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Bang on floorboard when going over bumps


RayInStl

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I have what feels like something hitting the floor beneath my feet anytime I hit a sudden bump like a pot hole. Initially, I thought it was the radius arm bushings, since it's right around that area. But when I look at them, they don't look loose or bad. They could probably be changed, so I might just do it anyway, but what else could be banging there? I checked the trans mount and it looked good too. Maybe body mounts? They are quite rusty, so maybe one is looser than it looks?
 


alwaysFlOoReD

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Maybe the two piece radius arm crossmember bolts? The first gen tib has a swaybar that travels along under the radius arm crossmember, maybe the ttb does too? In which case the bolts and bushings for the swaybar should be checked. Also sounds does travel so it could be something not directly under the floorboards.
 
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adsm08

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I'd check those body mounts over good. I had the same issue and that's what it turned out to be. The rear of my cab was sitting on the frame.
 

RayInStl

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It's not so much a sound, as a feel. It really feels like something is knocking on the bottom of the floor directly below your feet. It's not a violent knock. More like someone tapping on the floor with heavy pipe, but just tapping. You can tell there is weight behind it, but it's not hitting hard. If that makes any sense. lol.

Here's some pics I took of things this afternoon. Maybe someone will see something I didn't. My rear main seal is leaking, so that's why everything is covered in oil. But the sway bar bushings looked ok to me.

On the body, should I be able to see daylight between the frame and the cab? How much of a gap should there be? I looked briefly at them while I was under it, but I also know from past experience with a Jeep CJ-5 that they can look "ok" until you remove them and then you find out that what looked like a metal mount was actually rust and dust held together by mud and grime.











 

85_Ranger4x4

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I would pick on the radius arm bushings first, they look original and are probably petrified by now.

Sway bar bushings could probably use help too, could be pivot bushings.
 

tinman_72

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I had the exact same thing with my '93. It was the body mounts under the radiator. Every time I went around a left curve it felt like someone was slapping the floorboard directly under my seat with a metal beam.
 

adsm08

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On mine I can't see light because of the angle, but I can get my hand between the cab and frame, now that I fixed the bushings.
 

RayInStl

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Ok. I'll inspect all of the body mounts. That makes a lot of sense. Thanks.
 

alwaysFlOoReD

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[quote/]

This looks like it might be deteriorated. The bushing can be frapped inside and the arm moves within, contacting the metal. I've pulled one apart and the metal hole was eggshaped, but there was also more damage to the bushing than what I see in your pic. The passenger side should also have a heat shield that covers most of the bushing protecting it from the exhaust...I don't see it. They are a pain to get the nut off. I've found out since that the factory uses thread locker so heat might have helped me. I think you could back the nut off to get a look at the bracket and the interior of the bushings. I replaced mine without removing springs by using a ratchet strap to pull the axle forward. Of course look at the other stuff mentioned first because they are easier to do.
 

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