M916A0 (AMi) and spicer 1750 aux transmission

So we went on another run earlier this week, only for a refill and just rough math in my head AMi gets about 4mpg at 55-58 mph. Also 55 is a bit slow going to a fire. She has no problems tanker yanking full to the top of water, so another .81 od behind an aux should get the top speed at 2100rpm to 69mph with no HP issues. Hopefully lowering the RPM will help with the MPG as well. I know it takes along time to pay for parts on MPG alone, so the mpg would only be icing on the cake.

Doing some research, I have found an aux transmission to throw behind the transfer. Spicer 1750, looks to be large enough to contain the torque



I know that I loose my front axle running in OD, but I can set it up so that the air operated part wont work unless the aux tranny is in direct.

Has someone done this before?

What other negatives am I not seeing.

Any suggestions, comments, complaints? I have read alot of threads on the duece's with the little brownie, but never saw one that someone actually did.

Rear driveshaft will be too short with a brownie box in there.

On 11R24s it should be around 2100 at 61mph with the cat transmission. Only other thing you could do is go to 16.00s. That will get it to reach 70. Or turn your gov spring up to 2300 or so.

The aux wont work as the driveline cant be made that short To go between them.

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You could look into this setup. This is a Transfer case/4speed aux made together by Dana/Spicer. I do not know the ratios. It should allow fitment. It is a totally different transfer case though. It is a Dana spicer transfer case the Aux unit is an 8031

https://www.globaltransfercasesupply.com/pdf/transfer-cases/spicer-h201-transfer-case-s.pdf

Can you switch to a regular manual transmission that has a lower OD, or double OD? I’m not familiar with your truck drivetrain config, but modern OTR trucks do what you want, unsure of their axle ratio vs yours.

Regular 916s have a .83 or and direct drive transfer case.

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It will run out to 2300, I dont like winding it that fast.

Cant go 1600's, it would be too tall for the trailer, already too tall but just biding my time to change out the 1100's on trailer to 11r24.5's.

I failed to look at the length on that spicer, 28" of driveshaft and 26" of aux gearbox, that wont work.

Has anyone found ring and pinion replacements that would work? I think the front will be the unobtanium.

155mm said:

It will run out to 2300, I dont like winding it that fast.

Cant go 1600's, it would be too tall for the trailer, already too tall but just biding my time to change out the 1100's on trailer to 11r24.5's.

I failed to look at the length on that spicer, 28" of driveshaft and 26" of aux gearbox, that wont work.

Has anyone found ring and pinion replacements that would work? I think the front will be the unobtanium.

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What about putting 1600s on the truck and 395 MVT and LMTV wheels on the trailer. Be your cheapest bet. We have pallets of 80 to 85 percent tires for cheap. It would give the trailer more offroad clearance as well

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simp5782 said:

You could look into this setup. This is a Transfer case/4speed aux made together by Dana/Spicer. I do not know the ratios. It should allow fitment. It is a totally different transfer case though. It is a Dana spicer transfer case the Aux unit is an 8031

https://www.globaltransfercasesupply.com/pdf/transfer-cases/spicer-h201-transfer-case-s.pdf

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So that setup runs the aux before the xfer. will do more research on that, any clue what it came out of?

155mm said:

So that setup runs the aux before the xfer. will do more research on that, any clue what it came out of?

Click to expand...

Cement mixer.

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It might be easier to just go Soni's way, change the ring and pinion

https://www.steelsoldiers.com/showthread.php?62707-M920-Differential-Gears

155mm said:

It might be easier to just go Soni's way, change the ring and pinion

https://www.steelsoldiers.com/showthread.php?62707-M920-Differential-Gears

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I dont know what the difference in the 915 rears and the bigger truck rears is. but ive got a 915 bogie that needs a home. I believe it has 4.44s in it per the part number in the TM. might be easier to swap the whole rear bogie over. I believe the suspension and everything is the same.

I know the yokes are different as they are mechanics style between the axles on the 915 and they are 1710 series spicers on the front axle input.

Can I get pics? Is it a cut off, frame, springs, axles? or just bogies with springs connecting them.

155mm said:

Can I get pics? Is it a cut off, frame, springs, axles? or just bogies with springs connecting them.

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I've got the whole 915 frame but I could cut it anywhere. I pulled the motor and transmission out. About the only pic I have until I get back home.

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your making to much work pull the axle shafts and replace the chunks if you want to re gear. once you have done the rear what are you going to do about the front I believe the awd front axle is different from the drivers.

snowtrac nome said:

your making to much work pull the axle shafts and replace the chunks if you want to re gear. once you have done the rear what are you going to do about the front I believe the awd front axle is different from the drivers.

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You are correct that the front is different, but if we get the backs working, then we (me and the mouse in my pocket) only have to find gears for the front.

155mm said:

You are correct that the front is different, but if we get the backs working, then we (me and the mouse in my pocket) only have to find gears for the front.

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Somewhere on here is a discussion about the 916 fast gearsets, and I believe that Soni got the last ones ever made or some such story.

simp5782 said:

What about putting 1600s on the truck and 395 MVT and LMTV wheels on the trailer. Be your cheapest bet. We have pallets of 80 to 85 percent tires for cheap. It would give the trailer more offroad clearance as well

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Click to expand...

Is there enough clearance for 395's on the trailer? I am hoping the 11r24.5's fit

NDT said:

Somewhere on here is a discussion about the 916 fast gearsets, and I believe that Soni got the last ones ever made or some such story.

Click to expand...

NDT,

I think that is the thread I link to on post #11