Routine maintenance: tighten chassis bolts

[szabi]

In the Bentley manual for the 2004-2008 Prius, there is a routine maintenance item titled "Chassis fasteners, inspect and tighten" (P. 4-19). However, just what fasteners they mean is not further specified. Can an owner more experienced than I am please explain what fasteners they mean?

[hobbit]

Bentley is just parroting the Toyota maintenance book here, which
says the same thing. I don't think anyone's actually gone around
under the car tightening bolts, except maybe me and Patwong,
and I'd be hard pressed to assert that anything was actually *loose*...
.
_H*

[patsparks]

I have come across lose bolts, so worth putting a socket on the bolts around front and rear subframes every year or two.

[Patrick Wong]

Thanks to Hobbit for giving me undeserved credit on this issue. My philosophy is that if I don't hear unusual noise, why worry.

The Toyota repair manual lists the following areas to check "if necessary" (page 99-8, 2005 manual). Note that #1 lists "Canada", which implies that this section is not applicable to US vehicles - but that would be an erroneous conclusion...

Also note that the cabin air filter inspection and replacement is listed as #2. Not sure how well these two topics relate; maybe the repair manual editors couldn't find another suitable location to list the cabin filter.

"BODY
ON-VEHICLE INSPECTION
1. Canada:
TIGHTEN BOLTS AND NUTS ON CHASSIS AND BODY
(a) Tighten the bolts and nuts on the chassis parts listed below, if necessary.

Front axle and suspension

Drive train

Rear axle and suspension

Brake system

Engine mounting

Other chassis parts

(b) Tighten the bolts and nuts on the body parts listed below, if necessary.

Seat belt system

Seats

Doors and hood

Body mountings

Fuel tank

Exhaust pipe system

Other body parts

2. REPLACE A/C FILTER
(a) Remove the glove compartment.
(b) Remove the filter case from the filter outlet.
(c) Remove the filter from the filter case.
(d) Replace the filter with a new one.

(e) The installation procedures are the removal procedures in reverse order."

[tochatihu]

After years of ocassional offroading I tried to find loose chassis bolts on 2001 Prius. All were above/at spec. Maybe my torque wrench was out of calibration though

I reckon this is not your highest concern. If the braking and steering/suspension systems are in order than you are probably doing an admirable job of Prius underside maintenance.

[KTPhil]

Use the tool Lisa described in "My Couson Vinny":
Vinny Gambini: Maybe you didn't twist it hard enough.
Lisa: I twisted it just right.
Vinny Gambini: How could you be so sure?
Lisa: [sighs] If you will look in the manual, you will see that this particular model faucet requires a range of 10 to 16 foot-pounds of torque. I routinely twist the maximum allowable torquage.
Vinny Gambini: Well, how could you be sure you used 16 foot-pounds of torque?
Lisa: Because I used a Craftsman model 1019 Laboratory Edition Signature Series torque wrench. The kind used by Caltech high energy physicists. And NASA engineers.
Vinny Gambini: Well, in that case, how can you be sure THAT's accurate?
Lisa: Because a split second before the torque wrench was applied to the faucet handle, it had been calibrated by top members of the state AND federal Department of Weights and Measures... to be dead on balls accurate!
[She rips a page out of a magazine and hands it to him]
Lisa: Here's the certificate of validation.
Vinny Gambini: Dead on balls accurate?
Lisa: It's an industry term.

[szabi]

Thanks, Mr. Wong, this is just what I needed.