Any Transmission Or Overdrive Swap Recently

[Hummer Guy]

I know this is a dead and beaten on topic, but has anyone yet recently swapped over to a better overdrive transmission or transfer case that's readily available? If so, please tell us what you had to do and the details to it, how much you had to cut the driveshafts, did you need to move the transfer case back, did you have to move the brake hoses, and what you did for the parking brake etc?

I see tons of details and swaps for the engine, brakes, power steering, and other conversions but I don't see too many details or pictures of other transmission swaps, I know for sure there has to be somebody who has swap the transmission for a better one.

I would like to take on this task at some point so I can have a very low cruise RPM in the 55-60Mph range, while the 395s are alright, I would probably go back to the 9.00R20 size if I had a better overdrive, the truck felt way more peppy, turn sharper, and the brakes where better. I would go for another wheel and tire design over the NDTs if I took that route though.

 

[Sumner]

I really wish i had jumped on the Waterloo overdrive gears when they were still available. Been looking for an unused set, or even a trans that has em installed for a while now.

 

[biscuitwhistler37]

Not recent but I'm pretty sure @Jeepsinker has done both. If you don't want to mess with the trans, either rockwell or our version (cant remember 100% which) has a 4.90:1 swap for the axles, definitely not cheap though.

 

[Hummer Guy]

I really wish i had jumped on the Waterloo overdrive gears when they were still available. Been looking for an unused set, or even a trans that has em installed for a while now.

Yea same here, I never see any transmission with them on the market unfortunately, I never even see a truck with them on the market anymore

 

[Hummer Guy]

Not recent but I'm pretty sure @Jeepsinker has done both. If you don't want to mess with the trans, either rockwell or our version (cant remember 100% which) has a 4.90:1 swap for the axles, definitely not cheap though.

I don't want to imagine how bad the acceleration would be with 4.90s on the bigger tires with a load though

 

[Jeepsinker]

I have the Waterloo overdrive and 11.00R20 tires but I haven't changed my differential gears. I may in the future, but it's quite expensive and labor intensive.
I could've sworn that Ouverson offered a gear set in the neighborhood of the 5.13 or 5.30 range or something like that. Not sure I want to jump from 6.72 all the way to 4.90s, even with my Cummins. That would put a lot more strain on everything between the diffs and engine.

I do have an Eaton transmission that may go in someday, but I haven't done it yet.

 

[Hummer Guy]

I have the Waterloo overdrive and 11.00R20 tires but I haven't changed my differential gears. I may in the future, but it's quite expensive and labor intensive.
I could've sworn that Ouverson offered a gear set in the neighborhood of the 5.13 or 5.30 range or something like that. Not sure I want to jump from 6.72 all the way to 4.90s, even with my Cummins. That would put a lot more strain on everything between the diffs and engine.

I do have an Eaton transmission that may go in someday, but I haven't done it yet.

Yea, I've considered the OD Eaton 5 speed, but the one that can fit is very hard to find. I went from 395s back to the 9.00R20. I feel like the 395s put way too much stress on the truck and it really turns the truck from a slow goat to a slow pig, not to mention how awful the brakes are with 395s. I really would like to get 2,000-2,200 RPMs at 60Mph on the 9.00R20 tires.

Before anyone says it, my brakes are 100% operational and works perfect

 

[williamh]

I went with the 11rX20 tires. Get a nice smooth ride and it doesn’t put strain on the drive train ie. rubbing on anything.

 

[Cracked Pison]

I too am looking for an overdrive option... have a very low mileage stock drivetrain M35A2 and everything works great but the OD is barely OD and really limits my cruise speed. Ive been looking for a small AUX box like a brown sharpe OD box but that would make the drive shaft so short. Ideally i'd like to have a higher ratio 5th gear set to install in the trans but from what I read on here, there was one option that is now out of production... is that correct?
I have a 1970 diamond REO C114 thats just a hobby truck that has an eaton fuller 9513 that had no overdrive. I pulled it apart and did a "gear flip" (is what I understand it was called in the 70's) where I swapped the input gear and its mating gears on the counter shafts to essentially raise all of the ratios in the box. This produced 3 ODs when including the split. It works pretty well but if I were to pull a heavy load, the gear splitting gaps would be bigger than ideal.
All that to ask... is that possible/has anyone done it on the spicer 3053A? I've not taken mine apart, so I don't know - it might not be possible if the input shaft has the input gear made on it. I'd appreciate any advice on reducing the RPM at cruise speed. Thanks!

