DownShiftin 93 W250

[ABGordon]

I was driving down the road in my '93 Auto doing about 55 when I felt the trans downshift, and I heard the RPM's upshift, and I was required to press down on the gas to maintain my speed.



This has happened a few times since the initial surprise.



Is this how the truck is letting me know the overdrive doesn't work like it done used to work?



What is the recommended next step



1. adjust the TPS?

2. cut the wires and install a manual od toggle switch?

3. install the column mounted od switch?

 

[Philip]

1. This is most likely culprit. You need a volt meter to check it. If memory serves me right. With the key in the on Position. You need to check voltage aross the black and white wire. Then slowely move the throttle to WOT and watch the voltage change. If you see any drops or dead spots then the TPS is going bad. Also check the plug by the TPS to see if it has any corrision in it and it is tight when pluged together.



2. Not my prefered method.



3. This is just makes it easyer to turn off/on OD. It won't stop the problem you have right now.

 

["Mad Max"]

could also tighten the little 12mm (?) nut under the TPS switch on top of the pump. It sometimes gets loose and makes for erratic OD operation. If you look under the TPS switch and bracket you'll see the shaft and there's a litle nut on it. If it's loose tighten it down (clockwise) until it get's snug. Don't overtighten it.

- Sam

 

[dan brooks]

It may also be the speed sensor. I've adjusted my TPS a few times, but still get intermittent funky OD operation. A quick cleaning of the speed sensor with some contact cleaner gets it working good for a while. I'll replace the speed sensor next time it acts up - it's cheaper than the TPS and hopefully will fix it for good.

 

[tugboatphil]

3. install the column mounted od switch?

Al,



Regardless of the solution to your problem, go ahead and do this one. It's just a regular shift lever for the 98 and up models. As I get older, lazier and can't stop the growth of my belly, it is the best add-on I've put on my truck. SamsRams has a post on this with the part #, but if you go to the dealer, it won't be hard to get.

 

[ABGordon]

I am going to check the TPS with my multimeter this weekend. My 12mm open/box end wrench will be in my back pocket. I have already purchased the O/D shift lever from the dealer ($49. 00 plus tax). I'll report back on what I find.



Thanks for the info/advice/guidance, and especially, the TWO CENTS!

 

[JimmieJacobs]

Just for giggles, unplug your TPS connector and spray with contact cleaner.

Mine was back shifting regularly and it cleared my problem up.



JJ