Some useful info: the last time I used 4x4 I went pretty hard on it trying this bumpy hill climb in the snow about 20 times but got it, went home and parked 4x4 engaged and working. Hubs locked overnight then forgot to free them the next day and drove about 400km locked. Freed them that night after the drive, went to use 4x4 last weekend and that’s when I noticed it wasn’t working. Also winters coming to an end and we’re getting above freezing temps, spring time.



So yeah my 4x4 isn’t working on my 94 truck. Everything stock 94 pickup but the rear axle and engine so shouldn’t matter for my issue. As it’s just front independent suspension wheels not spinning. Standard Aisin ones.



I took the hubs apart this weekend they were a bit jammed but seemed to work fine. Regreased them and put them back in the locked position but no 4x4



The shifter seems to work as it will go into 4L just only rear axle. The drive line is spinning and cv axles spinning as well. That’s why I figured hubs but am now stumped and looking for advice.



Any tips advice greatly appreciated thanks!

 

Well, if you have confirmed that your CV axles are spinning then perhaps you have a broken CV joint. I broke one once and I did not know that I had broken it, only when I saw that neither front wheel was spinning in some mud. With your hubs locked, crawl under there and see if you can spin either of the CV axles. Sure a hub could also break, but I think it is more likely that your CV is busted.

 

that seems like a likely cause, thanks very much

 

I thought all '94s had ADD (Automatic Differential Disconnect). You've got locking hubs, but yours wouldn't be the first truck where someone added it. With the ADD open, the front drive axle will turn in 4wd, and the front half-shafts will turn driven by the wheels, but the two won't be connected.

Driving 20km on drive pavement with 4wd engaged isn't doing your drivetrain any good.

 

you’re right about it being ADD issue I’ve only got 1 vac line running into my diff. Just gotta find my missing line and get ˟˟˟˟ connected right hopefully

thanks for the input!

 

Update: 4x4 working! just got back from a long rip in the snow 4L all the way. I ended up finding it was the differential actuator vac lines which were the issue. Im on manual hubs luckily so I emptied the diff, pulled the actuator and manually set it to engaged by using a hose clamp to close the 'unengaged space' and so locking it permanantly engaged. This way the diff is always engaged but I can unlock the hubs and put the t case in 2H when on pavement and when offroad I wont have anymore issues with it unengaging.

Thanks for the help folks!