Top speeds in a M1008?

[JesseJaymes]

New owner of a M1008. I was inquiring as to what a "normal" or allowable top speed is ?

I am aware of the 4.56 gearing and such, but was hoping for at least 50MPH. Tires are 265/75/16's, so I think they spec out at 32". I am looking for some larger tires, but did not want to defeat the great low gearing.

I know I am wizzing up a rope, but I am somewhat dissappointed. I knew it was not a high horsepower rig, but it seems aweful weak. I also knew it was gonna be slow, but 45 is really slow. And of course to my untrained ear, it seems as though it will fall apart at any second.

And the speedo is reading slow. About 3-4mph @ 45. I see there are gears available to correct this. I know larger diameter tires will help, but I would only go to about 35" or so. Plan on a 4" lift with a shackle flip in the rear and TUff Country springs up front. But I may wind up off loading it. I was really stoked for the 14FF, Locker, and Dana 60. Truck is real clean. But it's off roading performance is pretty lacking.

Also, I researched for an hour or so. The overdrive units for the TH400 are all over $2K, is that correct? More than I have in the entire truck.

Are there any options ???

 

[tlm47201]

Well, 55 is the pest speed to max at, however short bursts to 65 arent too bad. Over 55 the mpg goes way down. Most folks would swap to 3.73 or 4.10 gears . The 3.08gears in the M1009 are too tall, it needs 3.73.

 

[Recovry4x4]

50 mph = 2421 RPM, 55 mph = 2663RPM, 60 mph = 2905RPM and 65mph = 3147RPM. All this figuring in with your 400 Turbo, 208 case, 4.56 gears and 265/75R16 tires. Consider a 700R4 swap for the .70 OD and a 3.06 first gear. A well built 700R4 is a great tranny. The 700R4 would drop your RPM down to 2203 at 65mph.

 

[FMJ]

My 1008 with 33" Swampers drives nice at 60-65mph, and yes it is gutless......up here at 3500-4000ft elevation.........

I'm considering a Banks turbo install for mine.

 

[Recovry4x4]

Ed, 2943rpm at 60MPH and 3189rpm at 65MPH. For all your calculating needs. http://www.grimmjeeper.com/gears.html

 

[AJMBLAZER]

As the truck sits the easiest way to get better speeds is taller tires. Mine had 34" tall tires (36x12.5-16.5 HMMWV tires) when I got it and now has 38's (11.00R16 Michelins) and can do 65mph all day. It's SO much quieter and better to drive than it was. These things really need at least a true 36" tall tire to be drivable without OD gear in the trans.

Easiest way to get OD is to swap in a 700R4 using factory parts. Better is a 4L80E or NV4500 but they aren't cheap or easy.

Your speedo error is actually pretty decent. Most car makers will accept a 5% deviation in speedometer readings when new due to tire height differences and other factors. I wouldn't bother dicking with yours until you get the big tires on it. Fix it then.

 

[86M10086.2L]

yes, the gear vendors unit is expensive. But in most likelyhood thats what I'm gonna install on my M1008. I have a 4 inch lift on mine with factory rims and Nitto Terra Grapplers 285/75R/16's. I run 50-55mph tops I've done jaunts at 60 mph but it makes me nervous. I plan on using all the lift that I installed so I don't plan on running any tire bigger than a 33. Also when I find a wreck, I'm gonna do a SM465 swap. Larger tires, or gears and are a much easier and cheaper solution to the mph/mpg/rpm issue these trucks have, however they are a quite permanent solution. They work all the time no matter what, whether you want it or not. The overdrive unit or a overdrive tranny lets you select when you want it and still utilize the attributes the original setup provided. Thats why I'm getting a gear vendors unit. When I'm in the woods, the mud or on the beach I want my 4.56's. But most people don't use their trucks like me, so you have to decide what your doing with it. I was about to buy a M1009 and not use the truck that much, but its cheaper inthe long rung to buy tho overdrive unit. Just my two cents.

 

[AJMBLAZER]

yes, the gear vendors unit is expensive. But in most likelyhood thats what I'm gonna install on my M1008. I have a 4 inch lift on mine with factory rims and Nitto Terra Grapplers 285/75R/16's. I run 50-55mph tops I've done jaunts at 60 mph but it makes me nervous. I plan on using all the lift that I installed so I don't plan on running any tire bigger than a 33. Also when I find a wreck, I'm gonna do a SM465 swap. Larger tires, or gears and are a much easier and cheaper solution to the mph/mpg/rpm issue these trucks have, however they are a quite permanent solution. They work all the time no matter what, whether you want it or not. The overdrive unit or a overdrive tranny lets you select when you want it and still utilize the attributes the original setup provided. Thats why I'm getting a gear vendors unit. When I'm in the woods, the mud or on the beach I want my 4.56's. But most people don't use their trucks like me, so you have to decide what your doing with it. I was about to buy a M1009 and not use the truck that much, but its cheaper inthe long rung to buy tho overdrive unit. Just my two cents.

Go read some of MaxPF's threads in the diesel forum on CK5. He's spectacularly unimpressed by the GV unit. Not as tough as some seem to think and has some definite flaws for a 4x4.

Dude, you could fit 35's easy with a 4" lift. Why stick with 33's? Even with 38's I'm still undergeared!

 

[ARMYMAN30YearsPlus]

What is the biggest tire I can put on my M1031 sorry if this is a hitch hiker on your post but they are brothers

 

[AJMBLAZER]

Armyman, there was a thread on here recently that addressed that. You might do a search for M1031 and tires and see what comes up. I think the word was that the rear wheel wells on the box limited the tire size compared to the pickups.