Extended Radius arms or double shocks?

[kstjohn]

Ever since I lifted my '91 Explorer (3") the front requires constant attention to maintain driving in a straight direction (even on the freeway). I have had the alignment done twice and that's not the problem. It has been recommended that I get longer radius arms. I don't get it. If everything thing has been changed proportionally, why doesn't it ride as it did when I purchased it? My question now is...would it be better to go with extended radius arms or double shocks in the front to correct this? Also, is there anyone else who has experienced this and if so, what have you done to correct this?

All comments are more than welcome.

Thanks in advance


Ken

 

[Rick]

Loose wheel bearings can cause the truck to wander. Have those been checked lately? Did the shop who aligned your Explorer check the front end components for wear before they aligned it?

Longer radius arms will give you more positive caster which helps high speed stability and may reduce the wander you are experiencing. I personally don't feel that dual shocks will do much to improve your situation on the road. They will help control the front end off road.

 

[MW4HD]

Wandering...

Hey Ken, Rick's absolutely right, the longer arms WILL help quite a bit with the caster in your alignment. The more positive the caster, the better your front end will self center after turns and hold the road in hard cornering. Also, both sides having the correct split will keep it from pulling on slightly banked roads. You don't want too much positive caster though, it'll eat up the tires. Everything you did was probably proportionate, but when adding spring rate you've also got to strengthen everything else up, AND, the alignment specs between a stock Explorer and a ifted one should NOT be the same. You want atleast 2 degrees more positive caster than factory...

 

[Gofast]

Ken, I was just getting ready to post about this topic.

My 94 Xlt is lifted 5.5", I've had 5 alignments since it's lift 2 months ago. I have a constant pull to the left. I take it in to get aligned and it fine, for a day maybe. Then back to the pull.

I discovered that my caster is out of whack from side to side. When they do the alignment both sides should match, say +4.0 ( Not the real spec, just an example )If one side is only +3.5 then you would have a pull to one side. What I found on mine was that the caster kept changing..

Caster is the tilt or position of the wheel. If you measure from your tire to the edge of the wheel well it shoul match side to side. ON my passenger side I could get 2 fingers between the tire and the wheel well. On the drivers side I could put 5 fingers between the tire and the wheel well.

How to fix....

We ( 4WD parts ) suspect that the orginal Radius Arm Bushings ( 169K miles ) are toast and that they compress and throw the caster out of whack. There putting in new poly-don't-sqiush bushings today. Hopefully this will fix the alignment problem.

Good Luck

 

[Rick]

Another tip... the TTB Explorers like to be aligned with the driver seated in the truck. This has made the difference between a slight pull and a perfect alignment.

 

[Gofast]

Great Point Rick, I didn't think about my 200+ affect on the alignment. I will sit in the truck for the next alignment.

Does anyone have recommended specs for an alighnment on a lifted truck? Or is it get as much Caster as possible so you can fit 35's in there?

 

[MW4HD]

Hey y'all, what you want is a split, meaning the passenger side should have anywhere from 1/2 to 3/4 deg MORE positive caster than the driver's side. Optimum caster would be 4deg positive pass side and 3.25deg driver's side. Camber should be set at .5deg positive and toe, depending on wheels, should be set at 1/8" in...

 

[Pendarus]

How receptive would my Ford dealer be to aligning the truck with me in it. Would my 280lbs make a large difference in the specs? I have a pull to the right that Ford calls a defective tire. I also have the 60mph shakes that Ford calls a unbalanced tire. I've had 3 alignmnets and had the tires rotated and ballanced twice. I think the two dealers I went to are full of s**t (McCoy Mills, Fullerton and Tutle Click, Irvine).

 

[MW4HD]

Hey Pendarus, they won't be very acceptive of that at all. They don't even want you watching, for good reason though. Liabilty insurance is EXTREMELY expensive, and OSHA makes surprise visits every once in a while to check compliance with safety regs. You may have an out of round tire also. Have them check runout in the tread's center on each tire, after all, there's really no ROUND tire. The pull from what they refer to as a defective tire may very well be a bad split in the caster or the tire IS causing what's called radial pull, 'worn in a certain pattern, more to one side than the other.'

