Gear Ratio - Chevy????
 

how can I find out what gear ratio is in my '96 Chevy C-1500???
Is it somewhere in the VIN??
Starting to boat shop, and want to know what I can safely tow - or should I just be truck &boat shopping ( much less feasible...) :(
It already has all the heavy-duty trailering package - but the gear ratio makes a huge difference in what I can tow (legally) from 5000 to 7500 #'s - can make a big difference in boat choice.
Any help??

Re: Gear Ratio - Chevy????
 

Many axles have a tag on them listing the gear ratio and carrier type. Have you checked for it? Also I'm sure many here will tell you that any half ton pickup can pull a load, but stopping it is what's important.

Re: Gear Ratio - Chevy????
 

sticker on the inside of the glovebox lid.

The RPO for axle equip are G-codes

example...G80 is positraction

another example GU6 is 3.42 ratio, GT4 is 3.73 ect.

Re: Gear Ratio - Chevy????
 

or jack the truck up and mark the driveshaft and a tire with chalk and go one tire revolution counting the driveshaft revs. if it's just under 3...it's a 2.73. If it's just 3+ it's a 3.08
barely three and a half is a 3.42

Re: Gear Ratio - Chevy????
 

That Truck Came With 373 Unless Ordered Otherwise!

Re: Gear Ratio - Chevy????
 

Oh praise the board!!!!

Thanks guy's - I should have it figured out tommorow morning. No tags, any more hint's on that glove box code???
The 3.73 is what I was hoping for - allows me 7500#'s - maybe I can still look at the Cig Bullet's.

Thanks. Bouy

Re: Gear Ratio - Chevy????
 

only if was a stick V6 was that the standard ratio!

2 wheelers with a V8 got a 2.73 or a 3.42 (optional choice)

Re: Gear Ratio - Chevy????
 

It's a 5.7 with factory tow. Couldn't pass up the deal, only had 46K, I haven't even put 10K on it. Great running truck - just want to use it as a work/tow truck.
According to the manual , a 3.73 wil get me 7500#'s. If thats the case, sh$t BABY, IT'S ALL GOOD!!!! :D :D
Otherwise, I need to start looking for a bigger truck... :rolleyes:

Re: Gear Ratio - Chevy????
 

There is a 95% chance it is not a 3:73 with it being a two wheel drive.

Re: Gear Ratio - Chevy????
 

OK - I haven't ventured out to start checking the truck yet, but , how difficult would it be to cange out the gears to allow me to tow the higher weight??
would it be best to just replace the entire axle?

Re: Gear Ratio - Chevy????
 

GT4 is 3.73
GT5 is 4.10

Re: Gear Ratio - Chevy????
 

I went that route and just went to the junk yard and bought a whole new axle for around $200 with the gear I wanted and then bought a hypertech computer to reset the speedo and the shift points. Like they said look for the smaller motor trucks they will have the bigger gear I had a 2wd s-10 blazer v-6 that had a 342 maybe I found a 4 banger s-10 that had a 410 worked out perfect.

Re: Gear Ratio - Chevy????
 

If you like the truck then rebuild and re-gear the axle for your needs. The 89 and newer chevy 1/2 tons used a 10 bolt 8.5 inch rearend with 30 spline axles. Gm cut corners when they made it a 30 spline by just boring out the old 28 spline casting on the differential case. They are prone to breakage(the side bearing shears off the case,usually on passenger side),the factory gov lock posi (which i doubt you have if its 2 wheel drive) also breaks quite easy. When I rebuild them at my shop I use a heavy duty open diff case or a eaton clutch type posi,they both have a sturdier shoulder where side bearings go on. You could regear it and upgrade the differential at the same time for 750$ worth of parts and a day of your time if your mechanically inclined,Smitty

Re: Gear Ratio - Chevy????
 

Buoyhunter:

If your truck has a GVW of 7200 lbs you probably have the HD rear axle. The Differential will look different, wont' have the 2 notches the std. Gm axles do on the bottom at 5 and 7 o'clock.m This is a much stronger axle than the regular half ton axle.

The tranny is your other weak link- trailer only in Drive , NOT OverDrive ON THIS MODEL.

You have plenty of power with the 350 Vortec.

Wannabe

Re: Gear Ratio - Chevy????
 

A Bullet is #8900 Dry, No trailer....Trust me...1/2 ton aint gonna get it around here. Sorry......

Re: Gear Ratio - Chevy????
 

Front Side of the axel tube on tha passenger side is a series of numbers stamped into the housing that will tell you the gear ratio. You may have to "wire wheel" the area to see it as it usually gets covered up with grease & dirt, but it is there.... Ill try to find the link that will tell you & post it. Is for GM vehicles only. :D

This site will decifer all the GM "Spid Codes" located on the glove box door, & or the trunk lid of most cars> http://www.fl-thirdgen.org/rpo/rpo.html

This may work to decode the VIN of GM Truck, I know it works for cars for certain years. Tells you where it was built, etc....> www.nytmare.org/fiero/vin/decoder.htm

Re: Gear Ratio - Chevy????
 

Yeah, I was being "wishful".

Re: Gear Ratio - Chevy????
 

acccording to the sticker, the rear-end is a GU6 G80.

=
3.42 / limited slip posi.

OK - that puts me at 6500#'s

Gofastboater - thanks for the link, that helped alot.

Smitty, $750 would probably be worth it, thanks for the info and advice

Re: Gear Ratio - Chevy????
 

The 9.5" h.d rear end you speak of is a rarity in the 1500 series trucks from 80's and 90's,I have rebuilt the transmissions and rearends in at least 500 chevy 1/2 tons in last ten years and have only seen (2) 1500 series w/9.5" rear end. If buoyhunter has one in his truck other than the junk G80 gov-lock posi blowing up they are very strong rear ends,Smitty
I posted a picture zoomed in on a broken gov-lock drive gear,it is real common problem even in the hd trucks.

Re: Gear Ratio - Chevy????
 

;) :)

Re: Gear Ratio - Chevy????
 

Arctic; I agree it is rare but this 9.5" is the same axle as the 2500 had just w/ 6 lug axles and not 8 lugs. We have one in our 1500 (1995- 4WD) at home, has the higher GVW and this seems to be the key reason. These are HD axles, I use this truck for light snow plowing- no problems at all.

Wannabe