Steering shaft question

I pulled an upper steering shaft assembly from a totalled 2010 Prius today, with the intention of replacing the one on my 2013 (hopefully it will be compatible). However, due to awkward access and time constraints, I was forced to cut the three cables that were attached to the donor unit, rather than trying to disconnect them. My thinking was that I would be able to disconnect the remaining sections of the cables and simply plug in the ones already on my car.

The two larger cables have 'plugs', each secured by two small bolts so after removing these, I was able to unplug the first one but the second one, with the yellow covered wires, does not seem to be a plug at all but more of a sort of pass-through arrangement (see attached pictures) . I can lever it up a little and it will move slightly in four directions but the wires seem to be attached internally to something underneath the plastic moulding.

Has anyone on the forum ever worked on something like this and can perhaps advise me as to how to disconnect it. I don't want to try and force it off and risk causing internal damage. The place where I bought this specializes in Toyota hybrids so I asked one of the mechanics about it. He said he had never replaced one but seemed think that the wires were soldered inside, which I thought was a bit strange, given that the other two cables could be unplugged. If it can't be removed, my only solution would be to cut the existing cable and splice the wires but I'd rather avoid that, if possible. There doesn't seem to be very much info elsewhere online so I'm hoping someone here can help.

Thanks,

Al

 

Thanks for the very prompt response! Yes, that's certainly worth a try so I'll take the bolts off tomorrow and report back.

Yes, I now have two units but have not removed my original one yet.

I've been getting a rather sharp rattling sound when driving over bumps or even raised paint road marks, which seems to be coming from just behind the steering wheel. I'd read somewhere (maybe on PriusChat) that this whole unit needs to be replaced but after buying this for $50, I was chatting to someone else and was told that it may only be a replacement damper that's needed. It sits in the housing held in place by the two bolts you mentioned so I may end up just swapping these, assuming the used one is better than mine.

 

After doing a little bit more research, it seems that this statement may not be quite correct. He was referring to what he called "the snowflake", due to its shape. This diagram, which may or may not be quite the right one for my vehicle, shows part #'s 45253A & 45254B (snowflake) as being located where the electric motor meets the main housing. It also shows them as not being reuseable but fortunately, they do not appear to be too expensive.

I'll let you know what I find.

 

Yes, you are correct. I had followed the yellow harness back about 15" to a plug up behind the dashboard. The wrecked car was fairly close to another junker so because the driver's door could not be fully opened, access to work was limited. Although I could touch the plug, there was no way for me to get access to remove it. The car had been involved in a front-end smash and the damaged windshield was partially lying on top of the large facia panel. It would have taken quite a bit of time to remove everything and get access to the plug and unfortunately, my time was severely limited. If it is necessary, I have no problem splicing the four wires.

 

I'm not anticipating too much trouble in removing the same part from my car as I won't have any access issues like I did yesterday. I couldn't get the driver's door fully open because of another junk Prius that was alongside. Actually, there's nothing else pertaining to the steering that I would be able to salvage anyway as I have the complete unit, plus the intermediate shaft. When driving my own car, there is no indication of any play in the steering and I'm not getting the clunking sound that usually means there is a problem with the universal joints. The mechanical-sounding rattle I'm getting is definitely coming from the top end but I'll have a better idea later this morning.

 

Well, I was able to see why I wasn't able to completely remove the yellow harness from the upper shaft unit. When I removed the two 12mm bolts and slid the upper part off, the wires were connected to the ring seen in the picture. The ring has two metal bands which correspond to the two discs near the bottom of the black section. I assume it detects how much the wheel has been turned, either manually or by the motor. The good news is that when I dismantled my own unit, I was able to carefully slide the top part off and have just enough slack in the yellow harness to to allow it to be fully removed.

The bad news is that this job took far longer than I had anticipated, not so much dismantling but getting the replacement main part back in position was a real bear. This is what the intermediate shaft bolts to and is quite heavy as it include the electric motor. The problem was that there is a 3" bolt that sits quite far back and not only supports this part but also provides the pivot for adjusting the steering wheel up and down. It was really difficult trying to hold it up to the correct position to get the bolt inserted. I managed to jerry-rig a 'pulley' system using a heavy duty cord with a handle. The cord was looped through a hole on the mounting bracket then was tied off on the part I was trying to install. I was able to pull down on the cord which lifted it up into position to get the bolt inserted. Getting it aligned so that the bolt would thread onto the captive nut was even more tricky but perseverance eventually paid off.

Back to the good news. The rest of the installation went quite well and when I reconnected the 12V battery and powered up, there were no unusual lights displayed. So, I took it out for a quick 2-mile test run and this time, there were no rattles at all so I reckon it was $50 well spent.

Thanks, PriusCamper and ChapmanF for the input and suggestions. I hope my report is helpful to anyone else who might need to tackle this job. I've left out a lot of the details but if anyone has specific questions, I'll try to help.

Al

 

Yes, that makes sense. Thanks for the info.

 

I'm not absolutely certain but from what I remember, there was only one of the 'snowflake' parts installed in mine and it was disintegrated. I think the 45254B supercedes the 45254A and would suggest you buy both then you would have what's needed when you strip down. The extra part could probably be returned for a refund.

 

Although I had previously mentioned the posiibility of having to cut and reconnect the 4 wires, that in the end was not required. However, I would have had no problem in doing it if it had been necessary, as I have been soldering for over 60 years and know how to make a reliable splice. Also, quite a few of my earlier cars had no power steering option and they were not a problem to drive. Now, if power steering were to suddenly fail on a modern car, it would definitely cause a bit of a shock at first but it would still be possible to drive.