M40 adjustments

**TimG** · #1 07-28-2009, 06:52 PM

Thank you for the information. It is the original CW transmission and it shifts very well now. If it is adjustable, I was going to play with it to see if I could make it bang a bit harder.

**Mr70** · #2 07-28-2009, 06:54 PM

Tim
Which posi rearend ratio are you running...3:73...4:10?

**TimG** · #3 07-28-2009, 07:04 PM

The original 4.10, it's kind of a beast.

Chevy454 · #4 07-28-2009, 07:19 PM

LOL...all these guys wanting firmer shifts from there 400s, and I'm going the opposite direction...

**WILMASBOYL78** · #5 07-28-2009, 07:40 PM

I don't htink the governor will have a big impact on normal driving upshifts....adjusting the modulator or modifying internal pressure with a shift kit will work better. The governor has more of an impact on WOT shift points and down shift for passing gear.

Tim, I would try using an adjustable modualtor(aftermarket) and not mess with the factory unit. The more you restrict the vacuum....the firmer the shift and it will hold a little longer.

CW tranny and 4.10 gears are a trip...we have that setup in our 70 L78 car and it really works

...and, with the stock modulator.

**TimG** · #6 07-28-2009, 10:31 PM

It sure does, if I hit it just right, I can leave long black marks in second gear.

**RPOLS3** · #7 07-28-2009, 11:00 PM

Wilma you are correct.

The governor revisions affected the shift points (up or down). I was able to dial in WOT shift points that were substantially higher than stock since I was starting with a pretty lo-perf trans. The shift improver kit is what really firmed up the shift itself as I chose not to adjust the modulator at all. Both things were pretty low buck modifications I could do myself that I felt really worked well for my application. My goal was to duplicate as close as I could the performance of an LS6 M40.

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