M39 series 5 ton transmision swaps and axle info

[OPCOM]

Looking uin the FAQ I see this info:

M39/G744 Series
Engines
Continental R6602 Gasoline Engine- M39 series
Mack ENDT-673 Diesel- M39A1
LDS-465-1A Turbocharged Mutifuel Engine- M39A2

Transmissions
M39 and A2 series with Gasoline engine or Multifuel engines- Spicer 6352 5 speed/manual (direct)
M39A1 with Mack - Spicer 6453 5 speed/manual (OD)

Is it possible to use the overdrive transmission from the M39A1 Mack powered truck in the M39/A2 multifuel-powered truck?

I also notice the 5-tons use outer axle seals like the 2.5, yet I have not sen anyone complaining of leaking seals, like on the 2.5 ton trucks. Is it less ofa problem on the 5 ton?

anyway I am reading the manuals now, esp. about the axle ratios and the like.

 

[AMGeneral]

Well OPCOM,

The answer is YES,you can swap the OD trans to the gasser or Multifuel trucks,BUT it turns em into a real dog. The huge jump in gear ratios from 3rd to 4th in the OD trans takes you from 2100 rpm to 1100-1300 rpm with the Mack and "Cummins" powered trucks,way below the peak torque of both the gasser and Multi.

Granted,the truck will probably run 65+ mph with this setup,but it isn't really feasible.

True,the axle seals are similar,but I have several 5 tons that have leaking rear seals,I think it is just the fact that most people drive their 5 tons less than their deuces because of fuel mileage issues.

 

[jwaller]

I'm always fixing the axle seals in my 5T bc I put a lot of miles on it. I just don't post about it bc it's the same exact process as the deuce and I don't feel it need to blab about it.

 

[DaveP]

I'm always fixing the axle seals in my 5T bc I put a lot of miles on it. I just don't post about it bc it's the same exact process as the deuce and I don't feel it need to blab about it.

 

[OPCOM]

haha well that answers that.. I think an M800 series will be the better choice, but the limit is the Cummins engine at 2100RPM. Maybe with 53" tires.. 900 series are out of my price range, and also maybe slow too.

so, changing the question to the 800 series, is there any swap or upgrade for the Spicer 6453 transmission used in the 800 series w/ cummins? I'm looking for the ratios, have not paged though all the manuals yet.

 

[OPCOM]

I have looked through all the manuals and cannot find the gear ratios for the Spicer 6453. Does anyone have the ratios?


There is also a 6453A listed on some truck parts sales websites. I wonder what that is?

 

[Trango]

BTW, I was searching the net earlier today for this ratio, and then I remembered I have the Spicer 6000 book in the archives.

Checking that book shows:

6453 .78
6453A .83
6453B .78

This is straight from Spicer. I know this is too late for the original poster, but this may help someone performing a similar search.

Best,
Bob

 

[73m819]

I know that 819 has a hole between 3rd and 4th which I can drop the 819 in, now with the od, I'm either lugging in 4th or at the top of the tac in 3rd ,would changing to a NON od trans help, if I did that, what would be the top speed at 2100 compared to the od, . id be glad to give up a little top speed for a better driving truck, right now, on flat road, the 819 will do right at 65(1200s), right at tac, when i had my gasser m52, it drove great with the non od (55 with 1100s at tac, 53 a touch under tac), though it was like a pu compared to the 819

 

[Hammer]

Easy, top speed of the non-OD tranny will be the same as yours topped out in 4th gear (direct drive.) 4th Gear in the OD = 1.1, same as 5th gear in non-OD tranny.
Which, puts my 818 with the 16's on it back down to 50-53 mph if I was to go that route. Which is too slow for my usage.

 

[gimpyrobb]

I think I have a spare non-OD trans Ron.

 

[73m819]

what would this do for the 3rd/4th hole

 

[gimpyrobb]

Wish I knew Ron. I have a gasser M62 converted to multifuel so I usually start in low range 1 through 5 then shift to high range, 4 & 5th. Since I snapped a crankshaft and put in a new motor, I tend not to drive it far anymore.

 

[gimpyrobb]

I guess since 5th is now 1:1 it would put 4th gear somewhere in between.