FJ40 Steering Wander with Lift

[Jared74FJ40]

Hey,

I am new to the forum and a new FJ40 owner after driving a couple FJ60s over the years. I just picked up a 74 that isn't pretty but should be a good platform for a daily driver to spruce up over time.

The truck is lifted on what the previous owner says are 4 inch lift springs, and has 6 inch pin - pin shackles. The steering is a bit vague and the truck is downright scary on broken secondary roads. My understanding is that this is likely a castor issue. I would like to purchase the correct shims but wanted to get some input from those with more experience than me. Here are some photos of the truck, let me know if you have any ideas for what might be a good starting point to try and get the truck a bit more manageable day to day, or if there are any other clear issues that should be addressed with suspension geometry. As a side note the tie rod ends have been replaced, the suspension has a bit of toe in and everything seems pretty tight. And now for some pictures:

Thanks for any insight you can provide,

Jared

 

[John Smith]

You're correct, your problem is caster. Put an angle finder on the top of the knuckle to find out where you are now or take it to a suspension shop and they will give you a reading. Based on that you will know what degree shims you need.

 

[JasonH]

You're on the right track. You'll need to address your caster. You could guess and throw some 4 degree shims in there and get pretty close. Or you could measure the caster and shoot for at least +1 degree. Not much more than that as it appears you're still running stock steering.
Some shorter shackles in the front wouldn't be a bad idea either.

 

[Jared74FJ40]

Thanks for the input! If I was to shorten my front shackles by about 2 inches would that improve the caster? The truck sits a bit high on the front end so I had toyed with the idea of drilling new holes in the shackles and trimming the excess. I feel as though trying to get the shims right while also changing the shackle length would be kind of like shooting at a moving target though. I have a 2* shim the PO gave me that I could add right now as well.

Thanks for the quick responses!

 

[edwjmcgrath]

Unless you go to stock shackle length, you're going to have negative caster.

You have a couple of options depending on what you plan on for tires. You've got a huge lift for those tires.
4" lift is plenty for 33x10.5" tires. So if you plan to stay at 33 or less, you could just replace the shackles with stock ones and you will might be done with the caster problem. If you want to maintain the shackle lift, you will need caster shims.

What you want is just a little bit of positive caster. If you have too much, it will be really hard to steer (if you have manual steering). Your best bet is to get it measured by an alignment shop and then get just a little bit more. If you want to skip that step, you can get 4* and install those. That will probably do the job.

 

[Snowdogyyz]

Make sure you get steel caster shims, not the aluminum ones. Contact orangefj45 if you want some good steel ones. I got mine from him. I went with 4 degrees and I have about a 4" lift (SUA). Drastically improved steering, although you'll need to check your tie rod ends, center arm, etc, etc.

 

[Jared74FJ40]

Thank you for the suggestions. I decided to get a set of 4.5 inch pin to pin anti-inversion shackles from MAF and will be starting with a 2* shim as thats what I have sitting on the bench. I think that should be a significant improvement. I would eventually like to run larger (35") tires but have no problem trimming the quarters and dont like how jacked up the truck looks now with the 6 inch shackles (not to mention the sketchy handling on the rough roads we have up here in maine).

I also purchased MAFs complete clutch kit as my clutch is slipping currently.

Thanks again for the input, allowed me to make some decisions about how to move forward with a bit more confidence.

 

[Roboosfj40s]

I had to go with 4 degree caster shims and replace my 33 x 14.5 x 15 Super Swampers and now it drives and steers with one finger. I do have Saginaw and a 4" lift. But now running 33 x 12.5 x 15s. The difference in tires and shims completely eliminated bump steer problems.

 

[camcruiser13]

look in the for sale section i got some for sale. new in box dont need them anymore, all yours

 

[camcruiser13]

heres a link to make it easy on you

https://forum.ih8mud.com/sale-parts/568069-4-degree-spring-wedges-shims.html

 

[Jared74FJ40]

Thanks for the help guys! Got some 4.5" anti-inversion shackles from Man-A-Fre along with some 4 degree shims installed on the truck and what a difference! I still get a bit of a death wobble on occasion but the vibrations are no longer transmitted through the steering wheel and it is more of a vibration and comfort issue than a control issue. Here is a photo of the truck with the shorter shackles.

I also installed a bikini top from JTOutfitters, waterproof seat covers for the disco 1 front seats from rovers north, and a stereo from west marine. It is becoming quite the daily driver!

I am in the market for tires, front disc brakes, and power steering now.

I am leaning towards 255/85/16 tires but am tempted to go larger. I have been looking at trail worthy fab's deal on hummer take offs and the price of those tires is attractive, but I am uncertain if 37's would kill the driveability of my truck. I have no problem cutting sheet metal to fit larger tires as the quarter panels are diamont plate and I would like to go with TJ flares eventually anyway.

How is the JT Outfitters disc brake kit? Is there a cheaper way to go that would still be effective? I have looked for a parts mini-truck and fj60-62 locally but had no luck.

Any other ideas or input would be appreciated.

 

[willyfj40]

Greetings , from another rookie in maine. I picked up my first fj 40 last September, it has the same diamond plate tub as yours.....must be a popular item in these parts.
My rig came with the JT outfitters disc brake kit installed, so I can't compare to the drum brakes, but I am pleased with the braking / stopping distance.

1975 FJ 40

 

[Fast Eddy]

If you haven't already done it, replace the front leaf spring bushings, adjust and grease the drag link end, grease and tighten the center arm and make sure you don't have any plan in your rag joint if you have one. Also, make sure you don't have play in your knuckles.

If you do all these things at once you will surely notice another substantial difference.

 

[DSRTRDR]

I have the MAF disk brake kit and it stops great

however, drum brake axles/shafts would be overtaxed by 37s

X2 on the bushings

 

[Jared74FJ40]

If you haven't already done it, replace the front leaf spring bushings, adjust and grease the drag link end, grease and tighten the center arm and make sure you don't have any plan in your rag joint if you have one. Also, make sure you don't have play in your knuckles.

If you do all these things at once you will surely notice another substantial difference.

I replaced the bushings when I did the shackles. I will look into greasing and checking the center arm and drag link end.

I am thinking of getting the JTO brackets and discs but sourcing the calipers separately. I think I can do the front brakes for about $350 with this combination of parts, plus I already have some new braided brake lines on the bench.

Has anyone run the military takeoff wheels and tires from trail worthy fab on an FJ40? Are the stock axles strong enough for this setup? I don't do any hardcore wheeling but the extra clearance would be nice when on logging roads up north for fishing and camping. From what I have read these tires wear nicely on road as well which is a plus. A set of 4 wheels and tires for about the same amount of money as 4 tires in another size, along with replacement sets for ~ $250 is pretty attractive.

 

[mumphra]

I would get caster shims bushings wouldn't hurt either. put the wheel in front instead of behind, does it get the shakes violently bad. My buddy had the same issue I know this is horrible but he called his truck the michael j fox, it got the shakes after 45, his was horrible like scary scary horrible put shims in it and 100% fixed.
just my 2 cents

 

[TCinVA]

I would look into getting the plates from Poser on this forum, rave reviews unlike the JTO kit.