powerwagon440

my 93 wont shift into overdrive unless i back off. it will go to 70mph without shifting then i let off the pedal then it will shift then i can get back into it. does the trans linkage need adjusted or?

Bushy

There are a number of components involved in the 3-4, 4-3 shift. They are the TPS, the speed sensor, the PCM, the crank sensor, The throttle valve cable, and one or two others as I recall.<br>The single most common cause is the TPS. It goes out of adjustment over time... sometimes it fails completely.<br>It is located on the injection pump, just ahead of the AFC housing. I'll post a link to my web page pics on this for you to look at. I also have a detailed &quot;how to&quot; on checking and adjusting it for personal preferences which I'll gladly email to you. Just drop me a note with your return email address, and remind me its for the TPS adjustment test file and it'll be on it's way.<br>Don't give up hope just yet...<br>Here is the link I mentioned. Feel free to poke around in all the picture galleries especially the VE pump gallery too..<br><br>http://www.turbodieselregister.com/u...mp;albumid=489<br><br>bob.

powerwagon440

ya if u would like to send the how to adjust the tps that would be great my email is rowdyram318@hotmail.com thanks alot! Andy

greatwhite

When mine does this, it is the kickdown cable (throttle pressure? cable) that has slid in its clip. Undo the clip and slide the cable forward all the way. Problem solved. Dunno if this will sove your problem, but its worth a try

Bushy

If I may suggest,.... use alot of care when adjusting your throttle valve cable setting. Bill K says that this can roach a tranny quick if it's done improperly.<br><br>Make adjustments in small increments, after first measuring the 'current' slot gap.<br>Also, crawl under the truck and make sure the throttle valve lever is full forward before adjusting. In my case I had to add on a 'universal throttle return spring' to help that lever return to full forward position.<br><br>Bob.

powerwagon440

well i had a new throttle cable put on there cause it was all streched but it was still doing that so i popped the hood and looked at it and jiggled the cable a few times and it worked for about a week and then it hasnt worked since!

Bushy

I think the shortest distance between working and not working is this......<br><br>Bill Kondolay<br>DTT Transmissions<br>Call Toll Free: (866)-504-4002<br><br>Phone and talk to Bill. If he can't get you straightened out, sell it... or have him build you one you can't hurt. <br><br>Bob.

Bushy

That's exactly the point I had hoped to make... there are a number of components that affect/have input to determine shifting, shifting timing, pattern, and more. Dont throw parts at it, do a good diagnosis first.
When you changed the speed sensor, did you do a good close inspection of the drive gear component? Check the 'square slot' that the drive gear uses as well. Sometimes the slot is worn round or the drive stub (usually square too) is worn and spinning in the gear assembly.
From personal experience, you should also consider using contact cleaner on ALL connections, use dielectric grease afterward, then do a quick wrap with elect. tape for that last bit of sealing it provides.
Do the same for ALL the connections under the hood, and under the truck. Man it really saves time and trouble. One look at them and you'll know if the tape seal looks frayed, or damaged, etc. It really pays off in less maintainence time and repair costs.


Glad you got it working though.... now... more fuel

Bob.