I had the hard shift into reverse problem after I purchased my 2006 Mountaineer and took it to Ford for repair. From what I have read online, this can be a common problem with the Explorer and Mountaineer, same truck. The truck came with a 6 year 100,000 mile powertrain warranty, so at about 44,000 miles I took it to Ford and a day later I had it back. I was told there is an internal solenoid that is failing and causing erratic shift behavior and hard dump into reverse, they replaced it. I didn't have the shifting problem, just the hard dump in reverse.

It has been almost 20,000 miles since the repair and the truck hasn't missed a beat. I am sure whoever traded this in it was because they didn't want to pay the repair cost. I got lucky and only had to pay the deductible on the warranty. Problem though, my wifes 2006 Explorer is starting to act up with 39,000 miles on it and I will argue paying full price for this repair. I hope this post helps anyone with this problem.

I just took my 2006 Mountaineer into the dealership again today to flush the transmission fluid in the hopes that it would make shifting into reverse better. After reading many many complaints on the 2006 Ford and Mercurys I had the chip flashed at the cost of $92 plus other $60 service fees and it ran better for about a week. Now it is clunking worse than ever! Ford dealer says after the $142 bill today the next step is taking the whole transmission out and inspecting, what a load of crap that is. I haven't read through all the posts yet but saw one person replaced the TSP sensor himself? Would order that part and try it. Right now it is just extremely irritating going into reverse, but also notice a slight pause going from 2nd to 3rd and it actually got worse AFTER having the chip flashed. I am so ticked off, I wish they would do a recall but I'm assuming that would be horrendously expensive for them. We need to get a class action law suit going, I can't even trade the damn thing in like this.