4L60E Shifts too soon??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

lofly'a · 04-29-2018, 03:41 PM

SHIFTS TOO SOON, through all gears?

my recently rebuilt 94 SWBRC 350/4L60E shifts from 1-4th way to fast unless i am really accelerating. if i take off at a fairly slow pace it will shift out too fast. sometimes it hunts through the gears up and down unless i accelerate or let it coast. never slips and shifts fine under moderate acceleration. any ideas?

**Palf70Step** · 04-30-2018, 08:08 AM

Have not heard of that one my self. Hopefully one of the smart dudes will chime in for ya. I know if I was easy on my 94 I was in OD at 35 ish with a light petal. I always assumed that was to get better MPG in someone's mind.

Was it a shop rebuild or one you and a friend did? If it is a shop I would have them recheck it.

lofly'a · 05-01-2018, 09:40 AM

built it myself. have done 5 or 6 4L60Es and lots of 700R4s. never saw this issue. really works great when hauling, or towing my 19' Bass boat. just shifts odd when empty under no load.

**Palf70Step** · 05-01-2018, 09:50 AM

Since the shifts are controlled by the ECU, maybe something in its programming?

lofly'a · 05-02-2018, 08:41 AM

Quote:

Originally Posted by Palf70Step

Since the shifts are controlled by the ECU, maybe something in its programming?

Point taken, but i thought OBD1 programming was preset and not possible to reprogram like OBD2 - (Chip change only). this issue did not exist before the rebuild, so wonder what "I" did wrong is what i'm after.

**Palf70Step** · 05-02-2018, 07:22 PM

Yeah, I was just popping ideas that randomly hit my head. I have reached my limit on ideas. Not sure what to look at now. Must be some adjustment that was done differently than what was in there b4 the rebuild.

04-29-2018, 03:41 PM	#1
lofly'a Registered User Join Date: May 2000 Location: Alexandria, LA 71301 Posts: 1,450	4L60E Shifts too soon??? SHIFTS TOO SOON, through all gears? my recently rebuilt 94 SWBRC 350/4L60E shifts from 1-4th way to fast unless i am really accelerating. if i take off at a fairly slow pace it will shift out too fast. sometimes it hunts through the gears up and down unless i accelerate or let it coast. never slips and shifts fine under moderate acceleration. any ideas? __________________ -02 avalanche (daily driver) -66 gto ragtop 389/400 (garage queen, hand-me-down from dad) -72 Tribute Trans Am (6.0LS/T56 6-speed) in progress -2003 YUKON (Wife's) -71 gmc swb fleet (current project, gonna shave everything, bags, stuff w/ 20's, gen III powertrain) -48 3100 SWB - 12/31/23 LONG TERM Project

04-30-2018, 08:08 AM	#2
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,634	Re: 4L60E Shifts too soon??? Have not heard of that one my self. Hopefully one of the smart dudes will chime in for ya. I know if I was easy on my 94 I was in OD at 35 ish with a light petal. I always assumed that was to get better MPG in someone's mind. Was it a shop rebuild or one you and a friend did? If it is a shop I would have them recheck it. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God! Last edited by Palf70Step; 05-01-2018 at 09:48 AM.

05-01-2018, 09:40 AM	#3
lofly'a Registered User Join Date: May 2000 Location: Alexandria, LA 71301 Posts: 1,450	Re: 4L60E Shifts too soon??? built it myself. have done 5 or 6 4L60Es and lots of 700R4s. never saw this issue. really works great when hauling, or towing my 19' Bass boat. just shifts odd when empty under no load. __________________ -02 avalanche (daily driver) -66 gto ragtop 389/400 (garage queen, hand-me-down from dad) -72 Tribute Trans Am (6.0LS/T56 6-speed) in progress -2003 YUKON (Wife's) -71 gmc swb fleet (current project, gonna shave everything, bags, stuff w/ 20's, gen III powertrain) -48 3100 SWB - 12/31/23 LONG TERM Project

05-01-2018, 09:50 AM	#4
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,634	Re: 4L60E Shifts too soon??? Since the shifts are controlled by the ECU, maybe something in its programming? __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

05-02-2018, 07:22 PM	#6
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,634	Re: 4L60E Shifts too soon??? Yeah, I was just popping ideas that randomly hit my head. I have reached my limit on ideas. Not sure what to look at now. Must be some adjustment that was done differently than what was in there b4 the rebuild. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!



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