ring and pinion count- teeth versus GM stamp - The 1947 - Present Chevrolet & GMC Truck Message Board Network

vtwinsport · 11-08-2009, 03:50 PM

afternoon, I just pulled the diff cover and counted teeth on my ring and pinion.
43 on the ring and 10 on the pinion. that should give me 4.30 rearend gearing right?
There was GM stamping on the ring gear of 14:43 (along with some other number) which would indicate a 3.08 rear end, but the teeth count doesn't match up. Could a previous owner have swaped the ring gear but not the pinion?
what gearing do I have do you think?

Keith Seymore · 11-08-2009, 06:24 PM

If you counted 43 and 10 (and counted correctly) then you absolutely have a 4.30:1 axle ratio.

I can't explain why the ring gear was stamped 14:43 if you are only counting 10 teeth on the pinion gear.

It is not possible to swap the ring gear without swapping the pinion, because then the two gears would not mesh.

K

68 TT · 11-08-2009, 08:26 PM

Can you read the stampings on the end of the pinion gear?

vtwinsport · 11-08-2009, 08:40 PM

Unfortunately, it's all closed up now but I don't remember seeing any stamps on the end of the pinion, only on the ring.
I am pretty sure I counted properly but that ratio isn't one I've heard of before for these trucks. I must have miscounted.
I wanted to take a look before I ordered new parts and my desired ratio- 3.73.

**N2TRUX** · 11-08-2009, 09:04 PM

I think the 43 indicates your 4.30

James McClure · 11-09-2009, 09:44 AM

Vtwin, you determined the ratio exactly right as Keith indicates, BUT, you counted wrong. The stamping is right, (I have never seen the stamping be wrong BTW) you have 3:08 just like mine. To the best of my knowledge (33 years as GM tech), GM never made a 4:30 ratio gearset. 4:10 & 4:56 are the only 4 series gearsets I am aware of. Jim

68 TT · 11-09-2009, 01:19 PM

4.88's were an optional gear ratio you could order on my 68 Camaro when it was new.

I had a 70 Buick GS 455 that had 4.33 gears and it was all stock so I think they were original.

**Hart_Rod** · 11-09-2009, 01:51 PM

Jack it up. Mark a spot on the tire. Turn the pinion until the spot on the tire makes one revolution. If it's a 3.08, the pinion should only turn slightly over 3 times.

HarrisonTX · 11-09-2009, 03:57 PM

Hart, i have absolutely never got the tire method to work, and tried on many many different cars. Cars that ive put the ring and pinion in myself, and it was no where close to correct, both limited slip, and open diff. rearends

Is the truck running? There is a HUGE difference in 4.30's and 3.08s on the freeway. With a factory sized tire, and a non-overdrive tranny, you probably wouldnt be able to do 75mph

68 TT · 11-09-2009, 04:06 PM

You should be about 2000 rpm with 3.08's and 30" tall tires and about 2900 rpm with 4.30 gears at 60 mph. Pretty easy to tell on the tachometer if you have one. About a 30% difference in RPM.

I'm over 3200 rpm at 60 mph with 5.13's and 32" tires. I'd love to have only 4.30 gears

vtwinsport · 11-10-2009, 02:37 PM

Thanks guys,
Yeah, I definately miscounted. My rpms are too low at 60 mph.

11-08-2009, 03:50 PM	#1
vtwinsport Registered User Join Date: Nov 2008 Location: edmonton, alberta Posts: 293	ring and pinion count- teeth versus GM stamp afternoon, I just pulled the diff cover and counted teeth on my ring and pinion. 43 on the ring and 10 on the pinion. that should give me 4.30 rearend gearing right? There was GM stamping on the ring gear of 14:43 (along with some other number) which would indicate a 3.08 rear end, but the teeth count doesn't match up. Could a previous owner have swaped the ring gear but not the pinion? what gearing do I have do you think? __________________ 76 Silverado, 2wd, long box, 350/th350, 3.42 posi, edelbrock performer 64cc heads, edelbrock 1405, 2101 intake, Hedman Headers, Comp Cam XE262 http://beerbreadbike.wordpress.com/

