Any Idea what seems to be shaking/bouncing?

Tiny
SYLLINX
  • 2000 DODGE DAKOTA
  • 6 CYL
  • AUTOMATIC
  • 160,000 MILES

I have had this problem for a year now and really wondering what is causing it. I can go over a speed bump at 3-5mph and it feels like middle of truck to bed of truck is kinda shaking up and down like a paint mixer. I have tried 6 sets of shocks now and nothing helped, you don't even see the bed shaking but you feel something shaking. If you talk it sounds like you are beating on your chest. While driving there is no vibration. I did notice my transmission mount does not look normal to me so I replaced it thinking it would help, but it's crushed again. If you find a picture of a new mount you will see it doesn't always look like that lol. Any help would be nice.

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Tuesday, July 31st, 2012 AT 1:35 PM

15 Replies

Tiny
SYLLINX
  • MEMBER

This is the mount I really want if it will help.

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Tuesday, July 31st, 2012 AT 2:03 PM
Tiny
KHLOW2008
  • EXPERT
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This mount is not designed for too much weight and seems it is being overloaded or the quality is suspect.

I would suggest checking the engine mounts. If they are bad, they would put more stress on the transmount.

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Tuesday, July 31st, 2012 AT 2:26 PM
Tiny
SYLLINX
  • MEMBER

I plan to go home check every inch of the engine mounts. I just thought if engine mount was bad that it would shake really bad when driving 70 on highway. There has to be something causing this, I hope to find out today what is going on.

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Tuesday, July 31st, 2012 AT 2:37 PM
Tiny
KHLOW2008
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Bad engine mounts seldom cause vibrations on highways. Vibrations would be felt more when gears are engaged with vehicle stopped.

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Tuesday, July 31st, 2012 AT 3:00 PM
Tiny
SYLLINX
  • MEMBER

As long as nothing happens today I will go home and check all the mounts and report back.

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Tuesday, July 31st, 2012 AT 4:01 PM
Tiny
SYLLINX
  • MEMBER

I checked everything I cannot find one single thing loose and no broken mounts. I can lift transmission with my hands a little but I guess it's suppose to have some slack.I used a jack to just check if cab was loose and it didn't give at all. So I don't think cab is bouncing. I loosened all the leaf spring bolts and rechecked them, they are all freshly greased. Tempted to just see how it rights if I torque the crap out of the leaf spring bolts. I can't stand how it's riding.

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Tuesday, July 31st, 2012 AT 11:37 PM
Tiny
KHLOW2008
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How are the conditions of the leaf spring and shackle bushes?

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Wednesday, August 1st, 2012 AT 12:33 PM
Tiny
SYLLINX
  • MEMBER

The bushing on the shackles are brand new. Installed last week and grease bolts. All other bushings are factory. Almost started to put poly bushing so there wouldn't be any slack for sure. It just really feels like something is bouncing free or possibly the bushings have shrunk. When I can find some way to mount my camera i'm going to tie it under truck so I can try to see what is going on. The back end sits higher than the front so the springs seem good.

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Wednesday, August 1st, 2012 AT 12:45 PM
Tiny
KHLOW2008
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Mounting a camera would be a good idea. Btw check the exhaust mounts and ensure the exhaust system is not swinging too much.

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Wednesday, August 1st, 2012 AT 2:18 PM
Tiny
SYLLINX
  • MEMBER

Thats a good idea, although I have a small thrush muffler and no exhaust pipe so there is less weight to swing around but the shop could have mounted it wrong I guess. I do have two snapped bolts on both side of engine in the exhaust manifold(could be cause of muffler-can't even hear a leak thank god). Please add a way to edit a post lol.

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Wednesday, August 1st, 2012 AT 2:38 PM
Tiny
SYLLINX
  • MEMBER

I recorded driving around some but couldn't get a spot that would make it feel as bad as it usually does. I filmed transmission then rear springs and muffler. Muffler never seemed to move at all. I'm starting to think it's the bed somehow or the frame mount bushings. Going to film tomorrow again when I can ride through some rougher parts of town.

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Wednesday, August 1st, 2012 AT 10:59 PM
Tiny
SYLLINX
  • MEMBER

Going to remove ubolts soon and check center pin bolt. When I was looking at the ubolts they look like it's trying to rotate around to top of axle. It could be angle but I will post picture later. I'm thinking my center pin bolt is destroyed. I remembered that the previous owner was rear ended before I bought it.

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Monday, August 6th, 2012 AT 3:50 PM
Tiny
KHLOW2008
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Yup, that sounds like a broken center pin with the torquing of the U-bolts maybe below specs.

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Thursday, August 9th, 2012 AT 5:55 AM
Tiny
SYLLINX
  • MEMBER

I did some measurements and if correct pin is broke. The bottom leaf spring on the right has 12 inches of spring behind the axle and the left side has 12.5 inches. The bold on the right side is pressed into the metal plate that the ubolts connect to while the other bolt on the left is centered almost perfectly. Might just replace the leaf springs since they are 12 years old. I guess I can call it solved lol.

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Thursday, August 9th, 2012 AT 2:40 PM
Tiny
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Good luck :)

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Thursday, August 9th, 2012 AT 3:08 PM

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