4L60E Shift question
Thread Starter
Racer
Joined: Apr 2002
Posts: 311
Likes: 0
From: Charleston S.C.
4L60E Shift question
I bought BFG drag radials. They made a tremendous difference. (1.6 60 foot). But, now for the problem. Car leaves hard but won't shift normal. Hits rev limiter and shifts very late. I aired the tires back up and drove it home(150 miles) shifted great and drove fine. I found a abandoned road and made a run. With tires spinning it shifted fine up to third before I let up.
It seems to have something to do with the increased grip. I made 4 runs at the strip. Highest trans temp was 208. I tried manually shifting and in OD with the same results.
I have a increased capacity trans pan. Could the fluid be sloushing to the rear of the pan and causing cavatation.
The fluid level is 1/8" above the high mark for fluid temp of 190 on dipstick.
Thanks,
Kerry
It seems to have something to do with the increased grip. I made 4 runs at the strip. Highest trans temp was 208. I tried manually shifting and in OD with the same results.
I have a increased capacity trans pan. Could the fluid be sloushing to the rear of the pan and causing cavatation.
The fluid level is 1/8" above the high mark for fluid temp of 190 on dipstick.
Thanks,
Kerry
Le Mans Master
Joined: Nov 2000
Posts: 7,294
Likes: 1
From: Coral Springs Florida
Re: 4L60E Shift question (corvette4life)
Think about a Transgo shift kit.... :rolleyes: More info here http://www.txchange.com/transgo.htm
Thread Starter
Racer
Joined: Apr 2002
Posts: 311
Likes: 0
From: Charleston S.C.
Re: 4L60E Shift question (vstella)
It has a transgo shift kit in it. Also a 9 disc third, billet shell, etc.
Programming was done by Ed Wright. I called them today and spoke to John. John said that he has had similar complaints with the 95 computer. He said that when you get them to hook hard they don't want to shift. He said that Ed has solved some but he doesn't know how. He told me he would talk to Ed tomorrow morning.
Has anyone else heard of this?
Thanks again,
Kerry
Programming was done by Ed Wright. I called them today and spoke to John. John said that he has had similar complaints with the 95 computer. He said that when you get them to hook hard they don't want to shift. He said that Ed has solved some but he doesn't know how. He told me he would talk to Ed tomorrow morning.
Has anyone else heard of this?
Thanks again,
Kerry
Thread Starter
Racer
Joined: Apr 2002
Posts: 311
Likes: 0
From: Charleston S.C.
Re: 4L60E Shift question (vstella)
I spoke to John at Fastchip (Ed Wright) again today. He said to send it back and they would take care of it. He wouldn't explain how.
What could they be changing?
Thanks,
Kerry
What could they be changing?
Thanks,
Kerry
Pro
Joined: Apr 2002
Posts: 708
Likes: 0
From: Alexandria VA
Re: 4L60E Shift question (corvette4life)
I am curious what could have been changed as well considering I am 100% stock, stock tires, stock gears and I have YET to get a good 2-3 shift. I am on my 3rd trans and 20th retune with the computer, never seems right.
Mike
Mike
Thread Starter
Racer
Joined: Apr 2002
Posts: 311
Likes: 0
From: Charleston S.C.
Re: 4L60E Shift question (Bravery)
I sent the computer back to Ed Wright. They said they could solve this problem. They reprogrammed it and sent it back to me next day free of charge. But, it didn't solve the problem. I called them they said they have done all they can. They said it has to do will the stall speed in the computer. They said they have fixed two other with the same programming and that mine must be different. They couldn't offer any other suggestions.
I have a Vigilante convertor so I called Precision Industries. They said They had encountered this problem. They said that it has to do with difference engine rpm and transmission output rpm monitored by the V.S.S. during the burnout. The computer sees this and switches into "fail safe" or "limp" mode. Solutions are, (1) switch to a LS-1 computer or (2) Shut the car down for 10 seconds after the burnout. This clear the limp mode and the car should shift fine.
