Looking For 3-Speed Manual Trans Ratios - The 1947 - Present Chevrolet & GMC Truck Message Board Network

C10 - C90 Bill · 01-07-2007, 02:22 PM

Looking for the gear ratios on '60 to '66 3-Speed Manual transmissions.

Typically on a 6 cylinder trans.

Any info would be appreciated.

b454rat · 01-07-2007, 04:22 PM

Dunno the numbers of the tree speed, maybe here??

http://members.cox.net/jeepinrandy/r.../transinfo.htm

ol Curt · 01-07-2007, 04:35 PM

Here's the 4 speed, looking for the 3

GM Saginaw transmission ratio identification
# of grooves 1st 2nd 3rd 4th Notes:
0 2.85 2.02 1.35 1.00
1 2.56 1.81 1.37 1.00 Third gear on cluster has 25 teeth
1 2.56 1.81 1.44 1.00 Third gear on cluster has 21 teeth
2 3.11 2.20 1.47 1.00
3 3.50 2.48 1.65 1.00

*** The grooves are found on the input shaft. I am sure there are exceptions to this rule.

ol Curt · 01-07-2007, 04:41 PM

Quote:

Originally Posted by ol Curt

Here's the 4 speed, looking for the 3

GM Saginaw transmission ratio identification
# of grooves 1st 2nd 3rd 4th Notes:
0 2.85 2.02 1.35 1.00
1 2.56 1.81 1.37 1.00 Third gear on cluster has 25 teeth
1 2.56 1.81 1.44 1.00 Third gear on cluster has 21 teeth
2 3.11 2.20 1.47 1.00
3 3.50 2.48 1.65 1.00

*** The grooves are found on the input shaft. I am sure there are exceptions to this rule.

I believe these are the different ones for the three speed...
Saginaw 3-speed 1st 2nd 3rd
No Lines (grooves) 2.85 1.68 1.00
1 Line (groove ) 2.54 1.50 1.00
2 Lines (grooves) 3.11 1.84 1.00
3 Lines (grooves) 3.50 1.89 1.00

C10 - C90 Bill · 01-07-2007, 07:07 PM

Appreciate all the replies.

I should have mentioned earlier that the standard issue, non-synchro first gear trannys are what I believe are Muncie's. I did a little research and I believe they are SM 318 Muncie's which sound right to me.

b454, I searched the sight that you mentioned and saw just about every one but a SM 318. I also believe the last year GM used them was '66 or '67.

Curt, Do you know if the ratios you listed would also be for a SM 318?

ol Curt · 01-07-2007, 09:16 PM

Not for certain they are exact, but all were close to those listed.

ol Curt · 01-10-2007, 09:16 PM

I found 3 speed gear ratios for a couple of trannies listed for a 66 C10 if you're interested.

The service manual just lists a Saginaw 3 speed, a Borg Warner wide ratio and a BW Overdrive. The first two did not have a syncro first gear.

Let me know.

Bob (ol Curt)

rwgregory · 01-11-2007, 04:25 AM

According to the GM Factory Overhaul Manual, May 1968 edition the SM 318 gear ratios are:
1st- 2:94 to 1
2nd- 1:68 to 1
3rd- 1 to 1
Rev.- 3:14 to 1

ol Curt · 01-11-2007, 07:40 PM

The numbers I had were from the '66 Chevrolet Truck Shop Manual....I'll assume you no longer need them

C10 - C90 Bill · 01-12-2007, 12:29 PM

Appreciate the replies.

Curt (Bob), Sorry I've been a little slow to your response, I've been away from the computer for a few days. The numbers rwgregory listed seems to be the ones that I have been looking for, but also wondering if they match with the info that you have from your '66 Shop Manual. (2.94 1st)

ol Curt · 01-14-2007, 01:42 AM

Yup, same

C10 - C90 Bill · 01-14-2007, 11:49 AM

Quote:

Originally Posted by ol Curt

Yup, same

Thanks

rmccloye · 06-15-2012, 09:26 PM

How do i get a hold of one those manuals? I'm rebuilding my SM318 this august.

1Bad62Pro/Street · 06-15-2012, 11:09 PM

Here you go:
http://67-72chevytrucks.com/vboard/s...=327764&page=2

http://www.nastyz28.com/chevy-manual...tification.php

http://67-72chevytrucks.com/vboard/s...ad.php?t=66523
Posted via Mobile Device
Posted via Mobile Device

rmccloye · 09-15-2012, 08:55 PM

Thanks. I am also on the search for some highway friendly rear end gears. I try to stick to two lane highways when traveling and even at 55-60mph my truck is whining. I've been looking and how comfortable do you think I'll be with 3.08 and sm318 with 700-15 tires? I hope to get an sm420 or sm465 soon but sticking to this for now.

01-07-2007, 02:22 PM	#1
C10 - C90 Bill Registered User Join Date: Nov 2001 Location: Moneta, VA USA Posts: 3,081	Looking For 3-Speed Manual Trans Ratios Looking for the gear ratios on '60 to '66 3-Speed Manual transmissions. Typically on a 6 cylinder trans. Any info would be appreciated.

01-07-2007, 04:22 PM	#2
b454rat Senior Member Join Date: May 2004 Location: Binghamton, NY Posts: 3,461	Re: Looking For 3-Speed Manual Trans Ratios Dunno the numbers of the tree speed, maybe here?? http://members.cox.net/jeepinrandy/r.../transinfo.htm __________________ 2000 GMC CCSB 454/4L80 6” lift SAS 1999 Chevy CCSB 454/NV4500 6” lift 1999 GMC Yukon 350/4L60 4" SAS

01-07-2007, 04:35 PM	#3
ol Curt Junior Member Join Date: Dec 2006 Location: Newburgh, IN Posts: 1,247	Re: Looking For 3-Speed Manual Trans Ratios Here's the 4 speed, looking for the 3 GM Saginaw transmission ratio identification # of grooves 1st 2nd 3rd 4th Notes: 0 2.85 2.02 1.35 1.00 1 2.56 1.81 1.37 1.00 Third gear on cluster has 25 teeth 1 2.56 1.81 1.44 1.00 Third gear on cluster has 21 teeth 2 3.11 2.20 1.47 1.00 3 3.50 2.48 1.65 1.00 *** The grooves are found on the input shaft. I am sure there are exceptions to this rule.

