Odometer worm gear REPAIR Thread
 

I was looking for a Tutorial or video of how to replace the worm gear in my 99 F350. I've found enough information on everything but the 7.3L.


I found no help anywhere so I took upon myself to create a tutorial on how to and what your options are to repair your odometer.

The gear just showed up, $30 for that little thing?? :-arrgh


Hope this helps!

I thought the speedo/odo read through VSS and the tone ring in the rear diff?

So if you find the magic to remove the clear lens form the gauge assy...post it.

There's several videos on YouTube to remove the gauge cluster, once it's removed the clear lense simply pops off.

Now, getting to the worm gear.:-arrgh:-arrgh. More to come....

If you attempt this change the MOTOR & The WORM GEAR.
 

Since I couldn't find any information on changing the worm gear so I decided to give it a shot. So this is a tedious, royal PITA! I pulled the dash apart and got the instrument gauge display out. You will need a small socket set, 7/32, flat screwdriver, small pick and several boxes of patience!

DO NOT REMOVE THE CLEAR COVER FROM The DASH DISPLAY EXCEPT TO CLEAN
-This protects the gauges. See next note:

YOU DO NOT HAVE TO REMOVE ANY GAUGE DIAL INDICATORS
-I did and screwed up my speedometer and tach...both are off a bit now. I will fix this later when I replace the odometer motor.

ALL ACCESS IS FROM BEHIND THE GAUGE CLUSTER

REPLACE THE MOTOR AND THE WORM GEAR AT THE SAME TIME-YOU DON'T WANT TO DO THIS A SECOND TIME!!!!


The following refers to the BACK OF THE CLUSTER. Gauges are facing down.

There's a ton of soldering and electrical connections...be gentle. You'll see in the video the connection at the TOP of the cluster needs to be disconnected. The white portion on both sides, slides down and releases the plastic piece that has ALL YOUR DASH ELECTRICAL CONNECTIONS. Take your time when you remove it and especially when re-installing it.

>>>Replacement of JUST THE WORM GEAR DID NOT FIX IT!!! I drove 1/10th of a mile per the trip odometer and it quit working.
Next step will be to replace the motor and attempt to adjust the speedometer and tach.

More to come...

Great work! Nice video documentation of a new project as well. Videos like this provide endless visual aids for anyone else facing similar problems.

Reps sent!

Alright, I've been in the Gauge Cluster several more time and can't figure out where the problem is, I did however see my reflection once...That may be a clue. :-missingt
SO: I quit trying to fix mine and ordered a dash cluster off of eBay. It arrived today and I installed it. Works perfectly!:-jammin

To put your two options into perspective:
1) Changing your gear $35 for gear and a time consuming PITA repair.

2) Replacing Gauge Cluster: EBay mine was $74 plus $10 for 2 years insurance. Prices ranged from $74 to $190. Plug and play more or less. 30 minutes work.

Several things to consider going with the Replacement Cluster:

1) Adjusting mileage
-numbers roll UP
-Don't get greedy, I only adjusted the farthest two digits from the left 420,969 became 370969. The last thing you want to do is break it again.

2) Bulbs- check them all before installing.

3) BEFORE removing your cluster, take a picture of the cluster lights when you turn on the key...then compare the location of the lights of the original cluster to the new cluster once installed BUT before you button up the dash.
-I got lucky everything worked. :)
-Yes, some of the lights are in different places but everything lined up. :-X22


4 DO NOT RESET TRIP ODOMETER WHILE DRIVING! :-X19:-X19

5) It MAY be possible to exchange the backside of your cluster with the new one.
-This contains the electronics of your cluster NOT the odometer.
-At your risk.

6) Save your original cluster- bulbs, socks, resisters etc.


NOTE:
My E99 original cluster did not have a CC Light in the dash, the New cluster (2000) does have the light in the cluster. Turning on the CC, the dash light does NOT turn on. Could have a minimum speed before CC turns on, I'll update if it works at higher speeds than 30mph.


Hope this helps someone make an informed decision when deciding whether to take on this repair.

Great info, I'm running an E99 and you just saved the day for ordering anything but!!

Never would have thought! repo sent amigo!!

Denny

Thanks for this...might need it...down the road.

I do not engage CC until almost 45 mph. (Any lower speed causes transmission to fish between OD and passing gear.
I do have a chip.)

You can see it in the image below labeled 10. I put a small LED in for my cruise control indicator because the other bulb was very dim.


https://cimg5.ibsrv.net/gimg/www.for...7e98e659e9.gif

UPDATES

Alright, drove the truck to Denver today. The odometer worked perfectly. The CC works, CC light does not work. My production date was 8/98 so CC light must not have been wired in the system.

I am running a 2001 PCM so that is not the issue either.

Thanks for that, Sous.
Hmmm, I'd like to hear the solution there, I could swear that I read where someone installed a later PCM and the CC light just went to work all by itself.

And how are you liking your '01 PCM? My E99 one is live tuned but I do have that '01 parts truck on the operating table.

I am late to this party but I had a problem with my odometer and trip set button.
While changing out some dash bulbs I sprayed it with a tiny bit of WD40. Has worked great ever since.
Now if I could just find the short in my fuel gauge wiring this easy, everything would be working in the dash.