1986 Chevrolet Silverado - The 1947 - Present Chevrolet & GMC Truck Message Board Network

skidoo911 · 08-24-2015, 10:08 PM

Guys,
I'm wondering where i find the gear ratio I have? 305 engine and a 3 speed transmission. seems to rev fairly high at 60 mph. thinking it 3.73 or 4.11.

Kaysen · 08-24-2015, 10:53 PM

Pull the cover and count the ring and pinion teeth to be certain. Since you didn't provide an rpm or tire size there is no way for us to know.

Keith Seymore · 08-25-2015, 07:16 AM

Do you still have your SPID label? It will show GQ1 for base axle (and will not specify the ratio) or will have the optional ratio listed with a description (GU6 = 3.42, GT4 = 3.73).

To answer your question directly: you have not provided enough detail. Need to know 2wd or 4wd, and three speed manual or auto.

Here is the powertrain chart from the generic info packet in the GM Heritage Center archives:

https://www.gmheritagecenter.com/doc...olet-Truck.pdf

Base axle is typically 2.73 or 3.08 (2wd) or 3.08/3.42 (4wd). 4.11 was not available.

In any case your best bet is to remove the cover and count teeth, as there is no guarantee it has not been changed within the last 30 years.

K

skidoo911 · 08-25-2015, 11:43 AM

It's a 2wd with a turbo 350 3speed. And a 305 motor stock.
Posted via Mobile Device

08-24-2015, 10:08 PM	#1
skidoo911 Registered User Join Date: Mar 2013 Location: edmonton, alberta Posts: 4	1986 Chevrolet Silverado Guys, I'm wondering where i find the gear ratio I have? 305 engine and a 3 speed transmission. seems to rev fairly high at 60 mph. thinking it 3.73 or 4.11.

08-24-2015, 10:53 PM	#2
Kaysen Registered User Join Date: Dec 2013 Location: Marietta, OK Posts: 277	Re: 1986 Chevrolet Silverado Pull the cover and count the ring and pinion teeth to be certain. Since you didn't provide an rpm or tire size there is no way for us to know.

08-25-2015, 07:16 AM	#3
Keith Seymore Registered User Join Date: May 2009 Location: Motor City Posts: 9,210	Re: 1986 Chevrolet Silverado Do you still have your SPID label? It will show GQ1 for base axle (and will not specify the ratio) or will have the optional ratio listed with a description (GU6 = 3.42, GT4 = 3.73). To answer your question directly: you have not provided enough detail. Need to know 2wd or 4wd, and three speed manual or auto. Here is the powertrain chart from the generic info packet in the GM Heritage Center archives: https://www.gmheritagecenter.com/doc...olet-Truck.pdf Base axle is typically 2.73 or 3.08 (2wd) or 3.08/3.42 (4wd). 4.11 was not available. In any case your best bet is to remove the cover and count teeth, as there is no guarantee it has not been changed within the last 30 years. K Attached Images __________________ 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/

08-25-2015, 11:43 AM	#4
skidoo911 Registered User Join Date: Mar 2013 Location: edmonton, alberta Posts: 4	It's a 2wd with a turbo 350 3speed. And a 305 motor stock. Posted via Mobile Device



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