Trip Odometer broken gear - easy fix

[SteveinNC]

At 388,683 miles my trip odometer quit working and wouldn't reset, I tore it apart and the 30 year old plastic gear split from fatique. Thought about several options and then it hit me. Took 120 grit sandpaper and roughed up both sides of the gear and applied JB Weld kwik set epoxy to both sides while the gear was held together in a small vice.
The JB weld takes the stress off the old plastic. Reamed the center hole again and reassembled it and works like a champ.

Hope this helps others,
Steve

 

[Drunkcanuk]

Have any pictures to go along with this?
Sounds like a clever solution.

 

[SteveinNC]

Have any pictures to go along with this?
Sounds like a clever solution.

Here are pics of both side of the gear. Notice I keep the epoxy out of the gear teeth and only on the sides. The JB Weld Kwik set was pretty easy to work with. I mixed it 1:1 resin and hardener and mixed it with a tooth pick. Kept mixing until it started to "set" a little bit and then simply applied it the gear being held together in a vice with rubber jaws.
Obviously did one side of the gear and let it set for several hours. I did help it with apply a hair dryer for extra heat a couple of times. Flipped the gear over and roughed up and appled the epoxy to the other side. You don't have to be real precision with how thick the epoxy is because where the gear is there is plenty of room on both sides for clearance.
Biggest issues is keeping the gear teeth clean of epoxy. I did hot both sides with a file to knock off the high spots. Don't know if that was really necessary.
Be careful in reaming out the center hole. It need a decent interference fit to grip the SS shaft to properly work. So don't go too far. My little reamer was .121 dia. and gave a good snug fit. But it was less snug that factory press fit.

This "fixed" gear is located below the black spur gear on the right side of the trip odometer in the fully assembled pic.

Steve

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[SteveinNC]

now to figure out how to recalibrate my tach. I must have bumped the needle in the process of fixing this gear. My RPMs are approx 850-900 lower than they should be.

 

[mwilliams55555]

To set my tach, OBD 2, I used a scanner live data stream while driving, also checked out speedometer for proper calibration, I think even under $40-$50 ones will show you, hope this helps, and welcome to the family, some really great information and people on here, Mike

 

[someotherguy]

Steve's got a 1993 so he's OBD1. Tach signal can be read using a diagnostic tach/dwell meter hooked to the spare terminal w/white wire next to the coil, or with inductive pickup on #1 spark plug wire. Speedometer checked against GPS works great. You can install the cluster so it operates but leave the lens off so you can adjust the needles as needed before full re-assembly.

Of course you'll want to confirm your other gauges as well. They weren't set very close to accurate originally, so it's a great opportunity to get them closer now. Oil pressure via mechanical gauge, voltmeter at the battery, temperature gauge with an IR thermometer scanning around the thermostat housing for max temp w/engine warmed up, and finally the fuel gauge.. ugh.. I went the "easy" path by filling it up, setting for "full", then drive it down to it showing exactly half then fill up again and see how many gallons it took vs. tank capacity. Not the most accurate but it worked for me.

Good move on fixing the gear, certainly age played a big part in the plastic failing but what also happens to plenty of them are people resetting the tripmeter while the truck is in motion. It's only supposed to be reset when stopped.

Richard