Toe-in with singles and radials - thoughts?

[Trango]

Lately, I've been trying to track down the cause of a weaving on highways with semi ruts, which manifests itself as a dead spot in the wheel and a slow, well, weave from the rear tandems.

This task is is tough because I've changed just so much on this truck. I'm singled with dually wheels in back on the outside track, and the front wheels are custom to match the rear track.

Lately, I've shimmed the wear-bushings on the axle brackets that hold the rear leafs, to eliminate some movement... this has seemed to help. The steering linkage was also just a little loose around the ball stud, so I tightened that up as well - next step is to tighten up the steering gearbox itself, even though the steering wheel seems very tight.

Caster measures out to about 5 degrees, so that should be good.

My question to the group is how much caster are people with radials running? I just threw a tape on my front tires, and the measurement between the front faces of the tire was only 1/8" narrower than the rear, which means there was very little toe in.

Thoughts? I cringe to take this thing above 60 on heavily scarred roads.

 

[cranetruck]

Caster for the deuce should be about 4° regardless of tire type (bias or radial). Make sure it's the same on both sides, sagging leaf springs will effect the caster.

Keeping the rear tandem axles couples without a differential will effect the steering effort on hard pavement, don't know about it causing weaving, though.
Toe-in sounds good at about 1/8".

Camber is easy to measure, but can't easiliy be adjusted.

Bearing preload is important and shouldn't be too loose. I do mine a little tighter than prescribed in the TM, it will effect toe-in and camber and cause premature tire wear, but shouldn't effect caster.

The shocks dampen high frequency vibrations and shouldn't be an issue here. BTW, the leaf springs have a built-in damping action from friction between the leaves, so never oil or lubricate leaf springs.

What about tire pressures?

The regular bias ply NDCC's on the deuce don't need to be balanced after mounting, but perhaps yours do if they are custom.

Explain "semi ruts", pls.

 

[alphadeltaromeo]

Thoughts? I cringe to take this thing above 60 on heavily scarred roads.

Interesting...and how fast "can" you go with it?

 

[Trango]

RE: Re: Toe-in with singles and radials - thoughts?

Thanks for the notes.

Semi ruts around here are twin tracks in the road bed, that aren't caused so much by heavy truck traffic, as trucks with chains on them. The abrasion from the chains beats up the asphalt so bad that even my 2001 audi has issue with so-called trammeling from the pavement.

As far as a theoretical top speed.... I think I run out of gear at about 80. Never, in my right mind, would I go even that fast, though.

So I've adjusted the toe in to be a little more aggressive, and I have a test drive perhaps later this week. I'll report back with my findings.

Oh yes, thanks for the idea about the wheel bearings... I hadn't considered those.

 

[steelsoldiers]

RE: Re: Toe-in with singles and radials - thoughts?

Hey Trango, nice to see you again. It seems like it has been quite a while since I have seen you here. What's new besides your wandering singles?

 

[Trango]

RE: Re: Toe-in with singles and radials - thoughts?

Thanks for the welcome.

I've been pretty busy with other projects. I pulled the engine in my Audi allroad in December for some bigger turbos, and I've been working working working on my crawler - rearsteer, diy beadlocks, front link suspension to replace the bent front leafs, etc.

I also picked up a 13609 Eaton overdrive airshift tranny... I'll hopefully swap that into my deuce over the summer, along with a split of the braking circuit and front disks. Always something to keep me out of trouble.

Best
Bob

 

[steelsoldiers]

RE: Re: Toe-in with singles and radials - thoughts?

Man, you've always got some cool one-off projects going, Bob. Keep us posted on the tranny swap and the brake upgrades. Better brakes will make you feel better with all that extra top speed

 

[spicergear]

RE: Re: Toe-in with singles and radials - thoughts?

Trango- possibly with your big wide singles the outer edge of the tire is just starting to climb the side of the rut which pushes you to the other side...then you hit the other and it pushes you back to give you the weave. I KNOW this is a BIG spread but semi ruts do the same for motorcycles as you end up pin balling back and fourth. What I'm taking to long to get at is that it may not be anything with your steering or shims or angle of anything BUT...the nature of the beast with that type, size, weight (etc.) tire on the truck.

 

[mucekok]

RE: Re: Toe-in with singles and radials - thoughts?

i had a similar problem with my truck after going to singles... turns out the u-bolts on the front axle were loose allowing the axle to shift when changing lanes. drives great now.

 

[Trango]

RE: Re: Toe-in with singles and radials - thoughts?

I will definitely be checking out the ubolts and the wheel bearings!!!

PS BTW next project, which I need to finish before April 12th, will be a wastegated exhaust brake. I have the pacbrake unit now, along with a Chelsea PTO "safety-gated" (meaning, un-accidentally-bumpeable) air switch. The issue is that the Cat 3208 can't take more than 32psi in backpressure, so you need to run a wastegate. Well, I found a 46mm or so external wastegate on ebay for like $60 meant for the tuning world (just needs some heavier springs or shims), and I'll weld that in parallel with this pacbrake. Voila - semi-easy backup braking system, without the hassle of splitting the braking circuit... which happens later this summer.

Oh yeah, final random thought - if anyone gets Skiing magazine, look at the March/April 2007 issue. On page 38, in the "Calendar" section, you have the Thrift Store Ski Party, Arapahoe Basin, Colorado:

"Hit your local Salvation Army for one-pieces, headbands, and all things polyester. Then head west on I-70 to Abasin's Beach for Kegs, 1000 Jello shots, a functional hot tub, and a DJ spinning from a 40 year old flatbed..."

That's my mate's party. I'm rocking the deuce as the stage.

Best,
Bob

 

[OPCOM]

RE: Re: Toe-in with singles and radials - thoughts?

you'll have to show us some of the party pictures!!