I've been trying to aqcuire a saginaw 3 speed overdrive transmission to put in my 53 chevy pick up truck. I have a regular 3 speed full synchro in it now. The closest I've come is, I purchased the back end of a 3 speed (full synchro) overdrive thinking that I can mate it to my regular 3 speed. Is this possible? I read an article that someone posted on here somewhere stating that it would not be possible due to some internal linkage which locks out the overdrive when the transmission is shifted into reverse. I PREVIOUSLY STATED THAT Cosmo49 POSTED THAT INFORMATION BUT THAT IS NOT THE CASE. Is this conversion really not possible? Is there any way around it? Any help would be appreciated. I also linked a screenshot of the article and my non od tranny and the tail end of the tranny that I picked up. In advance, THANK YOU! http://i395.photobucket.com/albums/pp34/sickytwisted/Screenshot_20170331-205536.png http://i395.photobucket.com/albums/pp34/sickytwisted/IMAG0081.jpg http://i395.photobucket.com/albums/pp34/sickytwisted/20170401_082647.png http://i395.photobucket.com/albums/pp34/sickytwisted/20170401_082721.png
If you're working with a TRUE Saginaw 3 speed, and not a later Muncie (rare), Borg Warner, or the earlier Muncie 318/319, and the overdrive unit is in fact from a Saginaw, then it should be possible. I'd consult the Saginaw 4 speed to Saginaw 4 speed with overdrive conversions being done. The Saginaw 3 and 4 speed transmissions use the same case and mainshaft, but the case will need to be modified (hole drilled and lever made). If the overdrive unit you have is from any other 3 speed, then it won't work, even if it's the R-10 Borg Warner unit used with other 3 speeds. The early Muncie 3 speed with overdrive, and the Saginaw 3 speed with over drive, use the R-10 Borg Warner unit, but they are not the same, and the mid-plate/bolt-up is different. Rather than do all that work, find a Saginaw 3 speed with overdrive to start with. Consult ChevyTrucks.Org/tech/overdrive.htm for the Saginaw 4 speed with overdrive conversion; the mods (drilling the case hole and fabbing the linkage) would be the same for a Saginaw 3 speed. Get the rebuild gasket kit, and you will see where on the gasket the hole needs to be drilled in the case; the same gasket kit is used with both Saginaw, with or without overdrive, 3 speeds. I am Butch/56sedandelivery.
Saginaw 3 speed case without overdrive will not accept a Saginaw overdrive unit. The o/d unit that mates to the case is a larger O.D. than a tail shaft housing without overdrive. Of course the case could bored to size & a hole drilled for the reverse lockout shaft. If your truck is some what stock, use the older peanut Muncie 3 speed with overdrive, they are plentiful & cheap. Saginaw's with overdrive are not cheap.
I put links to pictures in the original post. I started taking things apart and honestly, I think it'll work once i drill a 3/8 hole for the lockout. The gasket between the front and rear of the tranny came out intact and left a clear impression on the case where the hole needs to be drilled. I dont know about a lockout lever as I haven't read the article but in a 3 speed overdrive, does the 3/8 rod not serve as a lockout? Does anyone have a link to that article? Does anyone have a picture of what this tab looks like and it's location? Hey 42Merc, I have a lot invested in this saginaw so I'm going to keep going with it until I can't. Hopefully things won't get to that point.
The reason I said to make sure you actually had a Saginaw transmission, is because a lot of guys refer to the old 55-65 Muncie 318 trans as a "Saginaw"; the Muncie 319 is just a Muncie 318 WITH overdrive. Somewhere I have the article from a magazine that details the Saginaw 4 speed with overdrive swap. There are also a few 3 speed transmission that were not early Muncie's, or later (1966) Saginaw's, such as the HD, full synchro Muncie (rare), the Borg Warner T-85 for GM applications (also rare), and the Ford Toploader/Dearborn used in some Pontiacs (crazy)! The Saginaw and later Muncie look very similar, and many guys don't know the difference. If I find the article, I'll send you a PM. I am Butch/56sedandelivery. OK, I found the article! Like I said, the Saginaw 3 speed and 4 speed transmission use the same case and similar main shafts; that's why the BW overdrive from a Saginaw 3 speed can be attached to a Saginaw 4 speed, although it takes some minor modifications. The early Muncie cases are different, non overdrive VS overdrive, and can't swapped back and forth, or their overdrive onto a Saginaw 3 speed/4 speed. Send me your name and address in a PM, and I'll send you the article. I WANT THE ARTICLE BACK! It does't copy very well or I'd just make a copy. I am Butch/56sedandelivery.
So i drilled a 3/8 hole for the lockout pin in the main case. Test fitted the parts and they fit perfectly. I turned the gears with my hands and things look to be aligned and moving together smoothly. I'm not a transmission mechanic. I'm not even a mechanic period, but from what I see so far, this thing is going to come together for sure. I just hope that I can keep this thread alive for the next guy who comes across this. Thanks so far fellas. Btw, seeing those gears intermingle with each other when I put the two halves together was so damn exciting!
