out of ideas on this one HELP!!!

[David Barnes]

Hey all;
About a month ago I noticed driving along at 55-60mph on the highway, the entire truck 'bucked'. Kinda like going over a speed bump, but I did not go over anything. Happened once again a few days later. Took it to the dealer, they found no codes, road tested it, says transmission, etc all is fine, rides like it should.
3 weeks go by until the problem occurs again twice leaving my street, kinda felt like the tranny is downshifting fast, then going back where it should. Take it back in, they drive it etc, scan, no problem found. This happens again, I take it back, they attach a VDR (vehicle data recorder) and when the 'event' happens I press this button so it can collect data. This was Monday this week. so I am 'collecting' data and waiting for it to happen again. I thought tranny, but they don't think so (course they also will not tear it apart without something to go on). Fluid was changed at 55k (it has 69k now) and is still purple, etc. This truck is not driven hard. Anyone have any ideas on this???? Its getting kinda frustrating.

Thanks

 

[sapogmxr]

im thinking tranny clutches. But i dont know jack. Just saw no one replied. trying to help you out. Good luck man.

 

[410Fortune]

It kinda sounds like a fuel problem to me, like its loading up. Faulty 02 sensors or a bad fuel pressure regualtor can cause a similar surging to happen.

I have had a similar problem with my truck a few years ago, going up hills it would buck and surge, turned out to be the fuel pump was on its way out.

If it is in the transmission for sure then cross your fingers.

Is this an AWD truck?
Have you tried searching these boards for similar problems?

 

[David Barnes]

thanks for the replies so far

Thats for the replies so far guys.... its got the 'auto' 4 wheel drive. It does have the limited slip differential option also. The problem is that this problem is SOOO intermittent... at first I thought torque converter locking up.. etc..
Its under warranty, but I am getting tired of taking it back for nothing...
Hopefully the VDR will record whats going on when it happens.. what do you all think??
If it was tranny or drive train wouldn't it be a LOT more often??? this problem can happen once all week long!!!


thanks..

 

[Todd W]

Dave,
I have experienced the same problem. My dealer can't find anything wrong also. This occurs after extended run time and is at highway speeds and just happens for a split second. Please let me know if you find anything out it is very disconcerning to have it jerk at 70mph.
Thanks, Todd

 

[tcmercil]

The same thing happens to my 98 explorer sport - 4speed w/overdrive - - but it's only happening when the road conditions are slippery - - mostly snowing?? when it's not - - it perfectly OK....

It is like a speed bump and doesn't sound good at all!!!

Have you found anything out at all regarding this?? I just posted something today regarding it.....

 

[David Barnes]

I'm not the only one... whew..

Well at least there are a couple other people with the same/similar issue...

It also has happened at slow speeds (ie getting on the on ramp on the thruway)...

Any other ideas??? Like I said, I have a data recorder installed by the dealer, collecting data then they will look at it...

 

[m6500]

you describe a buck like going over a speed bump. Well i had a noise as if i ran over something , took several months and unfortunatley it ended up being the transfer case. i posted the problem and the first two replys i got pointed to the transfer case and that is what it ended up being. Sorry.

 

[swep1]

Any chance that your ABS light came on afterward?

Mine did that about a year ago...highway speeds (60-70 MPH), all of a sudden it "bucked" like I had run over a speed bump or something in the road. Took it a couple of days for the ABS light to come on. Had my mechanic check it out and it turned out to be a wheel bearing going out.

 

[jared ajlouny]

the same thing happens to me, it only happens when the car has been running for about an hour or two. it happens randomly, and it happens when i have my foot on the gas at highway speeds and need to slow down fast so i let go of the gas completly and it makes this big noise/bump feeling.

 

[jared ajlouny]

isnt the transfer case for 2wd/4wd? if im in 2wd on the freeway, it cant be that makeing the nosie/bump, right? please help me on this i dont want it to become a huge problem, and im almost out of money becasue of the california budget cuts and i work for the county, so hopefully this wont be expensive.

 

[cdsl227]

My truck bucked intermittently when I had the heat and or a lot of accessories on, but didn't buck with no accessories on.

