Highway speed of 5ton

[grizcty]

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

Got a question, not related to the subject.
But related to the picture, with the AR platform you posted.

What is holding the AR secure in place?
Or is the barrel just placed through, & supported by the ring?

 

[saddamsnightmare]

November 28th, 2009.

TIME to look for a GM Topkick or General being auctioned out, or a Navy Peterbuilt or Autocar (there was a sweet pole setting truck on EBay a coupla weeks back), as they have the speed and power you want. Everyone forgets the M series were designed as off road trucks and if the engine doesn't limit the speed the axles will. You could install civillian axles and get the road speed, but you'd lose the off road capabilities pretty fast. One has to be realistic in one's wants, just go buy a civillian truck and be happy (Say a nice Mack B-71).

Just my .02,

Cheers,

Kyle F. McGrogan

 

[vtdeucedriver]

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...

I was just reading this and then thinking about a pic I have seen and then low and behold, larry posted it Makes me feel all warm and fuzzy with anticipation!!

Thanks for the help for finding a 6453 but I need one in the North East, but if ya do, tell me anyways.

 

[BugEyeBear]

"vtdeucecriver"

FYI: I started another thread related to this topic

http://www.steelsoldiers.com/5-ton-up/44115-spicer-6453-od-tranny-info.html

A couple of sources are listed there.

HOPEFULLY this thread will eventually help us to find 6453s at a reasonable price.

 

[Driver523]

In the 5 ton the 6453 bolts right up and matches everything---I have heard but don't really know that it wasn't the same with a deuce, the tranny tunnel different in a deuce????---Yeah Jeff--I took that photo---got a couple better somewhere----one the speedo is straight down----and ya know?---she rides better the faster ya go----The 6453 is one turn input and almost one and a quarter output-----If ya wanna do some fab work the Aux. gear boxes are good also---you can pick up a 3 speed--keep your front shaft---low--direct--and od---if you want to cut in the front end just go back to direct with the Aux. box---------Driver

 

[BugEyeBear]

In the 5 ton the 6453 bolts right up and matches everything---I have heard but don't really know that it wasn't the same with a deuce, the tranny tunnel different in a deuce???---------Driver

The Deuce OD & Non-OD Trannys are direct bolt-in replacements for each other.
Although unless you have a Gasser most people now have the OD Trans.

----The 6453 is one turn input and almost one and a quarter output-----Driver

A 1.25 output rotation would tend to indicate roughly a 0.800 ratio.
Which seems to support the numbers I calculated above.

 

[Driver523]

Now I may be wrong on all this BUT--this is what I have heard---When they came out with the Mack in the M-54 it was because we needed the higher horse power/torqe for the mountain passes in the highlands of VietNam---but with the lower RPM of the Mack ( 2100?? ) they then needed to bring the Mack up to speed with the higher RPM of the multi-fuel ( 2450 or 2650 I forget ), thus the over-drive tranny for the Mack and a compairable speed with the Multi-fuel-------could this be?------------Driver

 

[vtdeucedriver]

Hey Larry,
I believe I am right on this but I will work on it to confirm. What I do know is that the ENDT-673 was put in the trucks before VN ever really picked up. Hense how Jack brought over Mack powered M52A1's in 1966 with the 64th Trans.
The ENDT-673 was also a over the road Civie engine in Mack B-series trucks (I believe early 60's is when they started production ) so since the military wanted to remove Gas engine from the system, the MACK was installed. Just as the war picked up, the govt looked at this Multi-fuel engine..........the 427 for the deuce and then the 465's for the M35 and 5 tons. Since the war was picking up, they produced the multi-fuels to keep up with demand of combat losses with production trucks.

As far as gearing, yes the mack is a bull engine and the trans was matched with its powerband. Hense the difference with the multi. When talking with guys who drove tractors with macks. When climbing the passes, they wanted to stay within their powerband.........(have it written down somewhere and 2100 sounds right) Yet they would be overtaking a multi. If they came up on a multi, the mack guy would keep rolling at that RPM and give a push up the hill. I have a few miltary reports on feedback from maint units in vietnam about the reliabilty of the Multi in the field. Lets just say that it was not very good. Even talking with the guys with the 5th Maint BN (who did the heavy maint on 8th GP trucks) did not like them and did many changes due to blown engines caused by over reving.
I will see if I can find my notes on what the RPMS were between the engines on the passes.

