New Process 440/MY6 3spd OD Trans

Impalaguru

Well Known Member
Supporting Member 1
Anyone ever heard of using one of these in a car? There were used in early 80s chevy pickups. Supposedly they are almost a direct bolt in for a muncie.
Ross
 

scotty t

 
Supporting Member 1
there is a guy on a corvette forum i visit that is running one i will get some info from him
 

oil4kids

Well Known Member
these transmissions are great, have low 1st of 3.09 and 4th gear is 0.73 overdrive. 3rd gear is 1:1

they are just like the 833 chrysler new process used in the mid 70s but have a heavier input bearing like the hemis used

there were 2 cases, but one bolts up like a muncie trrasns but need a bigger hole in the bellhousing
 

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Ronnie Russell

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Mark, In all honesty , I probably will not be using one these trans. , but the subject matter is interesting. Are shifters available for this trans, or does one have to be fabricated? How does the internal strength stack up to a M20 Muncie. Of course it is the overdrive gear that really got my attention. Quite frankly, a street car with 4 speed would benefit a great deal with this 3 sp with overdrive if strength is not sacrificed. Thanks for your input.
 

Impalaguru

Well Known Member
Supporting Member 1
Thanks for the info, guys!! From what I understand, it's a pretty rugged transmission. A friend of mine had one in an early 80s chevy 3/4 ton pick up with a 6.2 diesel. He drove that thing HARD!! He actually snapped the crank in it but the trans was fine! For me it sounded appealing because of the overdrive. I'd like to keep the RPMs donw on the highway so save the wear and tear on my 409. A majority of the driving I do with my car is highway.
From what I've read, they are the same length as a muncie. But looking a the shifter mount I think there would be some issues with it being back for for our type of cars. If you want to use the original shifter hole, that is. The shifter they used was, I think, an ITM Hurst knock off so I think mounting the shifter shouldn't be a problem. The problem would be moving the shifter forward. The linkage would probably have to be fabbed, too.
This is neat stuff!! Any other input is welcomed!!
Ross
 

scotty t

 
Supporting Member 1
I have detailed the conversion (probably in bits and pieces in several posts) on the forum. Please use the advanced search function in the C1/C2 section, and search for "MY6", and all posts by "plasticman" (in both current and archieved threads) .

Roughly, the MY6 was produced by New Process (Chrysler) for GM during 80 through 85 or so, for the full size light pickups. It is based on the Chrysler A-833 trans, which has a good reputation for durability and strength. There were 2 different bolt patterns (which require a different bell housing for each). I think the 1st version used the standard Chevy bell housing (truck version with the larger center hole, note the pass. car version that our Vettes came with). The truck version bell housing is still available via E-bay, bone yards, etc. The 2nd deign had an odd bolt pattern (that solved an interferance in bolting it up), but must be used with it's correct bell housing that was probably not used elsewhere!

If you are planning on putting this in a Vette that has the clutch stud bracket bolted to the side of the bell housing, that is an issue since the truck bell housing do not have that provision. I made a separate bracket, and has worked just fine.

The rear trans mount must be modified and spaced to work but again a no-brainer (at least in the C1 Vettes).

The overall length and splines/shafts are identical to the Muncie. No driveshaft mods required at all.

I and wmf62 used a Hurst Comp+ shifter, but the rods must be altered, and at least one lengthened. The mount for the shifter also needs to be designed or altered, depending on which shifter you use. My shifter tunnel hole had already been "enlarged" by a PO, and my shifter fits right in the same location, but on a new mounting plate. WMF62's 62 uses the original shifter hole, and we made a new mounting plate to keep it in that position (his Comp+ Hurst is different from mine in several regards, but they both "work").

The speedo is another issue, but a speedo ratio adapter box (easily available for $100 or less) fixes that (once you know the correction factor needed for your application).

The MY6 weighs about 30 pounds more than a comparable Muncie (only a rough guess). It is deeper in the main case "belly" than a Muncie, but otherwise about the same dimensions, and no tunnel mods required, and no issues hitting anything.

It has ratios of "about" 3.09 1st, 1.68 2nd, 1:1 3rd, and .73 OD 4th. Speed shifting is not it's strong suit. It is a very wide ratio box that needs an engine with a wide torque band. I am running a strong 350 with dual AFB's, and wmf62 is running a LT1 (350) with FI.
We are both very pleased with the results (and they have been in our Vettes for +1-1/2 years now). However, do not attempt to downshift this trans while rolling faster than 10 mph from 2nd into 1st gear (unless you double clutch, and 3rd to 2nd must be done with more care than a Muncie). Upshifts are no issue, but are not as fast as a good Muncie.
 

scotty t

 
Supporting Member 1
this info is from a corvette forum, it is not from my personal experience. it does sound interesting though.
 

Impalaguru

Well Known Member
Supporting Member 1
I thought I'd bring this thread back to post my updates on installing this trans in my 63!

I bought one on eBay last summer. I got the trans and a Chevy truck and a Dodge truck shifter. (Dodge also used this trans in their pickups the same time GM did) I also got the shifter mounts for both shifters. The Chevy truck shifter and mount proved to be useful later on. I had to find a truck bell housing. Very easy to do!

Like stated above, with the truck bellhousing, it's a bolt in! I used my factory clutch fork. The trans is a little heavier, wider and deeper but it fit in my car just fine. The mount pattern on the trans is the same as a muncie. I used a block mounted starter.

I had to move the shifter forward 1" and down maybe 1/2" inch, from where the mount location is on the trans. I modified one of the truck shifter mounts to get the shifter where I wanted it. I also had to use the 1-2 and 3-4 shift levers from the Chevy shifter, to help make room for the speedo cable. When I moved shifter forward it is very close to the drivers side, speedo hook up. Click here for a pic of the chevy truck shifter http://www.hotrodders.com/forum/picture-4-speed-56525.html

I fabricated my shifter linkage from some 3/8" bar stock. I cut some 3/8" fine threads so I could use my Hurst swivels. The truck linkage rods are useless for a car application.

For the speedo gear, I did some research and you can get the right plastic gear and housing to make it work. The other guys I corresponded with used an expensive ratio reducer. The gears and housings are the same as for a TH400. You have to get the correct housing to match the number of teeth on your plastic speedo gear. There are 4 or 5 numbers cast into the housing that correspond to the gears that work with that housing. Not sure why they are different.

How does it work? It works GREAT!!!! 65 is about 2000 rpm with my 27" tall tires and a 3:36 rear. Highway cruising is effortless. It shifts slower than the Muncie and not quite as smooth but it's not that bad. I won't win any races with this thing but so far it's just fine.
Ratios...
1st 3.06
2nd 1.56
3rd 1
4th .73

For less than $500 and a little time and research I have a nice overdrive transmission.

Ross
 
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