Truck bounce between 45-48 mph

[atvpilot]

Hey Guys,
Can anybody help me out on this? While driving at low speeds(45-48mph) I notice that there is a bouncing or shaking coming from the rear of my 2002 2500 HD/D/A CC SB. I had it to the dealer and they said it was probably my tires(upgraded from 245-75-16 to 285-75-16) I took it to my tire guy, he pulled the rears and rebalanced them and I am still noticing the problem. My tire guys told me that it is probably the wear pattern from being on the front and it should go away. It hasn't. It is possible that this can be associated with a drive line problem???

[jbplock]

How soon after you switched to and/or rotated the new tires did the problem appear? I had a similar problem on my 98 K3500 which turned out to be tires. I had them balanced numerous times and nothing helped. When I changed tires to Michelin, the problem went away. Regarding the driveline, have you checked the ujoints? Does the vibration persist when just coasting at the problem speed?

[JimWilson]

Could it be bad shocks? How many miles are on the truck? Does it get used hard?

[atvpilot]

Hi Guys,
Thanks for the input. The problem does persist while maintaining or coasting at the problem speed. The rear u joints were replaced in the late spring. The vehicle is my daily driver with some towing ,but I don't over tow the vehicle. The truck just turned 48,000 miles. I am thinking about having my tire guy replace the 2 rear tires with 2 new ones and see what happens.

[atvpilot]

Hey Guys,
Well I went back to my tire guy to day and he rotated the tires and the problem got worse. He checked all the tires for proper balance and they were all right on the money. So I left there and called the dealer and made an appointment for this coming Monday. After telling the service guy what I just had done he seemed to agree that it is drivline related. Gee I tried telling him that a month ago. He seems to think it may be a universal or a carrier bearing. It'a all greek to me, all I know is that it is very annoying and I have really had enough of it. I'll let you know what they find out. BTW I have 285/75/16 Sport King tires.

[White Truck]

If the problem got worse after rotating the tires, then they are likely the cause. Nothing else in the driveline changes when you rotate the tires, so the vibration should be exactly the same, if something other than the tires is the cause. What you need to do is find a place that can measure the tires for road force variation. What this means is that a tire can have a stiff or soft area on the tire that affects the way it contacts the road. This can be caused by a belt that shifts, either during the manufacturing process, if the tires are new. If used, the belts can shift as the tires age. This variation feels like a tire that is out of balance. The problem is, it can be balanced perfectly, but will not roll smoothly due to this. No amount of balancing will remedy it, the tire must be replaced if this is determined to be the cause of the problem. As your tire guy if he can measure this for you. If he doesn't understand this term, or just says he can't, find some place that is able to do this. The equipment to measure this is expensive, so I don't imagine that a lot of places will be able to do this for you. An example of the equipment used to do this is a Hunter GSP 9700. Google this phrase and look for a link to Hunter's site, this will explain this better than I can.

[jbplock]

White Truck,

Excellent post! I agree.... If the problem was worse after rotating and balancing the tires, it's the tires... I had a similar problem on my 98 K3500 crew cab. I put a new set of tires on the truck and after the first rotation I had a severe vibration. The tires were rotated (per the manual) such that they turned in the opposite direction after rotating. I had them balanced and rotated several times but the vibration never went away. I suspected either a belt shift and/or out of round condition caused my problem

[atvpilot]

I guess What I meant to say was that after the tires were rotated the shake was amplified. He did however rebalance the tires and they were all right on the mark. If the dealer doesn't find anything, I am going back to my tire guy and if he will put a different set of tires.I have a feeling he won't and I would hate to buy another set because it's just to expensive. Again Thanks for the info. Like I said I have the Sport Kings which are an off shoot of the BF Goodrich tires.

[atvpilot]

I fianlly figured out what the shake reminds me of. It feels like brake pulsation when you have warped rotors but like I said before it happend between 44-48 mph :confused:

[sdaver]

had the same problem w/ 285 tires they were goodyear ats.........switched to a 305 and it went away..........4 sets of 285s first......

[atvpilot]

Well guys,got the problem solved. I took it to the dealer and they ran a force balance test and an eva test and found the tires were the problem. What it all boils down to is this, the 285/75/16 Sport Kings were to big for the stock rims. They looked great on the truck but when they ran the EVA sensor test on the truck they said the tires were so far off that it was bouncing the rear axel like a basketball. So I went back to my tire guy,he contacted the mfg and pro rated the tires and sold me a set of BFG all terrain's-265/75/16 for $300.I am still out the 150. diagnostic fee, but the truck rides real smooth with no more bounce. Like I said the truck looked great with the 285's but the next time I upgrade, I think I will go with diferent rims.

[jbplock]

atvpilot,

Glad to hear you solved your problem! http://forum.thedieselpage.com/ubb/icons/icon14.gif

[JimWilson]

Originally posted by atvpilot:
What it all boils down to is this, the 285/75/16 Sport Kings were to big for the stock rims. They looked great on the truck but when they ran the EVA sensor test on the truck they said the tires were so far off that it was bouncing the rear axel like a basketball.Technically speaking, yes they are a bit too wide for the rims. But that wasn't you're only problem, because I've been running 285's on stock rims for almost 30K now, and my truck rides smooth as glass (and there are a LOT of other people with 285's that aren't having problems either).

My guess would be that the tires were a pretty crappy brand, which took a marginal condition -- the tires being slightly too large for the rims -- and pushed it over the edge.

[atvpilot]

Thanks Guys. Jim Thanks for the info I guess that's why I am in the business I am in and I am on this board being guided by you guys and I do appreciate it very much. BTW what kind of tires are you running on your truck?

[JimWilson]

Nitto Terra Grapplers. IMHO, the best AT-style of tire you can buy.

[atvpilot]

Jim what do ya think of the Bridgestone Revo's? or the BFG All Terrian's?

[JimWilson]

I don't have any experience with the Revo's, so I can't comment on them. But I do with the BFG's, and I can say I wasn't terribly impressed. They rode a bit harsh, and seemed noisier then an AT tire should be. They were expensive too.

AAMOF, my experience with the BFG's is what made me try the Nitto's in the first place; I wanted something different.

[jjackson]

ATVPilot, I have had the BFG A/T's mounted on American Eagle 8 inch rims since day one with no problems. Minimal noise, no balance problems. I went w/the BFG's because I pull a 5th wheel and they were the only tire I could find that had a 3 ply sidewall, which really add's stability when towing.

John

[atvpilot]

Thanks Guys for your input. ;)

[atvpilot]

Well so :mad: much for all the above nonsense. The bounce is back