Rustproofing the suspension

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Mendel Leisk, Apr 10, 2015.

  1. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    Yesterday I decided to raise the car, take a look at the suspension, with the aim to clean and coat it with a protective film. I had the sense to just take on the rear suspension for starters, lol.

    I used AD2000, Corrosion Inhibitor and Lubricant. Didn't research that much, hey, it's what I had. For the most part I applied by spraying it (with straw extender) onto an old toothbrush, worked it in, and wiped around with a rag. For unreachable zones, and main bolts, I sprayed, but tried to minimize this method, to avoid an oil bath.

    I wanted to deal with the main rear beam and everything welded onto it, the cup at the bottom of the spring, the shock connections, the trailing arm and the wheel bearing. I paid special attention to any welds/junctions, and made sure all the main bolts were cleaned and thoroughly coated.

    I spent about 6 hours, and at least one hour dealing with infuriating fasteners on trim pieces, some that were near impossible to remove even when new, doubly so now that they're rusted to near garbage. Toyota REALLY could improve in this department.

    Here's a pic someone took of the underside. I've highlighted what I dealt with yesterday, and some panels I took off for access. The circles are 10 mm (socket size) bolt locations, that were badly rusted, to the point I nearly rounded the heads backing them out. This is in west coast climate, very little salt on the road, garage stored, 4.5 years low mileage.

    The arrows are fasteners holding wheel well "spats". Taking them off is pretty much mandatory, and they have a hopeless fastener: a bolt on the inside, inside a little seat, near impossible to get a wrench or anything on. The nut on the outside is a flimsy metal/plastic combo. And they were badly corroded, chucked them and replaced with aftermarket black nylon "license plate" bolts and nuts.

    It's pretty much mandatory to take the wheels off too, for access.

    Capture.JPG

    I'll post a few phone pics in a bit.

    A few condition pictures. Not bad, but this is garage stored, low mileage, wet coast.
    image.jpg

    image.jpg

    This is the forward end of the trailing arm component:

    image.jpg

    Here's the bracket the (right side, looking towards front of car) wheel well spat connects to, the bolt goes inside it, spat (and paper fender liner on ours) goes over, then nut. Took a concerted half hour struggle to get the mother off. Rusted crap.

    image.jpg

    Reinstalled with nylon license plate bolt and nut:

    image.jpg

    Info:

    image.jpg

    Close to wrapped up:

    image.jpg
     
  2. mrstop

    mrstop PWR Mode

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    I have to agree with you on the need for Toyota to improve this area. Some areas, my almost 3 year old 30,000 mile Toyota look worse than my 22 year old Acura with over 250K and 14 year old Honda with 180K on them.
     
  3. alekska

    alekska Active Member

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    I'm impressed by your OTHER jack stand :) at the last photo

    - Alex
     
    #3 alekska, Apr 10, 2015
    Last edited: Apr 16, 2015
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  4. Yakoma

    Yakoma Active Member

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    That's a lumber jack stand.

    I like what you did there Mendel. Thanks for the tips.

    It's on my to-do list for the Prius and Scion. Got a buttload of Blaster Corrosion Stop to do the job. Just gotta do it now.
     
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  5. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    Oh, the stump? That's my life insurance, lol.
     
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  6. Tideland Prius

    Tideland Prius Moderator of the North
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    Impressive. My rear torsion beam has patches of rust as do my front coil springs. It's also garaged but I suspect the constant melting of snow in the garage (and slow dry ... or sometimes it doesn't dry and it refreezes the next time I take it out) doesn't help. I do flush out the snow before parking it in the car wash bay.
     
  7. Mike500

    Mike500 Senior Member

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    See the rust on the bolts. They were coated with zinc phosphate.

    In earlier years, they would have been plated with cadmium, zinc chromate or a more resistant rust protection coating. Current RoHS environmental standard have banned hexavalent chromium and cadmium.

    Most owners have no idea that a car rust from the inside and in unseen areas and believe that modern cars are well rust protected. NOT! as you have known in your photos.

    By the time rust penetrates to he surface of the painted body, the insides are probably long gone.
     
    #7 Mike500, Apr 11, 2015
    Last edited: Apr 11, 2015
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  8. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    Would galvanizing be a good sub, for the banned coatings. The open ended lug nuts I got from dealership, for Corolla steel rims i have with snows, have lasted good. A moot point, it is what it is...

    The circled fasteners in the first, full view of underside, just holding on plastic shielding: another year or two and they would need to be drilled out, or removed with impact driver. And I'm not in snow belt, and low mileage.

    You can see all the dinky screw fasteners at "bumper" edges, all their heads are total surface rust. One of the highlighted panels has one of those: it's coarse threads pretty far gone with rust. It screws into a bent metal clip pushed over a plastic trim edge. That clip also was pretty far gone.

    So maybe any recent car is going to have similar fastener rust issues, or are there still good options, but they're cheaping out?

    Did the front end suspension: more convoluted, not too bad. Found some more troublesome fasteners: the three 10 mm (socket size) bolts holding the front wheel well spats to another plastic underside piece. This time they were completely rusted: broke off a bolt head trying to back one out. It's not really a deal braker, you could remove the spat together with the connecting piece, if needed. Toyota could have just used permanent pop rivets there.

    The spat from the outside:

    image.jpg

    And an interior view, the nuts welded to a metal strip. Comepletely rust bound:

    image.jpg
     
  9. Mike500

    Mike500 Senior Member

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    Zinc phosphate is a better coating than galvanizing. The best galvanizing is not electro galvanizing but hot dipped. That, however, creates thick and uneven spots that interfere with fitting. Inserting bolts would be uneven as well as variable frictional contact would adversely affect torque values. There would be no way to assure that fasteners have been tightened to the correct torque.

