Overdrive problem
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Overdrive problem
I have a 1991 EB Explorer 2WD with around 288,000 miles on the engine and transmission.The thing has been running fine until about a week ago.Now it is running and shifting fine except it will not go into overdrive.I have no check engine light and I have already checked the wiring connectors on the transmission housing and they seem to be making good contact,also I have looked to make sure none of the wiring going to the tranny has gotten on the exhaust manifold as I have read on the Explorer Maintenance Forum sometimes happens.Any suggestions besides buying a rebuilt tranny? Thanks in advance
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From: UT
Can I assume it's an Auto tranny (A4LD)?
A problem in the 3-4 shift solenoid circuit won't necessarily trigger the CEL to come on. I think the first thing I would do would be to pull codes. Be absolutely certain that the problem isn't electrical before replacing the transmission.
A problem in the 3-4 shift solenoid circuit won't necessarily trigger the CEL to come on. I think the first thing I would do would be to pull codes. Be absolutely certain that the problem isn't electrical before replacing the transmission.
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Thanks for the reply mrshorty.I pulled codes today but the only one there was a code 74,something about the brake light switch.Can you or anyone else help me locate this 3-4 shift solenoid? There are 2 connectors I have found on the drivers side of the transmission (A4LD Auto) and thats as far as I have gotten.Thanks again.
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From: UT
KOER 74 is almost always operator error during the KOER test (you neglected to press the brake after engine id was output).
The shift solenoid is attached to the valve body. You access the solenoid itself by dropping the pan and the valve body. One of those connectors on the drivers side goes to the shift solenoids. It will have three wires: a red one and two others.
The shift solenoid is attached to the valve body. You access the solenoid itself by dropping the pan and the valve body. One of those connectors on the drivers side goes to the shift solenoids. It will have three wires: a red one and two others.
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mrshortly,How difficult is it to drop the valve body and replace this solenoid? I have done Tranny fluid and filter changes but never gone any further.Any help you could give me would be greatly appreciated.Thank you.
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From: UT
IMO, it isn't any more difficult than replacing a transmission filter. The valve body is the next part to come out. However, there are a few details (position of small ***** and springs and "hockey pucks") that make it necessary to be extra careful that you don't lose anything. I would stongly suggest getting a good reference manual before dropping the valve body. You may be able to get an ATSG manual from places that sell transmission parts, I get mine from Mitchell's transmission service and repair manuals at the local university/college library.
Of course, I wouldn't do this until I was reasonably sure that the solenoid was at fault. There are other causes of no 4th gear that may be fixed without opening the transmission, and others that require a full rebuild.
Of course, I wouldn't do this until I was reasonably sure that the solenoid was at fault. There are other causes of no 4th gear that may be fixed without opening the transmission, and others that require a full rebuild.
