Traded in my 05 2wd diesel while on vaction a few weeks ago to stop having trouble pulling my 10k boat out of water.

I noticed the first day there was a vibration/bounce when I drove away. Thought it might be because of tires having a flat spot from sitting a long time. I drove it around 400 miles while still on vacation. I took the vehicle in to have tires balanced. Was then advised 3 tires were out of round and needed replacement. I had two days left of vacation so I opted to wait until I went back home to local dealer.

Dropped the vehicle off last week and they road forced the vehicle 3 times. replaced all four tires and there is still a bounce.

I have the 20" rims and and tires. The bounce is more pronounced around 40-50 mph. I look out the side mirrors and it seems like the rear end is bouncing. Any suggestions or anybody else had this problem so I can advise dealer what to look for to fix. I am planning to take the vehicle in next week and this will be my second trip in. After the third time I can file lemon law but I really do not want to do that. Lemon law the consumer still loses at the end.

 

What model truck 2wd/4wd, short bed /longbed ??????
What spring pkg .some are stiffer than others
Shortbeds will bounce more !

Rich

 

Mine does this at about 45 mph, so did my old dodge. Its nothing more than harmonic vibrations lining up. I dont think there is much you can do about it, but you can search for it until you turn gray.

 

Harmonics result when everything is in resonance at a specific rotational frequenty. There are ways to fix this problem but it isn't easy. You have to find out exactly what is vibrating then change something like the mass of the object to change the resonant frequency. In this case shocks or springs "might" help but only 50/50 shot since we don't have a vibration spectrum analysis to tell us exactly what is vibrating.

I had a 64 corvette that had a harmonic at 60 mph when the speed limit was 60,, try telling that to the boys in blue. Jim

 

most people i know that have the 8ft bed have this problem. What we come up with is the fact there is a lot of space and no weight in the rear. So what we've done is put some extra weight in the bed... Rides SOOOO much better.

Weight is just 2 50# bags of sand.

 

UMMMMMM sand bags sounds like extra weight that changes the harmonics which can move the frequency range. But if it is smoother,, sounds like a plan. Glad it worked. Jim

 

I would say you need a better set of shocks!!!!

 

I have a 2005 crew cab 4x4 long bed w/gas motor that I bought brand new and I have the same problem. Weird thing is I didn't really notice it until around 3000 miles. Dealer did the balance thing w/ tires several times to no avail. I replaced the tires and still no better. Mine hops at 38-40 mph. It does not do it with a trailer hooked up so I was kinda believing the whole HARMONIC idea. When there is a load on the back of the truck there is no hop at all.I was attributing it to the long truck frame flexing with not much weight at all out back .Nature of the beast???Who knows. for now I just try to avoid cruising at the magic speed.

 

Mine does it with a 10k boat hooked up to it as well. Tongue weight is around 1k. I read the TSb and will advise them of that. The bouncing does it starting off as well.

 

I would lean toward the tires, I test drove my 06 and it had a shake in the steering wheel about 5 deg of center each way also the vibration/bounce. they did the road force test and ordered 4 new tires that I just had put on today which took 3 hrs to mount and balance 4 tires????( said they was having problems with the road force test.) so I am thinking that they might not be any better then the ones they took
off. Still have the vibration/bounce not as bad but I think it will be back soon as for the steering wheel shake it was fixed before I picked the truck up not sure if it was tire related or not.

06 F350 SCLB Fx4 6.0 18" rim contitrac 866 miles on the truck

 

2006 F250SC 6.0 4X4 (20in wheels)

You too? I just got mine back today. It was in last Friday all day( bought the truck on Wed.) I dropped it off tuesday and they have made no progress on it as of today, Friday. I have dealt wth this truck shop manager before and trust him fully. He was on the phone with Ford, Goodyear, regional reps, ntional reps, you name it. We are going to play again on Monday with the Goodyear guys. Myself, 20 years working on four wheeled animals. Seen alot, but this is a good one

What we found.
1. Steering wheel shakes at certain interstate speeds.
2. Rear end hops @ 50mph or so.
3. Steering wheel is more noticable when in slight turn as in maintaining course in lane.
4. Tires were balanced @ Just Tires straight off the lot after I noticed the problem. I was in the shop with the tech and he did his job perfectly. Some improvement, still there.
5. During balancing I could see that not one single tire was round or true. The tread went up and down and side to side very noticably.
6. On to Ford dealer. My guy found the same things to be true as above.
7. He replaced 3 tires, only to exchange one back out for an original because it was better than the new ones.

I have experienced this before on my 75 F250 and it was all tire balance. My opinion is that the 20's are so stiff that any little variance from perfect will show up in the tight suspension/ steering of the F250/350. All I want is to start with 4 round/true tires.

I'll repost with any updates next week as I get them.

 

...Welcome Travis, to Ford Truck Enthusiasts!

See you on the boards. ….

 

Wow,, if they aren't "round" and within specs, the square block might be balanced but it will never run/roll smoothly. There are mfg. specs for runout radial and lateral. Check the numbers and make sure the tires are within specs. If New Of The Rack don't meet the specs go to a different brand. Good luck

vettdvr

 

mine seems to be at 42 MPH. I tookit to dealer while stock. they replaced all 4 tires. still bounced. i told them i was going to lift it and they said it would help them to do it because they wouldnt have to try random piecies that would come with lift. I put lift on and they said it was because my lift. Needless to say it doesnt make me happy. I have great shock and 18" wheels and 35" tires. Tried 3 sets of tires including new stockers. My brother works at a tire store so that made the testing nice. Mine is a 05 f-350 C LB 4x4. Lifted. but it it stock.cant feel it until 40. 42-43 is worse and almost gone at 45. no other speed but ive searched tons. They checked axles, wheel bearings, brakes, carrier bearing angle, pinion angle for me and all came back fine.

 

If the sterring wheel shakes, I would be looking a the front suspension. Wasn't there a "death wobble" problem with the later model SD's and was this ever resolved?

I'm thinking the 20" tires may be part of the problem. As stated above the harmonics are a mass and position problem. Perhaps the tires are more sensistive the imperfections in the tires than the smaller diameter tires on the earlier versions of these trucks. I'm afraid harmonics are not my specialty and harmonics issues can be difficult to diagnose.

Unfortunately, some dealer service departments tend to be real good at swapping parts and a little short on diagnostics if they don't have a good decision tree to follow. Sounds like there isn't a real good decision tree for thsi problem from Ford. If someone takes time to think this through, it should be cureable. Their just aren't that many things than can be causing this.

Firs thing I would do is identify if this is a front, rear, or both problem. Nobody has been real clear on this so far unless I missed something.