C10 3 speed transmission question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wink05 · 08-21-2005, 11:24 AM

I'm in the process of planning a restoration on a 67 C10, currently with a V8 (non org 350), and 3 speed manual on the column. Question is......Was a 3 speed manual with overdrive offered as a factory option in the 67-72 C10s? If not, is there such a transmission from any other GM vehicle that would work?

Sweet72 · 08-21-2005, 12:37 PM

No OD trans were available for the Chevy trucks in '67-'72. Lots of folks here have done trans swaps and can offer good advice. If your interested in an auto OD 700R4, 2004R, 4L60 and 4L80's all will fit with some massaging. Welcome!

TP from Cntl PA · 08-21-2005, 02:45 PM

Sweet72.............I think your wrong on your observation. Owners manuals show the ratios in each gear and a 3spd with OD was listed in manuals.

71HUGGER396 · 08-21-2005, 03:22 PM

I think there was an overdrive unit on the 67 and 68"s. It was on option on the 3 speed manual. It sat behind the trans. Very rare.

Old Yeller 1970 · 08-21-2005, 06:59 PM

Is there an OEM manual with O/D that will work? Yes. The question is how much work you're willing to put into it to make it happen.
The O/D tranny's that come in Camaros, Vettes and late model trucks will bolt right up to your bellhousing but they could require different crossmembers and definitely require resized drive shafts.

Longhorn Man · 08-21-2005, 07:35 PM

Yes, there was an overdrive tranny. However, it is not of much value. Assuming you find one that works, you'll never get any replacement parts, and it'll basicly be a disposable part.
however, yes, there was a 3 speed manual with overdrive avalible with the inlines and the 283 and 307 engines. It was sold under RPO M10. It included the 4.11 rear gear ratio axle and you couldn't get any other gear ratio. It was avalible from 67 - 69, and only in C/10 models.

Longhorn Man · 08-21-2005, 07:38 PM

wink05, just noticing this is your first post...
Welcom to the board from Central ohio. Many ppl here from your neck of the woods.
You should be able to find out pretty much anything you want to know about these old trucks on this site...just ask and you'll probably get 5 answers.

What's the details of your truck...any pics? We love pics.

wink05 · 08-21-2005, 09:01 PM

Thanks for the quick and valuable info.........first post, not the last, with this kind of help. Photos later, just a 1 owner, barn find (outside the barn, that is!)........C10 SWB all orig, lots of Texas sun on it. Again thanks to all for your time and help.

Wink

Sweet72 · 08-21-2005, 09:50 PM

I thought I was wrong once, but realized I was only wrong in thinking I was wrong.

farside847 · 08-22-2005, 11:45 AM

Keep us posted if you do this swap! I would love an overdrive....

**pjmoreland** · 08-22-2005, 11:56 AM

I had a 67 with the three speed plus overdrive several years ago. The option was listed on the glovebox door, and as Longhorn Man said, it had 4:11 gears. It did get me as much as 21 MPG on the highway with a stock inline 6 engine, but I got greedy for power and got lazy and tired of shifting, so I swapped in a V8 and an automatic transmission.

farside847 · 08-22-2005, 12:04 PM

Quote:

Originally Posted by pjmoreland

I had a 67 with the three speed plus overdrive several years ago. The option was listed on the glovebox door, and as Longhorn Man said, it had 4:11 gears. It did get me as much as 21 MPG on the highway with a stock inline 6 engine, but I got greedy for power and got lazy and tired of shifting, so I swapped in a V8 and an automatic transmission.

How was it engaged? I heard somewhere that there was a pull knob on/under the dash that was pulled, then you let off the gas it would engage, then be on until you pushed the knob back? Did it work well for you or was it a PITA?

**pjmoreland** · 08-22-2005, 12:44 PM

I suspect that originally there may have been some sort of governer or something that assisted in shifting it, but if there was, it was long gone by the time I got the truck. There was a cable-actuated lever on the side of the overdrive unit, as well as an electric solenoid. The cable was activated by a nice chrome T-handle that was mounted to the bottom of the dash and said "OVERDRIVE" on it in large text. Pushing the handle in put the transmission into a freewheeling mode where the engine would go down to idle if I lifted my foot off the accelerator when I was driving down the road. There was a pull switch on the dash that activated the solenoid. The solenoid would engage the overdrive gear. I'd have to let off the gas and turn on the solenoid simultaneously, and once the engine RPM dropped the correct amount, the overdrive gear would engage with a CLUNK. I used it all the time because it got me better gas mileage, but it was a PITA. There were two things that bugged me about it. One was that if I didn't turn on the solenoid at exactly the right time, the overdrive gear wouldn't engage, and I'd blow out the solenoid fuse. The other annoyance was that if I forgot to turn off the overdrive, and came to a stop, I couldn't disengage the overdrive until I was moving again, and it would make 1st gear more like second, so it was a bit difficult to get going again. I definitely prefer the 700R4 transmission I have in my truck now, even if it isn't the most robust transmission ever made. It only cost me $65 at the local pick-n-pull wrecking yard and many hours of my own time (I like working on my truck anyway), so I'll enjoy it while it lasts.

