waltsfastz

iTrader: (4)

How can I tell if my 02 HD has an allison tranny? If not what does it have?

Mangled03gmc

iTrader: (95)

i dunno but i think the alli'ys are 5 speed auto..

James B.

iTrader: (1)

If you are talking about the one in your sig with the 6.0 it's a 4L80-E, not a Allison 1000. The Allison is included only with the 8.1 or the Duramax. All automatic Duramaxes have the Allison, all 8.1's get it too unless in a 2500 Suburban, Yukon XL, Avalanche which get the 4L85-E.

Mort

Look in your glove box for RPO Codes.

MW3 = 5 speed manual (NV4500)
ML6 = 6 speed manual (ZFS6-650)
MT1 = 4 speed auto (4L80E)
M74 = 5 speed auto (Allison 1000)

As James B. says you undoubtedly have the 4L80E with the 6.0L.

waltsfastz

iTrader: (4)

thanks fellas. I too thought it would only come with an allison if it was the 8.1 or dirtymax, However this dumbass at work was tring o tell me difrent. Thanks