Shifty Shifting

[SewperDrewper]

So I finally got my 91 7.3 IDI with the E4OD back on the road just to remember that it's still in limp mode. I posted on here a couple months ago about the issues I was having and it was recommended that I replace my Speed Sensor. I replaced the part to see absolutely no change in anything. I no longer have a speedo as it just sits at 0 and will occasionally bump up to about 20 MPH. Tach works fine...if I leave the plug that goes onto the speed sensor attached, I have 1st and 2nd gear. If I unplug that connection, I will have first when I put it into drive, but the first time it goes into 2nd, it will not go back into first until it sits in park for a bit. Also, if continued driving without connector plugged in, 2nd is SUPER TALL, and it seems like it has 2nd HI and 2nd Low...haha. It will creep up to about 2,000 RPM and then fall back to about 1,600 RPM before actually making the shift into 3rd...What help can you guys give me?

 

[flareside_thun]

You should still be able to pull codes on that machine. www.fordfuelinjection.com shows you how. If you've replaced the VSS on the rear end, then there's only a few more things that could cause your problem. The MLPS on the side of the transmission and a TPS, if it has one?

 

[SewperDrewper]

You should still be able to pull codes on that machine. www.fordfuelinjection.com shows you how. If you've replaced the VSS on the rear end, then there's only a few more things that could cause your problem. The MLPS on the side of the transmission and a TPS, if it has one?

Hey...thanks a ton for that link! What a killer website! The VSS was located on the transfer case...not the rear end. Is that standard?

 

[SparkandFire]

What was the condition of the drive worm gear on the output shaft on the TC ?

I was chasing down a wacky speedo issue once and found that worm gear had a concave bevel in it (rather than being square) so it wasn't touching the driven gear anymore.

BUT, I believe that VSS is for the cruise control, I thought the one on the rear diff was for the trans computer.

Do you have a sensor on top of your rear diff? That one's for the trans and the RABS I think ??

 

[SewperDrewper]

What was the condition of the drive worm gear on the output shaft on the TC ?

I was chasing down a wacky speedo issue once and found that worm gear had a concave bevel in it (rather than being square) so it wasn't touching the driven gear anymore.

BUT, I believe that VSS is for the cruise control, I thought the one on the rear diff was for the trans computer.

Do you have a sensor on top of your rear diff? That one's for the trans and the RABS I think ??

I have a sensor of some type...not sure if it's a speed sensor

 

[trackspeeder]

Hey...thanks a ton for that link! What a killer website! The VSS was located on the transfer case...not the rear end. Is that standard?

The VSS is located with the speedometer drive cable on all pre 92 units. Post 92 the VSS is on the diff.

Check the speedo drive gear and cable end. If it looks like what sparkandfire said in his post. Replace it.

 

[SewperDrewper]

So, there is a VSS on the rear diff as well as the transfer case...checked it out and Checker has it for $15, but it's a special order only part. Guess we'll just wait and see! Thanks for all the help!

 

[trackspeeder]

So, there is a VSS on the rear diff as well as the transfer case...checked it out and Checker has it for $15, but it's a special order only part. Guess we'll just wait and see! Thanks for all the help!

The VSS on the rear is for RABS on the pre 92 vehicles. The sensor that runs the tranny is on the speedometer cable.

 

[SewperDrewper]

The VSS on the rear is for RABS on the pre 92 vehicles. The sensor that runs the tranny is on the speedometer cable.

Thanks for the heads up. I picked up the sensor real cheap and felt good about knowing I have atleast two good sensors now! Haha. So, I picked up the part and put it in when I got home and there was absolutely no change...wasn't really disappointed. I was a little distraught however, so I ran codes from my EEC and it came up with 23, 129, & 29. 29 was a given which reads "insufficient input from speed sensor" Well duh, I've been driving with it unplugged. 23 was interesting though. That is the code for "Closed throttle TPS voltage higher or lower than expected" I just got done reading that another forum member had to change his TPS and his shifting issues were solved. I'll probably be picking up a new sensor soon, or atleast test mine. 129 kinda worries me since I have to go get my truck emission tested tomorrow for registration and that is the code for "Insufficient MAF/MAP change during Dynamic Response Test. Cross my fingers and hope I pass! While I was in the wrenching mood, I pulled the VSS that goes into the tail shaft and looked at my worm gear since I couldn't remember if my sensor came with a new one or not. It came with the new sensor and looked brand new. I took a light and a mirror and looked into the tail shaft though, and VIOLLA! The inner drive gear is stripped to oblivion! So, atleast I now know why my speedo doesn't work and might be heading into the right direction! Sorry for the picture quality, but getting it to where I could see was difficult, not to mention a phone taking a picture of a mirror lit up by another phone! Haha.

 

[SewperDrewper]

Anyone know how difficult it is to pull that tail shaft apart and replace that inner drive gear? I have a 93 Ford Ranger that uses the same setup for the Speedo, and if it's compatible, I could just steal the piece from there to use it as a trouble shooter until I know if that fixes it or not?!?!

 

[SparkandFire]

Drop the driveshaft, remove those 4 large torx bolts, pop the tail housing off, remove the spring clip and slide the gear off. The gear is held in place by the clip and a steel ball, slide the old gear off and the new one on.

I blue siliconed the tail housing when I put it back on.


The one I had looked like this one, but was a yellow 5-tooth.

This place has most of the gears, including the one pictured.

http://www.transmissioncenter.net/speedometer_calibration_______va.htm

 

[SewperDrewper]

So by what I could see yesterday, and recollect today, I have a yellow gear as well. The website you SparkandFire suggested doesn't list any part numbers for anything under 6 teeth. Anyone else know where I might find this guy? Thanks again for all the support. Oilburner proves it's awesomeness again

 

[SparkandFire]

Go here... I think it was a 7-tooth I had...

http://www.drivetrain.com/parts_catalog/transfer_case_replacements_and_parts/bw1356.html


Look at part # TRS-366997

$16.44

 

[SewperDrewper]

Thanks again man...you're awesome!

 

[SewperDrewper]

Go here... I think it was a 7-tooth I had...

http://www.drivetrain.com/parts_catalog/transfer_case_replacements_and_parts/bw1356.html


Look at part # TRS-366997

$16.44

Just for fun, I called the local dealership to see if they even knew what the part was...and after talking to service and parts for about 20 minutes, they figured out they had one hidden in the back! I picked it up for $7.61 w/tax! Got it in and fired the truck up and all my shifting issues are gone! The only issue is that my speedo is WAY off. I'm going to use the chart they had on the one website SparkandFire recommended to get the Speedo synced right and all should be good to go! Thanks again for all the help!