What is this VIBRATION in the rear @60 mph???

[zzman]

I have about had it with this vibration. . . and really this whole truck.



I hope someone could shed some light here. I have a vibration (like riding a scrub board) at 30mph then again at 60 to 70mph. It does not do it without the trailer. Only with the trailer empty or loaded. The trailer is a 40' flatbed that weighs 8k lbs. I would guess maybe 1000 lbs on the gooseneck ball when empty.

The vibration does not happen all the time , about 50% of the time. I don't seem to be able to find a common cause. It might happen more often on a SMOOTH road surface. I believe it does it when pulling hard from a stop until reaching highway speeds, then maintaining 60 to 70 mph. If taking off easy all the way to highway speeds, it appears to help. I have my smarty jr set on level 2.

I had the drive shaft checked yesterday, the center u-joint replaced, drive shaft balanced, carrage bearing replaced and seals replaced, rear tran and front diff. I have 2-1/2" blocks under the pads for the helper springs. They are slightly in contact when the trailer is hooked up.

The drive shaft is real close to straight when the trailer is on.



The transmission was rebuilt a couple weeks ago by the same guys that did the drive shaft, Standard Transmission in Ft Worth. I feel there is no issue with the transmission. The axle was rebuilt back in Feb or Mar, I don't think it is in there.

I do have weak springs on the right side. The right side looks like it is an inch or so lower than the left (without the overload blocks on).

I have never changed the shocks.



235,000 miles as of today.



Anyone have any ideas? I'm pooped out, can't go no mo.



Hows the Fords looking?



Thank you...

 

[rbattelle]

Wow, that's a lot of stuff you've already tried. How about tires? Could you have a bad tire that only misbehaves when loaded?

Could the trailer be the culprit? Any chance trying a different trailer at the same weight? Or pulling that trailer with a different truck?

Ryan

 

[zzman]

I thought about the tires, getting 4 for the trailer tommorow I think I'll have the rear truck tires re-balanced just for kicks. Those have been on there for a couple 3 months tho.

I don't have another gooseneck trailer or another truck.

The day I picked the trailer up (2-1/2 years ago) it did the vibrater thing then. I don't remember how or even when it quit.



I just remembered, A couple 3 weeks ago I lowered the trailer coupling a couple inches when I put the blocks in. That was to bring it back to level after the blocks raised it a bit. Could that some how or another do something to start shaking again????

Thats weird, I'll need to look at that. What do you think?

 

[zman]

Hey Ron - If you are going to get your truck tires rebalanced, have them done somehwere that has a Hunter road force balance machine. Since no wheel or tire is perfectly round, this process actually matches up the imperfections in each to make the tire/wheel assembly as round as possible. Go to this website to locate a machine near you.



I had horrible vibrations around 60 MPH, even after a regular tire balance. I could see the rear bed corners shaking in the rearview mirror! I had all four tires road force balanced and the vibrations are gone.



Also, if you plan to buy new trailer tires, make sure you get the trailer tires balanced as well. Most places won't do that unless you ask.



Steve

 

[CoastyAV8R]

I would fix the problems that you know have before trying to fix anything else. If you have a bad set of leaf springs, that would be the first thing I would look at since you have done everything else, otherwise you could very well be throwing a bunch of good money away. If it happens 50% of the time, chances are it's not the balancing of the tires since they turn 100% of the time.

 

[Rams-n-Hogs]

I had this issue with my trailer, a 20 ft bumper pull. The original tires weren't balanced. I replaced them with the tires and rims from my 96, (which were balanced), and the problem is gone. Gave me a good excuse to get new tires and rims for the 96, too.

 

[Wingate]

Did you say you put 2" blocks in the rear?. . Have you checked/reset the pinion angle? Usually this will cause strange vibrations and can be hard to pin down. If you are concerned about tire balance, I would contact Centra-Matic down the road in Alvarado and use their set up.



BTW... I wouldn't get too excited about the new Ford yet. I have 2K miles on mine and its starting to act like a spoiled 3 year old. Had CEL come on for not entering feedback mode, then on one occasion the display said it was cleaning the exhaust filter, then the next morning the little wrench emblem came on indicating it needs to go to the shop. But you can kill it and restart it and it will go away for the entire day. Only to come back on the next morning within the first 1/8 mile of driving. This is also the same time every morning that the transmission jumps out of gear from 1-2 and from 2-3!!!. .

 

[tolmsted]

FWIW



Maybe check the drive shaft u-joints for failure.



Just a thought as I had that problem of vibration.

 

[macdaddy]

Try Some Air Bags

Id locate a stock truck like yours and take some measurements for height (I use the Hitch to ground), and clarence between the overloads and the stops (Id use all).



Install some air bags and inflate so the truck is sitting in its stock position. Then give er a test drive with the trailer.



Mac

 

[dmaglov]

I am investing in some centrematics for my whole truck. After that, if I have more vibration issues I know the tires and wheels will not be involved. I am also pooped, but not gonna buy a Ford, just another RAM.

 

[rscurtis]

I would say that if the truck is OK without the trailer, then the trailer is the problem. The trailer is not going to create a wheel balance problem with the truck. As far as being intermittent, it is possible the trailer has several tires out of balance, and as they change orientation, cancel each other out or amplify each other.