 

[Jeepsinker]

I too am looking for an overdrive option... have a very low mileage stock drivetrain M35A2 and everything works great but the OD is barely OD and really limits my cruise speed. Ive been looking for a small AUX box like a brown sharpe OD box but that would make the drive shaft so short. Ideally i'd like to have a higher ratio 5th gear set to install in the trans but from what I read on here, there was one option that is now out of production... is that correct?
I have a 1970 diamond REO C114 thats just a hobby truck that has an eaton fuller 9513 that had no overdrive. I pulled it apart and did a "gear flip" (is what I understand it was called in the 70's) where I swapped the input gear and its mating gears on the counter shafts to essentially raise all of the ratios in the box. This produced 3 ODs when including the split. It works pretty well but if I were to pull a heavy load, the gear splitting gaps would be bigger than ideal.
All that to ask... is that possible/has anyone done it on the spicer 3053A? I've not taken mine apart, so I don't know - it might not be possible if the input shaft has the input gear made on it. I'd appreciate any advice on reducing the RPM at cruise speed. Thanks!

The Spicer 3052 and 3053A transmissions do indeed have the input gear made onto the input shaft. And yes the Waterloo overdrive kit is unfortunately out of production.

 

[Hummer Guy]

I too am looking for an overdrive option... have a very low mileage stock drivetrain M35A2 and everything works great but the OD is barely OD and really limits my cruise speed. Ive been looking for a small AUX box like a brown sharpe OD box but that would make the drive shaft so short. Ideally i'd like to have a higher ratio 5th gear set to install in the trans but from what I read on here, there was one option that is now out of production... is that correct?
I have a 1970 diamond REO C114 thats just a hobby truck that has an eaton fuller 9513 that had no overdrive. I pulled it apart and did a "gear flip" (is what I understand it was called in the 70's) where I swapped the input gear and its mating gears on the counter shafts to essentially raise all of the ratios in the box. This produced 3 ODs when including the split. It works pretty well but if I were to pull a heavy load, the gear splitting gaps would be bigger than ideal.
All that to ask... is that possible/has anyone done it on the spicer 3053A? I've not taken mine apart, so I don't know - it might not be possible if the input shaft has the input gear made on it. I'd appreciate any advice on reducing the RPM at cruise speed. Thanks!

I've been thinking about doing a big block swap possibly, I would much rather a diesel but a gas engine can easily cruise at 3k RPMs which would make doing 55-60 easy. I know the MPG would drop but the cost between gas/diesel would make the operating cost roughly the same. Not to mention, the torque won't be too much different so not much more stress on the transmission.

I know the 395s bring the cruising speed to 55-60 but I feel like those tires put a lot of stress on the whole truck and in my opinion, it turns the truck from slow to extremely slow

 

[biscuitwhistler37]

Transmission swap ideas

So I’m just sitting here thinking about different trans swap ideas for the Deuce. This is not necessarily a pressing matter. Just thinking about if I ever had to put a trans in mine. Anybody ever put a 6 speed Eaton in? I know the ten speeds and such won’t fit but I was a heavy diesel tech and...

www.steelsoldiers.com

Couple good reads in there.

There was a thread I read a while back about a big block in a deuce, I don't remember what the results were, but it has been done.

 

[tooFATtoDRIVE]

Forgive me if I am talking a total bs here but how about using a two-gear auxiliary transmission box in a configuration changed 180 degree. This means that the output shaft is the input shaft.

So, if the auxiliary box had, for example, 1:2 reduction, the 180 degree setup would reduce the engine speed by half. Imagine, if the truck in question needed 2200rpm to cruise at 60mph, now it would be 1100rpm, assuming else was constant.

The question remains if two speed boxes, for example Fuller 2-A-92 or AT-1202 (see HERE), or perhaps the older version 2A62 (for this one I do not know the spec) could be run this way but there would be a benefit in reaching out to Eaton/Fuller technicians and asking this very question.

Whoever manages to get that info, please post it here, there might some of us contemplating such a modification and this knowledge would be a benefit to them and the forum as a whole.

Thoughts on the idea then?


Edit: I found the ratio info for the 2A62 auxiliary box:



Source: HERE

 

[tobyS]

My M35A3 4x4 has taken many different turns. We rebuilt the Allison 1545 and put a trans mount PTO on it, but that doesn't solve the 1/1 final ratio issue (so I have not put it in). I want highway speed and stuck with the 6.72, the shaft has to turn fast... aka OD. Eaton FSO would be my choice with the Cat3116, but I'm very willing to move the TC back and make a total replacement, engine and tranny. By not shortening it, I have to have a carrier that moving the TC back could eliminate and about anything could be fit. How about an 8.3 from a 5 ton?