Aloha, my 94 F-150 xlt with a 351 5.8L. is vibrating upon acceleration. usually between 20-35 miles an hour. I had my u joints changed, the rear u joint was bad so i changed both.drive shaft balanced and output shaft, yoke and rear end inspected and everything appears ok. I took it for a run and noticed that I get a nasty cab vibration whenever i accelerate. If I release the gas it stops. This happens going down hill and up as long as I am pushing on the gas. If I coast down a hill I do not get this vibration at all. I am changing the engine mounts tonight as I suspect they are shot. Not quite sure but better do it cause of the 168,000 miles. Getting the bolts out is very hard and now need to get a friend with a compressor and air system to remove nuts for mounts. Anyway just trying to figure out what may be the problem. My logic may not be accurate but It puzzles me to have this violent vibration only when i press the gas. My theory is the mounts are shot and causing a slight enough change or torgue in engine seating and therefore affecting the whole driveline. Upon acceration the engine shifts cause it isn't sitting right with the mounts. What do you guys think?

 

That vibration could easily be caued by motor mounts or by a torn rear transmission mount. I'd look at the transmission mount first because it is easier to get at.

Is the vibration independent of engine RPM? If you have an auto transmission try accelerating with the transmission in 1st gear, then try the same run with the transmission starting out in 2nd gear. If the vibration is the same, the problem is probably suspension or drive train related. If the vibration changes very much, it will mean that you need to look closer at the engine or transmission.

168K miles of Island driving involves *lots* of low speed stops and starts and is tough on a vehicle.

Aloha,
Lou Braun

 

Thanks, I'll try your suggetion this afternoon. My automatic transmission mounts looked solid. It has been changed in the last 2 years.

 

Aloha Lou, Violent shaking was independent of RPM. I changed the mounts which were bad. balanced tires, rotated tires, checked wheel bearings, ball joints, tie rods and fluid levels in all drive train. Everything ok. The major shaking and vibration is history but now there is a slight vibration almost feels hollow when I accelerate between 45 -55. Can be up hill or down. Goes away whn I release gas pedal. Any thoughts?

 

The remaining vibration could be the torque converter clutch slipping. Do a search on "E4OD shudder" to see posts on the subject.Typical of this syndrome is that the vibrations happen only in 3rd gear or overdrive, and only with modest throttle pressure. If the vibrations go away when you press down harder on the gas pedal (still within the same speed range) then it is fairly likely this is what you are feeling.

 

Thank you will check it out immediately! One quick question Where and how do I check the harmonic Balancer?

 

Also, don't forget to try it in neutral sitting still. Slowly rev the engine up and see if it vibrates. If it does then it is the harmonic balancer that needs to be replaced.

At 168K it's very possible that it has slipped. Mine has 155K on it and has a slight shudder at about 1400rpm.

Hope this helps.

 

Helps more than I can say thank you.. but Thank you very much!

 

Aloha, Can anyone describe a "Shudder" I may be feeling more of a hesitation at this point in acceleration.Appears to be flucuating between 30 -45 miles an hour. Only when pressing gas pedal. What i felt as vibrations seem to feel more like a studdering or jerking type og movement. When I release gas it goes away immediaetly. I checked all vaccum hoses, spark plug wires and inspected the rear drive shaft and universals again. I have collected as much information on the torque coverter as I can and trying to see what this would entail. It sounds expensive and may be out of my present ability. Maybe a time to learn though. Am I describing a "shudder"? Would a coil change make any difference in this problem?

 

There are lots of threads on the subject. Do a search on the FTE website for "E4OD shudder" and you will find many different descriptions of the same phenomenon. To get you started, here is one of them:
https://www.ford-trucks.com/forums/s...=e4od+shudder+

If the vibration does not happen in neutral, has a frequency of about 3 vibrations per second, happens only in this speed band, only with modest pressure on the gas pedal, and only when the truck is warmed up, there is a good chance it is the infamous shudder problem.

A coil change (be it ignition coil or coil spring) will not make any difference. You can try the TCC cut-out switch as a diagnostic, as I suggested in the thread I linked to above. There are various "anti-shudder" additives or trans-fluids that sometimes help.

From your general description, I would say your truck has about the same symptoms of shudder as mine. A lasting fix requires replacing the torque converter. I have not bothered with this...

 

Thanks fefarms, I really appreciate the input and suggestions. Will continue to go thru threads.

 

I don't know who did the u-joints but maybe the driveshaft needs indexed, when I did my u-joints I forgot to mark the position of the driveshaft in reference to the yoke and got some strange vibes. I turned the driveshaft 180* and no more bad vibes

 

FeFarms
I think you just described my problem. What would you suggest I try short of pulling tranny.. I did change the fluid 3 7 months ago... Any input greatly appreciated... I got 96 f150 e4od 302 2wd....

 

Unfortunately there's no great answer to this issue.

A 1996 truck should have most of the improvements to the E4OD. There are a couple of vendors of anti-shudder additives for transmission fluid. Alternatively, you could try Mercon-V instead of Mercon-III, Ford switched to the newer spec in 1997 to attempt to address shudder amoung other things. Get one of the dual-spec Mercon/Mercon V fluids, such as Pennzoil if you try this.

If it is a high-miles transmission (125000 +) you may be facing a worn torque converter clutch and the only way to clear out the shudder is to replace the converter. A new converter costs about $250, plus the labor to R&R the transmission. It is not as expensive as a full trans rebuild -- for that you'd be pushing $2000

 

FeFarms
There is only 78000 miles on the truck .... The shudder is pretty slight right now but I can feel it...I am unsure of an additive any suggestions or will the Mercon v be the ticket to try first. Also would I just drop the pan and replace part of the fluid or is there a way to get more fluid out...
Also can I check the convertor by cutting the wire to the TCC at the tranny and driving it . If the shudder is gone then it is the converter.. ( just gotta make sure to cut right wire) Then just hook wires back together. I believe the TCC is part of the Transmission Selenoid Body and the wire harness to it is on the right side of tranny behind the heat shield. (this sound right) So I would cut the wire in that harness I guess. I think I can pull the tranny myself if it needs a converter but dont want to do it if it is not the problem, so a test would be great.
My final question is I plan on towing my car to a show and need to clear this problem up. I am wondering when towing is it best to have the overdrive off all the time?? Or will it overheat the tranny. My truck has the tranny cooler in front of radiator too. Or will you damage the overdrive towing with Overdrive on? I just got the truck and am unfamiliar with it....
Thanks again sorry to be bothering you so much, it is greatly appreciated..