Inliners International Forums General Discussion Drive Train 3 speed overdrive

Hi

I hope someone can give me some info on a mid 60's GM three speed over drive. My questions are if they are any good or not? What if anything should I look for,good and bad? And what is a average price for one of these trannys? Thanks for any info you can give.

Steve

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The overdrive transmissions with O.D. were like the non O.D. in the sense they were not high performance but they worked good when set up correctly..Not sure of the year but GM started installing fully syncronized three speeds in the later sixties..Pretty rare though..I had a 1967 El Camino that was factory stock with a 327 and three speed with O.D...It got great mileage and was great to drive in the city because you could use second gear and shift from low to high and vice versa...I grew up with overdrives and they were good for the lower horse power engines..My Willys four cylinder could cruise all day at 60MPH and get better than 30MPG..At 25 cents a gallon it didn't cost much to get around..I would put more overdrives in my Chevy trucks if I could find them..Especially the inlines I have..With todays gas prices it would be great to get the better mileage plus be able to get on it somewhat..All of GM's three speeds were pretty tough..You just can't abuse them much by speed shifting..Of course all the American manufactors built them at one time or another..and they too were not high performance..You will probably pay a good price for a good one..I keep checking the parts yards..They do show up once in a while..Always pull the side cover of any transmission to check for wear and damage.A guy tried to sell me a 1964 three speed with O.D. and after closer inspection I found the O.D. to be beyond repair..Overdrive seemed to go away in the 70's..In the eighties they seemed to reappear some..I might look for a newer one that I can fit into one of my older trucks.. It will probably be a manual shift but that would be OK..You can buy new O.D. units for a healthy price..That is another subject...Good Luck...AL...

The best GM 3 speed overdrive transmissions were used in the late 1960s and early 1970s Chevy and GMC pickups.They were mated to a Saginaw 3 speed transmission.I have been told the OD unit could be mated to a Saginaw 4 speed,giving you 8 forward speeds.I had OD transmissions years ago in Ford and Studebaker cars.I like them.You could drive along in OD and when you wanted to pass someone,you just step down on the gas and it is like passing gear in a automatic trans.I presently have a couple of the 55 to 57 Chevy types that I may be listing for sale.
EvilDr235


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Two types of people drive old cars.Rich people because they want to and poor people because they have to.
Remember EvilDr235 has a cure for Your sixness.

Seems I remember that the early 60s Chev 3 speed with od had two different input shafts. The one for 6 cyl narrowed behind the splines while the one for the V8 was thick. Sam

The ones with the splines machined under the t/o bearing coller were the Muncie 3 spd.transmissions with the 4 bolt side cover.GM quit using them in the mid 1960s.Both will fit V8 or 6 cylinder engines,but the 6 cylinder one was not a good idea behind a V8 with a heavy foot.The Saginaw 3 and 4 speed transmissions are from the same transmission families.The transmission shop that said the OD unit could be installed behind the Saginaw 4 speed was Transmission Exchange in Portland,Oregon.There is lots of Inliners club members in the Portland area that might be more helpful.There was the Tip Toe Matic overdrive unit made in Portland,but I think it was only made for closed driveline cars only.I once heard of a unit called a Watson box,but no nothing more about them.
EvilDr235

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Two types of people drive old cars.Rich people because they want to and poor people because they have to.
Remember EvilDr235 has a cure for Your sixness.

Hi

Thanks for the info on the 3 speed with od. I have the original tranny, 4 speed for my 53 3/4 ton, but not what I want to run long term. I want to be able to afford to drive this truck and I figured a saganaw 4 speed, or this 3 speed with over drive has got to be a better ride. My other option is a t-5 that I picked up for my 53 wagon which that project is on hold. Any Ideas on what is a good price for the 3 speed. Also how can I identify a overdrive tranny? This person started off with a price of 250.00 when I told himI could not afford that he said he would work with me because he had a truck bed full of different trannys and wants to get rid of them, but only had one 3 speed with overdrive. Any other info sure will be helpful.

Thanks Steve

The O.D. tranny will have a third lever towards the tail shaft for which the control cable connects..Plus the electric solenoid is evident..The saginaw four speed is from the same family alright..I found a Petersons transmission manual at a swap meet and inside is a lot of ratio information..The gear ratios between the three speed and four speed are pretty much the same..But you gain the third speed which a inline six could really use..I found (three) four speed saginaws at a local yard for five bucks each..The owner said GM couldn't built a tranny that was any good..FINE BY ME !!..Anyhow I put one in a 65 half ton with a stock 1974 250..It is a gas to drive...Pun ??..Price for an overdrive ???..Not sure..I think for $250.00 it should be in good shape..Or should I say it BETTER be in good shape..I would still be pulling the side cover to check it out....Al..

