i want 3.73,
but dont want to turn ~3krpm @ ~80mph
how much would it be to change the 4th gear of a 4L60E?
like during a rebuild, to reduce labor cost
is it possible to switch it to a smaller one?

 

You will still see the same rpm as if you changed your rear. I turn like 2700 @ 80. Good Luck man.

 

You will still see the same rpm as if you changed your rear. I turn like 2700 @ 80. Good Luck man. Also in reference to your ? yes it is possible.

 

I'm not sure of anyone who makes aftermarket ratio's for the 4L60. Let me know if you find someplace though, I'd be interested in knowing about it.

If you want to know how a rear end gear will work on the highway, try this: http://www.f-body.org/gears/

Choose 1998 F-body A4 trans. Then plug in 3.73 and hit "Calculate".

At 80mph you will be at 2700rpm. Yeah that's a big jump from your 2.73's 2000rpm, but even the factory 3.23's are at 2350rpm at 80mph. Also consider a 3.42, 2500rpm @ 80mph (I have 3.42's and they're great).

 

I've never heard of different ratios for a 4L60-E.