Ive noticed a new problem in the last two-three weeks, i thought it would go away, but it doesnt. It's defanitely a problem with the engine, and not drivetrain. When i am in OD, or D, right at 1500-1550 rpm with the torque converter locked, i gently ease into the throttle to keep a constant speed on a flat road or slight uphill, and the truck begins to violently shake up and down, not fore and aft. It feels like the truck is bending in the center between the front and rear axles, and wobbling up and down. I give it more load and it goes away, or slow down/speed the engine up and it goes away. It used to only do it in 60t, now it does it in any program.

 

Ditch the TN and get a 38R.

 

Oh, think that's it? Hmm might be, the boost gauge doesnt really move off the needle at 1500 unless im into it.

 

Naah, not really Kris. Just having some fun with you.

Does it seem to stumble when the shudder happens? I hate to think what first jumped into my mind so I would just recommend a buzz test and contribution test to eliminate those. I will not say what I am thinking.

 

Youre thinking those half-*** RDS rebuilt injectors, i know.

 

Actually I am not. They seemed to perform quite well at your last dyno.

Just thinking along the lines of what you have done with your truck recently and trying to figure out the likely culprit. What has changed since the shudder started?

 

Actually the shudder started to occur before the pull, however i dont recall noticing the problem before my last dyno run, but that day i also held the truck above 75-80mph for over an hour on end... Nothing out of the ordinary *shrug*

 

If you get a chance, do the buzz and contribution tests. I have a theory if you are sure it is the engine and not tranny back stuff getting worse.

 

Ok, tell me your theory in the meantime. When did MillerTime start tonight?

 

I know that you said that it's not drive train but could it be coming from the carrier bearing? I had a 98 F250 that would shudder at certain speeds when it was on it's way out.

 

I'll send ya a PM. I'm on #2 and then off to bed. Almost sounds like a diesel beer.

 

bumping this cause it sounds just like my issue. mines been doing it for the last year. it started right after i had the tranny replaced. i figured it to be a balance issue, but not sure whats out of balance or off. i have had tires balanced and rotated, checked front suspension, seems ok. can't figure it out.

it only does it on mine if i am lightly on the throttle and right at 40mph only. if i cruise, it doesn't do it, and if i get on it a little more, it goes away like Kris mentioned.

 

Getting worse... Started it up and cruised up a small hill out the driveway, and anywhere between 1500-2200 it does it. So bad i had to let out of the throttle.

 

Get AE on it, check Change in Rotational Velocity, I'll bet an injector is getting bad.

 

Been busy with another truck Kris? Guess you have not checked yours yet.