bobbed Deuce with 395 /85 R20 tire question

[wild_willy]

wondering if any one can give me some information on my duce that I bobbed , I put 395 - 85 - 20 tires on it and it was like I was driving on black ice so the steering box was worn out so after endless hrs of working on the steering box got her done took it for a drive seemed to help a bit just wondering what the tire pressure should be or does it jump all over the rd from the run flats , any info would be greatly appreciated
thanks

 

[Ford Mechanic]

I ran 55 to 70psi in mine on the stock rims. It's real common for a shimmy to develop after switching to 395's, that may be your problem. The fix is to adjust the caster. A couple of good threads

http://www.steelsoldiers.com/showth...caster-angle-solved-problems-with-G-177-tires

http://www.steelsoldiers.com/showth...-around-front-axle-shims-how-to-raise-vehicle

 

[Ford Mechanic]

You said you have run flats?? What type rims are you running? I have heard that they cause bad vibrations

 

[welldigger]

The caster fix will help with the wandering. I run 35 psi in the front and 30 psi in the rear of my truck. Most people don't realize they run their 395's or other large radials at unnecessarily high tire pressures.

If you have the runflats they can also cause an imbalance. In rare cases severe tire and steering wheel shake.

 

[m-35tom]

is your toe-in at least 3/16"??

 

[dezert ratt]

I had wandering issues and vibration issues. Re set my toe, and dropped the air psi from 90 to 55 psi. This helped a lot, next I will try changing the caster In the front axle.

 

[welldigger]

I had wandering issues and vibration issues. Re set my toe, and dropped the air psi from 90 to 55 psi. This helped a lot, next I will try changing the caster In the front axle.

Drop that air pressure a little more and see how you like it. A deuce isn't heavy enough to need that much tire pressure.

 

[Iron General]

I bobbed my deuce and put the same tire combination on it and had similar problems. I dropped the front tire pressure to 50psi and the rear to 40psi which seems to work well at all speeds. If you are using the MRAP rims like me, then you must make sure the disc inserts are exactly centered.

Iron General

 

[Section8]

I have heard tell that if you used to run with the old NDT tread bias tires then go to the radial 395's it can be a little unnerving.
I believe the radials like to drift a little on th corners due to the softer side wall than the stiffer bias ply.
I may be wrong on that but I think I remember reading a thread about bias versus radial tires somewhere here.
How did you luck out and find 395's up here in BC? The few guys I have talked to who are trying to sell them want new prices for 50% worn tires.
If you end up not liking them I will take them! Got 6 NDT tires on my old M135 not doing anything. Of course they are still circa 1956 but hey. .

 

[Iron General]

I have heard tell that if you used to run with the old NDT tread bias tires then go to the radial 395's it can be a little unnerving.
I believe the radials like to drift a little on th corners due to the softer side wall than the stiffer bias ply.
I may be wrong on that but I think I remember reading a thread about bias versus radial tires somewhere here.
How did you luck out and find 395's up here in BC? The few guys I have talked to who are trying to sell them want new prices for 50% worn tires.
If you end up not liking them I will take them! Got 6 NDT tires on my old M135 not doing anything. Of course they are still circa 1956 but hey. .

I have not experienced any problems with the tires rolling on turns, but I did not use them while the third axle was on the vehicle. I purchased a set of six new tires from the government web site and I am really pleased with their performance. I bobbed my truck so I only used four of the tires and I would sell the other two for 400 USD each if anybody is interested.

 

[rustystud]

I bobbed my deuce and put the same tire combination on it and had similar problems. I dropped the front tire pressure to 50psi and the rear to 40psi which seems to work well at all speeds. If you are using the MRAP rims like me, then you must make sure the disc inserts are exactly centered.

Iron General

Tire pressure is very important on these trucks. Especially when using 395's which where never meant to be used on a deuce. Look at the tire rating on the 395's . You'll see they are for a much heavier truck then a small little deuce.

 

[Iron General]

I put the same tires on my bobbed deuce and ended up lowering the tire pressure to 50 psi which helped with the ride and the control

Iron General

 

[red]

These tires are rated for over 12,000 lbs each, overkill.

Empty I run 35 front 30 rears and it does great. With the shelter in the bed I went to. 45 front 40 rears. Front was a little too high.

 

[rustystud]

A few years back, I was able to pick-up cheap a set of tires for my 1/2 ton truck. The catch was they where 12 ply ! Not knowing any better I aired them up to what it said on the side-wall of the tires, which was 80psi. The first time I hit the Highway I almost lost control and went into the Jersey barrier ! After researching the problem I found out that I needed to lower the pressure down to 40psi on all the tires. After that it drove just fine.

 

[mbrosch]

When I was active duty we ran radials on the front of all the tractors and the duces. They would push a bit in turns but were far better on the road than the bias NDTs. With any vibration issues you need to be sure the caster and camber are correct (read up on "Steering Geometry") Resolving problems by racking in toe in will cause bigger problems down the road.