It would ocassionally throw the CEL and put in a Camshaft Position Sensor code into the computer.

I took it to Ford they changed the CMP and the light came back on, bucking again- finally my 200amp alternator came in- swapped out the old one and no more problems.

I guess my amps and all just weakend the factory alernator so when the accessories where on it appeared to be charging fine, but just couldn't handle a load.

I don't know about your problem, but it's a thought check the electrical...accessories/heat/ac = bucking in mine and no accessories = no problems.

 

[David Barnes]

more info..

Ok... so It happened enough times today and I filled the VDR they hooked up to collect data, its back at the dealer now, they will look at it on Monday..
Another maybe not related issue, is that today after driving (lots of snow out etc and cold ) got home, and noticed the driver side front brake was HOT, I could smell it, Almost like the caliper was holding the brakes together....
drove another 15 miles to the dealer, and no problem...cool ( well as cool as it could be) and no smell...
any ideas on that one???

 

[David Barnes]

ABS light does NOT come on

>Any chance that your ABS light came on afterward?

Nope no ABS light, no lights anywhere...

 

[m6500]

david, search on my user name, the thread that i described my noise in was called clunk, I think. Mine had no codes and after showing the mechanic some of the descriptions of the t case problems he checked my old unit and agreed with the problem. he had taken the case out before and looked for problems and other than some filings he did not notice the problem with the positioning hole for one of the shafts. As i described in my clunk thread the entire drive train had been checked other than the transmission and they were getting ready to take a look in it when i said , i'm not paying labor for that unless ford can assure me that's the problem. When it was all done , with a new t case, the dealer negotiated the bill and i was satisfied with them, but not too happy with ford tech support as they were no help to the mechanic. The info i received here was right on as to the tcase though.

 

[David Barnes]

will check that Tcase issue

Thanks.. just wondering.. when you DID have the tcase problem, how often did it occur??? My problem can happen twice in 1 day, then not do it at all for a whole week... does this make sense???

thanks

 

[m6500]

david, mine started out very intermittent, maybe a couple of times in 300 miles on interstate. during the weeks of diagnostics it became more frequent. the mechanic was taking the X out for lunch and home some evenings when other folks could ride with him. Just before the case was replaced there was one section of road that had a dip in it that he said he could get it to do it almost every time. It seemed to be more likely to do it after a downhill or level section then going up an incline as you applied throttle you would get the clunk maybe once or twice as you accelerated. I'll be interested if you dealer finds any codes as we never did.

 

[David Barnes]

thanks

Ok sounds good... will let you know tomorrow.. thats when they are going to look at it... They have had it 5 times, and when they drive it , it does NOT act up...
We'll see... seems like my symptoms are just like yours... and like I said, its VERY intermittent...

 

[David Barnes]

arrrrgh this is getting crazy!

Ok.. so ready for this??? (You probably knew this would happen based on your experience).. NO PROBLEM DATA collected! It looks fine!!!
Is there anything you can recommend I do/say to get this people to look at the transfer case? I can understand the warranty company not wanting to pay to have someone rip apart something if they are not sure... but I think we are getting low on options huh??
I guess maybe I make them keep my truck until they get it to happen???
You mentioned 'weeks of diagnostics' exactly how many weeks and dealer visits did it take for them to take YOUR problem seriously..???

Thanks for the assistance...

 

[m6500]

david, i assume you have read my thread "clunk". the mechanic is aware of how i use and maintain by X so he believed me when i took it in when i first started hearing the noise , he checked for codes and test drove it but since he didn't experience the noise he asked to keep it awhile and he used it to drive home for lunch for several days. Finally he heard it and the drive train disasembly started as described in "clunk" I think they had the truck for 5 weeks but it wasn't until the last three days that they changed the t case, which had to be ordered. I can't recall if i gave the details of the information describing the problem in the t case, but i found a descrition of the fix by serching this forum, the fix envolved filling the shaft hole and redrilling it. That post mentioned you would have to have the equipment and skill to correct the defect and most likely a new case would be the route to follow for most folks. don'
t know the details of your warranty but i had to pay myself as i was out of warranty. As i mentioned before the mechanic took it as a personal thing when he couldn't find the problem and it became his pet project.