8.1 versus 6.00
Looking at used Chevy/GMC 2500HD's for a TT of about 10,000 GVWR. Would make sure that it has the tow package. We do travel in the Rockies and would like experiences and or opinions on the 8.1 versus...
Forum Discussion
RCMAN46 wrote:blt2ski wrote:
Manuals no stall outs.
New 6 so has a 4.10-1 first gear. Vs 3.1 in almighty Allison, and 2.48 in POJ4m80/th400 derivatives.
Marty
The lowest 1st gear I could find in current manual transmissions is the 6 speed Ram uses.
It has a 1 st gear ratio of 6.34. You stated the GM 6 speed auto has a 4.1. The 6l80 is actually a 4.027 first gear. Couple that with the 2 to 1 ratio of a torque converter the equalivant 8.05 ratio will out pull the Ram manual 6.34 at standstill.
Thus the manual will stall on a much smaller hill than today's automatics.
Even the Allison will do better at a 6.2 equalivant ratio as there will be no clutches to burn out in the attempt.
I would agree with this, other than I have been taught told to deduct 20% from those figures for slippage and heat. So the allison is really aroud 5-1, and the diesel gets a 1.8 TC not a 2-1 as the gas got. At least that is my memory......not that it is worth much today.
I was recalling the gm auto at 4.1, did not know it was the 4.027, I would take this trans over an allison.
the comments re transmissions experience, are from the last 30 yrs of driving vehicles. The manuals back in the day were better than the autos. th400 1st is 2.48, so 5 or 4-1 equal with slippage, vs a muncie iirc in the 6.8 range. Not that it should count, my mdt has a 10.08 first.
marty
