Posted by moss6 on June 20, 01 at 16:59:25:
In Reply to: How to find out the Gear Ratio? posted by Sean on June 20, 01 at 10:06:42:
Two ways to absolutly establish rear end ratio and not take it for fact that the coded ratio is still installed in the vehicle.
One way is to jack one rear wheel very slighly off the driveway surface (making sure your other wheels are chocked and the truck can't roll) slide under the truck and with a piece of chaulk mark the tire at a point adjacent to the drive surface and also the drive surface at the same point. This will refernce your tire rotation. Next slide over to the drive shaft where it connects to the rear end and mark the drive shaft along with a corresponding point on the third member housing, this will referance the drive shaft rotation. Now rotate the drive shaft keeping count of how many turns it takes to make one rotation of the tire. So about three and a half turns = 3.42; about three and three quarters turns = 3.73 and so on.
The second method offers the benifit of changing your rear end oil which probably needs replacing anyway. Remove the third member cover count the number of teeth on the ring gear and the pinion gear then divide the ring number by the pinion number and that is the ratio. I don't know the tooth ratios but it should be something like fifteen tooth pinion fifty six tooth ring = 3.73 etc. Then scape off the old gasket clean out the old gunk in the housing install new gasket buckle it up,top it off and youv'e accomplished two tasks. You know your ratio and have properly serviced that neglected rear end!
PS If your body proportions prevent you from doing this in the drive a lift will work quiet nicely also.