M35 Top Speed increase?

[DrFoster]

Again, Robert, putting an overdrive box behind the tranny is not so much a matter of cutting down the driveshaft, as it is moving the whole transfer case back a foot or so to fit such a device in there.

See, the tranny and transfer case are pinned together by a tiny little "spud shaft", which is a driveshaft made from two u-joints with a slip spline between em. Once you put that spudshaft into the equation, there is less than an inch to do ANYTHING between tranny and the accompanying divorced transfer case.

Me, I went to a .695 tranny, with 45" tires. My "theoretical" top speed on the flats is around 80 MPH.

PS, final bit of info, rear axle spacing is at 48".

I looked into this a little more. You're right about the spacing. HOWEVER, if a person was so inclined, they can put the splitter behind the transfer case and just use the rear tandems to get the better speed/mileage/acceleration/whatever.

This would be a deadly setup if you tried to go into 6x6 while trying to still split the gears behind the transfer case, but it is at least possible. I guess you'd have to take off your front driveshaft to keep from having a total failure from an "oops".

 

[rdixiemiller]

Saturn surplus has the adapters.

 

[Rattlehead]

Why not put an auxiliary trans after the transfer case, to run in high range only when in 4x6 mode on the highway? You probably won't ever need to go 60 mph + when in 6x6. At least I hope not.

Not sure how big those brownie box transmissions are, or what ratios they have? I would love to be able to do 60 on flat highway while turning 2000-2200 rpm.

 

[DrFoster]

^^^^ That's what I said up there ^^^^

 

[73m819]

that idea would be a desaster for a sprag unit

 

[bomar76]

tiui

 

[Recovry4x4]

The whole concept of speed increases on a vehicle that has marginal brakes to begin with leaves me scratching my head.

My sentiments exactly. While I woulnd't consider my brakes marginal, the entire vehicle was engineered for a max speed of 60 MPH back when the M34s came out. I think I'll just keep cruising a 55 and seeing all the wonderful things I've missed over the years, while moving at 70+.

 

[DrFoster]

I'm thinking about increasing MPG at 55, not breaking the sound barrier... Errr, I guess with the deuce it's almost GPM.... LOL

 

[cranetruck]

I calculate the mpg at highway speed (55-60mph)....

 

[DrFoster]

What do you get? About 7-8 with the crane hanging into the wind, or is it like a canvas rig at something like 10-12?

 

[Trango]

The kinetic energy difference between 60 and 65 MPH isn't that much of a killer... You're only talking about a 17% increase in braking distance.

For me, the coolest part about increasing the gearing is lowering RPM's AT 60 and AT 65... not necessarily trying to break the sound barrier by going 80 or whatever it is I could theoretically do.

Time to get motivated to go work on the junk...

 

[DrFoster]

Bob, call me at 720-629-4747 when you start working on your truck. I love doing that stuff and would be happy to buy the beer and give a hand.

 

[Trango]

Hi Robert,

Eh, pretty solitary work here... I'm making a little angled panel for the pyro. It's alot of sheetmetal work... lots of hammering, welding, grinding.... but I'm a couple hours away from being done.

Man, I just wish I were more motivated today. I've had just a killer week so far, and it's catching up to me today.

 

[wallew]

Brad900,
I have owned numerous trucks, none of them this large, but have on several occasions changed tire sizes. This required me to go to my local speedometer shop and they have always been able to get me within one or two mph of the correct speed. Worst the cost has ever been was $35 because they didn't have the reducer gear in house and I came in twice.

Find a local speedometer shop (most larger cities have at least one) and give them a call. You will know in less than two minutes if they can or will help. jim