KDSS bolt style and corrosion condition comparison (1 Viewer)

[FerrisBueller]

We're all aware that the KDSS bolts and housing are prone to corroding (located on left-hand side, below 2nd-row door, attached on inner frame rail). The bolt style pre-2018 model year was an Allen-head bolt, which have been observed to strip easily or break the narrow Allen bit when corroded. The 2018+ bolt style is a normal hex bolt that should avoid the stripping, but it has been suggested it might be more susceptible to corrosion.

Unfortunately, there's simply not many data points on this forum yet regarding the 2018+ design for a good comparison. This poll will hopefully help assess the more widespread KDSS bolt style and level of corrosion / stuck-ness.

Also feel free to post photos of your KDSS bolt for reference, along with the state where your 200 spends most of its time and any preventative or unsticking maintenance you do.

 

[FerrisBueller]

I'll start. My 2018 LC has lived its entire life in Texas. Mostly clean / very minor surface rust, never had a problem turning the hex bolts. I try to spray them with LPS-3 once a year on a hot, dry day.

 

[bloc]

@Taco2Cruiser have you seen any more of this in the shop?

 

[CharlieS]

2013 & 2016. They both lived in NYC then VT. Both had both KDSS bolts heavily rusted. One vehicle required welding to break them free, the other one came off with lots of time, patience, penetrating fluid and heat.

 

[LTSR]

@FerrisBueller whats the build date of your 2018? i think i recall some early 2018 builds with allen heads

 

[FerrisBueller]

@FerrisBueller whats the build date of your 2018? i think i recall some early 2018 builds with allen heads

Mine is pretty early, with a February 2018 build date.

 

[Madtiger]

The 2018+ bolt style is a normal hex bolt that should avoid the stripping, but it has been suggested it might be more susceptible to corrosion.

I think that the suggestion of 2018+ hex bolt “more susceptible” to corrosion was by one member only.

For me, i greased it up (excessively) since day 1…and have not needed to greased it up again because grease still looks good.

 

[CharlieS]

I imagine either design would be fine indefinitely if greased or lps3 coated from day one. Alas, that isn't a standard maintenance procedure.

 

[rlynch356]

hUmm mine is a 2017... and I have Hex Bolts... no issues

 

[FerrisBueller]

hUmm mine is a 2017... and I have Hex Bolts... no issues

Oh interesting. I think yours is the first 2017 I've heard of with regular bolts. Maybe they changed them at the end of 2017. What is your build date?

 

[bloc]

Oh interesting. I think yours is the first 2017 I've heard of with regular bolts. Maybe they changed them at the end of 2017. What is your build date?

Plausible it could also depend on which factory the chassis came out of... would be interesting to dig into that as well.

 

[rlynch356]

06/17
Nc/sc it’s whole life.. need to pull the guard off
And treat it.. mostly I think its dirty ))
11th Digit 4 = Yoshiwara factory

 

[JOFS]

I have one 17 with hex and one with regular bolts

I bought the one with regular bolts as a leftover in 2018 so suspect it was a later build.

Truck currently getting its snow tires mounted so can’t check.

John

 

[Taco2Cruiser]

@Taco2Cruiser have you seen any more of this in the shop?

Oh yeah, they all look terrible. (Current count is 220 200s)

Every 200 I work on gets my little fix for it. I just can’t let a cruiser leave knowing that it will one day, mess with someone.

I tape off the set screws and enamel the housing. After that is dry, I open the screws the normal three revolutions, apply anti-seize to the exposed threads and screw them back in.

No yearly under coating, they simple stay movable for the long haul. Side note, really any on the stuff people spray under their truck for rust, just doesn’t work. There’s still rust, and now it’s so much harder to clean up the rust, and paint.

 

[fajitas21]

I tape off the set screws and enamel the housing. After that is dry, I open the screws the normal three revolutions, apply anti-seize to the exposed threads and screw them back in.

I know it's very bad to open to screws too far, but is there any harm in the number of times you open these valves? Not that I'd say we regularly open them, but every 3 - 4 years I'll do lift work (shocks, etc) and just wondered if that added up.

Lastly, when you say 3 revolutions and then anti sieze, I assume you're just sneaking some on it where it meets the metal?

 

[bloc]

I know it's very bad to open to screws too far, but is there any harm in the number of times you open these valves? Not that I'd say we regularly open them, but every 3 - 4 years I'll do lift work (shocks, etc) and just wondered if that added up.

Lastly, when you say 3 revolutions and then anti sieze, I assume you're just sneaking some on it where it meets the metal?

As long as they aren’t over-torqued there should be no harm in opening them repeatedly.

I took it as three threads would end up with anti-seize, and this should prevent corrosion working up the threads.

 

[bloc]

Oh yeah, they all look terrible. (Current count is 220 200s)

Every 200 I work on gets my little fix for it. I just can’t let a cruiser leave knowing that it will one day, mess with someone.