 

[SShafranko]

Did you say you never changed your shocks? Never?



Please change your shocks!

 

[zzman]

Well I think I fixed it. At least there is no vibration, I've traveled 3, 4 thousand miles or so and still no vibration. I hate saying it because it will probably be back now.

I had all the tires (8) on the trailer changed. I did have the "ST" 235/80/16 "E" on there. Many differant brands too. They all had the same tread design and all of them wore uneven. I replaced then with "LT" 245/75/16 "E" in the Nitto Dura Grappler highway tread tires. What a BIG differance. These tires hardly squat at all when loaded, only get slightly warm on the highway with 100 degree outside and seem to be wearing pretty good so far. Best of all, NO VIBRATION, could this really be the problem??? You know the front axle is about 30' or so from the gooseneck ball connection, I just can't believe this could cause my issue. I have not had the vibration since the tire change, has anyone ever heard of this??? WOW I surely hope it is fixed. I have done nothing else to the truck. Next month I'll be getting new tires for the rear of the truck, the same as the steer tires, Nitto Dura Grapplers is there any other!

Thanks

 

[zzman]

You know I did take loose one of the rear shocks to see if it was not working well.

It wanted to extend on its own. I couldn't pull it or push it hardly at all, seem to be working good enough for me.

With the truck loaded the drive shaft is almost straight, the ride is better with a load than not, with out the trailer one could use a kidney belt but I almost always have the trailer on. Life is good

Ron

 

[RVTRKN]

zzman, that is a problem more often than not, by assuming your tires are good by just looking at them. Never run different brands on a trailer, or any vehicle for that matter unless its for an emergency. On a trailer, because the wheels don't turn in the direction of the turn, they will drag until suspension straitens out, this causes the sidewalls to weaken and cause uneven wear and is for the reason of an ST trailer tire. Some will argue that point, but no matter what tire you run you should keep the same brand and model/size, as well as rotate them often so you will wear them evenly and therefore extend there service life.



I had an experience last year where I had a vibration in my rig after a rest, in extreme cold weather and contributed it to a weather related issue. I pulled over and inspected my trailer tires. It turned out, when I got home that I had a flat on my inner passenger side dual tire. It was strange because as soon as I was in warmer weather the vibration went away. Lesson learned there, is inspect all tires.

 

[zzman]

When the trailer was brand new, it had Triangle brand unbalanced tires on it. When I left the factory, the moment I got to 60 mph it vibrated something terrible.

The first thing I did was balanced all the tires. That I thought helped somewhat. One tire came apart in the first month, Triangle replaced it. After about 3 months 15k miles or so, I think 2 or 3 of the tires were almost slick on just 1 side of the tire. Not the side of tire but all the way across but the opposite side was still good. Even the tire next to it was not worn that way. So I began exchanging them with Goodyear Marathons as they wore down. About the time I exchanged the last set, (replaced in pairs) the first set was about worn out or wearing uneven real bad. I began trying differant brands (in pairs). This is how I ended up with many differant brands on the trailer.

I had "ST" tires on our 24' travel trailer a few years back (maybe 9 yrs). We went to Colorado about a 1900 mile round trip (our first trip), when we got home the tires were dipped so bad the wires were showing. Went to Wal Mart and replace with regular car tires. They lasted about 6 yrs until we sold it and then they were still 1/2 good.

I believe the "ST" tires are not for me. I've probably had about 25 "ST" tires and atleast 25% appeared to be not round or made cheaply. They are probably made to run as a single tire and about 25% duty.

Thanks guys

 

[RVTRKN]

When the trailer was brand new, it had Triangle brand unbalanced tires on it. When I left the factory, the moment I got to 60 mph it vibrated something terrible.

The first thing I did was balanced all the tires. That I thought helped somewhat. One tire came apart in the first month, Triangle replaced it. After about 3 months 15k miles or so, I think 2 or 3 of the tires were almost slick on just 1 side of the tire. Not the side of tire but all the way across but the opposite side was still good. Even the tire next to it was not worn that way. So I began exchanging them with Goodyear Marathons as they wore down. About the time I exchanged the last set, (replaced in pairs) the first set was about worn out or wearing uneven real bad. I began trying differant brands (in pairs). This is how I ended up with many differant brands on the trailer.

I had "ST" tires on our 24' travel trailer a few years back (maybe 9 yrs). We went to Colorado about a 1900 mile round trip (our first trip), when we got home the tires were dipped so bad the wires were showing. Went to Wal Mart and replace with regular car tires. They lasted about 6 yrs until we sold it and then they were still 1/2 good.

I believe the "ST" tires are not for me. I've probably had about 25 "ST" tires and atleast 25% appeared to be not round or made cheaply. They are probably made to run as a single tire and about 25% duty.

Thanks guys

The "ST" tire is a cheap tire and I have never known a good brand, I did the same for my boat trailer getting car tires with not much more success. Next year I will be getting michelin ribs for my 5ver, a very expensive tire but they have a good reputation. As far as OEM tires go, well you said it all.

 

[HBarlow]

You found and corrected your problem

Unbalanced or bad tires on a trailer will transmit vibration through the hitch to the tow vehicle.