70mph+ vibrations

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Ok guys put on your detective hats and get ready to hit me over the head... anywho, my truck vibrated pretty violently at any speeds over 70-75mph. I am going to have my tires rebalanced but I still dont think that it could shake that bad from the tires. I think something is worn out but I dont know what it would be. The truck has 120k on it. The faster I go the worse it gets and the shaking feels like there is a jack hammer in the car and some one left it on. (at about 80mph) Any one have any ideas on what it could be?

-Bryan
 

scottm

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I have the same problem. It goes away after driving in heavy rain, comes back again after grinding through wet mud and clay. I guess I could clean the muck out of my rims, but I'm in it a couple times a week. I'm too cheap to put coins in the carwash that often, and too lazy to clean the mud off my driveway, so I just live with it 'till it rains. I'm sure that helped, no need to thank me.
 
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Bryan,
If you still have the vibration after the tyres are balanced then post back with the specifics on your truck and we'll try to help.

Tyre size, brand, tyre mileage, wheels?
Lift? Shocks?
Driveline mods?
Other symptoms?

-B-
 
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Bryan,
While it is at the tyre shop, have them check for out of round, particularly on the one you suspect is causing the problem.

A long time ago, I had a new tyre that was egg shaped. They could balance it, or they *told* me they could balance it, but it would wobble down the road and the higher the pressure and faster you would go, the more it would bounce.

-B-
 
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If you are going to check the balance, find a shop with the Hunter GSP 9700, to dynamically balance your tires, money well spent. It balances your tires in all dimensions and checks tire and wheel for round as well as doing it under load. Go to www.gsp9700.com find a few shops near you and call them and see what they charge, I found a range on 15-40 bucks a tire. The GSP9700 is well known on the BMW forums I use, and it worked for my car(BMW). I figure since the tires and wheels can weigh alot more on LC's it might be even more important to get a thorough balance.
 
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I found a range on 15-40 bucks a tire.  

:eek: Holy smokes. You did see that Mr. Bryan runs Boggers right. It seems to me to me that the first time he went wheeling you would throw that expensive balance out the window... Especially if they are Bias ply. Which vary well may be the source of his problem. Maybe he will chime in on this. That’s a really cool unit but IMHO not worth it for a truck that sees trail duty.

Brian; What size are they and are they radials? If you get them balanced and you cure the shaking it may be worth it for you to look into an interior balancing agent. Like Equal or the proffered redneck method... Golf balls :D
 
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chiming in as someone who still uses a tires balancer a couple of time a week... the hunter unit kicks ass I will not argue that point but more importantly is the difference between a static ( just the inside of rim) and a dynamic (in orund both edges) balance for your tire. I know when I mounted my 33" bfg atko I went to 15x8 steel rimsit took three passes with the balancer to get it right. well not perfect right according to the dynamic readings (off by .25 of an ounce on 2 rims) but pretty damn close.
Just another thought if you are running swampers are your blocks wearing out in a front to back slope? if so you are definitely out of balance and probably over pressured.
ok off my soap box now.
Dave :beer:
 
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ok now i'm chiming in. Well, today was a sad day for the boggers, they are now on ebay. I am going to order bfg mud terrains and have those put on. The vibration was from the stock tires, but those will no longer be on the truck. The truck vibrated with the boggers on before i went offroading and with the stock tires on. So... yea I'm still stumped, but workin on figguring it out.

-Bryan
 
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:eek: Holy smokes. You did see that Mr. Bryan runs Boggers right. It seems to me to me that the first time he went wheeling you would throw that expensive balance out the window...

I did not see what type of tire he uses, but if anyone does alot of time on the street it would be worth it IMHO. I just hate driving on the freeway with the wheel shaking and my teeth vibrating ;)

Best thing to do would be buy your next set of tires at a shop that uses one of the Hunter machines, and then use the free lifetime balance offer that most tire shops have. A lot of times they will balance on one of their regular balancers and use the Hunter if they can't get it right.
 

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Are you guys talking about oversized, off-road tires needing all this balancing? I've never heard of modern radials needing this much attention to get them to ride smooth. For all their crapiness, GM Ford and Chrysler SUVs do at least ride smooth on big, stock rubber.

Also, it's really shocking how much a little crud in a rim can shake the vehicle when you hit a certain speed and set up a harmonic with the suspension. I'd check that carefully, and look for missing wheel weights.

Thanks Christo for the tip on mud in the rotor, hadn't thought of that. It's suprising how deep of mud I get in on my 265s, pulling a trailer. I get pretty brave when there's construction equipment nearby that can lift me out.
 

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ok now i'm chiming in. Well, today was a sad day for the boggers, they are now on ebay. I am going to order bfg mud terrains and have those put on. The vibration was from the stock tires, but those will no longer be on the truck. The truck vibrated with the boggers on before i went offroading and with the stock tires on. So... yea I'm still stumped, but workin on figguring it out.

-Bryan

Let me know where on ebay you got 'em. I'm looking for some tires for the 40. It'll never see 70 mph with me driving unless I drive it over a cliff.
 
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I've had the same issue 3 times! and each time it was my u-joints.
I was not able to 'check' for any stickiness when moving them from underneath but when took them off it was obvious that one was sticking.

Park the cruiser on level ground (makes it a LOT easier), block the wheels and chalk mark each driveshaft all the way from the front to the rear (incl where it connects to the axle). In that way putting it back is a lot easier (phase/angles etc.). Make sure u don't wipte off the chalk marks while handling the shafts. Easy enough to loosen the bolts and drop it. Quick to test - if its not supple and uniform movement then changout.
Note: front and rear u-joints are different part nos

Getting them out can be a real pita (first one had to use a very strong vice (or block of wood with custom groove to hold position) and a sledgehammer. However that was really bad - one of the spider arms (in the form of a cross) was not longer circular but like a football(american i.e.) or rubgy ball shaped.
Putting them in is easier (remember to clean/little sandpaper/grease) to get to slide in.

I've found that an standard slotted oxygen sensor socker is a perfect fit for banging out the spider (after taking off c-clips of course) or a previous used spider cap!

Lal
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96 TLC with 84K
 
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NO MORE BAD VIBES! I greased the hell out of the u-joints about a week ago, and I drove 100mi. on the xpressway and now its smooth as glass. I took it up to 90mph and nothin. It was great!

-Bryan
 

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