Serious steering issue - 79 Scout II - detailed info

[Tom]

Guys,

I've got myself a serious steering issue with my Scout II. It could best be described as "inadvertent lane changes" when hitting bumps, and "variable" steering in corners. I have included a ton of information for those who have the time to help. In a follow up post to this thread I'll include what I've found out so far. Any help is appreciated.

Vehicle - 79 SII -- entirely new front end. Rebuilt 44 with stock springs SUA. New tie rod ends, new upper and lower ball joints. New poly spring bushings in stock shackles. Has factory sway bar installed. Standard steering box with new rag joint. 30 inch Cooper STT mud tires on 15x7 stock rallye wheels. Castor correction kit by "the Scout Ranch." Front end is very tight - no slop - except the inherent slop in the rag joint. Stock U bolts, Monroe gas shocks (new 13,000 miles ago). Front-end aligned on computerized alignment machine. 304 V8 engine, wide T19 3.54s, open frt diff. 50PSI max in tires. All tires are at 40PSI - 4 ply sidewalls. Tires wearing fine overall - no cupping - but they do show signs of "scuffing" from heel to toe on center lugs only. New poly body bushings. Solid body mounts, rockers, etc (all new 13K miles ago)

Overall situation -- This Scout goes straight with no problems at all. I can cruise at 70mph with one finger on the wheel. No wandering issues whatsoever. The problems are with cornering. Imagine a slight corner on the highway at say 60 mph... the Scout enters into the corner fine, but as the weight begins to shift the Scout seems to slide - almost like being on grease - almost seems like the tires are flexing OR the body is rolling - but steering seems greatly effected - which is scary given how touchy the steering is in a Scout II anyway -- very scary --

Also - if traveling over say 35mph - if you hit a bump then steering position seems to change with a resulting change in vehicle direction. Not exactly comforting at highway speeds, especially on two lane roadways. Sometimes resulting steering change causes an UNINTENTIONAL LANE CHANGE. Maybe just a foot or so out of "my" lane - just a foot is all it takes for a head on crash.

Worse case scenario is being in a slight turn and hitting an expansion joint or pot hole while at highway speeds. Crazy things happen --

I've been driving my Scout like this for 13,000 miles, but really got the crap scared out of me the other day. I usually drive about 55-62 mph... I'm in no hurry, but the other day I was moving about 68 and came into a corner, hit a bump, and had some wild results. Any help you can give me would be appreciated.

I've thought about the following --

1. Stock springs are worn out and have no ability to absorb shock(s) from the road surface.
2. Shock absorbers too stiff. (Did I mention this Scout rides ROUGH).
3. Caster set differently between two front wheels --
4. Tires - I'm not the only one running mud tires - and find it hard to believe that my tires are causing this problem... I COULD get my hands on a set of 30x9.50 BFGs and could mount them and see if the problem continues.
5. When I installed the ball joints I did not have a torque wrench capable of the high torque setting required for them so I tightened them with my impact wrench - my friend - a long time mechanic said this was okay.

Any thoughts on where to go with this?

I've got an appointment at the alignment shop to check it out - I just don't think it is alignment - unless the caster is set differently between the two front tires

[Tom]

Here's what I've found out since I started working on this problem two weeks ago:

1. I found a torque spec on the shackles of 30 ftlbs. Mine were set beneath that. I left them there.
2. I went to the alignment shop. THEY SAY THE SPECS CALL FOR TOE OUT ADJUSTMENTwhich I found extremely odd. We found out that even with the Castor Correctors I had -1 degree caster (negative caster). We installed 2.5 degree caster shims on the leaf springs. The result is 1.3 degrees postive caster. This did not solve my problem. The "hit a bump" and "change a lane" problem still exists.
3. Entire front end is tight. No problems whatsoever.
4. Steering box is tight.
5. Rag joint is okay.
6. Left rear tire is slightly ahead of right rear tire, but only slightly, and not enough to cause this problem (according to the alignment guy).


I'm really at a loss for ideas here. I don't have a steering stablizer, or steer-straight brace, but am considering them. I'm hoping someone out there has had this problem and solved it, and can tell me how.

I'm sure you're wondering how/why I've been driving my Scout this way for over 2 years. The answer is simple, I didn't drive it much, and just accepted it as the way the Scout was. Only recently did I start driving it a lot (350 miles last week) and now this problem is on the front burner...

Please help.

Thanks -- Tom

[MuDgOd_1967]

Scouts have a tendancy to flex at the steering box. Check out Super Scout Specialists site, they have brace that will help cure that problem.

I have one one my Scout and it worked well. But now I have a tire issue that is causing me to make change lanes.

Nick

[Tom]

The brace is the next place I'm going, but before I throw more money at this problem I want to make sure I'm headed in the right direction.

Did you have this type of problem before you installed your brace??

TIA -- Tom

[Tom]

If someone is interested in the exact alignment specs -- I have them at work and can post them this afternoon.

T

[GregF]

Tom, I see that Nick has brought up the same thing I was going to say. We have had our 76 since it was new. A number of years ago it started changing directions when the rig hit bumps on the road. It tookout a lot of the fun of driving it that we used to enjoy. I have never done as much to the front end as you, however all the steering components checked out tight. Then I heard about the frame flex problem at the steering box. We installed a steering brace (Straight Steer) and that stopped the movement of the box and the wandering stopped.

I hasten to add that there are those on this board that think the problem should be fixed, not band-aided. They will say that the frame is cracked in the steering box area and should be reinforced and welded up. That is a good thing to check but mine was not cracked, only flexing. Therefore, the straight steer was the answer for us. HTH.

Greg

[Tom]

Greg,

I appreciate your answer. If my frame is cracked, I will weld it, and have the tools to do so. After everything I've done in the past two weeks the only thing that I could think was really the culprit was either the tires or the frame flex. I guess I should give Rick a call at SSS and throw some more $$ their way.

Anybody else want to second/third the opinions already expressed?

You can bet that as soon as I have this brace installed I'll be posting about how it performs.

Tom

[Tom Mandera]

How are your leaf spring bushings?

Your spring hangers are in good shape, too, right - not torn from the frame and letting things wobble around.

Do you still have the STOCK SUSPENSION or is this a lifted Scout?

I set my toe-in to "0" or as close as I can get it. Having this off will make it want to 'dart' a bit, but not necessarily change lanes.

Wheelbearings are still tight, too, right?

Do you have the factory anti-sway bar installed?

How were the caster correctors installed so that you had NEGATIVE caster with them? If installed incorrectly, they may also be giving you camber which could cause some handling quirks and tire wear problems.

[CareyWeber]

Tom,

I'd check the frame above and below the steering box to see if it's seperating if it is weld it.

I thought toe-in was suppose to be between 1/16" & 1/8"?????

Carey

[Doc Stewart]

Toe-out specs are incorrect. Tire size affects toe in. The wider the tire, the less toe-in you need. My Scout 100x31 tires are set at 1/8" toe in
With toe-out, your truck will wander.

The zero caster from the factory makes Scouts inherently wander. 1.5 degrees caster should be enough but you can go as far as 6 degrees. Mine tracks straight at 4 degrees done by cutting and welding the axle tube.

Scuffing on your center tread knobs indicates under-inflation.

Suggestions: Weld and reinforce your steering box mount. Set your toe-in. Inflate your tires to 50 lbs and see if you have any 'wander' left.