    As I stated in many other posts, the flat contact horizontal points between plastic panels and metal traps salt bearing moistures which promotes rusting.

    Within a week of getting my car, I disassembled the plastic undercover, sprayed the edges and threaded captive nuts and screws with rustproofing and reassembled them. Three years later, when disassembled, I see no rust. The bolts come off easily. I have a 16 year old vehicle that I did when new the same way. The bolts still come off easily. It was worth the work.

    In you case, where there is already rust, I get a load of M6x1.0x25 10mm stand head A2 stainless steel hex head cap screws, which are cheap off of eBay and fender washers. I'd spray the rusted captive nut holes with rustproofing and drive the screws and fender washers in. You won't have the problem of rusted in locked bolts again.
     
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  10. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    I tried liquid wrench, then drill thru the center and a bolt extractor bit, on the one I snapped the head off. Hopeless, dubbed it one piece. It still holds in place.

    Thumbs down again Toyo.
     
  11. Former Member 68813

    Former Member 68813 Senior Member

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    my understanding is heated garage is worse for corrosion than unheated one. corrosion speed depends on temperature.
     
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  12. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    It's unheated garage. I've read with frequent driving an unheated garage is better. With infrequent driving a heated garage is better. We had next to no snow last winter, our winters in general are very mild, and only modest road salting happening.

    The fastener portion on the inside is not at the lowpoint in there, and there's honking big drain holes, evident in the picture.

    Yeah, I've managed to break off a bolt head on BOTH sides now, lol. Each side has 3 bolts, and the trim seems still quite secure with just 2 remaining. I tried liquid wrench (as I said) and after an extended time, very gently tried turning the bolt head back and forth. It finally broke off.

    I might just do nothing, since the only way to remove the piece seems to be by breaking of the remaining bolt heads (easily done, lol). As you can see in the pic, there's some sort of plastic retainer clip holding the strap in position. It doesn't show on the underside, so I'm thinking it might be plastic-welded to the inner panel.

    If I was going to remedy it, guess I'd get stainless bolts with oversized washers for the inside. It's frustrating poor design though, and the steel spec. is garbage.
     
    #12 Mendel Leisk, Apr 12, 2015
    Last edited: Apr 12, 2015
  13. Mike500

    Mike500 Senior Member

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    Water has a unique quality that cases it to expand when it freezes. Great mountains of granite and adamantine rock are eventually destroyed and weathered to sand, silt and clay grains by water.

    When kept in a garage, it the car get's above freezing, any ice accumulated in the seams of the car melts and get into the seams again with salt and dirt. Melted, an electrolytic reactions occurs eroding the metal. When the water freezes again, it expands as ice causing further damage.

    So freezing an thawing is more damaging than a car kept for days in freezing weather.

    The drain holes are a good thing. You need to keep them clear. Water that pools in anything made of steel rust through and make own drain holes.

    The correct remedy is o drill out the broken bolt with a cobalt drill bit of the root thread diameter and re-tap with the correct M6x1.0 tap.


    That's the permanent way to solve your problem so it won't happen again.
     
    #13 Mike500, Apr 12, 2015
    Last edited by a moderator: Apr 13, 2015
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  14. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    I have a bunch of these, think I found them strewn all over a Honda dealership lot, years back. Maybe I'll try the drill and tap. For M6x1.0 would a 3/16" dia pilot hole be ok? I'd rather err on being slight oversize, these things are only holding plastic, and doing the tap in situ I'd hate if the whole piece started to turn.

    I don't have a drill and tap set though, haven't done this since high school.

    image.jpg
     
  15. Mike500

    Mike500 Senior Member

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    3/16 inch would be too small. Use a 13/64 bit at .203 inch is closest to the number 8 bit specified for a close fit for an M8 tap.

    You might be fortunate enough to remove the thread residue, but an M6x1.0 tap is really needed.
     
  16. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    Thanks for all the info!

    I tried drilling out for an extractor bit, finally threw in the towel. I was using a handheld drill. I have a drill press, was hoping to get the whole piece off the car, but there's one fastener type at back of wheel well that proved difficult to extract.

    It's still very solid with 2 of 3 bolts, I'm going to treat it as a single piece, lol.

    image.jpg

    image.jpg
     
  17. ursle

    ursle Gas miser

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    New Hampshire here, a local requirement, oil undercoating, yearly.
    Takes an hour, tech drills all cavities, works great less filling.

    Err, tastes great, less filling.
     
  18. Dale Earnhadrt

    Dale Earnhadrt Junior Member

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    WOW....SOMEONE AS ANAL AS I AM. I HATE BEING UNDER JACK STANDS!
     
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  19. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    Me too, the nervousness about jack stands. You get used to it, but I finally decided to be sensible and quit getting used to it. Almost without fail now, I push this tree stump under first. If it were to collapse the stump would stop it. Sometimes it's impractical, too in the way, but whenever possible I do this.
     
    #19 Mendel Leisk, Apr 26, 2015
    Last edited: Apr 27, 2015
  20. Dale Earnhadrt

    Dale Earnhadrt Junior Member

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    Try Eastwood for rust: Eastwood - Auto Body Repair Tools | MIG Welder | TIG Welder | Plasma Cutter | Auto Body Supplies & Accessories. They are pricey but have good products. The only reliable way to remove rust is to blast it off. Soda blasting is getting popular and it's an option for me because I own a monster compressor. Soda is way safer than sand.

    There are a lot of rust shops in Canada. I found a company that has, I think, the best undercoating gun, but getting it across the border was a hassle. Had to find a broker. Not worth it:

    Rust Proofing RP-100 "L015-208" - LEMMER

    Et il est meilleur si vous parlez francais depuis les francais l'aimez quand vous parle le langue.
     
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