rear end ratio - The 1947 - Present Chevrolet & GMC Truck Message Board Network

85chevy · 11-08-2004, 05:12 PM

Is there any way to tell what the gear ratio is in the rear end of my truck without having to take the cover off? The dealership said they do not have records that far back. Also, where can I find a good set of gears for a decent price?

Slonaker · 11-08-2004, 05:37 PM

My '86 has the gear ratio on the sticker in the glovebox. Maybe yours does too. Of course, on these old trucks, you never know what has been changed from original.

Slonaker

mckpaul · 11-08-2004, 06:07 PM

I've seen and tried a couple of ways. One way, jack up one back wheel and rotate it forward exactly two rotations watching and counting the turns of the drive shaft. Mine is a 2.73 rear end, the drive shaft turned 2 3/4 turns when I turned the wheel two times. You can take a piece of string about three feet long and tape the end of it to the bottom of the drive shaft and then turn the wheel, and then see how many wraps of string you have on the shaft. I even taped the sting to the drive shaft and marked the tire where it was centered on the pavement, then started th truck and moved the truck forward ONE exact turn of the tire until the mark was on the pavement again, and then turned it off and got under it and counted the wraps of string. NOTE - When you move the vehicle and BOTH wheels move forward one turn (as in when you are actually rolling or driving) you use ONE revolution of the wheel. You only use the TWO revolution method when you have one wheel jacked up and the other is stationary on the ground.

85chevy · 11-08-2004, 09:53 PM

Thanks alot. I have a sticker on the glove box, but the glove box lid is not the original one.

TIMSPEED · 11-09-2004, 12:54 AM

You can check the number stamped into the axle tube. You might need to use a brillo pad to clean the axle tube off to see it though. If you get it, it'll be a 3-digit code "xxx". Post it here, and someone can tell you what gears you have. (That's how I found out I had 3.42's, stock)

*gn4u2c* · 11-09-2004, 09:54 AM

Maybe its a dog because you have a 305 ?? Just kidding ! heck if you are close stop in I will pull the cover and tell you whats in there.

mckpaul · 11-09-2004, 02:08 PM

Quote:

Originally Posted by gn4u2c

Maybe its a dog because you have a 305 ?? ...

Hey, hey! I resemble that comment! Actually the only reference to a 305 on this thread is in my signature. But you're right, a 305 with a 2.73 is pretty much a dog in the short haul. On the other hand, it's great for normal everyday driving.

I have a sticker in my golve box, but it doesn't say anything about the rear end, only talks about bed measurements for a camper and load limits.

oldraven · 11-09-2004, 02:47 PM

I'm wondering the same thing. Except mine's too short. With the 383, the damn thing shifts into third at 60kph. (37mph) Far too early. Man do I need a tach.

cliffsta · 11-09-2004, 05:58 PM

LMFAO @ mckpaul. Beat this: I got 2.56 gears in mine with a 305! Now THAT'S a dog off the line, but i love it for daily driving, since that's what i do. I can hit like 45 or 50 in first

DennyB · 11-09-2004, 06:35 PM

This thread is located in FAQs

11-08-2004, 05:12 PM	#1
85chevy Registered User Join Date: Jul 2004 Posts: 29	rear end ratio Is there any way to tell what the gear ratio is in the rear end of my truck without having to take the cover off? The dealership said they do not have records that far back. Also, where can I find a good set of gears for a decent price?

11-08-2004, 05:37 PM	#2
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	My '86 has the gear ratio on the sticker in the glovebox. Maybe yours does too. Of course, on these old trucks, you never know what has been changed from original. Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

11-08-2004, 06:07 PM	#3
mckpaul Registered User Join Date: Dec 2002 Location: Houston Posts: 300	I've seen and tried a couple of ways. One way, jack up one back wheel and rotate it forward exactly two rotations watching and counting the turns of the drive shaft. Mine is a 2.73 rear end, the drive shaft turned 2 3/4 turns when I turned the wheel two times. You can take a piece of string about three feet long and tape the end of it to the bottom of the drive shaft and then turn the wheel, and then see how many wraps of string you have on the shaft. I even taped the sting to the drive shaft and marked the tire where it was centered on the pavement, then started th truck and moved the truck forward ONE exact turn of the tire until the mark was on the pavement again, and then turned it off and got under it and counted the wraps of string. NOTE - When you move the vehicle and BOTH wheels move forward one turn (as in when you are actually rolling or driving) you use ONE revolution of the wheel. You only use the TWO revolution method when you have one wheel jacked up and the other is stationary on the ground. __________________ Paul 1984 Chevy C-10 LWB/305

11-09-2004, 12:54 AM	#5
TIMSPEED Join Date: Jan 2003 Location: Modesto, CA Posts: 1,321	You can check the number stamped into the axle tube. You might need to use a brillo pad to clean the axle tube off to see it though. If you get it, it'll be a 3-digit code "xxx". Post it here, and someone can tell you what gears you have. (That's how I found out I had 3.42's, stock) __________________ I have a few cars... See Them Here

11-09-2004, 02:47 PM	#8
oldraven Registered User Join Date: Apr 2004 Location: Antigonish, Nova Scotia Posts: 869	I'm wondering the same thing. Except mine's too short. With the 383, the damn thing shifts into third at 60kph. (37mph) Far too early. Man do I need a tach. __________________ '86 C10 regular cab, 383 on propane www.cardomain.com/id/doasa '87 TurboCoupe 2.3Turbo intercooled 5-spd www.cardomain.com/id/oldraven '93 Jeep Grand Cherokee 4.0L

11-08-2004, 09:53 PM	#4
85chevy Registered User Join Date: Jul 2004 Posts: 29	Thanks alot. I have a sticker on the glove box, but the glove box lid is not the original one.

11-09-2004, 09:54 AM	#6
gn4u2c Account Suspended Join Date: Mar 2003 Location: southern pa Posts: 698	Maybe its a dog because you have a 305 ?? Just kidding ! heck if you are close stop in I will pull the cover and tell you whats in there.

11-09-2004, 05:58 PM	#9
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	LMFAO @ mckpaul. Beat this: I got 2.56 gears in mine with a 305! Now THAT'S a dog off the line, but i love it for daily driving, since that's what i do. I can hit like 45 or 50 in first __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

11-09-2004, 06:35 PM	#10
DennyB Led Sled! Discs R 4 ME! Join Date: Jan 2001 Location: Toms River, NJ, USA (Transplanted Hoosier) Posts: 7,327	This thread is located in FAQs __________________ "Never ride faster than your Angel can fly" I.M.O.M,W,J&C Patriot Guard Rider



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