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Feels like driving on rumble strips under light accleration

23K views 60 replies 10 participants last post by  shawn1648 
#1 ·
No codes are showing up.

It feels like I am riding on rumble strips. If I floor it, it does not do it. Its A LOT worse at 1000-1500 rpm but I can feel it good up to 3000 rpm.

I checked the tran fluid level, it's good and it was flushed 6 months ago. I'm not exactly sure how to check the driveshaft u joints but I grabbed the driveshaft and tried to rotate it or move anything, its all tight except just a tiny bit of play when i rotate, maybe two millimeters.

What about rear end fluid?

I am leaking coolant from the hose at the bottom of the radiator where it connects to the engine as of last week. I've kept it topped off. I don't know how that would cause the shake.

I checked for vacuum leaks and all the hoses look good except the hose that runs to that black plastic box in front of the passneger headlight. The hose looks a little worn.
 
#2 ·
#3 ·
Awesome! From everything I have been reading, it sounds like just what you said...in the trans, possibly TC shudder. I will try the lucas fix.

I just had the tranny flushed and filled less than 10,000 miles ago. I tow my fishing boat 3-6 days a week with it.

Does anyone know what the "TC check" is? From what I can find on here, I'm supposed to tap the brake and if it stops, its TC shudder. But will that work when the shudder only happens during acceleration?
 
#4 ·
Does anyone know what the "TC check" is? From what I can find on here, I'm supposed to tap the brake and if it stops, its TC shudder. But will that work when the shudder only happens during acceleration?
Your torque converter is a locking converter. Once its in OD, it locks to the engine. By pressing or tapping the brake while still on the gas, your RPM's should rise for a second because it unlocks the torque converter. That is how you test the lockup.
 
#6 ·
The torque converter doesn't lock "until" it hits OD. So get it moving past 40ish and when you feel OD kick in, tap the brake while still accelerating and watch your tach (if you have one).
 
#10 ·
Ok, I will test it on my ride home tonight.

Above 45mph...I'll try tapping the brake to see if my rpm's jump up. Should I try to lightly hold my foot on the brake just enought for the break light to go on and see if the shudder stops? Otherwise, just by tapping it, I won't be able to tell if the shudder stops.
 
#11 ·
The longer you have your foot on the brake, the longer it stays unlocked. Just remember to keep your foot on the gas at the same time.
 
#13 ·
And enough speed for 2nd is?

I did a test this morning to confirm 2nd and 3rd. I was going 60 in 2nd, pushing just past the 4k mark. Tapped and held brakes, and the motor did not rev up. So does this mean it was locked, and continued to stay locked? Or does it mean, it never locked?

3rd gear does lock as I felt and seen the RPM's goes up. So the converter unlocked.

Thought this would be good info for this thread.
 
#15 ·
And enough speed for 2nd is?


Note that you have to have a rather large differential between TP_REL and VS. Tapping the brake while you're feathering the throttle in manual 2nd won't do it.
 
#14 ·
I tested it. My rpm's did rise but the shudder did not go away, at least it didn't feel like it did. Lots is happening during this test. It almost feels like the truck isn't shifting when it should and the rpm's are staying ultra low around 1500rpm, but definitely feels like I'm on rumble strips. It goes away almost completely once I get over 60mph. I'm on my way to pick up some lucas trans fix.
 
#16 ·
lucas trans fix did not fix the problem.

the whole truck shudders but you can really see and feel it in the steering wheel.

I noticed a wah-wah-wah hollow repeating sound while driving on the highway, windows up. Sounded like tires out of round type sound (tires only have 10,000 miles on them and they are BFG Long Trails) but its not the tires.

There is a noise from underneath, sounds like a bird chirping. Didn't bother me before, but now I think it could be related.

Ujoints? Diff?
 
#17 ·
I think that the fact that you're really feeling it in the steering wheel, is telling you that there is a problem with a tire or wheel. Did you get down and feel the tires for a bubble/seperation and check to make sure the lug nuts were tight? Maybe you lost a wheel weight? Try moving the front tires to the rear to see if the change makes a difference.
 
#19 ·
Have you checked your rear drive shaft bolts? If they are loose it will give you that rolling on rumble strips effect. I've owned my 96 since new and a couple of years ago the bolts would occasionally come loose, I put a 1/2 wrench in the truck so we could tighten them. After a few rounds of that we put lock tight in the bolts and have been good. I still have the wrench in the truck just in case.
 
#22 ·
when you have this shutter, is it engine speed relaited or drive train speed reliated?

when you feel it shift the trans into a different gear did the shutter change or is it the same?
 
#23 ·
I was trying to pin that down today. It doesn't get faster as I accelerate but it does get more intense as I approach 2000rpm and then it starts to die off in intensity until the truck shifts and the rps drop back down in between 1000-2000 rpm.

If I mash the gas, there is no shudder.

Could a bad fuel filter or clogged cat cause this? The ff is 6 months old.

I'm going to put in new plugs tomorrow, even though they are only 6 months old.
 
#24 ·
Sounds like a misfire or engine balance issue. Take a look at your harmonic damper and make sure it's not wobbling, and that the rubber isn't squeezing out.
 
#29 ·
Stick your head down there, or get at it from underneath, and do a thorough visual inspection. Another trick I like to do is use a timing light and use the ignition coil wire for a signal, so it flashes very fast. The damper edges shouldn't move at all, to your eyes. If it's shaking or loose, you'll see it.

could this be TPS related?
Yup. It'd be a good thing to test.
 
#28 ·
I should mention that it feels like it won't downshift when i give it gas. It just stays in too low of an rpm range while i slowly get faster until its ready to change gears. I really have to mash the gas to get it to go....this is all when I am already moving at a good speed.

could this be TPS related?
 
#41 ·
there is no need to run high test in these factory motors. your timing is either advanced too far or your combustion chambers have alot of deposits on them from something.


Would a water pump that is on the virge of failing cause vibration like this?

***edit - installed new water pump bc of leak from weap hole. was not the cause of the shudder.
it could always be possible because of the bearings going in it. but since you put a new pump on and the shudder is still there it makes me beleive ur trans is going out with all that gray sludge you said you got from it.

better start saving up
 
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