Highway speed of 5ton

[jasonjc]

I just looked up so info on tire speed ratings. Here is a link to what I found. If any one knows more or finds out more pleas post it. thank you.

Tire Speed Ratings - Tire Load Ratings -

 

[Hammer]

The test consists of a tire mounted in a fixture at the rated inflation pressure and applied to a wheel at the equivalent of the rated load in a room at 77F. To pass the test (and receive the rating) the tire must sustain the speed without failure for 10 minutes. There is a warmup procedure that is tied to the speed rating desired.

 

[Hammer]

So, for my 16.00R20 tires, rated at 14,540 lbs and 115 psi, they are rated at a MAX speed of 55 mph.
This is FAR different from how we are typically driving these.
My truck weighs around 20k.
Which means about 5,000 lbs on each front tire, and 2,500 lbs on each rear tire.
And on my last trip, cruising 65 mph, on 100° days on fresh BLACK pavement, and my tires were barely warm. Mainly because of ambient temperature cause by the very hot pavement.
Anyways, my 20k lbs is nothing compared to the total weight rating of the tires at 87,240 lbs.

 

[Hammer]

Oh, and when the tire manufacturer states the Max Speed, they are not referring to a speed rating like mentioned above. But getting the info on how they rate tires like that is kind of tough.
Medium and heavy truck tires are not speed rated like passenger tires.

 

[steelsoldiers]

80's IH Air Force Crew Cab 4x4 9L. Internationl. Just happen to have what you need.

Me like!! That would be the ultimate camping and tailgating truck!



To Jim, the original poster, please don't take all of the negative comments personal. I know you are new to SS. Most, if not all of us, have thought about doing the same thing or have done the same thing when we first got into the hobby. After a while, we realized that these trucks were not made for speed. Just because they can do it doesn't always mean we should. We try to triumph safety over all else here. It doesn't always happen, but we try.

Ultimately it is your decision. We all have opinions and you know what they say about opinions. What ever you decide to do, just keep your safety and the safety of others in mind. A 49-53" tire going out at 65 mph on the steering axle could have deadly consequences.

 

[bubba_got_you]

[FONT=&quot]i don’t think an mv is what you need in this situation. Speed is not what these trucks where built for. These trucks are off road HEAVY LOAD movers. Now I understand the cool thing and I drive my m37 almost dally but it is only around town at about 35-40mph. I have done 65 in the m37 (its modified) on 1-2 hour drives with no problems but my azz hurt and I could barley hear. I know the m37 is not what you are talking about but it is only 6000lbs and the 5ton is a LOT more and a LOT louder. [/FONT]

 

[BugEyeBear]

OK, so let's say I have an M54A2 with the LDS Multifuel, the stock tranny (Spicer 6352 w 5th in the down position, i.e. Direct, non OD), and stock 11-20 NDT tires.

Is my safe highway cruising speed 50-53MPH?
What would my RPMs be at this speed?


AND IF I were to swap in an OD Tranny (Spicer 6453) what sort of top speed increase could I expect?
Does anyone have the gear ratios of these two trannys?
(I could calculate the speed difference if I had that...)

Thanks!

 

[emr]

Truth to be told, It I believe is more than my opinion it is the militarys also, top speed of these trucks safe is 40 mph with the big tires, now that may seem silly, but I really think doing over 55 to 60 with an experienced driver ready to handle what comes next is the most that anyone should do, but then again it is to each his own, tires rated at 50 mph are just that , one can try to wiggle anything they want, and sure they will go faster, But when the hits the fan and someone gets hurt and the truck is said by measurements to have been doing 65 and the truck and tires where never built for that , it is a big ...Guilty...and when one of these trucks lets go at these speeds of over 60 and even less, i do not care how many trucks U have driven it will only be luck to save, well alot of it will be luck there is always experience to help out, But all in all, trying to make these race trucks , I always have to chime in and say please do not do it,

 

[BugEyeBear]

OK, I'm NOT trying to race the thing...

I simply asked what the SAFE highway cruising speed is stock (without over-revving), and what sort of improvement I could expect if I installed an OD tranny.

You can't legally do 40mph on the highway, so that answer doesn't help me.

I thought it was a pretty simple question....

"JEEEEEZ........"