Bruce68SB · 08-25-2005, 06:37 PM

There was a 3-speed with overdrive transmission option on our trucks. It was the saginaw 3-speed with overdrive. The main shaft and main case are interchangeable with the saginaw 3 speed and saginaw 4 speed transmissions. The overdrive unit was internal to the transmission. It was housed in a modified saginaw tail housing. I think they used a governor to tell it when to kick-in. There was the cable control, that basically locked out the over drive from kicking-in if you did not want to use it. There was also a soloniod control that was hooked to a carburetor kick-down switch. Also called a detent switch. In the mid 1970's Hot rod magazine published an article about making a saginaw 4-speed with overdrive transmission, from a saginaw 4-speed and a saginaw 3-speed with overdrive tail unit. Since the main case and the main shaft were interchangeable, it could be done. I actually did this myself. I had alot of fun with punching the trottle on the freeway and having it automatically kick down to 4th gear. The saginaw 3-speed with overdrive is out there, but I have not seen it much in the self-serve junk yards. But I bet collectors and trans shops have them. Hope this helps.

armyavncowgirl · 08-30-2005, 01:37 AM

i have a saginaw 3 speed transmission.

Livrat · 08-30-2005, 01:58 AM

Bruce68SB is almost correct on the applications..they also come in the mid sixties chev cars too but are fairly rare) and totally correct on the conversions using the Saginaw 4 speeds and the overdrive off the 3 speeds to make a 4 speed overdrive.. they are a blast to drive.. it is an easy coversion I have done several over the years.. Keep looking they are out there....

08-21-2005, 11:24 AM	#1
wink05 Registered User Join Date: Aug 2005 Location: Denison, Tx Posts: 25	C10 3 speed transmission question I'm in the process of planning a restoration on a 67 C10, currently with a V8 (non org 350), and 3 speed manual on the column. Question is......Was a 3 speed manual with overdrive offered as a factory option in the 67-72 C10s? If not, is there such a transmission from any other GM vehicle that would work?

08-21-2005, 12:37 PM	#2
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	No OD trans were available for the Chevy trucks in '67-'72. Lots of folks here have done trans swaps and can offer good advice. If your interested in an auto OD 700R4, 2004R, 4L60 and 4L80's all will fit with some massaging. Welcome! __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

08-21-2005, 02:45 PM	#3
TP from Cntl PA Registered User Join Date: Apr 2003 Location: Central PA....In the Berg of Nisbet Posts: 790	Sweet72.............I think your wrong on your observation. Owners manuals show the ratios in each gear and a 3spd with OD was listed in manuals. __________________ '72 K-20 EFI'ed 250 Inline/4spd stake body, Farm Truck '71 C-20 Cummins Diesel Powered, In storage thanks to $5.00 diesel! '69 3500 GMC 305V-6/4spd, Still under reconstruction.......... Inlines Rule! 6 soldiers standing is better than 8 laying down!!!!!!!!

08-21-2005, 03:22 PM	#4
71HUGGER396 Confirmed Truckaholic Join Date: Oct 2000 Location: Sarver,PA 16055 Posts: 732	I think there was an overdrive unit on the 67 and 68"s. It was on option on the 3 speed manual. It sat behind the trans. Very rare. __________________ 1968 50th STEP SIDE SHORTY, 350/350, a/c, ps, p,b Daily Driver, 1970 Cst short fleet, all black, 350/350, 1970 2wd Blazer, 2wd, 6 cyl. 3 spd, original, now a 454, 350turbo, 3.73 posi, on the road 1971 2wd fleet shorty, 454, 700r4, 3.73 posi, SOLD to 67OLDSTYLE72 "My rig's a little old but that don't mean she's slow" - SAWYER BROWN's Six Days On The Road SEMPER FI "I use to be a lean mean fighting machine, but now I'm a huffin, puffin, over stuffin love muffin"

08-21-2005, 06:59 PM	#5
Old Yeller 1970 DON'T TREAD ON ME Join Date: May 2005 Location: Crosby County, TX Posts: 989	Is there an OEM manual with O/D that will work? Yes. The question is how much work you're willing to put into it to make it happen. The O/D tranny's that come in Camaros, Vettes and late model trucks will bolt right up to your bellhousing but they could require different crossmembers and definitely require resized drive shafts. Last edited by Old Yeller 1970; 08-21-2005 at 07:01 PM.

08-21-2005, 07:35 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Yes, there was an overdrive tranny. However, it is not of much value. Assuming you find one that works, you'll never get any replacement parts, and it'll basicly be a disposable part. however, yes, there was a 3 speed manual with overdrive avalible with the inlines and the 283 and 307 engines. It was sold under RPO M10. It included the 4.11 rear gear ratio axle and you couldn't get any other gear ratio. It was avalible from 67 - 69, and only in C/10 models. Last edited by Longhorn Man; 08-21-2005 at 07:38 PM. Reason: Would you believe there were TYPOS in my responce?!?!?!?!

