Posted by Ken Dunnington on Thursday, September 23, 2004 at 11:10AM :
In Reply to: Re: 5.83 vs 4.89 Difference in Performance posted by Lucian Drumond on Wednesday, September 22, 2004 at 8:32PM :
I would go with 4.89 and 11.00R16 tires with an engine upgrade and keep direct fifth. I'd rather have my cruising gear be straight through to the diff vs OD. With a five speed, you can get "granny" first, then have essentially a close ratio four speed to work with above that. I have collected a few transmissions just for this purpose. One is the IH T35, a Clark copy.
Ratios: 7.17, 3.96, 2.36, 1.41, 1.00
2nd through 5th are essentially the same as the close ratio four speed BW T19's 1st through 4th.
The IH T36 is a close ratio five speed so this may fit better with the concerns of
Keith with the wide gap between 1st and 2nd while off road. Ratios: 6.21, 3.43, 2.05, 1.225, 1.00
Then the T34 which is the OD version of the bunch. Ratios: 6.21, 3.43, 1.81, 1.00, .823
This one is a little strange as IH used 1st and 2nd from the T36, a unique 3rd, the 4th slot became the OD gear and the fifth slot remained direct. So the pattern is a little weird because where top gear normally is is actually 4th, and where 4th normally is is actually the OD 5th gear.
I know this IH stuff is not really much of a help for Dodge guys but it is a nice example of three versions using the same trans case, and the ratios that were thought by designers to be useful.
Anyway, I say gear the truck, if possible, to run a DD 5 speed.
4.89/11.00R16(38")/1:1 = 2810 rpm @ 65mph. Not bad for a large gasser pickup truck.
Ken