Hello folks, I'm having issues with my 4 wheel drive system. I have been slowly eliminating parts that I thought had failed only to find out they haven't actually failed yet. Currently I am experiencing no 4 wheel drive but the transfer case, axles and hubs are properly working. I pulled the fill plug on the front differential and can see that the ring gear spins while the hubs are locked in but when I engage my transfer case the front wheels do not spin. Front driveline spins while engaged and low range, high range seem to work properly while engaged as well. I'm thinking that the Pinon gear is either stripped or shaft is broken. Any advice is much appreciated. Thank you!!

 

chock the wheels. lock the front hubs.
transfer case in neutral, or rear wheel drive.
try spinning the front driveshaft. if it will spin, you have an issue in the front axle.
from there, you will have to open the axle housing to see what is wrong.

 

Yep it spins while hubs are locked and transfer case in 2 wheel and/or neutral. Now with it on stands all the way around, in gear and locked in 4 wheel drive, both drivelines spin with no noise but front wheels do not spin. I am just going off what I've been told about similar problems and I believe the pinion gear is messed up in some way. Wanted a better idea before I just go tearing into it only to find nothing was wrong. I will be disassembling the front end it sounds like. Thank you for your reply and advice.

 

it could be a broken pinion, broke spider gear in the center section, bad center section, or possible a broken axle.
does i have a dana 50 , or dana 60 in it?

 

On the Vin tag it gives axle code 39, looking that up says it has 3.55 non-limited slip Dana 50.

 

ok, than you are going to have to split the axle and remove the differential.
if it had a D-60, you could just remove the cover and inspect it.

 

I've been looking at diagrams of the dana 50 and it seems to be fairly simple to pull apart, rebuilding it will be the interesting part. First differential rebuild I'll be doing.

 

So I got the differential taken apart. Turns out my pinion gear is destroyed. I removed the rear differential inspection plate and counted both the ring and Pinon gear teeth to confirm they ratios match. Both are 3.54 gears. My question is, the front was 46/13 and the rear is 39/11, does the tooth count need to match?

 

no the front is always slightly off for traction.
as an example: you have 3.53 front and 3.54 rear.
my 88 has 4.10 front and 4.11 rear.
my 2014 has 3.72 front and 3.73 rear.

 

Ah, okay. Learning a lot about gears since this is the first time I've ever had to mess with them. I appreciate the help you have given.

 

no problem. that is what these forums are about, helping each other.
i have 50+ years of useless knowledge cluttering up my thick head.
so if i can send some out, there is a little more room to add something new.