Interesting Info I've Learned Regarding Prius Rear Alignment

Hello all,

I've been talking to a local toyota shop foreman in lives in my town who is registered to this bored. (wvtoyotatech) I shared with him that I was going to have the alignment checked Friday (today) and told him that I would probably end up having to shim the rear and he gave me a very interesting reply that I wanted to share with anyone. I've never heard of this before, but in no way shape or form am I doubting this guys knowledge I just wanted to pass this info along. Hopefully we'll get some other opinion/info on this as well.

Here was his reply:

"One thing to remember about the rear of these cars(and is widely neglected on this site) is the rear uses a torsion beam setup with toe correcting bushings. Pretty much, the rear end "shifts" when the vehicle corners, so the toe constantly changes on the rear as you drive. One reason everyone's rear alignment seems off when they have it checked is the shop is failing to "center" the rear beam before checking the alignment. If there is any type of turn made to get on the alignment rack it causes the beam to move. If it is not centered then the specs may be off. After lining up to get on the rack, we always make several stops going forward and backing up to get the beam as centered as possible. Dragging the rear tires slightly by using the parking brake works well also. The big problem with shimming the rear on these cars and other Toyotas with the same rear suspension setup, is that it may bring the reading within spec while it's on the rack but most likely as the car is driven those shims will actually cause the rear specs to be out as the beam move back to center."

Unfortunately I set up my appointment at a different dealer then where wvtoyotatech works or otherwise I would be taking it to them. I will post my results as soon as I can.

Now, let's get some technical talk going.

 

Dogfriend I was suggesting that everyone just needs to be aware that in order to get proper alignment result the car needs to be set up properly. We'll see how my current appointment goes as i'm supposed to go at 3pm. Thanks everyone for your replys. Oh dogfriend, btw my dealer hasn't been so smart yet so we'll see.

 

Bob,

The work, etc that you have done is very credible and get me intrigued in this in the first place. Do all firestone dealers offer this lifetime alignment? Any restrictions after you pay a certain initial price? I'm at the dealer right now, they seemed real thrilled about checking alignment on a fairly new car.

Thanks for all the replies.

 

Well they certainly didn't do a good job. They deflated the tires to 32psi (car felt like a boat), they got grease on the arm rest, according to the sgII they drove 3.2 miles and aparently went WOT as the sgII recorded a max rpm of 4963 and I certainly don't drive my car that way, car came back with 35mpg less then when I got out of it, the print out they gave me had dashed lines for the values for the rear(rear values were my main concern) even after I specified I wanted the alignment of all 4 wheels checked with nothing adjusted, they said they found they front toe to be out of spec so they did me a "favor" and adjusted it and now the steering wheel is off center. The best part, they took two hours to do this even tho I was the only in the shop. It appears that after pumping the tires back up to my usual 54/52 that the fuel economy is doing just fine. Pulled 68.Xmpg in 15°F weather over 3X miles. Well now I just need to find a place to check the rear.

Thanks for everyones replys.

 

Bob,

Thank you for replying to my questions. We have a local firestone shop here so I think I will give them a call and see if they offer that here.

Take care,
Josh