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Suspension Dry Rot

Discussion in '3rd Gen. Tacomas (2016-2023)' started by cmp1234, Nov 15, 2022.

  1. Nov 15, 2022 at 5:07 PM
    #21
    71tattooguy

    71tattooguy Well-Known Member

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    I would be really worried having a mechanic tell you your shock is dry rotten!!! Maybe he should be a carpenter :notsure:
     
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  2. Nov 15, 2022 at 5:14 PM
    #22
    Junkhead

    Junkhead TRDude

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    My truck handled like the day I bought it. No bouncing whatsoever, felt safe on high speed turns, braking etc. When shocks get worn and the vehicle hits a speed bump/pothole, it will bounce up and down more than once.
     
    Last edited: Nov 15, 2022
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  3. Nov 15, 2022 at 5:24 PM
    #23
    Rock Lobster

    Rock Lobster Thread Derailer

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    Spacer pucks on old shocks that you just went to the mechanic for?

    o_O
     
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  4. Nov 15, 2022 at 5:29 PM
    #24
    Martian__

    Martian__ Well-Known Member

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    That’s a sign of worn shocks/struts. They are designed to dampen the spring oscillation. Properly working suspension will only let it rebound once and sit back at ride height. Another sign is tire wear, cupping, uneven wear, etc because the tire is just bouncing down the road like a basketball.
     
  5. Nov 15, 2022 at 5:31 PM
    #25
    Bishop84

    Bishop84 Well-Known Member

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    I'll call struts when they are rusted so badly you cant see the brand anymore, but this is silly.
     
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  6. Nov 15, 2022 at 5:33 PM
    #26
    Martian__

    Martian__ Well-Known Member

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    Dry rot also happens to rubber components. Rubber doesn’t last forever and begins to crack. They were probably talking about the bushings on the struts, shocks, control arms. These are the most common, your alignment will suffer from the play in these components. I guess there’s a few wood workers here to think the term only belongs to wood.
     
  7. Nov 15, 2022 at 5:49 PM
    #27
    Junkhead

    Junkhead TRDude

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    That’s exactly what I was trying to say, that the vehicle will only rebound once when the shocks are in good working order. I should’ve been more clear.
     
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  8. Nov 15, 2022 at 5:52 PM
    #28
    Junkhead

    Junkhead TRDude

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    My OME shocks look pretty sad after about a year. Not as bad as your buddies though haha.
     
  9. Nov 16, 2022 at 2:35 AM
    #29
    PackCon

    PackCon Well-Known Member

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    Doesn’t matter. Dry rot is a fungal infection. Can’t infect something that isn’t living.
     
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  10. Nov 16, 2022 at 6:51 AM
    #30
    gudujarlson

    gudujarlson Well-Known Member

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    How do you know yours were worn out?

    I don’t replace mine when the automobile starts riding like a pogo stick and that’s only happened once in my life. The shock seal failed and all the oil escaped.
     
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  11. Nov 16, 2022 at 7:19 AM
    #31
    maxmk8

    maxmk8 Well-Known Member

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    Take em off and compare the rebound to a new unit. Some shocks don’t rebound and sort of suspend in place also. It’s just a wear item like tires.
     
  12. Nov 16, 2022 at 7:28 AM
    #32
    Arries289

    Arries289 Yo!

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    Dry rot??? On a 3rd gen? Ummm, nope. Maybe a 1st gen, maybe.
     
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  13. Nov 16, 2022 at 7:31 AM
    #33
    gudujarlson

    gudujarlson Well-Known Member

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    I'm guessing that is an indicator that the shock is low on nitrogen which could affect the performance of shock by allowing bubbles to form in the oil. Whether you consider the shock to be shot is a personal matter.

    As an aside, here is a good video on shock absorbers.

    https://www.youtube.com/watch?v=fSMWw6PQVRM&t=16s
     
  14. Nov 16, 2022 at 9:15 AM
    #34
    TenBeers

    TenBeers Well-Known Member

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    Yeah.
    Dampers deal with high-speed shaft speed and low-speed shaft speed (on both compression and rebound). The low-speed damping that keeps you from bouncing can last a while. The high-speed is usually where things start breaking down and it is harder to feel. Anything over 50K miles is good, some people may get close to 100K. But anything over 80K is likely shot on the high-speed damping side. Most people will never notice. But I don't think I've ever gotten more than 50K on a set of dampers before I've noticed a difference. I'd always recommend swapping them out between 50K and 80K miles whether you think they are fine or not. But if you feel like they are doing fine, your choice.
     