I tape off the set screws and enamel the housing. After that is dry, I open the screws the normal three revolutions, apply anti-seize to the exposed threads and screw them back in.
View attachment 3185446View attachment 3185447View attachment 3185448
No yearly under coating, they simple stay movable for the long haul. Side note, really any on the stuff people spray under their truck for rust, just doesn’t work. There’s still rust, and now it’s so much harder to clean up the rust, and paint.

I like that you handle the shield mounting boss and other machined areas as well. I just might do this too.

Are you noticing a difference in how the bolt heads themselves corrode when untreated?

 

[Gr8Daneger]

Oh yeah, they all look terrible. (Current count is 220 200s)

Every 200 I work on gets my little fix for it. I just can’t let a cruiser leave knowing that it will one day, mess with someone.

I tape off the set screws and enamel the housing. After that is dry, I open the screws the normal three revolutions, apply anti-seize to the exposed threads and screw them back in.
View attachment 3185446View attachment 3185447View attachment 3185448
No yearly under coating, they simple stay movable for the long haul. Side note, really any on the stuff people spray under their truck for rust, just doesn’t work. There’s still rust, and now it’s so much harder to clean up the rust, and paint.

What enamel paint do you use? Primer/rust converter?

 

[fajitas21]

As long as they aren’t over-torqued there should be no harm in opening them repeatedly.

I took it as three threads would end up with anti-seize, and this should prevent corrosion working up the threads.

Ok thanks, and to follow up, I think I found a way to better word my question.

Would opening those bolts just a bit, and leaving them open while performing suspension work cause any issues? I don't want to introduce air into the lines and I'm trying to make sure I don't take any chances, but for extended work (like redoing front suspension) I wanted to keep the shutters open for a bit.

 

[Taco2Cruiser]

I know it's very bad to open to screws too far, but is there any harm in the number of times you open these valves? Not that I'd say we regularly open them, but every 3 - 4 years I'll do lift work (shocks, etc) and just wondered if that added up.

Lastly, when you say 3 revolutions and then anti sieze, I assume you're just sneaking some on it where it meets the metal?

Any metal, that rubs metal, does wear. That said, its so miniscule that the rest of the 200 will fall apart before those set screws wear to the point of failure.

To work on suspension with a KDSS truck, you open the set screws three revolutions, no more. Whatever threads are exposed, you can get anti-seize on. When you tighten the threads back in, you now have anti-seize on the threads that get corroded from the environment. I’ve only had to repair one KDSS from corrosion so far, six from Toyota dealership install failures, and one from an independent installation shop failure. At least the set screws that I’ve pulled out, the corrosion in only on the very, very end of the threads. That’s why I‘m very happy with just getting the very tip of the threads with some anti-seize on them.

As long as they aren’t over-torqued there should be no harm in opening them repeatedly.

I took it as three threads would end up with anti-seize, and this should prevent corrosion working up the threads.

You got it brother.

I like that you handle the shield mounting boss and other machined areas as well. I just might do this too.

Are you noticing a difference in how the bolt heads themselves corrode when untreated?

Nope. The bolt heads might be different, but the threads, and their exposure to the environment are exactly the same. For durability of the bolt heads, the Allen head style is more durable. The 8mm hex head was, in my opinion, not smart. So for those I have a snap-on Xtra drive socket. Which is designed for a tighter fit around the head. This bolt head, is not where you skimp on care. So that why I use this socket for the hex heads.

Snap-on Store

shop.snapon.com

For the Allen head, I have an impact metal, 5mm on a 1/2” drive with a long shank. It’s been a power house for the super crusty New England 200s. Even though I’m in NC, I mostly work on trucks from out of state.

What enamel paint do you use? Primer/rust converter?

I mechanical remove the rust first with wire wheels. Then I like Rustoleum Professional Enamel in Semi-gloss black

Ok thanks, and to follow up, I think I found a way to better word my question.

Would opening those bolts just a bit, and leaving them open while performing suspension work cause any issues? I don't want to introduce air into the lines and I'm trying to make sure I don't take any chances, but for extended work (like redoing front suspension) I wanted to keep the shutters open for a bit.

That’s what you are supposed to do. Open the set screws three revolutions (I mark with a paint pen to ensure I have the extra right of amount of revolutions), then perform all suspension work. Once all work is done, I jounce the suspension by a very short drive over some in even terrain, then part the truck on flat ground. Wait 15 minutes (as per the Toyota FSM), then tighten the set screws to their factory torque spec of 10 lbf.

If you go too far in unscrewing the set screws, you won’t get much air in, what will happen is you will get a bunch of pressurized hydraulic fluid blasting out. I had a customer call me after a Toyota dealership installed BP-51s and he said that the ride felt “off” and the was smoke coming from the driver side. Well… that was the KDSS fluid blasting over the muffler and burning off, then an out of spec KDSS pressure leaving no sway bar feeling. The dealership said they weren’t sure how to fix it, and just paid me to do it.

Best thing to do, is just follow the FSM when doing any work, and you’ll be golden. If you run into anything, just shoot me a message.