TC not staying locked | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

TC not staying locked

gearheadbob

New Member
Joined
May 13, 2006
Messages
4
Reaction score
0
City, State
Kemp, Texas
Year, Model & Trim Level
1992 Ford Explorer XLT
Guys,
The tranny has been rebuilt about 5K ago, The tranny was slow shifting in to reverse, so after communicating with Glacier991 and reading the valve body rebuild diary, I pulled the valve body and put a shift kit, new solenoids, and boost valve in it. They where the same as described in the rebuild diary.
Now for the new problem.
It shifts normal until overdrive kicks in. It engages around 43 mph and starts slipping at 48 mph It must be partially engaged because at 60 in 3rd it runs around 3k on the tac, If fully locked it runs around 2k. Right now it runs around 2500 rpm and is obvious it is not locked up.
It also has a new VCC and TPS sensor and new cables.

I just found out if you push the brake in slightly the converter will lock up and stay as long you hold the brake pedal in. Could it be the BOO switch? Is there a way to adjust it?

All help will be apreciated
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





I won't say it can't be the BOO switch, because it is certainly possible. When you run the EEC-IV self-tests, do you get any BOO codes? Do your brake lights come on? If you have cruise control, does pressing the brakes put the CC in standby?

After thinking through your symptoms, I wonder if you got it wired in right? It almost behaves backwards from what it should: On when the brake is pressed, off when it's released. If you put a voltmeter across the solenoid while driving, what do you see?
 






Mr Shorty,
Thanks for your response. The cruise control works fine. Yes, it goes in to standby mode when the brake pedal is pushed. I just had a friend run diagnostics on it. There where no codes. Yeah, I feel it is operating backwards too. No wires where modified so I feel all the hook ups must be correct. I am starting to wonder if the new solenoids on the valve body where correct. They where labeled for A4ld but the OD solenoid did look different than the one I replaced. I just figured it was an upgrade from the original. The solenoids can not be wired backwards because one wire is shorter than the other and the short wire will only reach one solenoid.
If there was a problem with a solenoid, wouldn't it not work at all? Could a relay be working backwards? I'm ready to drive it in to the lake nearby. Hahaha
Again, thanks for your help..
 






I'm going to assume that "There were no codes" means "all pass codes" and not "computer didn't respond". If my assumption is incorrect, figure out why the computer isn't talking to you.
"OD solenoid did look different than the one I replaced." Kind of have to be careful here. Which solenoid are we talking about (to be sure). Technically OD refers to 4th gear, but a lot of people use the term to refer to the TCC. Personally, I shy away form the term OD now. To avoid any confusion, I use 3-4 shift and TCC. In either case, the solenoids both operate the same, just want to be sure we're talking about the same one.
"Could a relay be working backwards?" I wouldn't think so. The transmission solenoid circuit are pretty basic DC circuits: common power supply from the EEC relay, and the computer acts as a ground side switch. The enxt thing I might do would be to put a voltmeter across the solenoid and see what it's doing.
 






Did you mix up the 2 solenoids when working with them? Solenoids are valves. In this case, one is normally closed, and the other is normally open. If you reversed them, I could understand how you are getting an inverse effect.
 






Thanks for your response guys.. I will be removing the valve body this week end to see if I became dislexic when I assembled it.
 






BrooklynBay, you where on the money. The solenoids were swapped around. With the new solenoids you can see in them and see what position they are in because they have slots in the side. I have a A4LD rebuild manual. In the back of the manual, there is a couple of pages that show schematics of what positions the valves are in when locked and unlocked. I swapped them around and now my 92 4x4 is back to normal.
Guys, thank you for all your help..

Bob
 












Back
Top