 

[emr]

It was, But as usuall it goes to how fast can some get these trucks to go, I only offer friendly advise, and hope it is taken that way, But again those who want to know how fast usually think its alot more than it is and the next question is how fast can I make it go...hence the over drive tranny so actually U did...U need flashers under forty around here on an interstate in a truck, And alot/most highways are well suited for 40, I do push up to 60 with my M925 sometimes and 55 with My M35 But that is only on rt 80 , and do the slow drive everywhere else, The M809 series is probably the least suited for highway use in long term because It is running the gear box from the gasser days and is very very low geared, They whine,changing the tranny ? then U need to change the gears in the rears also, then U need to upgrade the brakes, they were not made to go faster than the gasser either... And all in all i actually think that is what makes em sooo cool though, i have an M 813 and love that over rev when shifting it makes the truck to me...all the best, ...Randy

 

[BKubu]

Randy, as usual, I agree with you. Most guys forget that these tires were not designed to be run over 60 MPH and, in fact, I have had Michelin XL 1400s that were marked 55 MPH max. I have also had others where I did not see that warning so I am not sure if it was the run, or if the warning was no longer required. Suffice to say that they are not Z rated tires! Also, factor in the brakes, They were rated to stop the vehicle at slower speeds...I GUARANTEE you of that. The point is that these trucks were not designed for speed. If you want speed, you don't want a military truck. If you want durability in a rugged design, you want a military truck. Heck, I would rather buy a civilian rig to move my military trucks than vice versa.

By the way, I agree with Chris S...the only military vehicle that is capable of a consistent 70+ MPH is a Freightliner...but go try to find one. If you find more than one, please let me know as I would sell anything I have to get one!

 

[BugEyeBear]

It was, But as usuall it goes to how fast can some get these trucks to go, I only offer friendly advise, and hope it is taken that way, But again those who want to know how fast usually think its alot more than it is and the next question is how fast can I make it go...hence the over drive tranny so actually U did...U need flashers under forty around here on an interstate in a truck, And alot/most highways are well suited for 40, I do push up to 60 with my M925 sometimes and 55 with My M35 But that is only on rt 80 , and do the slow drive everywhere else, The M809 series is probably the least suited for highway use in long term because It is running the gear box from the gasser days and is very very low geared, They whine,changing the tranny ? then U need to change the gears in the rears also, then U need to upgrade the brakes, they were not made to go faster than the gasser either... And all in all i actually think that is what makes em sooo cool though, i have an M 813 and love that over rev when shifting it makes the truck to me...all the best, ...Randy

Thanks for the info Randy.

My understanding is that the M813 (M809 Series) has the Spicer 6453 Tranny WITH Overdrive (5th in the UP position I believe).
Whereas the M39 Series with the Multifuel have the NON Overdrive (5th in the DOWN position) Spicer 6352 Tranny.

I'm currently considering the purchase of an M39 Series Multifuel truck & I'm trying to determine what the typical highway speed is for this vehicle.
I'm assuming that the LDS Multifuel will run safely up to 2500 RPM, with a recommended cruising RPM of 2200 RPM.

So what I'm specifically asking is:
-What highway speed does an M39 Series with stock 11-20 NDT tires, LDS Multifuel engine, and stock Non-OD Tranny do?
At 2200 RPM?
At 2500 RPM?
-& what is the final drive ratio of the 6352 non-OD Tranny? Is it 1:1?
-& what is the final drive ratio of the 6453 OD Tranny?

Thanks!

 

[emr]

Well now that u may have all the opinions about what each of us feels U were asking that is sure to the point, and as a Jeeper, I see from your vehicles i must say i am also a jeep freak,... I have driven both vehicles for some distance and must say not exact but U are looking at low to middle 50's mph for those rpms, in my opinion and memory, some one may know exactly.I do not have any info for u on the other but there are guys who will chime in that know a heck of alot more than me, good post, ...

 

[vtdeucedriver]

Thanks for the info Randy.

My understanding is that the M813 (M809 Series) has the Spicer 6453 Tranny WITH Overdrive (5th in the UP position I believe).
Whereas the M39 Series with the Multifuel have the NON Overdrive (5th in the DOWN position) Spicer 6352 Tranny.

I'm currently considering the purchase of an M39 Series Multifuel truck & I'm trying to determine what the typical highway speed is for this vehicle.
I'm assuming that the LDS Multifuel will run safely up to 2500 RPM, with a recommended cruising RPM of 2200 RPM.

