I know I know read the other posts. I totally understand that, but I am at a loss here. I need help determining the gear ratio on the rear diff of a 1992 4 cyl 4x4 hardbody. On the drivers door sticker axle is CA41. I have not been able to find anything else on the truck to give any clues. No other stickers, or tags. This truck is super clean one owner we knew very well taken care of, and only has 100,927 original miles. The truck was stolen, and recovered with a bad ring, and pinion, and a broken front passenger drive shaft. A mechanic we know checked it out, and we got it for literally nothing. I have tried to contact diff shops in my area (Yucaipa Ca), and they all ask the gear ratio. I don't want to pay for towing to a place that will say "yea sorry cant do it, or get parts". The diff has a rear cover so it's not the type to pull out the front. I really want to get this truck working, and use it daily. Any help will be greatly appreciated.

Diff gear ratio is easy to calculate. Remove the cover, count the number of teeth on the ring gear and divide by the number of teeth on the pinion gear. My old H190A is 39 on ring, 11 on pinion, gear ratio 39/11= 3.54

Thanks D21hardking. I figured I was going to have to get into it myself to check. I really wanted to avoid it, but easy enough after reading your directions. Any recommendations on which ring/pinion companies to contact for a new set? I know Nissan is out of that question, but which after market companies would be a good place to start. Again thanks for the reply. Much appreciated

I would say talk to your local rebuilder as far as that goes. I'm not too familiar with who makes good parts. You could try the dealer. These diff's were still used in Frontier and Pathfinders....

If you want to buy time and get it going quickly as long as the rear drive differential is good you can purchase manual hubs and or remove the front drive shaft. I think the free service manual on this site Might help. Might also try Hollander auto parts or Car parts .com. The sites list used auto parts located at salvage yards throughout the United States. It will provide you a list of years and ratios that will interchange with your truck. Might consider going this way. Is the rear differential a Dana or a drop out? The drop out are the most common. The front differential should be a Dana never seen one with a drop out.

Also Member- Desert rat posted a form on this site listing the axel ratios number using the sticker located on the drivers door. Might do a site search or PM. Desert rat.

Thanks Guys. Its the rear diff that needs the ring, and pinion. I am in the process today of opening the back cover to count the teeth on the ring, and then the pinion. When I find that out I'll try looking for sources. I have a mechanic that says he will get a complete axle that is rebuilt, and put it in for $1250.00 sounds a bit steep, but it's an option. Again thanks for the info. I'll put it to use. any more suggestions are always welcome

The price quote is reasonable. The ring and pinion gears are roughly between 5 and 7 hundred depending on the ratio. Hopefully the bearings and races are good. The number you listed sounds familiar not positive but thinking the 720 truck used that same setup? Good luck.

Ok so I pulled the rear cover off the rear diff. the gears look ok no chips or irregularities. the pinion gear is super sloppy it moves away from the ring gear just by moving the tires forward or back, or moving the drive shaft. Has a 37 tooth ring gear with a 9 tooth pinion so its 4:11 gear ratio. I may be in luck? I will contact that shop that gave me the quote, and let him know what I have found. maybe its just a rebuild without the ring, and pinion. thanks for al the help everyone.