 

[vtdeucedriver]

In the 5 ton the 6453 bolts right up and matches everything---I have heard but don't really know that it wasn't the same with a deuce, the tranny tunnel different in a deuce????---Yeah Jeff--I took that photo---got a couple better somewhere----one the speedo is straight down----and ya know?---she rides better the faster ya go----The 6453 is one turn input and almost one and a quarter output-----If ya wanna do some fab work the Aux. gear boxes are good also---you can pick up a 3 speed--keep your front shaft---low--direct--and od---if you want to cut in the front end just go back to direct with the Aux. box---------Driver

Hey larry, you sent me the pic of the speedo straight down a long time ago..............LOVED IT!!!

 

[BeardedWarrior]

I know this is an older post but I have a question.
I have a 1970 m818 I'm needing it for work in the oil fields but I also need to at least be able to do 65 at a decent rpm.

14-1600 rpm if doable.
I have a 400 big cam out of a wrecked kenworth that has 13 Eaton on the back of it and i've measured the engine compartment and with some Crisco and a shoehorn it should fit but my biggest issue I see right now is the gear ratio in the axles and the transfer case.

Has anyone ever tried to upgrade the axles from 4.60 to 3.70?
We've had this truck for quite a while and I'd like to put it to work we have most everything we need to upgrade it ourselves I'm even thinking robing the air bags off an old freightliner we have to help the ride.

Basically to do what we're going to be doing I need a 6x6 flat bed hauler that can at least do 65 on the highway without screaming and drinking know what I mean.

Basically what I'm asking is Does anyone know where I can get some axles and Xfer upgraded at for a decent price or if it's even possible.

 

[Robo McDuff]

I did not read the entire old thread again, but know the discussions about this topic: these trucks are not made for "high speed" OTR work, they are designed for average 50 mph slow work. Save yourself a lot of money and time and buy something that is suitable for your OTR needs. One big problem most forget: the brake system is a 70 year old single circuit design made for military trucks mostly going slow and in terrain. One little failure in that system while doing 65+ (or even a lot less) and you end up with 25K++ lbs dead weight which is breaking free and impossible to stop. You really don't want to be in or anywhere near that truck when that happens.

 

[simp5782]

If you upgrade your brake system you would be fine. A 939 series truck would be better. The overdrive transfer case helps at high speed.

Even a nhc250 with a few mods will benefit from a 13spd. A big cam would be better though.

They have various axle ratios available for the Rockwell axle as well as a power divider option in some civilian applications.

A 916 is a little tall but more powerful and suited for off and on road use.

Csmdavis is in Hattiesburg and will have most of what you need including a overdrive transfer case from a 939 truck.

Where in Mississippi are you?

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[98G]

I know this is an older post but I have a question.
I have a 1970 m818 I'm needing it for work in the oil fields but I also need to at least be able to do 65 at a decent rpm.

14-1600 rpm if doable.
I have a 400 big cam out of a wrecked kenworth that has 13 Eaton on the back of it and i've measured the engine compartment and with some Crisco and a shoehorn it should fit but my biggest issue I see right now is the gear ratio in the axles and the transfer case.

Has anyone ever tried to upgrade the axles from 4.60 to 3.70?
We've had this truck for quite a while and I'd like to put it to work we have most everything we need to upgrade it ourselves I'm even thinking robing the air bags off an old freightliner we have to help the ride.

Basically to do what we're going to be doing I need a 6x6 flat bed hauler that can at least do 65 on the highway without screaming and drinking know what I mean.

Basically what I'm asking is Does anyone know where I can get some axles and Xfer upgraded at for a decent price or if it's even possible.

I've got an M818 with the original transmission and axles. 16.00 super singles. It runs 65mph or so and gets about 7mpg. RPMs 2000ish.

 

[BeardedWarrior]

I'm in Alaska right now but I work all over.
I knew I'd have to upgrade the air breaks again we've got two trucks I'm planning on robbing parts from but the company I contract with has been having issues getting to some of the more remote places out here with stock highway trucks and the 80s 5ton they have isn't fast enough for what it's being used for there's a lot of double handling going on and I know I can make some serious cash if I can get this truck to do what I need it to.

