Transmission Shudder Question

[TTG]

I've been getting a shuddering(like a bunch of small shifting motions) in my transmission lately, but only when I try to accelerate a little in 4th gear. If I'm on the highway cruising in 4th with O/D on it's fine, but when i try to sp[eed up at all without making the tranny drop gears it shudders and won't accelerate. I also tried turning O/D off, and it did the same thing. It doesn't shudder at all any other time. I've seen a lot of discussion about Transfer Cases causing this kinda thing, but since mine is a 4x2, I shouldn't have a TC, correct? Only thing I can think of is its been 20k miles since the transmission has been flushed and had new fluids put in.

Anyone got any other ideas of what it could possibly be? Any insight would be appreciated.

 

[performancenut]

Try a fluid change as you already mentioned and get some fluid additive which ususally resolves the Torque Converter Shutter Issue if indeed that is what is going on here.

 

[Glacier991]

Shudder is caused by a grabbing and releasing at the interface between friction material and steel. These interfaces occur in clutches, also where bands grab drums and also in the torque convertor clutch [where lock occurs around 30-40 mph]. Most shudder seems to be related to the Torque convertor clutch.

Shudder can occur because of inadequate apply pressures, it can occur because a modulated solenoid isn't doing its job, and it can occur because the fluid being using in the transmission is either wrong or not doing its job.

and a 4x2 does not have a Transfer Case, you are right.

Try reflushing, making sure you are using the correct fluid, and if it still shudders... consider trying an additive. Failing all that get it looked at checking pressures.

 

[TTG]

The scary thing about it is that it only happens in 4th, and only when I try to accelerate. Almost makes me think that my 4th gear is dying or almost dead. I can ride around up through 3rd gear with no shudders at all, and even ride in 4th at a constant speed with nothing. But any extra throttle in 4th and it shudders. Gonna get it flushed at Goodyear tomorrow, hopefully that fixes it. If not it probably being a costly transmission repair would be a decent guess, right?

On a side-note, my transmission has always shuddered if I gun it in 1st gear, mainly at low RPM, like from a stoplight. Anyone else have this or know why it does it?

 

[Glacier991]

I'd read up on the EPC as well. Others may have better more helpful ideas. Good luck.