Installed Radials, now truck wanders

[Bob H]

sandcobra164,
So you're saying the 1100 "Firestone's are much wider" than 1100 Michelins

While I don't have any Firestones to measure, I ain't buyin' it!

 

[jesusgatos]

The contact patch is, fer shur. The T831's have a very squared-off tread-pattern, as opposed to the big 'ol donut-shaped stockers.

 

[sandcobra164]

9 1/2 inches wide shoulder lug to shoulder lug is what I measured. I've seen trucks with michelins sitting right next to mine and it's easy to spot the difference in width. I don't have any michelin's to measure but the point I was making was that the michelins contact patch is narrower as the tires are rounded off on the shoulders and they resemble the original tires more. I'm here looking for a solution to my trucks problem and I think the wider contact patch is a relevant concern. Here's a visual of the tires on my truck. I've also posted that the issue could indeed be positive caster. Someone suggested pulling the caster plates from between the axle and springs. That sounds like a good suggestion and certainly one worth my time and efforts to try.

 

[Bob H]

Yep you are right the michelin is only 9 1/4" wide across the tread blocks.
but I guess mine are not worn out enough yet to be rounded on the edges.

Sure the F'stones have the outside blocks closer together than the XL's which may have an impact.

but I have to think yours is an alignment issue that wasn't as obvious with the worn NDCC's

edit:
running 65 front and 45 rear on mine (M36A2 long bed)
and as I said above it drives great.

 

[73m819]

everybody says lower the air pressure, wrong the lower the air more sidewall flex in radials, raise it, also you are running 50 in the rear and 70-90 in the front. what I think is happening is that your rears are walking because of sidewall flex, raise the pressure in the rears this will stiffen the side walls and help if not do away with the over steering

 

[kipman]

My truck has 1100 XL Michelin radials, it is has the hubs flipped, run 50 psi, drives fine.

 

[shenkmen]

sandcobra164, have you worked this out? Tried anything else? I'm curious about the outcome as I have T831's on my M35A2.

Thanks

 

[EMD567]

I have found that until the tires have a little wear, they tend to wander because of the extreme tread depth. UPS runs real thick recaps on the rears, and I can always tell when the mech. has slapped a set of 4 on the rear. The rear end squirms until you have about 5 grand on the tires. The fronts, while virgin rubber, don't seem to squirm, but will follow a divit or crack that is parallel to direction of travel.

 

[dburd72]

Has anyone solved this issue. I swaped my A2 over to Goodyear 11.00R20 g177's played with air pressure no real change thinking about fliping caster plates just wondering if it will make the truck hard to steer at low speeds. thanks for any input you might have .

 

[deathrowdave]

Flip the shims it will be a new truck. It will steer easier that before you flip them.

 

[gringeltaube]

a2s have 0 caster with the shim the correct way......

I always found around +2º... (Pic w/ mesurements). And I think steering wouldn't return to center if caster angle was zero?

..........flip it and you end up with about 6 degs. positive caster

Flip the shims it will be a new truck. It will steer easier that before you flip them.

Sounds like you have done it successfully? Can you post pics...?

See the exact dimensions here, of what I think you are referring to as "shim": http://www.steelsoldiers.com/deuce/46775-front-spring-pack-question.html#post527505
The first drawing shows what happens if that part was simply flipped, front to rear (and possibly left to right): over 10º resulting caster angle! and not to mention the now extreme U-joint angle at the front diff.

Second one is what I do to achieve about 4º positive caster...
That, combined with almost zero toe-in makes the trick to run (wide) radials with no more wandering symptoms, regardless of TP. (IMHO)


G.

 

[Shoprat 19th Engr]

When you change from bias ply tires you have to reset the toe end on the axle to 0 front and back where bias tires are set at 1/16 in on the front this may give you wander if you have not changed the toe end

 

[deathrowdave]

I had no Ujoint problems what so ever. Simple flip worked great for me. I am running 11r/22.5 , with power hydro assist steering.