11-08-2009, 06:24 PM	#2
Keith Seymore Registered User Join Date: May 2009 Location: Motor City Posts: 9,179	Re: ring and pinion count- teeeth versus GM stamp If you counted 43 and 10 (and counted correctly) then you absolutely have a 4.30:1 axle ratio. I can't explain why the ring gear was stamped 14:43 if you are only counting 10 teeth on the pinion gear. It is not possible to swap the ring gear without swapping the pinion, because then the two gears would not mesh. K __________________ Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/ Last edited by Keith Seymore; 11-08-2009 at 06:27 PM.

11-08-2009, 08:26 PM	#3
68 TT Still plays with trucks Join Date: Jul 2009 Location: Spokane, WA Posts: 3,556	Re: ring and pinion count- teeeth versus GM stamp Can you read the stampings on the end of the pinion gear? __________________ miSSed opportunity - ground up creation of an AWD 1994 454 SS that never was http://67-72chevytrucks.com/vboard/s...d.php?t=795577 69 C10 shortbed stepside 400 small block - built like what a super sport truck could have been 69 K20 lwb TBI 350 4L60E NP208 14-bolt Dana-44 w/disc 68 Camaro SS / RS 500hp 439 inch roller cam big block 4L80E 79 Malibu TPI 350 4L60 w/ Z28 steering & sway bars

11-08-2009, 08:40 PM	#4
vtwinsport Registered User Join Date: Nov 2008 Location: edmonton, alberta Posts: 293	Re: ring and pinion count- teeeth versus GM stamp Unfortunately, it's all closed up now but I don't remember seeing any stamps on the end of the pinion, only on the ring. I am pretty sure I counted properly but that ratio isn't one I've heard of before for these trucks. I must have miscounted. I wanted to take a look before I ordered new parts and my desired ratio- 3.73. __________________ 76 Silverado, 2wd, long box, 350/th350, 3.42 posi, edelbrock performer 64cc heads, edelbrock 1405, 2101 intake, Hedman Headers, Comp Cam XE262 http://beerbreadbike.wordpress.com/

11-08-2009, 09:04 PM	#5
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,023	Re: ring and pinion count- teeeth versus GM stamp I think the 43 indicates your 4.30 __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

11-09-2009, 09:44 AM	#6
James McClure One shot, one kill. Join Date: Dec 2007 Location: Saratoga Springs NY Posts: 859	Re: ring and pinion count- teeeth versus GM stamp Vtwin, you determined the ratio exactly right as Keith indicates, BUT, you counted wrong. The stamping is right, (I have never seen the stamping be wrong BTW) you have 3:08 just like mine. To the best of my knowledge (33 years as GM tech), GM never made a 4:30 ratio gearset. 4:10 & 4:56 are the only 4 series gearsets I am aware of. Jim __________________ 1984 K20 350M engine with 465,000 miles. Well, it's finally done!! Almost 2 years of work, but it was really worth the effort. Little stuff left to do is mount winch, wet sand & buff out and build belly pan\running boards. Body work takes lots and LOTS of beer!!!! God, Guts and Guns made America and God, Guts and Guns will preserve it! The worst thing you could do is get into my sights, but that don't matter, you'll never know it, cause you'll never hear the shotJim or Paladin whichever you choose.

