2-3 shift 4l60e
Thread Starter
Teching In
Joined: Apr 2015
Posts: 5
Likes: 0
2-3 shift 4l60e I have just finished my cam swap and sent in my pcm to frost to get tuned. Every gear works fine until WOT. The first time i got on it the shift from 2nd to 3rd banged off the limiter. I also have 17in instead of the stock 16in tires but didnt mention to frost since i got them after i sent him the pcm. Is this a tune problem or a tranny problem. Thanks!
Thread Starter
Teching In
Joined: Apr 2015
Posts: 5
Likes: 0
The diameter of the wheel doesn't matter. What size overall was it programmed for, and what size do you have now? Take a stick, lay it on top of the tire, take a tape measure, and get pretty specific from flat ground, to the bottom edge of the stick (top of tire). You could have 275/60/17's, or 235/45/17's, major differences.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Actually the tire size won't matter either. I often run with much taller M/T drag radials than my street tire. My 2-3 shift occurs when both the tuned 84 mph and 7000 RPM are reached; with the taller tires, the actual speed is about 90 mph, but the PCM still thinks it is 84 mph because it doesn't know I changed tires/wheels; obviously the PCM then doesn't know the actual speed. "It all comes out in the wash".
As GIZZ says, you (or your tuner) need to reduce the WOT MPH shift table by about 10%. I suggest also putting the WOT MPH values into the part throttle shift table for the 94% and 100% throttle values.
If that doesn't work, it indicates that your 3/4 clutch is slipping, which is a weak spot and the most common problem with the 4L60E. If you suspect that, I will move this thread to the Automatic Transmission section.
As GIZZ says, you (or your tuner) need to reduce the WOT MPH shift table by about 10%. I suggest also putting the WOT MPH values into the part throttle shift table for the 94% and 100% throttle values.
If that doesn't work, it indicates that your 3/4 clutch is slipping, which is a weak spot and the most common problem with the 4L60E. If you suspect that, I will move this thread to the Automatic Transmission section.
I have just finished my cam swap and sent in my pcm to frost to get tuned. Every gear works fine until WOT. The first time i got on it the shift from 2nd to 3rd banged off the limiter. I also have 17in instead of the stock 16in tires but didnt mention to frost since i got them after i sent him the pcm. Is this a tune problem or a tranny problem. Thanks!
It doesnt mean what Frost did is wrong but its literally impossible to do a mail order tune on a cammed stalled auto and get it to shift perfect everytime. What settings worked in ten other cars may not work in yours. Its very common to have to adjust each gear in person to get the shifting dialed in perfect on a setup like yours.
