Engine/Transmission (1994 - 1998) Foot pedal vibration

[GOODE11]

Hopefully someone can help me w/ these problems. Its a 97 Ram 2500 4X4 w/ a 5sp and 140,000 on it.



#1

When driving, there is a vibration in the foot pedal and the motor just doesn't seem to be real smooth in the powerband(engine noise). I can push in the clutch and keep the rpms up while moving down the hiway and the vibration in the pedal stops. Any ideas?



For reference, I drove a buddy of mines that has the exact truck except w/ 170,000 on it and there is not vibration and the motor is very smooth throughout the powerband.



I hope someone can help, its either fix it or send it down the road, b/c I will do a lot of hiway travel this fall/winter.



#2

There is a bad vibration (dash,steering wheel, seats etc... ) that comes on about 65mph. It is seperate of the above problem, b/c this only does it over 60-65mph. If you go over 70 you better grab your coffee cup b/c its going somewhere.

I've bought new tires, balanced and rebalanced, checked ball joints and tie rods, rebuilt track bar and it still does it.

Any suggestions? I'm getting the alignment checked next week, but I didn't think alignment causes shimmy/shake/vibrations. Maybe I'm wrong!



I hope you guys can help me, I've been a member for about a year and have really learned a lot. But I can't figure this out for the life of me.



TIA



David

 

[Matt42]

I'm taking a long shot on this, since your truck has more miles on it than mine.



1. I had a similar vibration problem, and the engine sounded "off. " It turned out that the throttle rod that connects the throttle cable to the injector pump was out of adjustment. On top of that, the rod had lightly jammed (yes, lightly jammed) against the engine block, so it transferred considerable vibration to the throttle pedal. Adjusting the rod fixed it. Detailed instructions are in the TSM.



2. The shimmy calls for more speculation. Does it come from one end of the truck instead of the other? If you let up on the throttle, will the shimmy decrease as you coast? Does the shimmy cause the steering wheel to try to rotate back and forth?



If it was a tire problem, new tires that are indifferently balanced will still bounce. Some indifferently manufactured tires will thump from day one. I have seen some of them separate in no time in the Arizona heat. (I got exactly 98 miles out of a Goodyear Wrangler AT. )



A possibility to look at is a bent drive shaft, or a bad drive shaft universal joint. Either or both of those problems will bring on harmonic vibrations at various speeds. (This could also be related to No. 1. ) If not fixed, a bad universal joint can break, dig into the road, and catapult your truck. I'd look there first, based on what you've done thus far.

 

[GOODE11]

Thanks for the reply Matt.



I will check the throttle cable.

How about a bad idler pully or wrong pump timing? Can they cause vibrations like this?



The front end shimmy, I guess is more of a shake and only effects the front end and cab area for the most part. I have rear spring issues but thats another topic.



I don't have a problem w/ the truck pulling and tires seem to be wearing ok. I'll have my driveline checked out when the alignment is checked.



Any other ideas?



Thanks Again





David

 

[Tardog]

GOODE11



Just a long shot, got new tires once and had a shimmy, went back to the same place and rebalanced but checked out fine. Then had them rebalanced on a newer (different) machine and some tires were out by as much as 3oz. It turned out that the calibration was out on the first tire machine? High speed vibes usually come from things that move at high speeds. Good luck.

 

[Eric_77]

Have you had the throttle cable recall done on your truck? was it even included? Anyway on my 96 they did the recall and ran the new cable wrong and it put a vibration through the pedal that would put your foot to sleep in 5 minutes. Took it back and they said you didn't notice it was real hard pedal?, hmm no my foot was asleep

 

[GOODE11]

Eric_77



I'm looking at the throttle cable now, it has quite a bit of play at the pump. The connection point to the pump w/ the large spring has quite a bit of lateral (side to side) play and is pretty snug horizontal movement wise.



Could this be the cause? I'll see if I can snug up the play at the pivot point.



Could someone look at their pump where the throttle cable attaches and tell me if their's has some lateral slop in it?



Thanks for the responses!



What do I need to see if the throttle recall has been done?





David

 

[Matt42]

The throttle cable doesn't connect directly to the injection pump. The cable attaches to a pivot (which also holds the TPS on automatics). The pivot bellcrank then pulls a dogleg shaped rod that actuates the injection pump.



Make sure that rod is in adjustment and hasn't twisted.

 

[GOODE11]

Matt,



The pivot that the throttle connects to is the one that has the play/slop in it. Should it?

I have owned many 1st gen trucks and knew everything about them, but this thing is a new ball game. The "dogleg" rod has very little play in it.



Thanks again





David

 

[Matt42]

Is the play in the pivot side to side, or rotational? It should wiggle a little either way.



It's possible for the dogleg to have no play at all and still be out of adjustment. For the vibration, it's important to make sure that the sides of the dogleg rod doesn't contac tany part of the engine or stuff bolted to it.



Beyond this, I'm lost.

 

[GOODE11]

Matt, the play is side to side, at least 3/8" either side.



I'm going to go over my buddies and see if his is like this. Other than that I'm at a loss as to whats wrong.





Thanks again.





David

 

[Matt42]

Wow Wow Wow

3/8 inch is a LOT of play. Even if that isn't the cause of the vibration, I would look into replacing the pivot assembly, or fixing it in some manner. If you have an automatic, a malfunctioning Throttle Positioning Sensor (TPS) can cause all sorts of bizarre mayhem. Maybe even surging.



My wife, who is an RN in geriatric medicine, reminds us that it IS possible for more than one thing to be wrong.



Let us know what happens and keep asking questions. Someone here will know.

 

[Dieselnerd]

Goode, if you have the factory chrome wheels, check the runout. Those wheels are a bear since most are out of spec and with the runout they want to bounce even if they are balanced. I now use Counteract Balancing beads and my bounce finally went away.

 

[GOODE11]

DieselNerd, I have AE Baha's on my truck, and they have been checked and balanced 3x's. Also what do you mean by run out, possibly a bent rim?





Thanks



David

 

[Dieselnerd]

Goode, they are not really bent, they were made crooked. There have been many posts about this subject. If you spin the wheel and hold a pencil stationary next to the wheel you may find as much as 3/8 "wobble" or it may be out of round and have up and down movement which is usually the culprit when you get a bounce at higher speeds. Worn shocks, trackbar, bushings, etc. only make the problem worse but those stock chrome wheels are usually the "root" cause.

 

[minghram]

I have the same issue as you with my 97 2500, 4x4, Club Cab, 5spd, long bed. My truck has 117,000 miles. I've been battling this issue for several thousand miles. I've installed new ball joints, track bar and new tires with no change in vibration. Furthermore, I swapped out the harmonic balancer with a friend and had no effect on the vibration.

Last but not least, I used a vibration analyzer at the front and rear of the engine block, and the guy running the test stated the engine had a vibration at 1. 5 times engine speed. The test was ran at 1000rpm with the truck parked. However, he didn't have time to dig deeper. Any ideas? Maybe a new truck... ...

 

[GOODE11]

I was getting ready to shoot this to the top again. I feel extremely sorry for you, this is the most annoying thing ever. People call me crazy for spending so much time under the hood.

I still have the problems from above w/ these repairs done last week:



Throttle recall

Overflow valve

Lift pump

Timing reset

New injectors



Its getting to be a rather expensive fix, if I ever find it.



But I'm w/ you on getting rid of the truck. The thing is I have so much time and money in the truck and like it enough that I've taken it on as a challenge. Its just getting fun to drive.



Let me know if I can relay any info to you or if you have any that may be useful to me please do so.





GOODE11