Bigger Tires with 4.56 gears - Steel Soldiers::Military Vehicles Supersite

bsalbrig · 01-09-2009, 00:11

I bought a M1828 from gov liq on the dec 29th sale, waiting on my first EUC now. What is the largest size tire that the 6.2 can handle with the stock 4.56 gears? I intend to lift the truck 6", not sure if I want recentered h1 wheels or no beadlocks at all. I have some decisions to make, my intent is to start acquiring parts now as I come across them, when I get the truck I will get it street worthy first in stock form, drive it a bit till I feel that I have all the problems sorted out then proceed with the lift and larger tires. I would like to go with tires larger than 37". It looks like a 30"tire with 3.73s would be about the same as a 37 with 4.56gears.

I intend to run this truck on the trails at Uhwarrie national forrest. (my stock M151a1 can do most of the trails there)

84cucv1ton · 01-09-2009, 00:17

i have 6" lift on my m1031. it will be a lot of flex when its done. i will be running 38" tsls. friends m1008 has very close to this set up says he can do 65 down the road no problem.

i recommend tuff country for springs i have 3 trucks with them. flex and ride pretty good. hope that helps

bsalbrig · 01-09-2009, 00:32

I am going with tuff country 6" front, for the rear I am not sure if I want 6" spriings or a combination of shackle flip and springs.

Do you know if your freinds truck has plenty of power when wheeling?

Did he have to cut the fenders of his truck?

84cucv1ton · 01-09-2009, 01:13

yes, both trucks are cut. not sure about power. my 6.2 is not stock and his is not even close to stock. cant help much there

hobie237 · 01-09-2009, 08:59

The biggest problem won't be the tires (although if you go too big they will be, but people regularly run 36s, and some run 38s, without issue), but the craptastic ratios of the TH400 trans. 4.56 is plenty deep, the NP208's low range is plenty deep, the only thing missing is a decent gear ratio, and the 2.48 first in the 400 just plain sucks. You'd be better off going to a 700R4 (if an overdrive is desired) or SM465 if a granny gear is desired. If money isn't an issue, you could get an NV4500 or a gear-splitter added onto the SM465 to get low range and overdrive.

84cucv1ton · 01-09-2009, 15:46

i dont know much about the inside of a th400 but i know you can get lower gears to put in it. think that would be a lot of time and money..

could you tell me a bit more about a gear-splitter added onto the SM465 to get low range and overdrive?? thanks

hobie237 · 01-09-2009, 16:14

Swapping the guts of a TH400 would be a waste of time. Just put in a trans with better ratios. The 700's ratios are better, so that comes to mind. Let me know if you need one.

There are gear-splitting units that give both low and overdrive, or just 1:1 and overdrive (Ranger units are the ones I see talked about most). The SM465 has a ~6.5:1 granny first, so that pretty much takes care of the low end of the scale- especially with the low range in the 208 and the 4.56 gears. Unless you're doing SERIOUS rock crawling, having an additional low range would be completely unnecessary. In the case of serious rock crawling, the ability to split gears upward (with the overdrive) would be kind of unnecessary, too, so the better option would be multiple transfer cases.

Anyway, my comment about the "low range and overdrive" was just that those transmissions were better in the low and high speed areas. Both have granny firsts, but the NV4500 has an overdrive 5th. Then again, the wide ratios of the 465 combined with the Ranger 1:1/30%OD unit would provide for eight forward gears, the lowest being an uber-low granny gear and the top being a 30% overdrive, but with more choices in between.

Either choice is pretty expensive, though.

84cucv1ton · 01-09-2009, 17:35

i get it. i guess you can build a 700. i have had bunch go out on me. friend too. never had a th400 go.

Croatan_Kid · 01-09-2009, 22:25

I've got 5" of lift up front and moved the axle 1.5" forward, 3" of lift in the rear. I run 39s and also have a 700R4.

It works pretty good, I just don't have enough power for my liking. So I'm swapping in a new motor, trans, and transfer case. I just don't like the look of a lot of lift with a little tire and I really needed to keep my truck as low as possible so it's still useable and so I can get it in my shop door.

AJMBLAZER · 01-10-2009, 00:47

38's and the stock setup are pretty good. I like the way mine drives. Wish it had more power but I'm not unhappy with what I have. In the future it will have more power and a better transmission setup but hey, that's the future.