The age old transmission question

[Pearat]

As with many of these trucks my transmission is the problem. I've looked all around the internet and it seems like there's not a straight answer in swapping in a manual transmission. Can it be done or would this require disassembly of the engine so it could to be modified to accept a flywheel? Next question: what's the biggest hurdle in a full engine and transmission swap? Since a short jack shaft is used between the trans and transfer case is used it seems like just about anything can be used as long as the trans has a deep enough gear set to get the truck moving. Keep in mind I'm not looking for originality or off-road prowess. I do want to keep it 6 wheel drive but its primary purpose will be a weekend toy to take the kiddos around in and be in some of the local parades. Let the opinions fly!

 

[clinto]

The standard thing to covert the M135/M211 (G749?) series to manual transmission is to take the entire CCKW transmission and transfer assy and make them work.

This is a phenomenal amount of work. If it were my, I'd rebuild the Hydramatic.

 

[Pearat]

I saw that there is a master rebuild kit for the hydra matic, but it seems like there are an awful lot of specialty tools to get it rebuilt and tuned correctly. Does this seem accurate or is it doable without all of the tools listed in the TM?

 

[chestypuller1371]

should be able to swap a pickup v8 in and a 2wd tranny then run it to original tcase. since its a divorced setup easy for swapping.

 

[gimpyrobb]

In case you were un-aware, the front axle spins the wrong way, so you HAVE to keep the stock T-case.

 

[chestypuller1371]

In case you were un-aware, the front axle spins the wrong way, so you HAVE to keep the stock T-case.

couldnt you just rotate centerchunk of
front axle?

 

[Westech]

no you can not do that.

 

[chestypuller1371]

funny wonder how guys are running these 2.5 ton rockwells in swamp buggys around here with the np205 tcases then.

 

[clinto]

couldnt you just rotate centerchunk of
front axle?

You know the G749 series does not use the later G742 style of Rockwell axle?

 

[USMC 00-08]

I've got one of these transmissions that needs a rebuild too, so I am in the same boat as you. Would be neat to find someone in the Tulsa/OKC area that can rebuild them for a reasonable price.

I'd like to do it myself but really don't know what all is needed yet either.

 

[m1010plowboy]

Did that transmission ever work for you? I've got 5 years on one that shifted real hard between 2 and 3 when I bought it so we thought it was gone too.

New oil, screen filter cleaning, flushing, replacing loose linkage pins, adjusting linkage, engine rpm, throttle position, luck and driving it kept me going.

If you've gone through all the trouble shooting in TM 9-8024 pg 136, (M135/M211 Tm's) http://www.steelsoldiers.com/forumdisplay.php?118-Korean-War-to-VietNam-War-Vehicles-TMs ..............and know the transmission is done, there are options.

This is still a favorite of mine but guys have chiseled big blocks in the frame so anything can be done.

Detroit 6V53 motor and a four speed transmission
http://www.steelsoldiers.com/showthread.php?98983-My-first-heavy-truck-xm215

Rad to firewall length is a restriction as well as frame width. Did some dry fitting with a 350 last year and even the distance to the TC is questionable. Then there's the e-brake set up, single stage brake system, shift linkages, compressor, air system and 12v vs 24v decisions. With the right wallet and skill set all of this is manageable so it just comes down to choosing the set-up.

I've got cabs off frames and drive-trains sitting on pallets so if you need some measurements, let me know.

 

[Pearat]

I'd really love to keep the 302 and put a standard behind it. Some of the big trucks from the early 60s had a new process gearbox with a deep gear set. The GM heritage center even lists an 8 speed Fuller for '62 I think, but I'm sure those are very rare. The hydra matic in mine will get 1st and reverse but nothing else. Maybe it just needs cleaning and tweaking.

 

[m1010plowboy]

One of the symptoms of loose bolts on the shift lever (g) is...... No shifts - stays in 1st gear.....so that may be a good thing.

If it only ran in reverse, the problems could be bigger and calling Ordnance Maintenance Personell to (k) replace the rear-band would be the solution.

With it working in two directions there are 26 possible outcomes so tweaking could work. There is a 'front band' gauge on top of the transmission and it's adjustable so if your motor is running good, there's always hope.

I need to correct the page number I gave for 9-8024 trouble-shooting....the correct page is 163....not 136. We do this more as we age.

 

[USMC 00-08]

The hydra matic in mine will get 1st and reverse but nothing else.

That is exactly what mine does, but only in low range. Put it in high and it kills the engine. Nothing will move there.

 

[topo]

Has any one looked at the end of a crank on a 302 to see if it has a hole for a pilot bushing ? I bought a CCKW that has the 270 engine transmission and transfer case still in it that I don't need if any one is thinking of trying to swap over or have questions .

 

[chestypuller1371]

You know the G749 series does not use the later G742 style of Rockwell axle?

oh heck i dont know how i got here i have such a hard time finding my way around computers and these forums, sorry

 

[USMC 00-08]

Pearat... I was contacted the other day about this truck in Lamont, OK. The owner sold the land that the truck is sitting on and will close on it in about a month. The truck is going to be scrapped if he can't get it sold. They were asking $500.

Story with it is it was purchased from the local fire department, driven to the land and there it sat unused. Looks like it has sat a while, but maybe it would be a good transmission for you and a whole bunch of spare parts.

I have no connection with this and if I didn't just have a major car repair come up, I would have been interested in it. PM me if you want contact info on it.

 

[hendersond]

Yes it can be done I have flipped the center section to use a different T case. You have to grind the housing a little bit for clearance. You will see where when you pull the center section. Then you cut 0.75" off one end of the axle shaft. I cannot remember which one. Many have been placed in boggers and pulling trucks around here. There is plenty of spline. One of mine may get a TH400 2wd transmission this summer behind a chevy v8. You have to make some mickey mouse linkage for the transfer case to engage the front axle in reverse