5 or 6 speed Allison

[Jim Brzozowski]

Is it possible that some 02 models came with experimental 6 speed Allisons?
My truck was special ordered by someone who did not pick it up. The sales person was a friend of mine an we found the truck and it was exactly what I was looking for and more so I bought it. I've never questioned this before now, but I feel 5 shifts everytime. I've even punched the throttle a little in each gear to see if maybe I was feeling TC lockup, but it wasn't locked up. If it shifts 5 times it has to be a 6 speed right?
Anyone else counting shifts?

[RdTxTd]

That last shift you feel is probably the torque converter locking up. Unless you're in tow/haul, it won't lock until after you're in 5th. Under light-moderate acceleration, mine hits 5th about 40 MPH and locks around 45-50 MPH. When coasting, I see the tach drop suddenly when it unlocks at just under 45 MPH.

[ 08-17-2005, 04:01 PM: Message edited by: RdTxTd ]

[Jim Brzozowski]

Yeah, that makes sense. I guess with the fuel prices up so much now I'm using light acceleration and noticed it doing just as you describe at around 50mph. I really didn't think the TC would feel that positive on lock up, but I knew by the rpm's that I had the same final ratio that everyone else has. Thanks.

[Onebigcanuck]

I just read that the 2006 will have a 6 speed and the 2010 a 10 speed Allison.

[bigchev]

Originally posted by RdTxTd:
That last shift you feel is probably the torque converter locking up. Unless you're in tow/haul, it won't lock until after you're in 5th. Under light-moderate acceleration, mine hits 5th about 40 MPH and locks around 45-50 MPH. When coasting, I see the tach drop suddenly when it unlocks at just under 45 MPH.

For some reason I have always thought that when in tow/haul mode that the converter would lock in gears 2 through 5.

Please correct me if I am wrong.

Thanks

[RdTxTd]

Originally posted by bigchev:
For some reason I have always thought that when in tow/haul mode that the converter would lock in gears 2 through 5.

I think you are correct. It does lock earlier in tow/haul mode, but I don't know exactly when. I think I read 22MPH somewhere, but I'm not sure. My post said "Unless you're in tow/haul, it won't lock until after you're in 5th."

Dave