They were careless, and they need to replace the sensor. Are they trying to weasel out of taking responsibility for the repair glitch?

 

Yes, they were going to charge me for the part (around $250).

 

Well I'll offer a different perspective... I broke one of my rear sensors when I did rear hubs. I like to think I know what I'm doing, and I broke one trying to get it out despite taking my time. I soaked it, tapped on it, pulled on it, twisted it, soaked it some more over the course of a couple hours, and I still couldn't get it out in one piece. And it's not like I'm a business working on the clock like shops have to, I had all the time in the world and I couldn't get mine out,

Maybe they could have/should have called and told you they couldn't get it out and given you the choice of getting it out yourself or acknowledging the possibility that it might be ruined as part of the job. But I'm not so sure I'd call them careless and accuse them of trying to weasel out of something that was their responsibility.

Sorry that you ended up with that additional unforeseen cost, but I know from personal experience that this is one situation where that can happen. You often hear about people getting charged with what you consider unnecessary or unethical charges, but I wouldn't count this as one of them.

 

I appreciate your comment. I haven't had this apart myself, so I don't know quite how it all looks. I assume the sensor shaft inserts into a hole in the knuckle (?) and there is a bolt holding it in. However, with the bolt removed, it may be stuck in place and next to impossible to remove. Does it need to be removed to press out/in the bearing or can it be left in if the wiring harness is disconnected?

Basically, I was planning to replace the sensor myself. I can get the part for significantly less than they quoted. Can the sensor be replaced on an assembled hub attached to the car? I would have done the bearing job myself (and may have broken the sensor myself) except that I have to do it outside and it's cold in New England at this time of year.

 

Basically, I was planning to replace the sensor myself. I can get the part for significantly less than they quoted. Can the sensor be replaced on an assembled hub attached to the car? I would have done the bearing job myself (and may have broken the sensor myself) except that I have to do it outside and it's cold in New England at this time of year.[/QUOTE]

Per my Haynes manual for '99 thru '06 Highlanders:

"For front wheel sensors on all models and rear wheel sensors on 4WD models, remove the mounting bolt and carefully pull the sensor out from the knuckle.
The rear wheel speed sensor on 2WD models is integrated with the rear hub, and cannot be removed without removing the hub."

 

Yes, the sensor just simply slips into a hole. This is one of those five minute jobs that can turn into a time consuming and/or expensive nightmare.

If all goes well, you remove one small retaining bolt, pull the sensor out of the knuckle casting, and unclip the wiring connector. I had the wheel off when I was doing the work and but there might be enough room to do it without even taking the wheel off. Might be, but I didn't try. But to answer one of your questions directly... Yes you can install the senor with the hub on the car.

I don't remember for sure if you need to pull the sensor to press the bearings out of the knuckles. I know you could pull the whole knuckle off the car with the sensor still installed, but I don't remember about the bearings. By the time I was pressing bearings, I had one sensor snapped in half and the other one came out easily like it should have.

If the senor comes out as intended, then the hardest part of the job might be getting to the other end of the wiring lead where the connector ends clip together. Probably depends on which corner of the vehicle the work is being done on, but I had to replace the right rear sensor on my 02 AWD and I had to remove some interior paneling just to get to the connector. I did front bearings as well, but it's been so long that I don't remember how the front wiring leads are routed. I didn't break either of the front sensors, so the process was uneventful and therefore unmemorable.

Anyway, the installation is obviously the reverse of removal. Clip the connectors together, insert the sensor into the hole in the knuckle and retain with one small bolt. It should slip right in without a fight, but the same rust that prevented the old one from coming out easy might prevent the new one from going in.