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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: 454c10 on December 01, 2014, 10:55:36 am

Title: Whats the gear ratio on a 1986 gmc c10?
Post by: 454c10 on December 01, 2014, 10:55:36 am

?

Title: Re: Whats the gear ratio on a 1986 gmc c10?
Post by: pholliday1 on December 01, 2014, 11:35:03 am

Really the only way to know is to pull the diff cover and count the teeth. The ratio really could be anything depending on past owners. There're rpo  codes listed in the glove box but even then you cant be sure.

Title: Re: Whats the gear ratio on a 1986 gmc c10?
Post by: zieg85 on December 01, 2014, 11:36:13 am

Standard axle in 1986 was 2.73 as far as I know.

Title: Re: Whats the gear ratio on a 1986 gmc c10?
Post by: Captkaos on December 01, 2014, 12:19:18 pm

What Zieg posted is correct for the standard ratio, but that would assume that it has never been changed or the axle swapped out. 
Which is as pholliday stated the only way to truly know is to pull the cover.  If you haven't ever done this it is a good time as the oil has probably never been changed.