I haven't started anything yet I'm just wanting to get some more insight on what I can accomplish with this rig.

I see a problem where I work and I see a possible solution but I would like to hear what people who know more about these things then I do think about the concept.

I'm the first to admit I know very little when it comes to these trucks but I'm willing to learn and listen to advise.

 

[simp5782]

It would be easier to just start over with a 939 series truck. Better brakes. Overdrive transfer case. And a bigger cab. But that is just me

There was a m931 tractor on the Facebook classifieds with a 350 big cam but needed a transmission for around 6k

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[sandcobra164]

I agree with Simp. I think you'd be dollars ahead to pick up a M931 or M932 tractor if you have a strong love for the NHC-250. Ideally you would find an M915 with a Cat 7155 trans to run the speeds you desire, have full air brakes and a Big Cam NTC-400. I personally have an M923 Cargo that hauls down the road comfortably at 60 or so mph at 1,900 rpm with 14R20 tires. It can run on the governor and show 72 mph on the GPS but the tires are only rated for 55 mph. Like some of the people who commented earlier in the thread, you need to define what you really want the truck to do. I love the M809 series trucks but like the M35 series trucks, you have a single circuit hydraulic brake system that will succumb to a single point of failure. The later M35 series trucks did go to a dual circuit brake system but the M809 series never adopted that as the M939 series trucks were already being fielded by then. We're all about good ideas on here and most are willing to help point you in the right direction.

 

[98G]

I agree with Simp. I think you'd be dollars ahead to pick up a M931 or M932 tractor if you have a strong love for the NHC-250. Ideally you would find an M915 with a Cat 7155 trans to run the speeds you desire, have full air brakes and a Big Cam NTC-400. I personally have an M923 Cargo that hauls down the road comfortably at 60 or so mph at 1,900 rpm with 14R20 tires. It can run on the governor and show 72 mph on the GPS but the tires are only rated for 55 mph. Like some of the people who commented earlier in the thread, you need to define what you really want the truck to do. I love the M809 series trucks but like the M35 series trucks, you have a single circuit hydraulic brake system that will succumb to a single point of failure. The later M35 series trucks did go to a dual circuit brake system but the M809 series never adopted that as the M939 series trucks were already being fielded by then. We're all about good ideas on here and most are willing to help point you in the right direction.

I think what suits his needs best would be a 916. Sounds like he gets into rough enough stuff to need the 6x6 that the 915 doesn't have.

The 809 and 939 series trucks are not road tractor specific enough to be ideal, even tweaked to bump up the top speed

A recent M916A3 would probably be ideal and require no mods....

 

[74M35A2]

Just checking in on this old dog. 67mph GPS verified, bone stock M925a2 @ factory governed 2150rpm on 14.00’s. Could easily exceed 70mph with the Pac Brake 5.9L governor spring kit and a few loosening turns of the fuel rack travel limiting nut.

 

[simp5782]

My 923 is for sale. She will run 65mph all day long in the air conditioning grossing around 65k.

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[BeardedWarrior]

I appreciate all the advice guys.
I'd like to use stuff I already have on hand and I'm sure your right about the larger truck.

The company has a 923 I think is what it is. It's hooked up to a 45ft flatbed but seeing as is so slow that drive it to a staging area near a road unload one truck and the load it onto the 923 and then it's around 47 miles to get to where their building this pump station we have another three months before we're scheduled to be done and then we have another one that's being surveyed 200 miles to the south east and it's in a similar Situation.

I just figure a truck that can go down to Anchorage pick up materials and then come back without having to be staged would save us time and money.

Again this is just me wondering if it's a waste of time or something that's worth the time and effort.

My brother is a professional diesel mechanic and he says he can build the truck in two Months at his shop but he says my biggest issue will be getting the gearing right in the axles and transfer case to run on all terrain highway tires.

Again I appreciate the advice it's probably something I'm going to have to tinker around with.

I'll let yall know what happens or if it works if nothing else I'll have a very unique conversation piece hopefully it's one my wife won't beat me over the head for.