I've used the Saginaw overdrive in a '51 GMC pickup, and loved it. Adapting it to a 4-speed Sag tranny is fairly simple - see the tech article at Chevytrucks for details. What this article doesn't mention is that you'll need to relocate the shifter to clear the solenoid. Patrick's Saginaw/Hurst shifter makes this possible, but the mounting bracket has to be modified and the reverse gear rod and lever have to be flipped to clear the rest of the linkage.

Finding a Saginaw OD unit can be difficult, they were only used from '65-'72 when GM started using 5-speeds. The earlier Borg-Warner overdrives use a lot of the same parts, but the two won't interchange.

A true overdrive is great fun. It provides clutchless shifting (if you're in no hurry) because it contains it's own freewheel clutch. And the free-wheeling is a cool feature in itself, but you have to lock it out if you drive a lot of grades.

I'd still be using the OD except for the fact that parts are getting hard to find.

You are right Jack..The O.D. trannys and parts are hard to find..I put a nsw clutch in a early S-10 a while ago and I was impressed with it's five speed.Seems fifth was O.D. if memory is right..Muncie comes to mind...The top loader was a nice feature..I wish now I had checked to see if the mounting bolt pattern was the same as the older GM..Also seems I saw an adapter for sale to adapt this gearbox to Ford flatheads..To get the RPM's down on a daily driver I wonder how one of these would work...Al..

[This message has been edited by inlineidiot (edited 10-12-2003).]

I have 2 Borg Warner 3spd overdrives (mid '50's)that I could be talked out of for a reasonable price. One is in my '50 Chevy, and works great - might need a new output shaft bushing, but I may have that part as well. The other one was rebuilt years ago, and has been stored since. I have a T56 6 spd that I plan to use in place of the OD. I'm located 62 miles east of Portland, OR.

Evildr235 and Phamtom Shafter, I may be interested in one of those overdrives--I aquired one for my 50chevy when I go open driveline. I haven't had a chance to see if it's any good -- if not I will be needing one because thats with adoubt the way I am going.Also if I remeber correctly the low gear ratio is a little higher to be more compatable with lower rear end gears. Most factory overdrives had 3:70's and many were 4:11's and some Studes had 4:56's---Paul

[This message has been edited by paulweldit (edited 01-02-2004).]

Hey, guys, don't overlook the New Process (now New Venture) 5 speed OD transmissions now available.

The 3500 series has an integral bellhousing that will bolt up to late, >'62, Chevy blocks, or if you have an earlier engine, Buffalo has an adapter-early CBOP block to late Chevy bellhousing-and there may be other varieties without an integral bellhousing. This is all aluminum and plenty strong for our 6 cyl. engines.

For heavy duty use, the 4500 series is cast iron and comes with Chevy, Dodge, etc., bolt pattern that bolts to the appropriate bellhousing.

Both these transmissions also come attached to a transfer case if you wish 4WD.

While these transmissions aren't cheap, They are modern, efficient, and have parts readily available. They have been available since '92, so are becoming available in wrecking yards. Everyone doesn't know what they are, so go to your friendly dealer to see what they look like and keep your eyes open. I got a good one with transfer case for $600.



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When I converted my '50 Chevy sedan to open drive line, I installed a '56 station wagon rear end, so I could change the rear ratio easily. With a stock 230 motor and the '58 overdrive, the 4:11 gear worked great, cruisin, pulling a trailer or on the freeway.

I bought a Saginaw 3sp w/ OD yesterday. $300 cash complete with 2 solenoids. Do a search on car-part.com looking for '67 - '69 Chevy trucks.

Gene

If anyone is interested in early 3spd.od transmissions,email me at EVILDR235@WEBTV.NET--It may take me a day or two to reply.
EvilDr235

Evil Dr, I am sending you am e-mail as I am interested in the OD Trans. for my 50chevy--- Paul

Ed - the NV4500 also has the ability to put a PTO on it not unlike the old SM420's Would make an excellent box on a big truck swap when upgrading to a 250/292.

I have a '58 Chevy Apache w the original 235. I purchased an old Borg Warner overdrive and got a mechanic to marry the best parts from both trannys into one. We could find no schematics to figure out the wiring. He claims that I need a 4 way switch, like from a Studebaker, but I am dubious. I know there has the some other ways to hook this up. I'm driving it and it's on the truck but remains locked out. Can anyone assist with parts list, schematics, photos of various installs? Any connections in the greater Bay Area? Any help would be appreciated.

There is a wiring diagram, etc.. in the factory shop manuals of the period.