thom
i personally doubted they would put a bouncing truck on dyno but was worth a try. would be nice to just strap it down and just touch 43 mph and let off. just to see if you got bounce.

maybe get a big forklift.
i might would just take drive shaft to shop just to check it. if it is out of balance i would take it back and tell them and let them fix it. but if they gonna have it for 2 weeks, that might first thing they do.

i hope they get you truck fixed. just to bad it could take into February to do it.

 

I have the same problem. At 40 mph the rear bounces up and down like i am riding in garden rows. Go above 40....it stops. Go under 40 and it does not bounce. I tried everything and no resolve. My truck is the 06 f250 crew fx4 LWB with 51k miles. I just have to watch my speedometer and when i get close to 40......slam on the pedal and get it up to 50. The only time i like the rear wheel hop is when i have a big chested woman riding with me. I will keep it at 40 the whole trip. However, yes, i would like to fix this problem so keep us informed. Thanks

 

Miller502,

Your truck falls into the time frame when Ford was offering a fix to the problem, especially if you have a factory hitch. If you look back on page 7 of this thread you will see a post by Paul where he outlineds the fix for your year/model. Here are the basics but read his post (#101 in this thread)...

INSTALL DAMPER SERVICE KIT - 5C3Z-5D008-A :
<TABLE border=1 width="100%" itxtvisited="1"><TBODY itxtvisited="1"><TR itxtvisited="1"><TD colSpan=6 align=left itxtvisited="1">INSTALL DAMPER SERVICE KIT - 5C3Z-5D008-A :</TD><TR itxtvisited="1"><TD width="50%" itxtvisited="1">SOME 2005-2007 F-SUPER DUTY VEHICLES WITH A LONG WHEELBASE (156", 158", OR 172")(396, 401, OR 437 CM) AND EQUIPPED WITH A HITCH MAY EXHIBIT A VEHICLE VERTICAL VIBRATION, OFTEN DESCRIBED AS "HOPPING", ON SMOOTH OR COARSE ROAD SURFACES IN THE 42 48 MPH (68-77 KM/H) SPEED RANGE. ALTHOUGH THIS BEHAVIOR IS CONSIDERED NORMAL FOR AN OVER 8500 GVW TRUCK, SOME CUSTOMERS MAY BE SENSITIVE TO THE CONCERN. TO IMPROVE THE 42 48 MPH (68-77 KM/H) VERTICAL VIBRATION, FOLLOW THE INSTRUCTION SHEET INCLUDED IN THE SERVICE KIT. NOTE: THE INSTALLATION OF THIS DAMPER WILL NOT IMPROVE RIDE ON SEGMENTED CONCRETE HIGHWAYS, STEERING WHEEL VIBRATION/SHIMMY, OR GENERAL HARSH RIDE CONCERNS.</TD></TR></TBODY></TABLE>

Good luck.


Speaking of this possible fix, Paul, did you ever run my VIN and see if it could work? Thanks,

 

You know, I just have to say, this is really scarying me away from the Ford P/U now. Based upon the latest comparison by Motor Trend, the Chevy beats the Ford in all areas other than interior design. That really sucks since I really do like the Ford and was really proud of them stepping up and making their own Engine and Tranny. But I be damned if I am gonna spend 60K on a truck that hops like this and they call it normal! I have yet to see a Chevy issue like this.
I really love my Excursion, but my old 91 GMC 1/2 ton has been a good truck! So, I am really watching this thread to see where it lands. Why is it taking Ford so long to get some answers? Seems over all these years, they think it is not a big deal and not an issue to worry with. That I don't get!

Somebody help me here!

 

RobertH,

If you read the whole thread here, Thom and Champ have stated multiple times that they consider their issue an anomaly. Considering that there are 150000 of these trucks running around the countryside and only 5 or 6 have reported issues like theirs, I would agree. Their claims are valid and Ford has been working with them toward resolution.

