2-1 downshift flare on 5R55E, TCC/EPC?

mp223 · 04-06-2012, 10:51 AM

Hi all, 1999 5r55e with 150K on the clock, fluid replaced at ~75k and again with a filter at ~140k. Otherwise all original.

When slowing down to stop I'll get a bump in RPMs when the transmission shifts from 2-1, eg: foot off accelerator and on brake, 1000 RPM -> 1500 RPM -> downshift 2-1 -> RPM drop to ~600 while stopped and idling.

I tried searching but only came across 2-3 flare issues. Could this be a symptom of my TCC or EPC solenoids going? Also, how likely is the IAC causing this problem?

**BrooklynBay** · 04-06-2012, 11:11 AM

Did you ever replace the servos?

mp223 · 04-06-2012, 11:18 AM

No. Everything is original.

drdoom · 04-06-2012, 11:25 AM

You may want to clean the throttle body, and check the associated linkage i.e. accelerator cable. Do a TPS test also.

**BrooklynBay** · 04-06-2012, 11:31 AM

Dried out servo pistons could cause a shift flare. Clean the bores & check for wear. Adjust the bands.

mp223 · 04-06-2012, 12:13 PM

drdoom: Throttle body was cleaned thoroughly a couple of months ago. Throttle cable is tight, TPS read 0.97v at idle and 4.something at WOT. I'm gonna pickup a couple of junkyard IACs and see what that does, my idle has always been low at ~500rpm and I wondered if the IAC malfunctioning could cause a jump in RPM in specific circumstances.

BrooklynBay: I'm getting conflicting information, do I have to drop the pan to check the servo pistons? Is there a particular servo I should be checking, perhaps a picture? I will try the band adjustment first.

**BrooklynBay** · 04-06-2012, 12:28 PM

There are two servos on the side of the transmission which usually dry out. The one in the pan is much cooler so I wouldn't worry about the seals on it. The bands should be adjusted after the servos are replaced. Keep in mind that both servos are a different diameter, and the internal springs on each one have a different amount of tension. Do one at a time to avoid confusion.

04-06-2012, 10:51 AM	#1
mp223 Wannabe Elite Explorer 1999 EB SOHC Join Date: Aug 2011 Posts: 41 Vehicle Specs (Original Poster)	2-1 downshift flare on 5R55E, TCC/EPC? Hi all, 1999 5r55e with 150K on the clock, fluid replaced at ~75k and again with a filter at ~140k. Otherwise all original. When slowing down to stop I'll get a bump in RPMs when the transmission shifts from 2-1, eg: foot off accelerator and on brake, 1000 RPM -> 1500 RPM -> downshift 2-1 -> RPM drop to ~600 while stopped and idling. I tried searching but only came across 2-3 flare issues. Could this be a symptom of my TCC or EPC solenoids going? Also, how likely is the IAC causing this problem?

04-06-2012, 11:11 AM	#2
BrooklynBay Aerostar Forum Moderator Brooklyn, NY 88 89 93 95 96 Aerostars Join Date: Nov 2005 Posts: 45,683 Vehicle Specs	Did you ever replace the servos? __________________ My list of useful threads. My photo gallery. My product reviews. My list of items for sale. Aerostar owners thread. Aerostar parts work in Explorers, Rangers, and Bronco II thread. History of the Aerostar thread. Aerostar Forum. New Members Forum. Ford/Lincoln/Mercury Forum.

04-06-2012, 11:31 AM	#5
BrooklynBay Aerostar Forum Moderator Brooklyn, NY 88 89 93 95 96 Aerostars Join Date: Nov 2005 Posts: 45,683 Vehicle Specs	Dried out servo pistons could cause a shift flare. Clean the bores & check for wear. Adjust the bands. __________________ My list of useful threads. My photo gallery. My product reviews. My list of items for sale. Aerostar owners thread. Aerostar parts work in Explorers, Rangers, and Bronco II thread. History of the Aerostar thread. Aerostar Forum. New Members Forum. Ford/Lincoln/Mercury Forum.

04-06-2012, 12:28 PM	#7
BrooklynBay Aerostar Forum Moderator Brooklyn, NY 88 89 93 95 96 Aerostars Join Date: Nov 2005 Posts: 45,683 Vehicle Specs	There are two servos on the side of the transmission which usually dry out. The one in the pan is much cooler so I wouldn't worry about the seals on it. The bands should be adjusted after the servos are replaced. Keep in mind that both servos are a different diameter, and the internal springs on each one have a different amount of tension. Do one at a time to avoid confusion. __________________ My list of useful threads. My photo gallery. My product reviews. My list of items for sale. Aerostar owners thread. Aerostar parts work in Explorers, Rangers, and Bronco II thread. History of the Aerostar thread. Aerostar Forum. New Members Forum. Ford/Lincoln/Mercury Forum.

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04-06-2012, 11:18 AM	#3
mp223 Wannabe Elite Explorer 1999 EB SOHC Join Date: Aug 2011 Posts: 41 Vehicle Specs (Original Poster)	No. Everything is original.

04-06-2012, 11:25 AM	#4
drdoom Wannabe Elite Explorer VA 1997 XLT 4.0 SOHC 4WD Join Date: Dec 2007 Posts: 1,502 Vehicle Specs	You may want to clean the throttle body, and check the associated linkage i.e. accelerator cable. Do a TPS test also.

04-06-2012, 12:13 PM	#6
mp223 Wannabe Elite Explorer 1999 EB SOHC Join Date: Aug 2011 Posts: 41 Vehicle Specs (Original Poster)	drdoom: Throttle body was cleaned thoroughly a couple of months ago. Throttle cable is tight, TPS read 0.97v at idle and 4.something at WOT. I'm gonna pickup a couple of junkyard IACs and see what that does, my idle has always been low at ~500rpm and I wondered if the IAC malfunctioning could cause a jump in RPM in specific circumstances. BrooklynBay: I'm getting conflicting information, do I have to drop the pan to check the servo pistons? Is there a particular servo I should be checking, perhaps a picture? I will try the band adjustment first.