They are not bad trucks but the transmissions will drive you crazy when they up/downshift....usually slamming into gear. And they make a funny noise going down the road.....kind of a mechanical popping racket.
Remember that everything on a 5 ton is heavier....everytime I think I want another one I just go out in the yard and move that spare brake drum about 25 feet....that usually kills the urge for a few months.
I would also reccommend the turbo version....the ones I drove were NA and would not pull the hat off your head.
Just my dos centavos.
Mechanical popping racket? Are you confusing it with the CAT 7155 transmission? I own six M939 series trucks and have owned others. I've literally put thousands of miles on them and I never noticed any particularly wierd sounds. This would be especially apparent in the A2s since they are so quiet in the cab.
For the guys who are after the A2s, I suggest you drive one. While I like them better, they are sluggish off the line as compared to the NHC-250 powered trucks. When you hit the throttle, it is almost like they don't want to go for a second or two. I don't mean that you are sitting still, but there is no real power from a dead stop. Once the turbo gets spooled up, you have more power. I have an M923 with a new (made in 10/0
NHC-250 that pulls stronger than any 6CTA that I've ever owned or driven. You punch the pedal and the truck lurches. Here are my pros and cons on the A2:
Pros
*quiet
*newer (made from 1989 until 1992)
*more modern and efficient engine
*CTIS, IF it works
*super singles (would be the same on the A1s, but not the original M939 series with the 1100s)
Cons
*quiet (some guys want a truck to sound like a violated bear...this ain't the motor for that)
*fuel filters...one small inline and one small spin on...susceptible to clogging
*some parts (air intake and exhaust coming off of the turbo, among others) are A2 specific...while you probably won't need to replace them, you will have a heck of a time finding them if you do
*CTIS almost never works...terrible design