As to the magazine comparisons, they did not use the latest version of the Ford for their evaluations. Not one published all brand comparison has tested the Ford with the 400/800 upgrade. The initial PUT.com, Trailer Life Magazine and Wards Automotive "shootouts" were all completed with the 390/735 power package Ford. Only PUT.com has retested the Ford with the 400/800 upgrade. They did an update on their earlier "Shootout" after testing the 400/800 Ford. They were clearly impressed by the new specification truck. In their initial "shootout" the Chevy scored the highest total points but were only 1/2 point ahead of the Ford. After the 400/800 truck was run, PUT.com publicly stated that they wish they had this truck for their shootout because it would have won.

PUT.com also has stated that the traction control system on the Ford is more sensitive than the GM. I can state from my own experience that the TC is too sensitive. The truck defuels at the first sign of traction loss. PUT.com said they were certain had they turned off TC the Ford would have been the winner in the acceleration tests. This fact can be easily demonstrated by looking at the acceleration graphs published by PUT.com in the first "shootout". Simply compare the graphs for the loaded or unloaded runs. You can see for yourself that the Chevy gets the Ford out of the chute. PUT.com mentioned that they just could not get the Ford to hook up at the launch. The lines in the graph are measurably separated. Look at the finish line end of the graph and you can clearly see the Ford has closed the gap to almost nil. It is obvious the Ford is coming on like gang busters. Another 200 feet and the 390/735 Ford would have passed the Chevy. I do not see Chevy out there campaigning for another "shootout" at the altitudes 90% of these trucks are actually driven. Analysis of the original PUT.com tests tell us why.

However, this did not stop Chevy from using some knowledge they gained by testing the Ford at altitude. This resulted in the challenge Chevy made to test these trucks at altitude. Ford declined to bite at this farce, which became known as "The Rumble in the Rockies" because they knew the outcome. Chevy got PUT.com and Diesel Power Magazine to endorse this "testing". Chevy bought both trucks and paid for the entire event. They handed Ford their hat. Even I am a little embarrassed. But the facts are fairly simple. They are about engineering choices made by the manufacturers. Without going into an even longer explanation, it is all about broad spectrum performance versus high altitude performance. The turbochargers are both built by Garrett. Chevy's is larger and breathes better at altitude. Fords is smaller but performs in the much more common lower altitudes better. Fuel mileage, drive train reliability and drive-ability considerations drove these decisions. If you plan to race up that hill on I 70 to the Eisenhower Tunnel, you might want the Chevy.

In all other cases, the Ford is right there...and often ahead.

If you would like to see some real owners testing their trucks on a steep grade, check out the thread linked below:

https://www.ford-trucks.com/forums/1...ith-video.html

You asked for somebody to help...I have tried

Regards

 

Excellent explanation Mr. rickatic. Thumps up.

 

RobertH,
Although Rickatic has stated it rather nicely, I will put it another way...
If it comes down to where Ford can not fix my truck and I have to get a new truck because of this bounce, would I buy another Ford? Yes, I would not hesitate, I love this powerhouse on wheels. It will pull my ~13K fifthwheel at 70 and still jump up to 80 if I need to pass some slow mover. This machine has untapped throttle that I am very hesitant to explore with my 5'er attached.
As to your question about why is it taking Ford so long to get some answers; When Ford has problem with a truck that has not been fixed by normal proceedures, they send a field service engineer to work that vehicle. These engineers are in limited quantity (as they are specialists) that it takes them time to travel to the distant locations and thier visits are scheduled in advance. My appointment is the 19th of this month and they might keep my truck up to 14 days to try and solve the problem.
Also, Rick stated that Ford has been working with us toward resolution, they are very concerned with customer satisfaction! Can that statement be said about GM or Dodge? Not from what I have heard from drivers of those products.
Again, for the record I would (will) buy another F-350 PSD powered truck in a heart beat, mainly due to the commitment Ford has shown me to resolve this rare problem.

 

The latest magazine mountain tests were done with a 400/800 truck

 

Sorry, I thought I was clear about that earlier in the post but I see it could be misconstrued. I figured that if PUT.com has already acknowledged the strength of the new flash, it would be obvious they would expect the Rumble truck to have 400/800. Indeed the "Rumble" truck was a 400/800 flash truck. It does not change the facts though. At altitudes that the vast majority of truck owners travel, the Rumble results are meaningless.

