I bought my 99 5spd Explorer from an auction, thinking it was really great. I still do, but certainly more problems than I would have expected. Not neccisarly because of the car, but what the preivous driver had done.

I found my alignment was off, (after a quick diagnositics from FTE :]) so I took it in to Les Schawb and said that I needed it aligned. After doing so, he pointed out that the electrical connection that trigers the shift motor was disconected, so I was running in 2WD.

He told me that whoever had this car before disconnected it due to the tire differences between the front and rear. Both tires were 235-75-15 but different tred padderns. He told me that connecting the transfer case now would screw everything up, freaking out the computer. He suggested purchasing all new tires. I told him that I swore AWD was working when I needed it, (Seattle Hills :[ ) but he said that was impossible.

The tires in the front are OPEN COUNTRY with about 50% tred left, and the rears are KUMHO AVENGERS with about 95% left. If I need all 4 tires with the same tred pattern, I will prob go with the KUMHO just because they have more life on them... and are cheaper. :]

Is this a dirty trick? he pullin the plug to get me to buy a set of new tires? Would that actually freak the computer out and cause damage?

What you guys think?

 

The first thing I would do is verify if AWD is working properly with the plug off. Then I would hook up the plug to see what the difference is. I suspect that maybe the plug is off for a different reason, like the AWD not working properly (thus bypassing it), but this all needs to be tested. I also think the comment about 'freaking the computer out' is BS. The computers re-learn themself whenever anything is altered. I do agree that once you have the AWD issue figured out, you should have matching pattern tires.

 

Actually the guy at the tire shop is correct & it looks like the previous owner disabled the AWD to avoid damaging it with the mismatched tires.

The system reads mismatched tires as a slipping tire & kicks the AWD in when it should'nt be.

Find a tire store that will "shave" a pair of Avengers to match the ones you have.

 

If you have a set with 95% left on them I would not worry too much about the mismatch... this would occur under normal tire wear (unless you really do rotate them every 3,000miles). The reality is that different vendors have different sizes under the same size listing. I learned this the hard way with my 4WD car a long while back. I had different brands front and back and when in 4WD it would bind up the drivetrain pretty good. I took it to the dealer and expected it to be a big bill, the shop manager took me to the car and showed me that the different brands measured (with a tape measure) a difference of 4" on the circumference. When in 4WD and driving on the snow (traction was not too bad, but I was being cautious) the driveline would bind up and then suddenly cause wheel slip. Changing the tires to all the same brand solved the problem from that day forward.

 

I just decided to buy some new tires first, as a percaution to anything that could be damaged. Since the tires on the rear have about 95% I decided to buy some fronts of that same brand. They had to order them in, and should be within the next 2-4 days. After that's all squared away, I'll plug back in that electrical connection and cross my fingers that whoever disconnected it, did it because of the tires and not for another reason.
Say your prayers for me guys :]