 

[kstjohn]

I appreciate the input from everyone on this. I decided to go and get the readings on the front end. The following is how the front end is set up:

Camber for Driver's and Passenger's side is -.6 degrees

Caster for Driver's side is +4.4 degrees
Caster for Passenger's side is +4.7 degrees

Toe for Driver's side is 0.00
Toe for Passenger's side is -.06 degrees

Please advise on what it should be. Again, it is for a '91, 4 door Explorer, with 3" lift.

Thanks again

 

[MW4HD]

Hey Ken, those are pretty good readings. What kind of kit do you have? Components? Maybe see if they can kick up the caster on the passenger side to 5.0+...this may take away the wandering for you...

 

[kstjohn]

The 3" lift kit is made by Rough Country. I purchased this kit in pieces as I was new to the "lift world". I first extended the radius arms with the 3" brackets (little did I know at the time, the problem then was just the passenger side factory radius arm bushing worn). Since this was the only modification I made at the time, I was really impressed with the ride and stability of the front end (even over bumps, the IFS didn't wander at all!). I then decided to get the remaining pieces and complete the 3" lift. Unfortunately, by proportionally putting everything back to factory specs, the steering was too sensitive (constant input to keep it straigh). This is why I'm thinking of purchasing extended radius arms because it only makes sense based upon my previous experience.
You mentioned about changing the passenger side caster reading to 5.0. How can this be adjusted as the radius arms determine the castor reading? (forgive my lack of knowledge on this).

Thanks again!

 

[MW4HD]

Caster adjustments...

Hey Ken, it's not your lack of knowledge that's a problem. It's the shop you're having aligned at that is the problem, not intentionally or even that they ought to know, but when you lift a truck, you CANNOT go back to factory specs. The caster must be higher than OE settings. They should be able to get a little more out of that side by either adjusting the eccentric cam or replacing with one of higher degree of correction and adjusting up to desired (needed) caster...

 

[Pendarus]

O.K. Lets say I have a perfect alignment job on my front end. The truck pulls to the right. From the info I have gathered, my problem is caused by the camber change from my big butt being in the drivers seat. If I measured the difference in suspension height, and shimmed the coil on the drivers side to compensate, the pull should go away. This being because I have reset the suspension height to the same measurment as it was when it was aligned. Correct?

 

[MW4HD]

Coil spacers...

Yeah, that's a good idea, but, won't solve the incorrect caster split. I'd probably throw about 250lbs in the driver's side front while they align it after you've spaced up the coils to make sure they don't over or under do it. BUT, the split MUST be right in the caster before it will drive straight or handle the way it should...

 

[kstjohn]

Measuring suspension height

What is a good way to measure the suspension height for each side of the front end of a '91 4-dr Explorer? I've measured from the top of the tire to the inside of the fenders and then measured from the ground to the bottom of each section of the IFS and have a difference in measurements. It appears that my driver's side is 1 to 2" lower than the passenger side.
I read an article about spring settling after installing a lift kit (3")and how shims my be needed to compensate for the difference in the driver's/passenger's sides height. Originally, I installed the kit, had it aligned, then after a while, the drift to the right started. I'm thinking that maybe this is the problem as opposed to my previous posts regarding extending the radius arms. What I don't understand though, is that if the passenger side is higher, shouldn't I be experiencing a drift to the driver's side (since it is lower).
Can anyone offer some advice on this?

Ken

 

[MW4HD]

Hey Ken, yeah, Ford's with TTB and Twin-I-Beam have always had a problem with sag on one side or the other due to varying coil bind on each side. Usually the coil with the baem or axle housing which is shorter on it's side will settle lower than the other side due to coil bind being higher on that side. It can also work in reverse, longer beam or housing and too much oscillation occurs and just wears the coil seat into collapse. It's a dirty little trick Ford played on us when they made them unequal length. BUT, it's the suspension that works better than just about any other for most purposes, desert race, hill climbing, rock-crawling to a certain extent, it just works and gives better traction on the 4WD's. Best way to measure is from the center of the front hubs to the bottom of the fenders as long as the body mounts are equal and one side isn't worn to the point of being lower than the other...