recommendations. At about 22mph, I encountered the in-famous DEATHWOBBLE. After coming to complete stop and..."Cleaning out my shorts"... I turned around and limped her back home. Immediately got on mud and starting searching...That's where I learned about Caster. Took her to the alignment shop and she's showing to be 5.5* degrees negative. My question is: What degree of shim should I use, 4* or 6*?. I plan on running 33's and she'll be my daily driver with light wheeling.

 

[Mark W]

Take that S/R kit out and put the suspension back the way it should be.

You need 2-4 degrees positive caster. You won't get that with shims.

Most OME springs under '60s need shims right off the bat. Add in that SR kit and it is worse.


Mark...

 

[rrv333]

Thanks for the insight Mark. I'm still learning so I wasn't sure how to proceed. Is that my only option?

 

[Mark W]

In my personal opinion it is by far the best.

The MAF SR kit is pointless on a '60 providing no gains in exchange for the complications.


You "could* use longer shackles at the back end of the springs.

You *could* cut the spring perches off and weld new ones on after rotating the axle back to the correct alignment.

Make sure that you have it all installed according to whatever instructions they provided. As little as I think of this setup, I am surprised that your caster is that far out.


Mark...

 

[rrv333]

I was surprised as well. Could it be my installation was that far off, or is this a common occurrence? Based on your thoughts though, I don't think its all that common to be so far out of positive.

 

[Mark W]

Every set of OME heavies I have personally dealt with needed a 2-3 degree shim. I have not installed the MAF kit for anyone. A couple of my customers have it and one has driveshaft interference issues the other had more caster issues. But it has been a while since I saw that rig and I don't remember exactly what his caster was, what springs he had and how he eventually solved it.

I would be surprised if every OME/SR combo that MAF sells is as far out of spec as your seems to be. No way they would not get negative feedback if that was the case.

Did you use shackles provided with the kit?


Or some other (shorter) shackles?

Did you modify the setup from how they provided it?


Mark...

 

[dtt255]

Is this an issue with all OME lifts?

 

[rrv333]

Used the shackles provided with no mods, on my part.

 

[rrv333]

Could the shop have measured incorrectly? I'm sure that they could've but with their machine, I wonder. My camber was within factory specs and the tech said that he only adjusted my toe-in very little...If that information helps any

 

[daveIT]

Is this an issue with all OME lifts?

Nope.

 

[rover67]

Does the orientation of the spring affect caster on OME's? If so maybe that's causing some issues?

 

[lehiguy]

Now that you have gotten this far, and assuming that you don't want to remove what you have done, you probably should consider doing a longer shackle. I did this years ago (I agree with Mark, virtually nothing gained) and I had trouble inverting the stupid little shackles they sell you with the kit. Also, the front hanger dangles way down low, you could cut two inches out of that and add it back into the shackle. That would cetainly help. Box the front of your frame too, it will suffer additional stress with the SR. Personally, I think you should toss it and just go spring over, but that's just my opinion.

 

[62Cruiser]

I installed the same kit from MAF. First, do you have your shackles in the correct oreintation? I run 4* shims in the front and a 6* shims in the rear. This put me back to a positive caster. I like the ride but because of the shims i ran into a couple more issues. First, I had to have a CV driveshaft installed to compensate for the pinion angle vibration. Second, I needed extended head spring pins to compensate for the shims. I still haven't found the correct spring pins with the "taller" head to fit in the shims, so i used washers to compensate, until i can find the correct spring pins.

 

[Tapage]

back on those years I need to fit a 3° caster shims to get back it to specs in my front axle .. ( longer shackles will solve the rear )

 

[rrv333]

Thanks for all of the information. What do you mean by "Box the front of the frame"? The kit didn't come with any detailed instructions, so I asked a co-worker to come and help with the install. He's from the jeep world but he's completed over 40 lift installs on all kinds of vehicles, except Toyota's. So I believe that the shackles are in the correct orientation. When I ordered the shims I also went ahead and ordered a couple of longer spring pins, just in case.

 

[RAMZ]

didnt your kit from manafee come with the shims????????????
I bought the same kit years ago and it came with shims.
this kit works fine (for light wheeling) just make sure your front
shackels are at the proper angle with the full weight of the truck on them.

 

[rrv333]

Yes from Man-a-Fre, and no shims. I've already ordered 6* degree shims and they should be here on the 17th. I'll post photos when I've got everything back together

 

[62Cruiser]

I don't know if you ordered the shims and extended head spring pins from MAF, but if you did, they sent me the only spring pins they had (besides the ones in the kit) and they were the wrong ones. They were a whole lot smaller, for some other application. You would think they would have the correct pins for the kit, considering the large majority of people who istall this lift need shims. I hope you get the right stuff. On a side note, some people say you should install steel shims, as opposed to MAF's aluminum ones.

 

[rrv333]

I read that earlier alum shims. I was thinking about getting them powder coated prior to installation. Has anyone ever heard of this being done with the alum shims/

 

[lcwizard]

Call Man-a-fre. Shims come in the kit but they are there to remove caster. When you install the kit you have about 6 degrees of positive caster,. The 4 deg shim drops it to about 2 deg. The easy way to
check without an alignment machine is to put an angle finder on your pinion flange, The FJ40
flange is very close to 90 degrees where an FJ60 is pointed upward and should read about 84 degrees.
If you really have 5.5 degrees of negative caster the angle of your pinion would be at about 78 degrees.
This would only change if someone had previously did a cut and turn on the knuckles