What is the highest ratio GM had and are the pumpkins the same as other model of the buffalo .I have to pull a V730 to replace the engine rear main seal that filling the 730 with engine oil,and want to change the ratio since it's a 8v71 turbo and top speed is 63 mph at 2250 rpm
A friend of mine had a 4107 with a 4:10 rear in it. His top speed was 71 mph.
4.1 with 11R-24.5 rubber (476rpm) and the V730 with .88 overdrive will give a final drive ratio of 3.608. This will give a 60mph cruise at 1717, 70mph at 2003, 80mph at 2289. Startability is not that good. But with a 4107 that probably weighs around 28,000lbs and an 8V-71T putting out around 1,000lb/ft torque, he should have a startability of 25%. Reverse is worse since it is like a gear between 1st and 2nd
I have 4.56 gears that give me 60mph at 1950. In a big parking lot that was empty, I tried reverse. Since my speedo works both ways. I got up to 40mph in reverse and chickened out. Good Luck, TomC
Not sure if this helps or even has any bearing on the situation but with a stock engine/tranny in a 4106 I could get well over 80mph. don't have a tach so don't know rpm.
they were only available with two ratios. 4:27 and 4:11. about 4 to 5 mph difference in top governed speed. 4106,7, and 8 had the 4:11's standard. 4903 and 5 had 4:27 standard, with the 4:11's as an option.Why they didnt offer 3:90 or 3:70, no one knows. Maybe their tests when designed new showed the engines were taxed when loaded with a numerically lower ratio, especially since low gear was actually second, and when in high gear, actually, not technically in overdrive.
I also dont know why Tom doesnt go to 4:27's to gain 6 or 7 mph higher cruising speed.
Clifford, the only thing I can find in my 4107 maintenance manual is that standard was 4 1/8 to 1. Maintenance manual doesn't show any options. I can't find any reference to the differential in the parts book I have.
Probably doesn't help, but at least it's one data point.
Arthur
manual too old, you missed it, or didnt mention in 4107 because wasnt needed or too early before it was mentioned. Its in the 4108, 4905 manuals.
4&1/8 is it, BUT while the tranny is out make it into a teal overdrive unit then you won't care which rear gear you have. My top speed is way faster than the tires are rated for and I love the overdrive. I can't believe that others haven't done it. Mine is a 4106 with a 6V92 with a 4&1/8. I think a 4&3/8 would work very good.
Lack of parts for it. The vs series have been obsolete for years. Great thing though.
John olebusman
You and I are the only ones with the O/D unit other then the original one. Parts are just too hard to get now. I love it. I can cruise at 65 mph at about 1700 rpm. Come to a hill and just drop it out of O/D. I also have a 6V92TA with it. Been using it since 2006.
I need the vs2-6 planetary gear set and clutches yet. Have the rest.