transmission Questions

[poor rich]

I know there are 2 different styles of transmissions used in M37s, I use to know where to find a picture showing the difference between them but I cant seem to find it to reference.
The transmission bolt pattern of the bell housing of my 318 is different than my early transmission.
Is there any drawing showing the bolt pattern of the newer style transmission that I can use to see if it would match my bell housing?
Rich

[MSeriesRebuild]

I know there are 2 different styles of transmissions used in M37s, I use to know where to find a picture showing the difference between them but I cant seem to find it to reference.
The transmission bolt pattern of the bell housing of my 318 is different than my early transmission.
Is there any drawing showing the bolt pattern of the newer style transmission that I can use to see if it would match my bell housing?
Rich

The early transmission used in M37's have the same mounting bolt pattern as the NP420 that was used in the B1 trucks. The 2 will interchange perfectly as an entire unit with the original bell housing, however internal parts are very different.

The answer to your question, if your early style unit will not work on your 318, neither will the later NP420.

[M-Thrax]

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[poor rich]

O.K. , I measured my bell housing, the D.R. side bolt holes are 2 1/2", the P.S. bolt holes are 2 3/4". Not parallel but not as offset as the tranny.
Does anyone know, if the civilian tranny bolt holes are truly parallel?
The reason for asking is this is the sticking point for going further with the swap out. The adapter plate I built from 3/4" AL. works great for mounting, but the tranny shaft is now too short, also the clutch sits at the very edge of the splines, I shure could use that 3/4 inch.
If the bolt holes in the bell housing could be welded shut then re drilled would be good, except the housing is only about 1/4 thick everywhere but the existing holes.
Rich

[wvcharlie]

I had the same problem. I have a 65 M37 and thought that my 318 swap would bolt right up. It did not. I could not figure out what the problem was. I had talked with other guys who said that a 318 bell housing would bolt right up to a later model NP420. I finally figured out that at some point in time, an early model transmission AND bell housing had been swapped into my truck. You can swap early and late transmissions AND their bell housings and they will bolt up to the stock six cylinder block. Back to your predicament. It may be easier to locate an NP435 from a civilian Dodge two wheel drive pick up from the sixties or seventies. They were put in half ton up through two ton Dodge trucks. You need to get the bell housing and flywheel too. This solves the problem of input shaft length you might have using the military NP420. Be aware that there were different Dodge bell housing configurations that will bolt up to the 318. That is why it is easier just to get everything at one time from a donor truck. I ended up getting an NP435 from a big 1968 Dodge D400 truck after wasting several hundred dollars trying to get various bell housings to work with my NP420. If you get a bell housing set up for a hydraulic clutch, it makes the swap a lot easier. These were usually cast iron. I hopes this helps and you can avoid my mistakes.

[poor rich]

The engine and bell housing came from a 1990 dodge 1/2 ton, but the attached trans. was to long, it went with the rest of the truck to the boneyard last spring.
do you remember what the bolt pattern of the NP435 was?
Rich

[wvcharlie]

Yea, that was the first mistake I made. Most all the transmissions from the 1980's and newer have that long tailpiece and will not work. The bell housing you have might work with an older transmission. The problem is. they made several different versions of the NP435. I would say make a template of the bolt pattern on your bell housing and measure the depth. Then head for the salvage yards. I would still recommend getting everything from the same donor truck. Don't forget about a starter also as it bolts to the bell housing. Or take the bell housing along with you. You might get lucky and the salvage yard might just swap you bell housings if you are buying a transmission and all the other stuff. If not, there is always ebay. I have two "mistake" bell housings I need to get rid of.

[poor rich]

I got a good starter with the motor, I think I've got a line on a dodge truck with a NP435, maybe I'll be able to scavenge that bell housing. But a good idea to take the mine with, just in case.
Rich

[Lifer]

Having done any number of engine swaps over the last 50 years, that was one of my biggest pet peeves. Some transmissions came with short tailshafts, others with long ones, and (occasionally) some with interchangeable short/long tailshafts with their respective housings. It made swaps s-o-o-o much easier when you only had to change out the tail shaft. I think ALL transmissions should come with a choice of interchangeable end plates, short shafts, and long shafts, don't you?

[poor rich]

Interchangeability or adaptability, or a better source of technical information.
What we deal with is obsolete equipment and technologies, there are no trade secretes or patent infringements.
Don't you think in this day of infinite data storage and retrieval that there would be an archive of the big 3s records, blue prints, technical data, ect.


Today I stopped at the only boneyard, I'm sorry salvage and recycling facility in the area. They only deal in late model vehicles but I thought maybe they might have a np435 laying around. The terd behind the counter couldn't figure how to look it up without a VIN#! Oh well!

Rich