Yet another speedo question.. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bob Gervais · 02-28-2005, 10:12 PM

OK, so I'm lazy.

I searched, and found the Nova site very useful for driven gear info. I'm wondering if anyone with a similar setup as mine has done the swap, and what driven gear you ended up with. My setup:

-87 Suburban 1500, 4WD

-3.73 rear gear

-700R4 trans

-33" tires

I'm pretty sure all I need to know is how many teeth are on the drive gear, and was hoping to get that information without having to pull the truck apart first.

Thanks in advance for any help!

gchemist · 03-01-2005, 02:21 AM

Your sub probably has the 17 teeth drive which will make the speedo off. You can use two different combos
15 drive - 34.159 driven (35 teeth - orange/pink)
18 drive - 40.991 driven (41 teeth - yellow) (BEST)
Two 2.078" diameter housings, each made from either aluminum or plastic, are available for driven gears with 34 or more teeth. One fits gears from 34 - 39 teeth and the second one fits gears from 40 - 45 teeth.
Info taken from http://www.tciauto.com/tech_info/speedo_gears.htm

02-28-2005, 10:12 PM	#1
Bob Gervais Truckless for the moment... Join Date: Jan 2005 Location: Cranston, RI Posts: 180	Yet another speedo question.. OK, so I'm lazy. I searched, and found the Nova site very useful for driven gear info. I'm wondering if anyone with a similar setup as mine has done the swap, and what driven gear you ended up with. My setup: -87 Suburban 1500, 4WD -3.73 rear gear -700R4 trans -33" tires I'm pretty sure all I need to know is how many teeth are on the drive gear, and was hoping to get that information without having to pull the truck apart first. Thanks in advance for any help! __________________ 1987 V1500 GMC Suburban, 350 TBI, Flowtech dual exhaust, Rough Country 2" spring lift, 56" 3/4 ton rear spring conversion, 33" BFG All Terrains, and the smokescreen engine mod -- Former truck, searching for another now...

03-01-2005, 02:21 AM	#2
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Your sub probably has the 17 teeth drive which will make the speedo off. You can use two different combos 15 drive - 34.159 driven (35 teeth - orange/pink) 18 drive - 40.991 driven (41 teeth - yellow) (BEST) Two 2.078" diameter housings, each made from either aluminum or plastic, are available for driven gears with 34 or more teeth. One fits gears from 34 - 39 teeth and the second one fits gears from 40 - 45 teeth. Info taken from http://www.tciauto.com/tech_info/speedo_gears.htm __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos



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