They suggested possibly Steve cole could help.
:confused:
:confused:
Kerry
I have a Vigilante convertor so I called Precision Industries. They said They had encountered this problem. They said that it has to do with difference engine rpm and transmission output rpm monitored by the V.S.S. during the burnout. The computer sees this and switches into "fail safe" or "limp" mode. Solutions are, (1) switch to a LS-1 computer or (2) Shut the car down for 10 seconds after the burnout. This clear the limp mode and the car should shift fine.
They suggested possibly Steve cole could help.
:confused:
:confused:
Kerry
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Pro
Joined: Apr 2002
Posts: 708
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From: Alexandria VA
Re: 4L60E Shift question (corvette4life)
As far as changing the computer, sure one could go with a 96 PCM which had OBDII electronics but you have to disable so many things to make it work, the car is no longer legal. I was told that high stalls (3000 and up) cause the computer to act up but I am on a STOCK converter, trans, gears, motor, everything and its still doing what you describe.
I found out that on some of the older transmissions, there was a recall for a faulty pump. Apparently, the production pump doesnt supply enough pressure in the trans for the 2-3 shift so the dealer replaces it and the problem is supposedly fixed.
Great plan although this was done on my latest rebuild and its still not shifting at WOT on the 2-3.
This is why I am never owning an OBDI automatic car again....
Mike
I found out that on some of the older transmissions, there was a recall for a faulty pump. Apparently, the production pump doesnt supply enough pressure in the trans for the 2-3 shift so the dealer replaces it and the problem is supposedly fixed.
Great plan although this was done on my latest rebuild and its still not shifting at WOT on the 2-3.
This is why I am never owning an OBDI automatic car again....
Mike
Thread Starter
Racer
Joined: Apr 2002
Posts: 311
Likes: 0
From: Charleston S.C.
Re: 4L60E Shift question (Bravery)
Bravery,
What tires are you using? Do you do a long burnout? If so, tell me how you do your burnout.
I put the scanner on my car and went into the transmission codes. I am getting a code 72. This does not turn on a light. So I didn't know I had a stored code. From the best I can tell, this is caused by the difference in engine rpm and output rpm of the transmission during the burnout. According to the service manual, the computer will default to " a delayed soft landing to third gear".
I feel like with the drag radials the converter stalls higher due to the increased grip. This then causes the computer to store the code 72 and soft shift third. Precision Industries said to do the burn out then shut the car down. This clears the computer. Then stage and run.
I am going to experiment with this friday. I'm also thinking of about backing into the water so the converter doesn't stall as high during the burnout.
Kerry
What tires are you using? Do you do a long burnout? If so, tell me how you do your burnout.
I put the scanner on my car and went into the transmission codes. I am getting a code 72. This does not turn on a light. So I didn't know I had a stored code. From the best I can tell, this is caused by the difference in engine rpm and output rpm of the transmission during the burnout. According to the service manual, the computer will default to " a delayed soft landing to third gear".
I feel like with the drag radials the converter stalls higher due to the increased grip. This then causes the computer to store the code 72 and soft shift third. Precision Industries said to do the burn out then shut the car down. This clears the computer. Then stage and run.
I am going to experiment with this friday. I'm also thinking of about backing into the water so the converter doesn't stall as high during the burnout.
Kerry
Pro
Joined: Apr 2002
Posts: 708
Likes: 0
From: Alexandria VA
Re: 4L60E Shift question (corvette4life)
At the track, I do a 1st gear burnout at 4000 for 10 seconds, let off the brake and let them spin for 10-15 feet, then stage.
On the street, it doesnt matter when I hit the gas, be it from a stop or a roll, the car wont shift into 3rd and when it does, it bounces off the limiter for 2-3 seconds and then shifts.
On the street, it doesnt matter when I hit the gas, be it from a stop or a roll, the car wont shift into 3rd and when it does, it bounces off the limiter for 2-3 seconds and then shifts.