The transmission is now in and working. Thanks to all who assisted me in this endeavor. I really appreciate it. Only thing I had to do to the case was drill a 3/8 hole for the lockout shaft (No welding of anything as would be needed on a 4 speed to 4 speed od swap), put the tranny together, wire it in and BOOM...70 MPH at mellow rpm's. I have straight pipes in mine and she sounds amazing doing 70. Thanks again.
What did you use for a shifter, or did you somehow use the stock column shifter? Did the stock 3 speed Saginaw R/1-gear shift fork have the correct pawl to work with the pin? How did you wire it up, and setup the engagement cable? I've got one of the OLD Muncie 319 overdrive trannys; I sold the 2 Saginaw 3 speed with overdrives I had, and now I regret doing that! It seems the Ford 3 speed/overdrives are easier/cheaper to locate, and there are a couple of different versions. There used to be a scattershield that bolted to a SBC/BBC/Late GM six, and had both GM and Fords transmission patterns. The Ford 4 speeds were stronger that the GM 4 speeds for racing, as were the MOPAR's. The Ford HD 3 speeds used the R-11 overdrive; a 4 pinion planetary (stronger), while the GM overdrives used the R-10 overdrives (weaker) with only a three pinion planetary in the overdrive. Mt thought was to find one of those scattershields, a T-85 BW or a 3.03 toploader 3 speed with overdrive, and it should be stronger than the GM versions. The 3.03 was also used in some GM cars; would it be possible to marry the 3.03 GM version with the 3.03 Ford version with overdrive, in order to get the overdrive? Finding the GM version would be the tough part! GM also used the BW T-85, but they are rare also; could one of those be used with the Ford T-85 version, and robbed of it's overdrive? I'm asking this of anyone who might know. I am Butch/56sedandelivery.
I used the stock column shift on it. I took the od butt and mated it to my non od main case after drilling that hole for the lockout. I got the wiring diagram from Cosmo49. He included an indicator light which I did not do, though I might. He's a very knowledgeable dude. For the engagement cable, I put a pto cable into the hole on the dash where the throttle cable originally went. I went with the pto cable because it needs to be a pretty substantial cable. Here's the wiring diagram.
Cool......years ago I swapped the old 3 speed saginaw out of my late 60s chevy pickup for a 55 chevy 3 speed O/D. I also used a PTO cable and a common on/off switch with no relay for the solenoid. It worked great for years 'til my kid destroyed the sprag unit one day. He installed a 700R4..no more shifting fun. The 292 got 17 MPG with the old overdrive trans and had 6 speeds forward.
Great to know you got it all working. I did the 3 to 4 speed conversion. This guy has a great manual that is worth picking up: https://fifthaveinternetgarage.blogspot.com/2015/10/borg-warner-r-10-r-11-tech-tips.html You might also want to look at some factory wiring diagrams. The one you posted will work, but a couple of additional wires will allow you to down shift out of overdrive for passing.
I had it wired with the coil interrupter and a toggle switch in the kick down circuit. When i kicked it out down, the truck would shudder and shut off. I have to look into that. Until then, I'll leave it as is. Sent from my SM-G920P using The H.A.M.B. mobile app
Guys I am going to revive this thread. I am new to HAMB and cant figure out how to start a new thread. Maybe I dont need to. This is first time I ever posted to one of these but I really need some help from someone that knows their crap. Obviously I dont. Starting to build from the ground up. Just gathering parts. So far, s-10 roller frame and some transmissions I bought the other day at auction. There are three trans but I cannot figure out what manufacturer they are based on what I have found on the internet. Maybe Saginaw or Muncie. Which one should I put behind a crate 350. Which is a better trans.. Cant find anything based on numbers etc. Please help. Attached are photos and info. 1) "X" GM 2 3918365 F207 (first two photos) 2) "X" GM 5 ???? with hurst shifter (second two) 3) GM 7 3952848 (last two)
The last two photos are of a Heavy Duty, full synchro, MUNCIE 3 speed. The others are of Saginaw 3 speeds. The Muncie is QUITE a bit stronger; used in trucks, and big block car applications using a 3 speed. Finding a direct bolt on shifter may be the hard part, but you can adapt things and make it work. The Saginaw's came in several different ratios ID'd by the rings on the input shaft. Use the Muncie if you plan on BEATING on it. A lot of people are't even aware of the Muncie 3 speed, and some think it's a Saginaw, as they look pretty similar. Both have a 7 bolt side cover, but the patterns are different; the top row of bolts tells the story, 3 top bolts Saginaw, 2 top bolts Muncie. Pick up a Saginaw; now pick up the Muncie. Big difference in weight? Strength? IMO, use the Muncie. I am Butch/56sedandelivery.
Thanks alot. That was quick. Glad I joined. Look forward to using your guy's knowledge to help me thru this first build.
Can you tell from the pics about what year range it came from in case I need to buy parts for it? Thanks again
mid 60s to late 70s? The trans with the extra mounting bolt hole on top, that started in 1973, used in trucks only.
Bruce would the trans work without the over drive lock out rod and just not move in reverse because of the overrunning clutch or would it hurt the transmission.
The HD Muncie was used 69-74. Why are all three transmissions painted silver, with a black side cover? Did they all come from a "rebuilder"? I am Butch/56sedandelivery.
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