  15. Nov 16, 2022 at 9:21 AM
    #35
    drizzoh

    drizzoh itsjdmy0

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    I'd have to assume they were referring to the bushings, which don't look terrible from the 1 pic I'm able to see.

    That being said, the OR shocks don't seem to last long. Good news is if you like the ride quality you can pick up a low mileage take-off set for ~$300ish and they are very easy to replace.
     
  16. Nov 16, 2022 at 10:39 AM
    #36
    mutely

    mutely Well-Known Member

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    We are (well should be) trying to help the OP. Go back to you original comment, it was basically saying they are lying to you because metal doesn’t dry rot.
    Whether or not the garage used the correct term for rubber fatigue, they were referring to the rubber components and not metal parts.
    Dry rot is a VERY commonly used term in auto industry for “bad / cracking rubber”. We can argue their use of a term, but that doesn’t help the OP, and absolutely doesn’t mean they are lying to him/taking him for a ride because they used a term you personally don’t agree with.
     
    Last edited: Nov 16, 2022
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  17. Nov 16, 2022 at 11:55 AM
    #37
    gudujarlson

    gudujarlson Well-Known Member

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    I'm not following you. What are you suggesting is wearing out? The only thing that I can think of that would affect the damping performance is the loss of oil and nitrogen due to failed seals and/or o-rings, and I can't think of why that would affect compression damping more than rebound damping. I suppose the oil might degrade after a while, but I don't know if that is a common issue in practice.

    If you want a better idea on what wears out in a shock absorber, watch a rebuild video like this one. A rebuild involves mostly just replacing the seals and o-rings, because they wear out due to friction and age and eventually cause the loss of oil and nitrogen.

    https://www.youtube.com/watch?v=CRaOceJt12U

    Keep in mind that the stock shocks are different than Kings in several ways, but I think the general idea of what wears out is the same.
     
  18. Nov 16, 2022 at 2:57 PM
    #38
    TenBeers

    TenBeers Well-Known Member

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    Yeah.
    Well, keep in mind that I am an internet expert, so pay attention and learn. LOL.

    What I mean is more related to people's perceptions and the bounce test, and that there is a difference between the high-speed circuits and low-speed circuits (not compression and rebound, although they may be valved differently). Degraded oil and metal fatigue of the valve components will typically affect high-speed damping performance more than low-speed, and won't be as noticeable just doing the bounce test. These degrade slowly over time, so to the driver it can be imperceptible. But slap a new set on after 50K miles, and I bet you notice a difference.

    Basically, I'm just saying that the bounce test is not a good test. No shock with over 100K miles on it is performing like it should.
     
  19. Nov 16, 2022 at 3:26 PM
    #39
    gudujarlson

    gudujarlson Well-Known Member

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    Do you have any evidence or theory that the shims wear out? I have done a fair amount of internet searching for information on the effects of repeated flexing of steel springs and I have found no evidence that the spring constant of a steel spring changes appreciably with use. I

    I found information suggesting that steel has distinct fatigue limit and such an infinite number of loading cycles can be applied to a material without causing fatigue failure. I'm not sure this says anything about the spring constant changing though.

    https://en.wikipedia.org/wiki/Fatigue_limit

    CAVEAT: Contrary to the wiki page, I believe this has been shown to not be perfectly true and steel will eventually fail; but still a lot slower than some other materials such as aluminum.

    Even if the spring constant does not change, it is possible for a material to plastically deform under repeated use. It is called creep. However, it's not clear to me that this is a major issue for a typical steel spring.

    https://en.wikipedia.org/wiki/Creep_(deformation)

    Note also, that AFAIK, a shock rebuild kit does not come with shims. It comes with seals and o-rings.

    One last note, the Toyota parts website and a few places on the net I have visited state that springs are not considered wear items. I don't have any links handy.
     
    Last edited: Nov 16, 2022
  20. Nov 16, 2022 at 5:09 PM
    #40
    TenBeers

    TenBeers Well-Known Member

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    Yeah.
    Nah, no real evidence, I'm not a real engineer, and I wouldn't worry too much about the shims being the culprit in a deteriorating damper. But dampers do go through a LOT of cycles. Deteriorating fluid, fluid blowing by the piston due to wear, and failed seals resulting in loss of fluid are the most likely issues. Blow-by is more likely during a high-speed compression since fluids don't compress, which is why doing a bounce test may miss half of the equation. Just saying, replace your shocks every 50K, or rebuild them.
     

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