So what I'm specifically asking is:
-What highway speed does an M39 Series with stock 11-20 NDT tires, LDS Multifuel engine, and stock Non-OD Tranny do?
At 2200 RPM?
At 2500 RPM?
-& what is the final drive ratio of the 6352 non-OD Tranny? Is it 1:1?
-& what is the final drive ratio of the 6453 OD Tranny?

Thanks!

I have a M52A2 and a M54A2, both direct drive.
1st answer at 2200 you should be about 40-42 mph, at 25 to 26 you will be at 50. I usually run at 45 but have seen 50 at time and I try to pay attention not to burry the throttle there.
The 6352 is 1 to 1...........Direct Drive
I dont know what the 6453 is but there are guys out there with them that will get to 60 at 2600. I WANT TWO OF THESE BAD!!! So if that tells you anything.
It just makes the multi 5 ton drive like a deuce. I am not trying to win any races either, I just want to bring those RPM's down.

Yes the OD trans has 5th towards the dash.

 

[BugEyeBear]

Yeah, I know my Deuce will cruise on the highway "comfortably" at 50-55mph.

& I was just trying to determine what to expect in the M39 Series with the non-OD Tranny.

THANKS "vtdeucedriver"!
I had a feeling I'd lose approx 5mph with the non-OD Tranny.
You have confirmed that!!
Looks like it will be a VERY LONG recovery trip if I do decide to purchase this 5-Ton.

I'm thinking that MAYBE down the road I might consider swapping in an OD Tranny. Not so much as to increase the top speed, but to simply allow the LDS Multifuel to spin at slightly lower RPMs...

IF I SOMEHOW come across 3 of the OD Trannys I'll let you know!!

 

[laserlee123]

Two weeks ago I bought a M820a2, 5 ton expandable van back, and drove it from Ohio to Minnesota, It was slow, 50 mph, loud and terrible mileage, 4 to 5 mpg. I since replaced the ten 1100-20 tires with 6, 1400-20 radials., which might get it going faster, but Y\you would be better off getting a car trailer and a f350 or f450 pickup to pull it, or a flat bed tow truck. I have a four car hauler also, that would do a much better job transporting a race car or three than my 30,000lb 5 ton m820.

Or what I use for hauling Harleys, see attached pic'S a 48 ft Featherlite and a ford f450. 7.3 turbo diesel .

Unless you need to drive of roadmost of the time the 5 ton, is not the way to go.

 

[BugEyeBear]

OK, I just ran the numbers...


Assuming a non-OD Tranny 1:1 in 5th gear, 1:1 Transfercase Output in High, 6.44 Axle Ratio, 11x20 Tires (42" Dia, 131.947" Circumference).


This will provide 19.40 MPH for every 1000 RPM that the engine turns.
So at 2000 RPM you'd be doing 38.80 MPH
at 2200 RPM = 42.68 MPH
at 2500 RPM = 48.51 MPH
(These numbers agree with what "vtdeucedriver" reported above.)


Then I found a posting that said the Spicer 6453 OD Tranny has a final drive ratio of 0.78.
IF THIS IS TRUE the folowing speeds would result:
at 2000 RPM = 49.75 MPH
at 2200 RPM = 54.72 MPH
at 2500 RPM = 62.18 MPH
These numbers seem kinda high!?!?


Can someone please confirm what the 5th gear ratio is in the Spicer 6453 OD Tranny??
This will allow me to calculate accurate MPH numbers...

 

[Driver523]

Kinda jumped in here late and haven't read all the posts yet--but I'll throw this photo in just for the heck of it---I have posted it before, Its the Ace of Spades with the 6453 out of a Mack M-54----with just a little twi-king to the IP-----hope you can tell something from the tach & speedo--------Driver

 

[Driver523]

Oh yeah---Ace is a Multi Fuel

 

[BugEyeBear]

Kinda jumped in here late and haven't read all the posts yet--but I'll throw this photo in just for the heck of it---I have posted it before, Its the Ace of Spades with the 6453 out of a Mack M-54----with just a little twi-king to the IP-----hope you can tell something from the tach & speedo--------Driver

Looks like you are doing approx 70 MPH at 2800RPM?

Is that what I'm seeing??


Using the numbers calculated in my above post, an OD Tranny would provide roughly 69.64 MPH at 2800 RPM.
Seems to agree with your results.

Even so, I'd STILL like to have someone confirm the final drive ratio of the Spicer 6453 OD Tranny.....