The other day after getting off the highway (after about 30 miles of 65MPH)my transmission behaved differently. It would not proceed to shift past second gear, and if I tried to accelerate past 35MPH it would start to slip badly. If I let off the accelerator and the truck slowed down to about 20MPH I would feel it catch again and I could then accelerate and maintain about 35MPH. I was able to travel about 20 miles like this to home. I called a local transmission shop the next day (who I trust, I have used them in the past). I drove the truck to the transmission shop the next morning (about 8 miles away) and the transmission behaved as it should, I was able to go fast enough to go into overdrive and everything seemed normal. The first thing he did was check the computer for any trouble codes, none were present. The overdrive light never came on the panel. The transmission fluid does not smell burnt. He was going to pull the pan down and have a look. I havent heard from him yet. Does anyone know what or what is happening that could be causing this. The truck has 81,000 miles and the fluid/filter was changed last at 49,000. Ironically I was about to change the fluid/filter on the day this happened. I thank all that respond.

 

I would start by replacing the mlps. I have seen similar problems caused by them.
Alan

 

Thank you Alan. What is the mlps?
Steve

 

Manual lever position sensor. also sometimes called transmission range sensor or (this is dumb but true) neutral safety switch. It is bolted to the side of the transmission and pretty easy to change.
Alan

 

This happened to me; it was the Throttle Position Sensor. I got it wet when I cleaned under the hood. No codes were thrown too.

 

Very interesting because I had done a post winter pressure wash of the engine compartment and under carriage the day before. I will let you all know what I find.
Steve

 

Hi.

You were lucky you didn't introduce any more problems.

PLEASE, Do NOT ever use a high pressure spray in your engine compartment! Water will get into places it has no business being ( like down in the plug wells, into sensitive electrical/sensor connectors, for example ).

Simple Green, a little low/no pressure water, lots of elbow grease and baggies over your alternator and MAF/open intake if you have one.

Good luck.

Cheers

 

I assumed modern vehicles were protected well against moisture, thanks for the tip.
Steve

 

Protected from moisture, driving through water above the floorboard, etc, yes.

Protected from a 2000 psi pressure blowings its way past seals, no.

 

Do a search under accumulator springs on this site and you may find your answer.

 

We do not have a F150 but we do have a 1997 Lincoln Town Car with a 4R70W transmission that has 60,000 miles on it and we are having a problem with it.

When the vehicle is cold it will shift just fine. When we drive it 5-10 miles park for a few minutes and then drive again it will shift from 1st to 2nd like normal but it will shift from 2nd to neutral. When it does finally shift to 3rd and then overdrive it will be fine untill we park again or have to idle for a while in traffic. It is like the heat build up under the hood or next to the transmission is causing a proble.

I have changed the fluid, filter, shift solenoid and the mlps, none of these have helped.

Could the new mlps not be adjusted right?
I have been told that it could be the throttle position sensor, speed sensor or the 2-3 accumulator.

Does anyone have any ideas?

Thanks

 

I talked to the transmission guy at a nearby Lincoln dealership and he told me that they had several cars with the same problem and most were the mlps. I told him that I had replaced that part and it did not help. He said that they had one that did not send any codes but it was a bad throttle position sensor so I repalced ours and that solved the problem.

About a week before ours started acting up I had cleand the maf with CRC Lectra Motive cleaner. I let the part dry before putting it back and even let the car set before starting it up. I really do not think that had anything to do with it but I can not think of anything else.

So if anyone else is having the same problem and can't figure it out, even if it is not sending any codes. you may want to try the same thing.

Thanks