Front Drop Bracket Necessity

[freeze]

A little information for the Solid Axle folk.

If you're upgrading your front leaf pack for more lift, run a drop bracket to keep your caster in check. If you just slap in some bigger arched leafs or put a longer shackle, you're caster will be way off causing your steering to wander all over the road and get serious bump steer.

Especially if you put in longer shackles, your diff will be pointing towards the ground and the front driveshaft will bind because the angle of the shaft will be to great.

Marlin makes a kit that you just weld on the front front cross member that drops the front leaf mounts lower and forwards to increase approach angle and preserve your caster.

Optimal shackle angle is 35-40 degrees, if your shackles are straight up and down, you'll get a really rough ride and not enough droop.

http://www.marlincrawler.com/sites/all/marlin/files/hangerkit513.jpg

[canadian bum]

I could see bump steer being an issue but if you just drop your axle straight down your caster will not be affected as the caster is affected by the angle of the knuckles and is an unadjustable thing on a solid front axle.

Your driveshaft will bind obviously but as soon as you start rotating your axle for better driveshaft angle at the pinion like cut of spring mounts and rotate till have a nice angle will mess up your alignment. This is due to the changing of the angle of the knuckle and the only solution to that is to cut and turn your axle.

And installing just lift shackles will cause problems with caster because depending on where your shackle is weather its in front of the axle like a Land Cruiser or behind the axle like a early SFA pickup it will change the angle of the knuckles. Now it won't be severe but you may notice it because it will be a couple degrees.

For those of you that don't know what cutting and turning is its a fairly simple process well you have to strip the axle housing to nothing. But the end of the housings where the knuckle mounts to (Spherical on the end of the axle tubes) slides into the axle tube and then is welded. So to be able to get a better pinion angle you have to return the knuckles to how they would normally be. Which means cut out the weld and spin the knuckle mount to the proper location that was the original factory angles to correct caster.

I would use this kit pictured for a SAS as I don't see how it would fix any issues mentioned. Pretty cheap if you have a welder and some time to take measurements. I think that is what it is supposed to be used for anyways.
http://www.marlincrawler.com/suspension/full-kits/front-spring-hanger-full-kit

The bump steer would only really be fixed if you got rid of the old push pull style steering on the early SFA trucks or the 40 series Land Cruisers maybe even the 50 series Land Cruisers had the push pull style. But anyways get a new IFS steering box and a high steer kit to get rid of the bump steer. The push pull stlye of steering is terrible and in my opinion dangerous.

I think its dangerous because I know how often a lot of people don't check over there trucks because well they don't know what to look for. Every SFA truck that I have worked on or previously owned I popped off the rod going from the steering arm down to the knuckle with a prybar. It's just the design of the rod itself and how it mounts. So when it gets worn out it can fall off very easily. To me thats not safe for anyone especially if you don't know what to look for when checking over components in the vehicle.

Here is the link to convert to cross over steering which will eliminate a lot of bump steer and is far superior. It's a High steer kits. http://www.marlincrawler.com/steering/high-steer

Now you could put on a steering stabalizer to help absorb some of the unexpected bump steer shocks. And maybe if you have a vehicle that never had bump steer but has a steering stabalizer the stabalizer maybe worn out. All a steering stabalizer is is a shock absorber basically some are right off the suspension. So it just slows down shocks. You shouldn't notice a diffrence in steering speed just less shocks coming through the steering wheel.

Anyways I think I have rambled on enough and all this information is most likely going to confuse more people than it helps haha.

[freeze]

This is mostly with the shackles on the rear of the front axle as it reduces caster instead of increasing it like the front shackle set up.

I ran both just a arched leaf in the front which caused decreased caster but the most problematic was the longer shackles. I modified the front track bar so it wasn't the bump steer from the drag link at the time. The drag link for the steering is ok as long as you keep the track bar. No track bar up front and that front axle will rotate pushing the steering rod back and forth with it. The drag link is not designed to handle suspension forces let alone axle forces. This is why there is a track bar for the front axle. The wandering and bumpsteer in my scenario was from the caster being negative.

http://image.fourwheeler.com/f/8990953/129_0404_steer_02_z.jpg

Running the drop hanger with the longer leaves and shackles got everything back to normal plus I didn't have to run an extended track bar up front with Marlin's hi-steer kit.

The high-steer is a huge improvement in terms of getting rid of the track bar for more articulation and strength because the J-Arm is super weak and prone to breaking with bigger tires.

[canadian bum]

What you said there makes sense. But if you ran lift springs with regular shackles your caster shouldn't have changed. It would only change if you ran longer shackles.

If you ran your own home built shackles this kit would be hard to get everything to line up. And typically when you lift a good size lift anyways you end up cutting and turning anyways to get a better pinion angle while retaining proper alignment.

[golana]

im not sure about these axles, but i know chevy guys on S10F would just cut off the spring perches and move them to keep the pinion angle correct, and the steering angles too.

i think these axles might be too square where the perches are welded on, but you may also be able to run an angled shim? ive seen guys do that too.

[freeze]

You could also cut and rotate your knuckles or rotate the perches. Shims in the rear isn't too bad... shims in the front is super dangerous.

[TyzToyz]

I've been running 4 degree shims in the front of my Runner for 4 years now without issue. I agree with the drop bracket, the angle of shackle and where the pinion is pointing, but I have not run into any issues.
My rig is an 85. I'm running 4" lift OEM rears up front, and SKY's 2" longer than stock boomerang shackles.

Tye

[RedApe]

I went to the drop bracket (2", Beerbilt), along with my 3" Conferr shackles that were re-drilled to 2". Victoria Driveline then built a custom drive shaft with long travel slip and a high angle DC.
Springs were 77 CJ5 rears, Ford F250 shock towers with 9012's... I was netting about 5.5" of lift in total.
This solved MOST of my angle problems.

I've seen the cut-n-turn done...and done poorly. If you know what you're doing with a welder, and heat dispersion/metal fatigue, you'd probably be ok. It scared me away from that approach.

[freeze]

I've seen the cut-n-turn done...and done poorly. If you know what you're doing with a welder, and heat dispersion/metal fatigue, you'd probably be ok. It scared me away from that approach.

Totally!

Regarding the shim under the front leaf....

Hopefully you're using a steel shim that's welded to the perch. The only reason I say this is, I did the same thing when I got longer shackles on the front... the caster and the pinion angle was really messed up....so I shimmed the front with 4 degrees. Problem solve, however, I ran that for a while before school whithout any known issues.

I then worked on the Toyota with some friends at school in Lethbridge, found out that aluminum shims... 1. slide around and bore out the centre hole... 2. because it was aluminum no matter how many times you re-torque the front u-bolts... torque spec would never hold.

Looking back at this running no track bar up-front with the drag link steering and aluminum shims... I could have killed myself or better yet... someone else. Because of the drag link and the lack of the track bar... the front end was loose anyways I couldn't feel the axle moving around under the shims! Then it went to modded track bar up front then lost the shackles and went with rears up front and no shims..... then went full Marlin cause I hated not having full flex from the track bar and the trade off was death steering from the drag link.

So... in short... steel shims welded to the perches are ok. Aluminum shims are deadly under the front end. I think it's the lateral forces that messes things up a bit. Still anything between a leaf pack and the perch isn't the best.