11-09-2009, 01:19 PM	#7
68 TT Still plays with trucks Join Date: Jul 2009 Location: Spokane, WA Posts: 3,556	Re: ring and pinion count- teeth versus GM stamp 4.88's were an optional gear ratio you could order on my 68 Camaro when it was new. I had a 70 Buick GS 455 that had 4.33 gears and it was all stock so I think they were original. __________________ miSSed opportunity - ground up creation of an AWD 1994 454 SS that never was http://67-72chevytrucks.com/vboard/s...d.php?t=795577 69 C10 shortbed stepside 400 small block - built like what a super sport truck could have been 69 K20 lwb TBI 350 4L60E NP208 14-bolt Dana-44 w/disc 68 Camaro SS / RS 500hp 439 inch roller cam big block 4L80E 79 Malibu TPI 350 4L60 w/ Z28 steering & sway bars

11-09-2009, 01:51 PM	#8
Hart_Rod ************* Join Date: Apr 2005 Location: Pensacola, FL Posts: 17,837	Re: ring and pinion count- teeth versus GM stamp Jack it up. Mark a spot on the tire. Turn the pinion until the spot on the tire makes one revolution. If it's a 3.08, the pinion should only turn slightly over 3 times. __________________ Rob - https://www.instagram.com/hart_rod_c10 As Iron Sharpens Iron, So One Man Sharpens Another. Proverbs 27:17 FOR SALE: DBW pedal bracket - http://67-72chevytrucks.com/vboard/s...d.php?t=651123 FOR SALE: Hood Brackets http://67-72chevytrucks.com/vboard/s...d.php?t=679945 1987 Silverado SWB - 34.5K original miles http://67-72chevytrucks.com/vboard/s...d.php?t=801834 1969 SuperBurb - http://67-72chevytrucks.com/vboard/s...d.php?t=200387 1968 Farm truck - http://67-72chevytrucks.com/vboard/s...d.php?t=358692 1968 SWB - http://67-72chevytrucks.com/vboard/s...d.php?t=551258 1948 Chevy - http://67-72chevytrucks.com/vboard/s...=122164&page=3

11-09-2009, 03:57 PM	#9
HarrisonTX Registered User Join Date: Nov 2003 Location: Waco TX Posts: 247	Re: ring and pinion count- teeth versus GM stamp Hart, i have absolutely never got the tire method to work, and tried on many many different cars. Cars that ive put the ring and pinion in myself, and it was no where close to correct, both limited slip, and open diff. rearends Is the truck running? There is a HUGE difference in 4.30's and 3.08s on the freeway. With a factory sized tire, and a non-overdrive tranny, you probably wouldnt be able to do 75mph __________________ '69 custom/camper '74 260z 302 chevy/tko500 swap in progrss '79 Malibu 355 all forged 4 speed car. '86 k5 blazer '06 Duramax

11-09-2009, 04:06 PM	#10
68 TT Still plays with trucks Join Date: Jul 2009 Location: Spokane, WA Posts: 3,556	Re: ring and pinion count- teeth versus GM stamp You should be about 2000 rpm with 3.08's and 30" tall tires and about 2900 rpm with 4.30 gears at 60 mph. Pretty easy to tell on the tachometer if you have one. About a 30% difference in RPM. I'm over 3200 rpm at 60 mph with 5.13's and 32" tires. I'd love to have only 4.30 gears __________________ miSSed opportunity - ground up creation of an AWD 1994 454 SS that never was http://67-72chevytrucks.com/vboard/s...d.php?t=795577 69 C10 shortbed stepside 400 small block - built like what a super sport truck could have been 69 K20 lwb TBI 350 4L60E NP208 14-bolt Dana-44 w/disc 68 Camaro SS / RS 500hp 439 inch roller cam big block 4L80E 79 Malibu TPI 350 4L60 w/ Z28 steering & sway bars

11-10-2009, 02:37 PM	#11
vtwinsport Registered User Join Date: Nov 2008 Location: edmonton, alberta Posts: 293	Re: ring and pinion count- teeth versus GM stamp Thanks guys, Yeah, I definately miscounted. My rpms are too low at 60 mph. __________________ 76 Silverado, 2wd, long box, 350/th350, 3.42 posi, edelbrock performer 64cc heads, edelbrock 1405, 2101 intake, Hedman Headers, Comp Cam XE262 http://beerbreadbike.wordpress.com/

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