08-21-2005, 07:38 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	wink05, just noticing this is your first post... Welcom to the board from Central ohio. Many ppl here from your neck of the woods. You should be able to find out pretty much anything you want to know about these old trucks on this site...just ask and you'll probably get 5 answers. What's the details of your truck...any pics? We love pics.

08-21-2005, 09:01 PM	#8
wink05 Registered User Join Date: Aug 2005 Location: Denison, Tx Posts: 25	Thanks for the quick and valuable info.........first post, not the last, with this kind of help. Photos later, just a 1 owner, barn find (outside the barn, that is!)........C10 SWB all orig, lots of Texas sun on it. Again thanks to all for your time and help. Wink

08-21-2005, 09:50 PM	#9
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	I thought I was wrong once, but realized I was only wrong in thinking I was wrong. __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

08-22-2005, 11:45 AM	#10
farside847 Registered User Join Date: Feb 2005 Location: Bay Area, California Posts: 991	Keep us posted if you do this swap! I would love an overdrive.... __________________ 1971 Chevy C10 Shortbed Stepside, 307v8 3-on-the-tree

08-22-2005, 11:56 AM	#11
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,300	I had a 67 with the three speed plus overdrive several years ago. The option was listed on the glovebox door, and as Longhorn Man said, it had 4:11 gears. It did get me as much as 21 MPG on the highway with a stock inline 6 engine, but I got greedy for power and got lazy and tired of shifting, so I swapped in a V8 and an automatic transmission.

08-22-2005, 12:44 PM	#13
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,300	I suspect that originally there may have been some sort of governer or something that assisted in shifting it, but if there was, it was long gone by the time I got the truck. There was a cable-actuated lever on the side of the overdrive unit, as well as an electric solenoid. The cable was activated by a nice chrome T-handle that was mounted to the bottom of the dash and said "OVERDRIVE" on it in large text. Pushing the handle in put the transmission into a freewheeling mode where the engine would go down to idle if I lifted my foot off the accelerator when I was driving down the road. There was a pull switch on the dash that activated the solenoid. The solenoid would engage the overdrive gear. I'd have to let off the gas and turn on the solenoid simultaneously, and once the engine RPM dropped the correct amount, the overdrive gear would engage with a CLUNK. I used it all the time because it got me better gas mileage, but it was a PITA. There were two things that bugged me about it. One was that if I didn't turn on the solenoid at exactly the right time, the overdrive gear wouldn't engage, and I'd blow out the solenoid fuse. The other annoyance was that if I forgot to turn off the overdrive, and came to a stop, I couldn't disengage the overdrive until I was moving again, and it would make 1st gear more like second, so it was a bit difficult to get going again. I definitely prefer the 700R4 transmission I have in my truck now, even if it isn't the most robust transmission ever made. It only cost me $65 at the local pick-n-pull wrecking yard and many hours of my own time (I like working on my truck anyway), so I'll enjoy it while it lasts.

08-25-2005, 06:37 PM	#14
Bruce68SB Registered User Join Date: Jan 2001 Location: Pomona, CA, USA Posts: 90	There was a 3-speed with overdrive transmission option on our trucks. It was the saginaw 3-speed with overdrive. The main shaft and main case are interchangeable with the saginaw 3 speed and saginaw 4 speed transmissions. The overdrive unit was internal to the transmission. It was housed in a modified saginaw tail housing. I think they used a governor to tell it when to kick-in. There was the cable control, that basically locked out the over drive from kicking-in if you did not want to use it. There was also a soloniod control that was hooked to a carburetor kick-down switch. Also called a detent switch. In the mid 1970's Hot rod magazine published an article about making a saginaw 4-speed with overdrive transmission, from a saginaw 4-speed and a saginaw 3-speed with overdrive tail unit. Since the main case and the main shaft were interchangeable, it could be done. I actually did this myself. I had alot of fun with punching the trottle on the freeway and having it automatically kick down to 4th gear. The saginaw 3-speed with overdrive is out there, but I have not seen it much in the self-serve junk yards. But I bet collectors and trans shops have them. Hope this helps.

08-30-2005, 01:37 AM	#15
armyavncowgirl C10 Junkie Join Date: May 2005 Location: Fort Hood, Texas Posts: 194	i have a saginaw 3 speed transmission. __________________ 09 Chevrolet HHR --- Cruck --- cross between a Car and a Truck Former rides: 1967 C10 LWB 1972 C10 LWB 1969 C10 LWB (parts truck)

08-30-2005, 01:58 AM	#16
Livrat Member #1049 Join Date: Jun 2000 Location: Troy Montana Posts: 3,940	Bruce68SB is almost correct on the applications..they also come in the mid sixties chev cars too but are fairly rare) and totally correct on the conversions using the Saginaw 4 speeds and the overdrive off the 3 speeds to make a 4 speed overdrive.. they are a blast to drive.. it is an easy coversion I have done several over the years.. Keep looking they are out there....



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