62 GMC Transmission ID 3spd Overdrive?

[Smo_King]

Trying to pin down the actual tranny type and #. Confused from what I have read on 6066/google.

Is this a factory 3 speed OD? Or can u add this aftermarket?

Gears run good as well as OD. It freewheels when engaged, there is an OD cable in cab, and from tracking the wires down there is a solenoid switch on dash as well.

Thanks for any info. LB 305 V6

original owner has been naggn me to buy it back. After I have spent two years cleaning up his messes lol.

http://www.ebay.com/itm/1955-1956-19...bfa706&vxp=mtr
best numbers match i have found. is there another number i missed maybe?

[Old Truck Man]

That's the original Muncie trans. The front case is the same as a three speed. The overdrive is all contained in the tail housing

[slorio]

Smo King:
That tranny with 4 bolt side cover is a 3 speed with non sychro first gear that was used in Chevies from the mid 50's through mid 60's. It is not factory for your GMC, however. They are great trannies that make up for the trucks being geared down in the rear end. One of the best additions to my 1966 GMC. I have the later version with 7 bolt side cover that has a synchro first.

Hope that helps.
Regards,
STeve
New Orleans

[Smo_King]

Thanks. Still confused after that haha. Not original tho hmm. Guess that explains the floor shifter spot in my cab. Is the rear end original then?

Is it a Muncie / BW if it is not orig?
SM31
T85 or T85N
Saginaw
http://www.classictruckshop.com/club...5n/rebuild.htm
http://speedprint.com/deves50/overdriveindex.php

[Old Truck Man]

Your overdrive trans is a Muncie used from 1955 thru 1966. The full syncro Saginaw was used beginning in 1965. if you look at the bottom bolts holding the trans to the bellhousing. the truck trans uses two bolts that screw into the trans lower mounting ears. the car trans in a truck requires longer bolts with nuts to make it work.

[Smo_King]

Originally Posted by Old Truck Man

Your overdrive trans is a Muncie used from 1955 thru 1966. The full syncro Saginaw was used beginning in 1965. if you look at the bottom bolts holding the trans to the bellhousing. the truck trans uses two bolts that screw into the trans lower mounting ears. the car trans in a truck requires longer bolts with nuts to make it work.

tyvm OTM!

[Old Truck Man]

Ok here are pictures. The first is of two Muncie overdrives. the next two are of the mounting flanges. notice one has threads and the other doesn't. the last two are of a Saginaw overdrive trans, notice the threads in the lower mounting flanges. overdrived did come factory installed in pickups. the threads in the lower mounting flanges proves these where factory installed in trucks.

[Smo_King]

Originally Posted by Old Truck Man

That's the original Muncie trans. The front case is the same as a three speed. The overdrive is all contained in the tail housing

So you are saying what po says. It is a factory 3 speed OD or there were factory 3ODs.

[Old Truck Man]

Originally Posted by Smo_King

So you are saying what po says. It is a factory 3 speed OD or there were factory 3ODs.

Yes The two overdrives that I have with the threads in the mounting flanges where personally removed from Pickups by me. the Muncie from a 66 and the Saginaw from a 68. and it looked like a factory install to me. both had a pull cable under the dash and a switch under the gas pedal. Back in the day you could special order almost anything. That is what Nickey Chev did. you could get 427 Camaros & Novas from them. So a factory installed overdrive in a pickup is entirely possible.

[1963c-10]

The 12 bolt rear end wasn't factory installed in 62 either, wasn't used until 1963. Someone probably swapped a bunch of parts of a later model truck. Does it still have the torsion bar front end?

[Old Truck Man]

Originally Posted by 1963c-10

The 12 bolt rear end wasn't factory installed in 62 either, wasn't used until 1963. Someone probably swapped a bunch of parts of a later model truck. Does it still have the torsion bar front end?

I have no idea if the overdrive in the original posters truck was factory installed. I just don't rightly know. I do know the two I have from all appearances where factory installed. Ive seen lots of weird stull. I seen ford Mustang three speed trans factory installed in Pontiac GTO,s and Olds 442,s -322 Buick engines factory installed in fifties chev trucks. Pontiac & olds engines factory installed in fifties GMC trucks. Ive seen 63 chev pickups with the flat faced cowl like the 64 thru 66. The only shure thing I know is there are no shure things. Im 62 and the older I get the less I know Why couldn't all my problems & questions have came along back when I was a teenager and knew everything? Its all good

[Old Truck Man]

Ok here is another weird transmission that several know it alls have told me never came from the factory. I used to drive it. It came with a 327 engine and TH 400 three speed trans 456 gears and no spin rearend.

[Smo_King]

Originally Posted by 1963c-10

The 12 bolt rear end wasn't factory installed in 62 either, wasn't used until 1963. Someone probably swapped a bunch of parts of a later model truck. Does it still have the torsion bar front end?

Yes tbar front end. Does the 12 bolt explain why I keep ending up with the wrong brake hardware? Even the front ones tho.

* as far as mine being original I am not sure/positive or saying? pics alone show it to be newer looking than rest of truck or rebuilt.

[1963c-10]

A good link on the TH400 transmissions
http://en.wikipedia.org/wiki/Turbo-Hydramatic

[1963c-10]

Originally Posted by Smo_King

Yes tbar front end. Does the 12 bolt explain why I keep ending up with the wrong brake hardware? Even the front ones tho.

Yep. Look for brake parts from the 12 bolt rearend..63-64 were 17 spline and they went to 30 spline in 65, but the majority of the brake parts are the same. They did have self adjusting rear brakes in late 64 I believe....a pic of the brake assembly with the drum off would help id it.

Stock rear end was the HO32 for 60-62 chevys....gmc's used dana's

[Smo_King]

Originally Posted by 1963c-10

Yep. Look for brake parts from the 12 bolt rearend..63-64 were 17 spline and they went to 30 spline in 65, but the majority of the brake parts are the same. They did have self adjusting rear brakes in late 64 I believe....a pic of the brake assembly with the drum off would help id it.

Front and back both have auto adjusters. Great info I have had problems with the brakes all winter. 3 sets of wtf parts.

[Old Truck Man]

Originally Posted by 1963c-10

Yep. Look for brake parts from the 12 bolt rearend..63-64 were 17 spline and they went to 30 spline in 65, but the majority of the brake parts are the same. They did have self adjusting rear brakes in late 64 I believe....a pic of the brake assembly with the drum off would help id it.

Stock rear end was the HO32 for 60-62 chevys....gmc's used dana's

Ok most of the time GMC used danas. My 62 GMC broke a axle. So I pulled it out and had to remove the rear diff cover remove a retainer bolt pull out a pin and horse shoe clip. the end where the horse shoe retainer fit was thicker than a axle from a 55 thru 59 chev. however a axle from a 1960 chev was the exact match. so apparently my 62 coil spring GMC truck had the chev rear end. I still have the old girl. It is over at my old place. Not too much left I used it hard for many years. The GMC speedometer it had showed past the 100,000 miles. It had over 500,000 miles when it finally died from metal fatgue. Badly bent frame! I went thru 4 engines several transmissions and two rearends. but Ill try and get a picture of it later.

[1963c-10]

Originally Posted by Smo_King

Front and back both have auto adjusters. Great info I have had problems with the brakes all winter. 3 sets of wtf parts.

Get parts for 1964+ 12 bolt and you should be in business.

[Old Truck Man]

Ok Im back I went to my old place and snapped a few pictures of my old GMC. as you can see it was a coil spring rear end.