different gears in the front than than the rear?

[wstrnhauler4x4]

I bought this truch with broken trans (95 CC 4x4 dually zf5 PSD 233xxx) Drove it on my car trailer in 4x4 and drove nice and smooth. So I rebuild the ZF5 and start driving it no complaints a solid ol' truck. snow starts to fly and I lock the hubs put it in 4x4 and it acts as if front and rearare going diff. speeds. I get home and count the pinion yolk revolutions in one tire rotation the front was 1 tire rotation was roughly 1.6 revolutions and the rear was 3 or so!! what the heck I have 235/80/17/ on front and 235/85/16 on rear could that be the problem? how do I figure the gear ratio? do I have to pull the covers and count? there is a 4:10 dually rear end on Clist for 100 so I need to find out quick

[GregsSD]

Make sure when you are rotating the tires 1 revolution that Both tires are rotating exactly 1 revolution, it sounds like when you checked the front you only spun 1 tire which will give you only 1/2 of the actual reading.

Use chalk or some kind of marker to make a mark for the pinion yolks so that you get an exact measurement so you can be sure which gears you have without having to pull the covers off and count teeth.

[j1mmy]

even if the front and rear are the same gearing, miss matched tires will destroy the drive train. no way front and rear are rolling the same speed with different tire sizes. 1" wheel difference, could roll something like 5mph off.

[wstrnhauler4x4]

I checkd before I put them on and the overall heighths are within a 1/4". I found a single wheel sterling with the gears I need, can I put my dually hubs and rotors on the single wheel axle? They are both sterling 10.25". Ford wants $750 in labor if I supply the master kit and ring and pinion and the axle I found is cheap. so it is kind of a no brainer can I swap the parts?

[Frozen Redneck]

You definitely need all 16 or 17 inch rims and matched tire size. And yes you can swap the hubs, just swap the axle shafts too, they're longer on the dually I'm pretty sure. If the rotations you post are correct though, you have a 4.10 front and 3.55 rear, or something along those lines. So swapping rear ends would fix your problem.

[Frozen Redneck]

Sorry I didn't read that whole post apparently! lock both hubs in and then recount that front, you probably have 4.10s though. The back is 3.55 if you counted around 3.

[Pistolgrip426]

Sounds like in this case you better pull the covers and check for sure, if they are 3.55 and a 4.10, there should be alot of scrap metal inside the covers, i cant even see it making it out of the parking lot with the hubs locked in, and all 4 rims/tires must match. Dana60 rears are a dime a dozen, i would rebuild your own housing. You can get a good tracklok with your gearset installed by a good axle shop cheaper than a ford dealer.

[wstrnhauler4x4]

so after checking axletags we had some mismatched gears. 4.10 in rear and 3.54 in front. I bout a 3.55 ring and pinion plus carrier and all the goodies for 60 and I just swapped it on to my traclock carrier and While I was in there I replaced the clutch paks for the trac lok. cruises 4x4 nice now and better mpg. I appreciate the help