Rear End Gear ratios

[GeneB]

My first exper. with 4x4 trucks.

I recently aquired a 1994? 4x4 offroad 1500.

Come to find out it has a salvage title.

The rear end came apart on a trip from Nebraska to Colorado.

The repair shop indicated they had quite a time locating the correct parts for repairs using salvage yards.

How do I check to see if the rear gear ratio matches the front ratio?

When I place the truck in 4-HI, and try to turn or back up, it bucks and acts as if the breaks are being applied. It seems to drive ok when going foreward though.

Doesen't seem to be a tag on the punkin. Would the 411 or 371 be stamped somewhere on the housing? Same for the front end?

Thanks for any input.

[citydriver]

If the front axle is original,you should be able to get the ratio from the RPO code list on the sticker in the glove box,you can match it against this list GM RPO's Or do a search on the web and come up w/a bunch more.....or if your sticker is gone or unreadable,you can go to your local Chevy/GMC dealer and they can run the vin...even w/a salvage title the original VIN may be somewhere on the truck...then you may have to pull the cover off of the replacement axle and count the teeth on the ring and the pinion and do the math (# of ring gear teeth / # of pinion teeth= ratio)

Yea it's a PAIN but it's the only way I can think of w/o replacing both axles @ once.........maybe someone else has another idea

[chvythndr]

Mark the driveshaft(s) then spin the front/rear tires depending on which axle you're checking. For 1 complete tire rotation, the ds should spin 3.73 times, 4.10 times, etc...

[snoman]

Mark the driveshaft(s) then spin the front/rear tires depending on which axle you're checking.  For 1 complete tire rotation, the ds should spin 3.73 times, 4.10 times, etc...

THis is the best way to be doubly sure of what is actually installed. BTW rear ends rarely shell out for no reason. If your trashed it was problay low on oil. When ever I acquire a used vehical, I always check/change all lube fluids so I know where everything is "at" service wise.

 

P.S. If you spin only one tire (other one is on ground) you multiply tire revs per driveshaft turn by 2 to get axle ratio.