Regards

 

Rickatic/Thom12, faith restored! Thanks for the clarification.

Where I was coming from on the bounce issue is some others have chimed in here with the same issue on much older models. Then, we see a TSB on the issue, so that lead me to believe this is something that has been known for a long time, but nothing done to resolve it. If an older model had it, and the entirely new redesigned models still have it, that just does not make sense to me.
Also, there is a rather large portion of folks out there that do not surf the web and talk on forums. We don't see those results, so I think there are many more out there. Also, others would not bother to take it in either.

So, thanks for the great explanation. I am extremely eager to see the results and very happy that Ford is jumping on this.

 

[quote=RobertH;9818261]Rickatic/Thom12, faith restored! Thanks for the clarification.

Where I was coming from on the bounce issue is some others have chimed in here with the same issue on much older models. Then, we see a TSB on the issue, so that lead me to believe this is something that has been known for a long time, but nothing done to resolve it. If an older model had it, and the entirely new redesigned models still have it, that just does not make sense to me.
Also, there is a rather large portion of folks out there that do not surf the web and talk on forums. We don't see those results, so I think there are many more out there. Also, others would not bother to take it in either.

I agree that the majority of truck owners do not visit these types of forums. However, this site in particular has some of the finest Ford Diesel Techs that come here every day to see what type of trouble us mortal 6.7 owners have gotten ourselves into. They are the eyes and ears that keep us abreast of what they see every day. They access internal Ford systems daily in the normal course of their jobs. Tech's have posted here many TSB's as they are issued. If there were troubles with this new drive train we would hear about it first here from the techs. So far, all I hear from them is the 6.7 is hurting their wallets instead of the customers.

Here's to the dealership techs...

Regards

 

Had my 2011 F-350 in at my dealer this past saturday for an oil change. I asked the service manager if he had any other complaints about the rear bounce other than mine. He said that I was the only one to complain so far. Said that Ford had not but out anything about it. But before I left three other new super dutys came in for various reasons nothing major and they told the service manager that the trucks all bounced in the rear. I was able to ride in one of the trucks and I thought mine rode rough at times but mine rode like a Lincoln next to his. So this dealership has four of these.

 

Allen,

Did you and the other owners have the service manager write up the bounce? Need to get these documented.

 

I've noticed that when it is very cold outside and the temp is below freezing my "hop" may or may not manifest itself. If my truck hops at 50, it also won't ride well above 75mph. If the truck isn't hopping at 50, then it will skeedadle on the interestate. . . . which it did today. Not what I wanted for today. While most would want the hop to vanish, I hoped it would show up in a big way today.

It was 14F when I left home. 19F when I got to the dealer. I met the Ford Service Engineer, nice guy by the way. He had been at the dealer getting updated by the service manager. I noticed that on the way to the dealer that the truck had no inkling that it had a hop. It had "hopped" all day yesterday and the day before. I knew this would happen. . . it didn't hop at all during the ride with the Ford service engineer. Nothing. We rode for an hour. I drove some. Zilch. He asked me all sorts of questions. My dealer service manager was with me and we agreed that it has done it in the past, but not doing it today.

So, when it warms up some here, I'll make another appt with the Ford service engineer. He was very open to trying to get to the root of the problem and encouraged me to keep in touch with him. He said he mainly is involved in very nasty issues like electrical issues that they can't pin down. We'll get together when I know the warmer temps may help the issue show itself. No one knows what the root cause could be at this point. The engineer suspects the wheels/tires, possibly the driveline. He's ruled out the trans, engine, etc.

The bad news, the service engineer didn't see the "hop" today. He's got to see the issue before it can be elevated up to a higher level. The good news is that I can come back later and have a 2nd observation/meeting. The door is still open and no one has closed the books on this issue, I just couldn't get the darn thing to rear it's ugly head today.

 

is this not what always happens...