7.3 4R100 won't shift - Ford Truck Enthusiasts Forums

Notices
1968-2013 Full Size Vans Econolines. E150, E250, E350, E450 and E550

7.3 4R100 won't shift

Reply

 
 
 
  #1  
Old 07-03-2018, 11:55 AM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.
7.3 4R100 won't shift

Would a bad speed sensor cause the speedometer to bounce around erratically? The trans is also not shifting higher than 2nd gear and the OD light is flashing on the shifter.
 
Reply With Quote
  #2  
Old 07-03-2018, 12:19 PM
Mark Kovalsky's Avatar
Mark Kovalsky
Mark Kovalsky is offline
Post Fiend
Join Date: Aug 1999
Location: SE Florida
Posts: 17,237
Mark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputation
What codes are stored in the PCM? That will give a great place to start.

If you're into the guessing at what part to replace game, I'd start with the vehicle speed sensor on the rear differential. That could cause both problems.
 
Reply With Quote
  #3  
Old 07-03-2018, 09:51 PM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.
I'll see if I can grab some. A code isn't going to tell me why the speedo is bouncing around though.
 
Reply With Quote
  #4  
Old 07-04-2018, 08:12 AM
Mark Kovalsky's Avatar
Mark Kovalsky
Mark Kovalsky is offline
Post Fiend
Join Date: Aug 1999
Location: SE Florida
Posts: 17,237
Mark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputation
Why not? There are codes for that.
 
Reply With Quote
  #5  
Old 07-05-2018, 04:35 PM
Clubwagon's Avatar
Clubwagon
Clubwagon is online now
Posting Guru
Join Date: Dec 2003
Location: Saint Augustine, FL
Posts: 1,797
Clubwagon is gaining momentum as a positive member of FTE.Clubwagon is gaining momentum as a positive member of FTE.
^^^ What he said.

If the OD light is flashing there is a transmission code set. Could easily be a VSS. If its full of metal it could be reading erratically.
 
Reply With Quote
  #6  
Old 07-09-2018, 11:19 AM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.
Sorry guys, I've been on vacation. I'm going to start it up today and see what codes I can grab. The VSS seems to be most likely the culprit. It ran fine the week before this started. Is there any way to check the VSS for functionality in case it ends up being a wiring issue?
 
Reply With Quote
  #7  
Old 07-09-2018, 08:47 PM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.

So I got 3 abs codes and I think this last one is it. Nothing else came up when I checked.
 
Reply With Quote
  #8  
Old 07-10-2018, 09:47 AM
Clubwagon's Avatar
Clubwagon
Clubwagon is online now
Posting Guru
Join Date: Dec 2003
Location: Saint Augustine, FL
Posts: 1,797
Clubwagon is gaining momentum as a positive member of FTE.Clubwagon is gaining momentum as a positive member of FTE.
An E350 with a 7.3 likely has a single VSS on the diff housing. Pull it and see if its got a bunch of debris stuck to it. If so, clean it off with a clean cloth and re-install, clear the codes and test drive. If the codes come back replace the sensor.

If the sensor doesn't have much of anything stuck to it, replace it, clear codes and test drive.

Good Luck.
 
Reply With Quote
  #9  
Old 07-10-2018, 11:19 AM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.
I hope there's not debris lol then I've got bigger issues.
 
Reply With Quote
  #10  
Old 07-10-2018, 02:34 PM
Clubwagon's Avatar
Clubwagon
Clubwagon is online now
Posting Guru
Join Date: Dec 2003
Location: Saint Augustine, FL
Posts: 1,797
Clubwagon is gaining momentum as a positive member of FTE.Clubwagon is gaining momentum as a positive member of FTE.
Maybe, maybe not. I have seen fouled VSS's come out of rear ends that were just fine. LSD clutches are notorious for creating the fine metal that feels like grease and fouls the sensors.

If you have a christmas tree with shards, that's a problem
 
Reply With Quote
  #11  
Old 07-12-2018, 08:36 AM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.

Didn't look to dirty. I wiped it off and put it back in. Pulled out of the driveway and the speedo worked fine for a few secs then dropped off to zero. So still no signal.
 
Reply With Quote
  #12  
Old 07-12-2018, 09:43 AM
Clubwagon's Avatar
Clubwagon
Clubwagon is online now
Posting Guru
Join Date: Dec 2003
Location: Saint Augustine, FL
Posts: 1,797
Clubwagon is gaining momentum as a positive member of FTE.Clubwagon is gaining momentum as a positive member of FTE.
That looks normal. Replace it. Most likely a bad VSS. I replaced VSSs in my vans, it seemed, every few years.
 
Reply With Quote
  #13  
Old 07-12-2018, 09:48 AM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.
Originally Posted by Clubwagon View Post
That looks normal. Replace it. Most likely a bad VSS. I replaced VSSs in my vans, it seemed, every few years.
Every few years? What brand do you use?
 
Reply With Quote
  #14  
Old 07-12-2018, 09:52 AM
Clubwagon's Avatar
Clubwagon
Clubwagon is online now
Posting Guru
Join Date: Dec 2003
Location: Saint Augustine, FL
Posts: 1,797
Clubwagon is gaining momentum as a positive member of FTE.Clubwagon is gaining momentum as a positive member of FTE.
Originally Posted by vicp21 View Post
Every few years? What brand do you use?
The OE units lasted for several years and well over 100K miles. I used the vans exclusively for long distance towing. Consequently, it seemed I always had a VSS failure on the road, a long way from home. I would end up changing the VSS in an autoparts store parking lot. So it was whatever brand the parts store I found off the interstate had.
 
Reply With Quote
  #15  
Old 07-17-2018, 08:34 PM
vicp21's Avatar
vicp21
vicp21 is online now
Senior User
Thread Starter
Join Date: Oct 2011
Posts: 159
vicp21 is starting off with a positive reputation.
I replaced it, but it's still not working. The connector is missing a tab so maybe it's loose somehow? Seemed like it would still have some type of signal.
 
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.