suburban shacking when towing empty or full WTH,

marty79

marty79

Well-Known Member
Joined
Nov 24, 2013
Location
Newton, NC
Hey guys I'm really stumped here. My 95 Suburban drives perfect with old tires we had and now with the new tires we got...so all good empty.
Towing with a car trailer empty or loaded, front end (maybe whole truck but seems front mostly) shakes above 53mph ish. Before that pulls fine empty or loaded, that speed or higher and shakes....sketchy at times. Without towing anything it runs 50-100mph no problems, smooth as it should be. Rear shocks are bilsteins 5100 and did an add a leaf but when I towed before that stuff, same thing.

This is with 2 different car trailers too!!! WTH. Last time I borrowed a trailer to take my rig out, same thing I couldn't go past 55 without shaking. Now with this other car trailer, same thing WTH>
ANY advise in direction I'm really confused or I'm just overlooking something simple?? thanks for input
 
My truck had a bad shake at 80. One of my front tires needed to be balanced. Problem solved
 
Simple things first, it could be a tire or wheel problem. If that's not it, it's probably either something in the driveline getting excited at a different angle/position (because things change position when you put weight on a hitch), or some vibration that is no longer getting damped because of a change in weight ( less weight on the front wheels, for example). The latter could include tires/wheels as well.
 
This thread is really disappointing, apparently "suburban shacking" does not refer to what I thought it did.
 
It's not tires ..it did it with old tires and wheels and now with new tires and new wheels.
What part of drive line do I look to first...rear?
 
RatLabGuy said:
This thread is really disappointing, apparently "suburban shacking" does not refer to what I thought it did.
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But you should know my threads wouldn't be about such things, sorry to disappoint:p
 
marty79 said:
Where would I look for this
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well, its shaky in the front, the weight is lifted from the front due to the trailer on the back. I would look in the front end area.
 
Jeff B said:
well, its shaky in the front, the weight is lifted from the front due to the trailer on the back. I would look in the front end area.
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ok ok i guess that was stupid question lol. I guess i meant what components? I've checked my front end many times, I'm big on maintenance. Shocks I know need to be replaced otherwise front end is tight...so I guess what part might "seem" tight on check out but with weight off the front a little, that part now acts up?
 
Jack up the front end with a floor jack. Do each side individually, put the jack under the lower control arms. Once the tire is off the ground use a pry bar to check ball joints, put pry bar under tire and lift up. Next grab front and back of the tire and shake the steering components. Normally the idler and pitman arms are loose. Pay attention to the inner tie rod ends too.
 
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cbjeeper said:
Jack up the front end with a floor jack. Do each side individually, put the jack under the lower control arms. Once the tire is off the ground use a pry bar to check ball joints, put pry bar under tire and lift up. Next grab front and back of the tire and shake the steering components. Normally the idler and pitman arms are loose. Pay attention to the inner tie rod ends too.
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I've done this many times lol but maybe I'm missing something...or something with what I would consider "ok" is otherwise not ok when it's got trailer weight on it!! What part would be the culprit the most? With some weight off the front end, what part would act up shimmying that might seem good when performing the check. thanks
 
obullfish said:
First thing to clarify, do you feel the shacking in the hand or in your ass?
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^^^
This!
So many things it could be. But, given the age of your Burban, and the fact you have changed the geometry, I'd venture to guess it's either because of the add a leaf's or worn bushings in the front end.
Could also be out of balance tires, warped wheel, drive shaft balance, needing an alignment, worn pinion bearing, etc.
As Shane said. if the vibration is in your ass when you feel it shacking (shaking) it's in the rear of your vehicle, if you feel it in your steering wheel, the shacking(shaking) is in the front end.
Good luck
 
marty79 said:
I've done this many times lol but maybe I'm missing something...or something with what I would consider "ok" is otherwise not ok when it's got trailer weight on it!! What part would be the culprit the most? With some weight off the front end, what part would act up shimmying that might seem good when performing the check. thanks
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Normally with milage above 150k the original idler and pitman arm will get floppy. When adding weight to the rear it unloads the front suspension and the front tires can shake like a grocery cart.
 
My old GMC would get a front end shake when I towed one specific trailer, a boat that was about 3k# total. Did fine everything else.

Put new tires on trailer, did bearings, etc, no change.

Truck had 200k, so it went ahead and did entire front end, and new shocks all around. Problem gone after that. So, really dont know what specifically caused it, but the shotgun approach solved it.

Sent from my SM-G930V using Tapatalk
 
I'll bet it's pitman & idler.. the idler arm gets loose and when unweighted will flop. (Not entirely unweighted, just partly) try having someone jog the wheel back and forth with tires on the ground and look for motion/slack where it shouldn't be.
 
obullfish said:
First thing to clarify, do you feel the shacking in the hand or in your ass?
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It's in the steering wheel/dash. Been busy but I'll get to really get in there later this week for testing...thank you
kaiser715 said:
the shotgun approach solved it.
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Well front end is only thing literally original so probably gonna just order all new stuff. The rest of everything mechanically is been replaced so it needs it lol.
I'm gonna still find the problem first for learning purpose
 
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