Hi my name is jeff and I live in a small mountian village in Crete ,Greece I grow grapes for wine and olives for oil.
I have a B2500 diesel 4x4 pickup
with a problem , lately I have felt that 4 wheel drive has not been right. So today I jacked the truck up on blocks and locked the Aisin hubs, engaged low range 4 wheel drive, started it up and had a good nose about underneath...
Well, the propshaft to the front diff is turning. The drive shafts to the front wheels don't turn unless I unlock the front hubs, but even when the shafts turn the wheels stay put. So hubs I think. The shafts seem to be merely drifting, and not driven. Next, I switch off and rotate the driver's side wheel – the drive shaft turns (?) It seems that the driver's side wheel IS locking onto the shaft.
Then I do the same with the other wheel but the shaft doesn't turn (???) Now I am puzzled. Start it up again and with handy piece of timber I find that I can stop the drive shaft turning with very very little effort, so they must be just drifting round with no drive as such. What can I deduce from this ? I think the passenger side hub is broken PLUS there is a problem in the front diff or the drive shafts.
Thoughts anyone? ... jeff...

 

My knowledge of 4 wheel drive is "old", and nothing with a mazda, however I'll state this. I own a 4x4 suburban, and had an 82 chevy with manual hubs.
The front drive shaft turning when engaged you shouldn't be able to stop it as you described, not engaged what you described stopping it isn't abnormal at all. I think you mean "lock" the hubs to engage the front axles. When I had my 82 I worked construction, and had alot of mud at times on construction sites. I keep the hubs locked, and engaged the transfer case when I needed 4 wheel drive.

The noise you hear probably is an indicator of problem now, or near future. Do you have a vidio camera? If so, post a short vidio would help.

 

I should have also stated, unless it is full time 4 wheel drive, both axles will not turn at the same time. It could be limited slip, in which case there is no ground for the drive wheel to slip, so it may not turn.

 

Hi Kevinpk, and thanks for getting back to me ,
I am begining to think that something inside the front diff is broken !( there is no noise coming from the diff) thinking about it, it is the most likely . I 'm looking into buying a second hand front diff and a pair of hubs,and getting them shipped from England , things like that are not available here.
We live in a out of the way place with only one vehicle,and two wheel drive is better than no wheel drive,and while it's working
it's working ..... thanks for your input ..jeff

 

Well I think I have solved this problem , Today I spoke to a guy who fixes cars and trucks in a village near here, after a bit of discusion (me in my bad Greek and him with no English) he tells me to take it to his mate in another village .
So of I go thinking that I am on a wild goose chase , Any way this guy turns out out to be a 4x4 genius who spots the problem instantly and fixes my truck in about half an hour and charges me next to nothing ! the problem was the Aisin hubs, very fine mud and silt in the hubs stopping them engaging . He cleaned it out and then we went for a test drive up a stoney 45 degree track no problem.
This guy is going to become a firm friend, next time I pass his place I'll drop off some wine .... jeff....

 

Good for you!