So i put a 91 ecu in my cherokee 91. I had a 92 in my 91 and the voltage regulator in it got fried. So i unwired the voltage regulator. Put in the 91 ecu the way it shoud be now haha. So i put in the 91 ecu in my 91 my check engine light went away. So i drove down the road put it in 4 high and it works so i press on the gas and i just heard grinding and the front tire did not spin. So i press on the gas in 4 high now and the front axle is making the sound when my 4 wheel drive tries to engage but is unsucseful. It constantly makes the grinding noise in 4 high and it goes away in 2wd. The 91 ecu was a manual and the old ecu was a automatic 92. Could it just be non compatible computers?

 

did it make this noise with other ecm, i dont see how a ecm affects manual linkage and front axle ingagement ?

 

Ok so i put the old ecm back in and no change its just my 4wd shifter fork there is a buzzing kinda grinding sound coming from it......what would be making the sound? like it sounds like its not engaging all the way

 

no oil in the case

 

My t-case oil? what would that do to it?

 

but the noise is coming from the fork shifter on the axle?

 

youve got a vacuumn problem then its not holding the fork ingaged

 

huh how do i go about this problem?

 

follow the line from the front axle as far as you can checking for leaks also check the ones on the tc case and the plg there

 

There is a little diff fluid kind of bubbling and leaking from the shifter fork spot its never done that. Should i take that off and check on it?

 

sooo took off the fork and it is fully engaged and there is no slop in the fork still a zzzzzzzzzzzzzzzzz sound

 

anyone?

 

could it be low transfer case fluid?