Inquiring minds want to know.

They prefer to have the operation first.




I don't know of any problems.  There is no better tranny than the Allison that comes with the can't get any worse diesel that chevy puts out.

4L60E seems to be OK. I know plenty of friends with them in their trucks that have MANY miles on them without any problems.

The 4L80E is one hell of a tranny, but it wasn't available in half-ton trucks. My dad's service truck (1991 3500, 454 w/4L80E) carries 8,000-9,000lbs of tools, welders, crane, air compressor, 100 gallon diesel tank, and many tools in the service body and has done so for 150,000 miles (he's only put about 40,000 on it, some public service department in Chicago had it before him). It's on the original tranny still and we haven't had any problems with it.

WIZZO

The light duty 3/4 ton trucks (6 lung wheels) with the Getrag is a problem. I believe that the gears are held togther inside a plastic box. My tranny (1992 K2500 GMC) had to be replaced. My wife's RL460E has been rebuilt twice. The first rebuild was done by an idiot. The second rebuild has been fine thus far and covered by warranty. We have several allison's here at the ranch and so far so good........

The 4L60E should be nearly bulletproof and the Allison is bulletproof.

My dad has a 2004 GMC 3500 with the Allison, it is a company truck but no problems in 2 owners.  

Before that, he had a '95 Chevy C-3500 with a diesel and IIRC a 4L80.  No problems IIRC.

The 4160 is a good tranny, it's in his C-2500, a '97.  

4L60 and 4L80 are great transmissions. I got 4L80 laying around I am thinking about retro fitting to my 71 Firebird(haven't checked to see if anyone is doing that yet though). 4spd and 4:11s are quite expensive with gas prices the way they are.