At approximately 119,000 miles, the PCM threw P0734 (4th Gear Incorrect Ratio).
Doing some research turned up that the transmissions in the Accent, Elantra, and Tiburon are known to have their overdrive hub bearing just kinda fall apart, and it will be fairly easy to see once you drop the transmission oil pan and see pieces of the bearing attached to the magnets.
Well, I pulled the car into my (unfortunately unheated) garage, got it up on jack stands, and removed the transmission oil pan. Attached to the magnets were several large chunks of bearing. Seems pretty conclusive to me!
Here's the steps I took to fix this issue: Remove air intake (very easy since I have a K&N CAI), battery, battery tray, battery tray bracket, front left tire, plastic wheel well, and inner splash guard. Support the engine and remove the left side engine mount bolt. This will allow the engine to sag maybe an inch, which is just enough to remove the transmission cover which holds in the overdrive clutch pack. The transmission cover is held on by a bunch of bolts, some of which are in awkward places. Once you manage to get all the bolts loosened and can pry the cover free of the transmission (since it's RTV'd in place), you can pull off the cover and install the new bearing. After that you just have to reinstall all the crap you removed, fill the transmission with SP-III, and voila, you once again have a working overdrive gear.
Overall I paid about $70 for parts, which includes the new bearing kit (from Whatever It Takes Transmission), new transmission filter, gray and black gasket maker, and the appropriate SP-III transmission fluid. It probably took me 6-8 hours overall to perform the work (though I tend to work at a fairly leisurely pace.) There were no particularly specialized tools involved, just a socket set, electric impact wrench, and a couple combination wrenches.
At approximately 119,000 miles, the PCM threw P0734 (4th Gear Incorrect Ratio).
Doing some research turned up that the transmissions in the Accent, Elantra, and Tiburon are known to have their overdrive hub bearing just kinda fall apart, and it will be fairly easy to see once you drop the transmission oil pan and see pieces of the bearing attached to the magnets.
Well, I pulled the car into my (unfortunately unheated) garage, got it up on jack stands, and removed the transmission oil pan. Attached to the magnets were several large chunks of bearing. Seems pretty conclusive to me!
Here's the steps I took to fix this issue: Remove air intake (very easy since I have a K&N CAI), battery, battery tray, battery tray bracket, front left tire, plastic wheel well, and inner splash guard. Support the engine and remove the left side engine mount bolt. This will allow the engine to sag maybe an inch, which is just enough to remove the transmission cover which holds in the overdrive clutch pack. The transmission cover is held on by a bunch of bolts, some of which are in awkward places. Once you manage to get all the bolts loosened and can pry the cover free of the transmission (since it's RTV'd in place), you can pull off the cover and install the new bearing. After that you just have to reinstall all the crap you removed, fill the transmission with SP-III, and voila, you once again have a working overdrive gear.
Overall I paid about $70 for parts, which includes the new bearing kit (from Whatever It Takes Transmission), new transmission filter, gray and black gasket maker, and the appropriate SP-III transmission fluid. It probably took me 6-8 hours overall to perform the work (though I tend to work at a fairly leisurely pace.) There were no particularly specialized tools involved, just a socket set, electric impact wrench, and a couple combination wrenches.
- John W., Spokane, WA, US