Rear end knock after Ironman lift

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jja

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I've been hearing this ever since I had the Ironman springs and shocks installed. Everything else on the truck is stock.

It sounds as if there is a loose piece of wood somewhere behind the plastic panels in the trunk hitting the plastic when the truck shakes. It happens only when there's a series of minor bumps, e.g on cobblestones. When I shake the truck when parked I can hear nothing. Going over speed bumps no sound again. But even crawling on cobblestones results in loud knocking.

I peeled off the rear end of the trunk plastic panels and found nothing loose behind. I start wondering whether the Ironman rear shocks are loose at the top mounting point and need some washers or something to get snug. However, that should not be the case since the Ironman kit is designed for the KJ so it should be perfect fit. What do you guys think?
 

CzarKJ

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Check out your rear upper control arm bushings/ball joint. Most likely cause.
 

jja

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Oh that I did. Nothing there. The truck has pretty low mileage 40000 so these are like brand new.
 

CzarKJ

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Oh that I did. Nothing there. The truck has pretty low mileage 40000 so these are like brand new.

I had to install washers on the upper and lower shock mounts on my bilsteins. Hopefully someone else will chime in that has installed an ironman.
 

Cardhu

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Can you move the shocks laterally along the bolt on the upper shock mounts.

Mine used to require a washer but after you've torqued them a couple times to change this that and whatever else, it squeezes the outer part where the bolt head sits tight on the shock.
 

jja

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The shock sits snug.

I wonder could one install the rear spring upside down.
 

dude1116

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I had to install washers on the upper and lower shock mounts on my bilsteins. Hopefully someone else will chime in that has installed an ironman.

Glad I wasn't the only one that just used washers and no fitment kit at extra cost lol.
 

tommudd

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The shock sits snug.

I wonder could one install the rear spring upside down.

Possibly you could have the spring upside down but looking at it would be very noticeable.
Check shocks again
Check rear tri-link etc
Remember you have changed the angles on everything so some strange noises could be coming from something you never touched.
I warn everyone that has a lift done here that you have the possibility of something showing up worn out afterwards
 

Jim McClain

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Tom, haven't you also suggested that something has to be tightened with the wheels & tires under load, rather than up in the air - or was that vis versa? Would doing it the wrong way possibly produce some noise?
 

tommudd

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I had to install washers on the upper and lower shock mounts on my bilsteins. Hopefully someone else will chime in that has installed an ironman.

Bilsteins are not designed for the KJ hence they are more narrow. OP said he used the ironman which are made for the KJ/KK so fit tight
 

tommudd

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Tom, haven't you also suggested that something has to be tightened with the wheels & tires under load, rather than up in the air - or was that vis versa? Would doing it the wrong way possibly produce some noise?

Yes but not knowing anymore like if he installed JBA UCAs or anything else its hard to say.
But if LCAs were loosened in the back for some unknown reason there is a possibilty
I'd bet when they installed them they routed something different or something real simple.
To the OP have you taken it back to the place that installed for them to check it out?
 

jja

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Yes I did take it back. They acknowledged the knocking was there. However, they said they can find nothing wrong with the suspension and it might be a defective Ironman spring or shock. In short they could not figure it out and they didn't seem to care. As it always happens when I let somebody else do something on my car to save time I end up spending more time fixing stuff after that.

So, I guess now I have to double check everything again. All the bushings and the A arm ball joint. If nothing comes out I will start removing Ironman parts and putting back OEM ones and see when the noise goes away.
 

robert.janowski

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Any suspension part should be torqued down under full weight of vehicle. This sets the preload on the bushings.

Sent from my SM-G900V using Tapatalk
 

jja

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And to answer a previous question - everything else but the Ironman kit is completely stock.
 

jja

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tommudd

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