Mraps on the front

[bones1]

Got them all installed yesterday. A big difference in ride quality, much smoother.
I will have to change the caster as it takes a little getting used to at speed.Overall very pleased with the MRAPs
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[LowTech]

395/85R20, my wife has had them on her truck for almost a year now, no rubbing issues at all even at full stuff.

Not to jump tracks . . . but, what are you using as steering on her rig? We've been running 395s on Mod'd Hemmits on the She Beast and I'm really thinking I need to upgrade to some kind of power assist for Elise. Some of the places we've been have def caused . . . lets say . . . a work out.
Not a good selling point when I'm suggesting we spend another month climbing over mountain passes on dirt tracks

 

[LowTech]

I'm really liking how yours is looking! Not sticking out in the front. The She Beast has that wider stance of the Hemmits (which is great for that truck, she never sinks or slips anywhere we've gone) and I'm really debating going w/ 11x20s (just don't like any of the rim choices), or doing what you did :-/ I just need to have a more agle truck in the little Draggin', something that I can get in & out of difficult places.

 

[3dAngus]

Not to jump tracks . . . but, what are you using as steering on her rig? We've been running 395s on Mod'd Hemmits on the She Beast and I'm really thinking I need to upgrade to some kind of power assist for Elise. Some of the places we've been have def caused . . . lets say . . . a work out.
Not a good selling point when I'm suggesting we spend another month climbing over mountain passes on dirt tracks

edit: Above post was misinterpreted. I'm assuming now, the author intended to say he is mounting 395s on Hemmit rims??? then putting on a deuce.

I guess you have to read several posts to understand this completely.

This thread is not about Hemmit rims, it is about MRAP rims and 395s.

If you are having trouble steering with MRAP 395s on a deuce, it is either an off road condition or there is something wrong mechanically. I doubt it is a case of putting "good" 395s on a deuce and it creating trouble over and above 9X20 NDTs. MRAP 395s generally make a deuce ride and turn better. If they don't, I would look further for anomalies in your installation.

Perhaps Hemmit rims are entirely different and your problem. I don't know, but it might be something worth investigating.

 

[DatGuyC]

Look great, but your hubs and drums are too clean! Mine look like they sat at the bottom of a lake for a month or 5 haha

 

[LowTech]

edit: Above post was misinterpreted. I'm assuming now, the author intended to say he is mounting 395s on Hemmit rims??? then putting on a deuce.

I guess you have to read several posts to understand this completely.

This thread is not about Hemmit rims, it is about MRAP rims and 395s.

If you are having trouble steering with MRAP 395s on a deuce, it is either an off road condition or there is something wrong mechanically. I doubt it is a case of putting "good" 395s on a deuce and it creating trouble over and above 9X20 NDTs. MRAP 395s generally make a deuce ride and turn better. If they don't, I would look further for anomalies in your installation.

Perhaps Hemmit rims are entirely different and your problem. I don't know, but it might be something worth investigating.

My post was about the 395s being harder than the 9.00x20s to control doing something other than driving down the pavement. We have both and I, at times, drive them both. There is a dif.

Saw Mdmorgan's avatar and thought I would ask if they were using power assist, . . . my bad. I'll shut up now!

 

[dstang97]

Did you keep the run flats? How is stopping and acceleration? I mounted my fronts and doing the rears soon. I really like the wheels we got.

 

[bones1]

I kept the wheels and tires intact. Truck rides smoother but wanders all over the road, like I knew it would until the camber fix this week. Need to adjust my brakes which are new as well then it will be a pleasure to drive. Acceleration if you call it that feels a little better to me.
Anyone know tire pressure to run in these MRAPs?.

 

[3dAngus]

I kept the wheels and tires intact. Truck rides smoother but wanders all over the road, like I knew it would until the camber fix this week. Need to adjust my brakes which are new as well then it will be a pleasure to drive. Acceleration if you call it that feels a little better to me.
Anyone know tire pressure to run in these MRAPs?.

.
Well, I give up. I used to have it. It depended on the mission, and the vehicle GVW. I do recall it was very high, higher than most, and you could not overinflate it with the deuce air supply system, which puts out about 90-100 psi. I'm currently running 85 psi in mine. They feel great. It's probably one of the reasons why they turn easier than the 9X20s.

The tires came preloaded from the warehouse with an average of 95 psi in them. Max rating is 127 psi.

You need the MRAP or Cougar variant cat 1 or 2 Operators manual to know for sure. They are going to be heavier than the deuce, but lighter then the Buffalo.
Some of the old pictures I had have the TP on the fender smudged out. Best I can do. Maybe some military guy has the tech manual and can cut out some excerpt for us on it.

 

[DatGuyC]

I thought I read somewhere that for even tire wear about 45 in the front and 25 in the rears?

 

[peashooter]

I would think it should be about the same as what the recentered HEMTT wheel guys run with 395's wouldnt it?... not that i know what that pressure is though. I'll stay tune to the answer myself on this one. LOWTECH, what kind of pressures do you run on & off road?

Also looking for some good pictures/advice on doing the camber mod that it sounds like most folks agree is needed when going to radials. Gringeltaub had a good drawing somwhere about removing 5/32" from the spring shims, but I'm curious what the best/easiest way to support the axle & lift the truck so one can remove the shims to modify.