01-07-2007, 07:07 PM	#5
C10 - C90 Bill Registered User Join Date: Nov 2001 Location: Moneta, VA USA Posts: 3,081	Re: Looking For 3-Speed Manual Trans Ratios Appreciate all the replies. I should have mentioned earlier that the standard issue, non-synchro first gear trannys are what I believe are Muncie's. I did a little research and I believe they are SM 318 Muncie's which sound right to me. b454, I searched the sight that you mentioned and saw just about every one but a SM 318. I also believe the last year GM used them was '66 or '67. Curt, Do you know if the ratios you listed would also be for a SM 318?

01-07-2007, 09:16 PM	#6
ol Curt Junior Member Join Date: Dec 2006 Location: Newburgh, IN Posts: 1,247	Re: Looking For 3-Speed Manual Trans Ratios Not for certain they are exact, but all were close to those listed.

01-10-2007, 09:16 PM	#7
ol Curt Junior Member Join Date: Dec 2006 Location: Newburgh, IN Posts: 1,247	Re: Looking For 3-Speed Manual Trans Ratios I found 3 speed gear ratios for a couple of trannies listed for a 66 C10 if you're interested. The service manual just lists a Saginaw 3 speed, a Borg Warner wide ratio and a BW Overdrive. The first two did not have a syncro first gear. Let me know. Bob (ol Curt) Last edited by ol Curt; 01-10-2007 at 09:18 PM.

01-11-2007, 04:25 AM	#8
rwgregory Registered User Join Date: Apr 2005 Location: Chula Vista, California Posts: 495	Re: Looking For 3-Speed Manual Trans Ratios According to the GM Factory Overhaul Manual, May 1968 edition the SM 318 gear ratios are: 1st- 2:94 to 1 2nd- 1:68 to 1 3rd- 1 to 1 Rev.- 3:14 to 1 __________________ rwgregory 67 GMC 2500 ,2w/d wide box 305 V-6, 4-speed

01-11-2007, 07:40 PM	#9
ol Curt Junior Member Join Date: Dec 2006 Location: Newburgh, IN Posts: 1,247	Re: Looking For 3-Speed Manual Trans Ratios The numbers I had were from the '66 Chevrolet Truck Shop Manual....I'll assume you no longer need them

01-12-2007, 12:29 PM	#10
C10 - C90 Bill Registered User Join Date: Nov 2001 Location: Moneta, VA USA Posts: 3,081	Re: Looking For 3-Speed Manual Trans Ratios Appreciate the replies. Curt (Bob), Sorry I've been a little slow to your response, I've been away from the computer for a few days. The numbers rwgregory listed seems to be the ones that I have been looking for, but also wondering if they match with the info that you have from your '66 Shop Manual. (2.94 1st)

01-14-2007, 01:42 AM	#11
ol Curt Junior Member Join Date: Dec 2006 Location: Newburgh, IN Posts: 1,247	Re: Looking For 3-Speed Manual Trans Ratios Yup, same

06-15-2012, 09:26 PM	#13
rmccloye Registered User Join Date: Oct 2009 Location: Fayetteville, AR Posts: 23	Re: Looking For 3-Speed Manual Trans Ratios How do i get a hold of one those manuals? I'm rebuilding my SM318 this august.

06-15-2012, 11:09 PM	#14
1Bad62Pro/Street "Where were you in '62?" Join Date: Jul 2004 Location: Cleveland County, North Cackalacky Posts: 5,013	Re: Looking For 3-Speed Manual Trans Ratios Here you go: http://67-72chevytrucks.com/vboard/s...=327764&page=2 http://www.nastyz28.com/chevy-manual...tification.php http://67-72chevytrucks.com/vboard/s...ad.php?t=66523 Posted via Mobile Device Posted via Mobile Device __________________ PROJECT: "FULL METAL YELLOW JACKET" 1962 Chevy C-10 Stepside Shortbed Nostalgia Pro/Street Pickup Truck PROJECT: "FULL METAL YELLOW JACKET Build Thread What Are You Workin' On? - 1Bad62ChevyPickup PROJECT: "TYRANNORAMBLER REX" 1969 AMC Rambler American Nostalgia Pro/Street Youtube Channel: Father Son Projects Youtube Channel: 2TIMOTHY2FITHTEEN "North and South Carolina Folks Click Here!" (((( ~ I have Parts For Sale & Miscellaneous Stuff ~ )))) "Well being as there's no other place around the place, I reckon this must be the place, I reckon...Nyuk Nyuk Nyuk" -Curly Howard Ph.D. Last edited by 1Bad62Pro/Street; 06-15-2012 at 11:18 PM.

09-15-2012, 08:55 PM	#15
rmccloye Registered User Join Date: Oct 2009 Location: Fayetteville, AR Posts: 23	Re: Looking For 3-Speed Manual Trans Ratios Thanks. I am also on the search for some highway friendly rear end gears. I try to stick to two lane highways when traveling and even at 55-60mph my truck is whining. I've been looking and how comfortable do you think I'll be with 3.08 and sm318 with 700-15 tires? I hope to get an sm420 or sm465 soon but sticking to this for now.



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