2000 Ford Expedition Transmission slipping

[mfreeoff]

Hello all,

I have posted here before and got a lot of good suggestions. I am hopeful that I will get a few suggestions on this one.

I have a 2000 Ford Expedition that is 4X4 and has the 4R70W transmission. I will first explain what the symptoms are and then what I tried.


If I am at a stop light for a minute or so, the truck wants to slip in all gears for about 1/4 mile and then the transmission feel good. If I come to a stop, but only for a few seconds, the transmission will not slip in any of the gears. If I come to a brief stop and go to reverse then back to drive quickly, the transmission wants to slip. So basically, if a keep the wheels rolling, or only come to a brief stop all is good. But if I stop for an extended period of time or go out of drive, the transmission wants to slip.

This is what I have done:

I first checked the transmission fluid and it is red and did not smell burnt. I dropped the transmission pan and there was no metal. I replaced the two solenoids, the Automatic Transmission Control Solenoid (part number SBA4938), the Automatic Transmission Torque Converter Clutch Solenoid (part number SBA4969), and replaced the transmission filter.

I added back new transmission fluid, which it seemed to take about a quart more then what I got out. I did wait until the truck was warmed up before I added the extra quart. I drove it afterwards but I am having the exact same problem.

Any suggestions would be greatly appreciated.

Mike

 

[99WhiteC5Coupe]

Hello all,

I have posted here before and got a lot of good suggestions. I am hopeful that I will get a few suggestions on this one.

I have a 2000 Ford Expedition that is 4X4 and has the 4R70W transmission. I will first explain what the symptoms are and then what I tried.


If I am at a stop light for a minute or so, the truck wants to slip in all gears for about 1/4 mile and then the transmission feel good. If I come to a stop, but only for a few seconds, the transmission will not slip in any of the gears. If I come to a brief stop and go to reverse then back to drive quickly, the transmission wants to slip. So basically, if a keep the wheels rolling, or only come to a brief stop all is good. But if I stop for an extended period of time or go out of drive, the transmission wants to slip.

This is what I have done:

I first checked the transmission fluid and it is red and did not smell burnt. I dropped the transmission pan and there was no metal. I replaced the two solenoids, the Automatic Transmission Control Solenoid (part number SBA4938), the Automatic Transmission Torque Converter Clutch Solenoid (part number SBA4969), and replaced the transmission filter.

I added back new transmission fluid, which it seemed to take about a quart more then what I got out. I did wait until the truck was warmed up before I added the extra quart. I drove it afterwards but I am having the exact same problem.

Any suggestions would be greatly appreciated.

Mike

Did you check the fluid level with the engine running and in park? Or with the engine off?

 

[mfreeoff]

Very sorry.. Yes, it was running and in park while it was up to temp when I checked the level.

 

[Billme]

Any follow up on this?

 

[mfreeoff]

not on my end.. Just ordered a rebuilt and tested valve body. I will let you know what happens when I get it on Thursday.

 

[Dustin Gebhardt]

Might be a bad front pump or clogged valve body. My guess: the line pressure isn't building up fast enough. This causes your slippage when at a standstill until the line pressure increases enough to clamp the clutches down. When you shift from D to R and back to D, your valve body is redirecting the built-up pressure to the R circuit and you have to rebuild the pressure in the D circuit again. Similarly, when you come to a long stop, the lack of RPMs in the front pump causes the pressure to fall off faster than it can maintain, causing the same slippage issues.

You could also have the wrong trans fluid or bad fluid. If the fluid is too thin, then it may build pressure differently than intended.

Just a guess on my part. My 4R100 in my old '01 blew the intermediate sprag and lost all power. I had it rebuilt with a heavy duty sprag and she ran like a champ until I sold her.

 

[xrayman3707]

Hello all,

I have posted here before and got a lot of good suggestions. I am hopeful that I will get a few suggestions on this one.

I have a 2000 Ford Expedition that is 4X4 and has the 4R70W transmission. I will first explain what the symptoms are and then what I tried.


If I am at a stop light for a minute or so, the truck wants to slip in all gears for about 1/4 mile and then the transmission feel good. If I come to a stop, but only for a few seconds, the transmission will not slip in any of the gears. If I come to a brief stop and go to reverse then back to drive quickly, the transmission wants to slip. So basically, if a keep the wheels rolling, or only come to a brief stop all is good. But if I stop for an extended period of time or go out of drive, the transmission wants to slip.

This is what I have done:

I first checked the transmission fluid and it is red and did not smell burnt. I dropped the transmission pan and there was no metal. I replaced the two solenoids, the Automatic Transmission Control Solenoid (part number SBA4938), the Automatic Transmission Torque Converter Clutch Solenoid (part number SBA4969), and replaced the transmission filter.

I added back new transmission fluid, which it seemed to take about a quart more then what I got out. I did wait until the truck was warmed up before I added the extra quart. I drove it afterwards but I am having the exact same problem.

Any suggestions would be greatly appreciated.

Mike

Mike,
I’m not anything close to a mechanic. My 2020 King Ranch 4x4 started this at 94k miles. It quickly progressed to large pauses in between shifts. Ford put a new transmission in under extended warranty. Sorry I don’t have any more help for you than that. Good luck

 

[mfreeoff]

Dustin,

I truly believe you are correct and that the valve body will not fix the problem. Your analysis of what is going on and the symptoms is SPOT-ON.. I know there is an O-ring that holds the pressure for the first gear line pressure is the issue. My truck is not worth the time or trouble to replace a 50 cent O-ring. I don't think the sprag is causing the issue, because it does not slip all the time and I don't think the sprag relies on fluid or anything. I would guess that a sprag would slip all the time or not at all. So, if the valve body does not work, I am getting rid of the truck. It's been a great truck and gave me very little issues.

Xrayman,

If my truck was a King Ranch, I would consider repairing. But mine is only an XLT. Also my truck has over 310,000 miles, so it has given me more that I could ever expect.

I will update this weekend, if it not too cold outside to work on the truck.

 

[Billme]

Light come on when Dustin mentioned a few things, and it gave me an idea on what to try, and it worked..
I got a bottle At-205 and put it in the transmission.. My 2000 XLT was doing the same.. In fact, on a cold start, it wouldn’t go forward with playing with the throttle to engage.. Every stop, I had to do that..
Anyway, after warming to operating temperature, I got it going, and made a 75 mile trip.. Each time I drive it, it got better. it no longer does it when I stop.. On a cold start, it does it slightly, so I’m expecting it to get even better, if not, I can live with it the way it is..
Btw, This stuff fix my rear seal leak couple years ago when I done my timing chain job.. I highly recommend this product

 

[mfreeoff]

Billme,

I don't know what is in that stuff and how to thank you as much, but after adding 3 bottles as it suggests, the transmission is 99% better!!! I only drove it 20 minutes or so, but I can definitely notice the difference. I will give it more time and report back.