Totora vitz KSP90, strut mount top cap space issue.

[Dharshana Anuruddha]

I'm having Toyota Vitz 2009 car, I have recently replaced the struct mount because of sound came from the car while going through rough road slowly. But after 2 weeks time again i saw the space as on below screenshot. Please advice is this normal ?I have replace KYB struct mount took from  Maradana.

 

https://ibb.co/MsNS7mB

 

 

 

[Dharshana Anuruddha]

[Monkey King Stu]

Did you ever figure this out? I don't see a reply here... I'm facing the same issue, replaced original with KYB, don't remember how it used to be, but now there a gap; mechanic says it's normal and only meant to touch when the shocks are in use and moving up/down 🤷‍♂️

*Update: some quick googling (tried before but didn't get the part names right so no luck) seems to indicate the gap is normal (even on a new top/strut mount) and gets bigger as the rubber wears out. One user mentioned an acceptable gap of 1/4" or 3/8" gap.

**Update: further reading seems to indicate that it's purpose is to prevent the strut from falling out when you jack up the car; makes sense...

Any feedback is appreciated.

Edited May 5, 2024 by Monkey King Stu
Updated after some online reading

[iRage]

  On 5/5/2024 at 12:11 PM, Monkey King Stu said:

Did you ever figure this out? I don't see a reply here... I'm facing the same issue, replaced original with KYB, don't remember how it used to be, but now there a gap; mechanic says it's normal and only meant to touch when the shocks are in use and moving up/down 🤷‍♂️

*Update: some quick googling (tried before but didn't get the part names right so no luck) seems to indicate the gap is normal (even on a new top/strut mount) and gets bigger as the rubber wears out. One user mentioned an acceptable gap of 1/4" or 3/8" gap.

**Update: further reading seems to indicate that it's purpose is to prevent the strut from falling out when you jack up the car; makes sense...

Any feedback is appreciated.

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Okay...so a physics lesson. If you take two objects and tighten them together, the sway/movement of one object will be fully transferred on to the second object by the joint. Depending on the two objects and the amount of sway, this will cause fatigue at the joint and eventually break.  So...sometimes you do need to have a bit of play when connecting two items together. E.g. train carriages, ceiling fans and the ceiling. Even plane wings are meant to wabble like that for the same reason.

Depending on the type of suspension, the top mount will differ. With some types (think of 3 bolt type top mounts with a mounting faceplate) this "gap" may or may not be visible. Your Yaris has a single bolt top mount. It is mounted by sandwiching the two support plates against the mount (there are pros and cons for this type of mount. This type of top of the mount in its normalcy is not that known for its heavy-duty usability. So typically found in hatchbacks and such. The setup loses a bit of directness when steering hard because there is too much flex. Cars like the GR Yaris also has the similar setup but with a lot of reinforcement. Whilst that has made it stronger there is a slight lack in directness in movement even then, which is why the facelift went with a 3 bolt setup.). 
Yes...over time the gap may appear to increase as the bottom bushings perching up the components wear out. Sometimes, after replacement, the gap may seem larger than what the original was because the components are new, so the gapping is different, or the parts used are compatible parts but not the exact part with the exact specs the car came with out of the factory. 

There is nothing wrong with this as long as there is no significant play when you turn the steering or the suspension moves up and down that the strut looks like it is going to get dislodged. 

Edited May 6, 2024 by iRage

[Monkey King Stu]

  On 5/6/2024 at 5:16 AM, iRage said:

Okay...so a physics lesson.

 

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Thanks for the free lesson 😅

The confusion was largely because of the incorrect understanding that the strut was partly held in place by the support piece, which is why I expected it to be flush with the body of the vehicle...

The other reason is that nobody actually seem to know the correct terminology for all these parts; not the mechanics, sellers, google... And I seriously think that using the correct official Toyota designated terminology rather than what the locals are used to, will probably do more harm than good... like "socket sober" 😅