jeep cherokee four wheel drive PROBLEMs

SuperJon · Feb 12, 2008

i have an 86 jeep cherokee and i'm haveing trouble with my four wheel drive .it engages into four wheel on flat ground but if i flex up on something or too much throttle it pops and out and kinda grinds . could this be a vacuum leak or transfer case problem??? :011:

Not Jobless · Feb 12, 2008

I assume the T-case is maiking the grinding sound?

Could be your t-case mount is FUBAR causing it to rotate/flex under forced articulation. This in turn is causing the shift handle to hit the floor and pop out of gear.

The vacuum lines control the fron axle actuator on the passenger side.

Check your mounts and shifter linkage 1st.

SuperJon · Feb 12, 2008

the shift handle still stays in tack just grinds but i'll check my mount and linkage

Pat · Feb 12, 2008

You probably don't have enough vacuum pressure to keep it engaged, mine did the same thing last week. A vacuum leak (could be anywhere) is most likely the cause. For me the easier fix was to make it full time engaged, with no front locker (daily driver) I can't even tell. I manually engaged the fork and plugged off the vacuum fittings on the cad diaphram. Otherwise there is the posi-lok cable which I will be adding soon.

Not Jobless · Feb 12, 2008

Pat said:
You probably don't have enough vacuum pressure to keep it engaged, mine did the same thing last week. A vacuum leak (could be anywhere) is most likely the cause. For me the easier fix was to make it full time engaged, with no front locker (daily driver) I can't even tell. I manually engaged the fork and plugged off the vacuum fittings on the cad diaphram. Otherwise there is the posi-lok cable which I will be adding soon.

The vacuum doesn't activate anything in the t-case, it's just a switch that activates the the collar on the front axle.

The grinding noise is coming from the T-case as I understand it.

Pat · Feb 12, 2008

I was just assuming, since its a common issue with the vacuum D30's.
It will grind, as the coupler tries to engage the splines on the shaft.
But I guess the first step would be to isolate if it's Tcase or front axle.
Put it in 4wd and lift the front tires off the ground.
If you can turn the front driveline by hand then its your transfer case.

zukkev · Feb 12, 2008

Jobless said:
I assume the T-case is maiking the grinding sound?

Could be your t-case mount is FUBAR causing it to rotate/flex under forced articulation. This in turn is causing the shift handle to hit the floor and pop out of gear.

The vacuum lines control the fron axle actuator on the passenger side.

Check your mounts and shifter linkage 1st.

I'm inclined to agree-check your mounts/linkage first!!! Something's moving around that shouldn't be....