 

[bones1]

I will tackle the spring perches this week, as I can barely steer the truck right now.
Thanks Angus, I will try them at 85lbs and see what happens

 

[DatGuyC]

Also looking for some good pictures/advice on doing the camber mod that it sounds like most folks agree is needed when going to radials. Gringeltaub had a good drawing somwhere about removing 5/32" from the spring shims, but I'm curious what the best/easiest way to support the axle & lift the truck so one can remove the shims to modify.

I just used a bottle jack to jack up the leaf springs off the top of the axle, then put a little 2x4 where the shim was so as to not possibly damage the centering pins on the axle and spring.

 

[dstang97]

I will tackle the spring perches this week, as I can barely steer the truck right now.
Thanks Angus, I will try them at 85lbs and see what happens

Why is it hard to stear? or just wondering?

 

[3dAngus]

I thought I read somewhere that for even tire wear about 45 in the front and 25 in the rears?

If you ran 25psi in a MRAP 395, it would be 5mph max and you would be doing that for sand or mud off road conditions only. They would essentially, be all but flat.

I recall hearing something like that for NDTs. I pretty sure the norm for paved road MRAP 395s is going to be closer to the 80-110psi range.

I'll see if I can find my sources. I haven't given up yet. I have found numerous pictures on the web with the TP listed above the wheel but I cannot make it out, even with magnification view. It just gets to distorted, but I have seen one before that was clear, and I honestly thought that one said 105PSI.

Here's a couple of online pics that show the difficulty in reading the TP. Maybe someone with younger eyes can make it out.

 

[bones1]

Hard to steer is the wrong term, the truck wanders all over the road. The caster fix and correct tire pressure will take care of it.

 

[gringeltaube]

I tried to respond to your last PM by attaching a little drawing. But for some reason that didn't work so here it goes:

1) ...what you can do as a temporary fix or trial, (just for a short test ride!) to determine if milling/grinding the spring seats will solve the wandering issue or not. (Note that the seat has a notch so that it does not interfere with the welding seam on the axle tube; if that was your concern...?)

2) ... what I have done so far to increase CASTER. (already posted somewhere, earlier on)


G.

 

[DatGuyC]

If you ran 25psi in a MRAP 395, it would be 5mph max and you would be doing that for sand or mud off road conditions only. They would essentially, be all but flat.

I recall hearing something like that for NDTs. I pretty sure the norm for paved road MRAP 395s is going to be closer to the 80-110psi range.

I'll see if I can find my sources. I haven't given up yet. I have found numerous pictures on the web with the TP listed above the wheel but I cannot make it out, even with magnification view. It just gets to distorted, but I have seen one before that was clear, and I honestly thought that one said 105PSI.

Here's a couple of online pics that show the difficulty in reading the TP. Maybe someone with younger eyes can make it out.

From the "MRAP wheels and tires on a deuce?" thread:

It is going to take some getting used to. Feels like a whole different truck. She does want to wander a tad and the steering is touchy now. Still working on getting the air pressure just right. Right now it is 40 in the front, 25 in the rears and still riding on the center a little bit. The rears are almost there. As far as Deuce, (doggy) his ears want to stand up so bad!

Not saying I know anything, I still haven't tested mine out, just what I read.

 

[3dAngus]

I tried to respond to your last PM by attaching a little drawing. But for some reason that didn't work so here it goes:

1) ...what you can do as a temporary fix or trial, (just for a short test ride!) to determine if milling/grinding the spring seats will solve the wandering issue or not. (Note that the seat has a notch so that it does not interfere with the welding seam on the axle tube; if that was your concern...?)

2) ... what I have done so far to increase CASTER. (already posted somewhere, earlier on)


G.

Bones, Please let me know if you try this and what your results are. Gringeltaube knows his stuff.

I also posted on another thread, while it is easier to turn, I do have some play in the 35-45mph area. It is uncomfortable so I usually try to stay away from there, and if I have to ride there, I keep the rpms as high as possible by riding in a lower gear. This better traction and drag seems to help immensely, but the vehicle will still want to wander, and it is two handed driving in that range. Otherwise, I can drive with one hand on, one elbow on the door, and watch the skirts go by.

You definitely do not want to drive in that fuzzy range at low rpms. This one is over my head and I'm hoping that someone with more knowledge on the green machines will try something that solves most of the problem.

 

[LowTech]

I would think it should be about the same as what the recentered HEMTT wheel guys run with 395's wouldnt it?... not that i know what that pressure is though. I'll stay tune to the answer myself on this one. LOWTECH, what kind of pressures do you run on & off road?

On the She Beast we are running 45 front and 35 rear, that's on a 109 that has more weight on the rear. Started at 75 and kept dropping it till the tires rode flat on pavement. Also helped w/ it wanting to change direction every time she hit a bump. Have only dropped it 5lbs to offroad, and that was in the softest sand. Doesn't really seem to need it as those tires just don't sink. I took some photos of our trucks in the same sand w/ 9x20 NDCC's on mine and 395's on hers, mine is in up to were the trend ends on the sides and hers is only lug deep.