Possible to change gears in tranny? th400
#1
Possible to change gears in tranny? th400
should I have any gears changed or switched up while its being rebuilt?
Right now I just dont have the money to redo the rearend right now. its a 2.73 with FULL posi.
I figure if i can switch up the gears somehow, i can offset the high rear end to give me better low end.
this is in a 1980 T/A by the way. Im new to domestic transmissions. so thats why it may be like im asking stupid questions.
Right now I just dont have the money to redo the rearend right now. its a 2.73 with FULL posi.
I figure if i can switch up the gears somehow, i can offset the high rear end to give me better low end.
this is in a 1980 T/A by the way. Im new to domestic transmissions. so thats why it may be like im asking stupid questions.
#2
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Yes, you can change the gear ratio in the tranny, but it requires a new planetary gear set and it's not cheap. The TH400's factory ratio is 2.48/1.48. You can get a 2.75/1.57 for greater torque multiplication, but again it's not cheap. We're talking more than half the cost of the tranny itself, in the $700-$800 range and should you eventually upgrade your rear gears and add more power, you may end up with traction problems. If you want to get the most out of your 2.73's, make sure you run the proper stall and run the shortest overall tire height you can.
#4
Bob
#6
Sounds like the company has copied JKilgores means of retaing the sun gear.Reversed helix angles on a common sun gear does not work.When the sun gear "screws" the ring gear in first gear with no thrust surface it eats itself up in short order. When they are not connected this is ok.Ill post a photo later of the right way to do it.