Folks,
First of all, thanks and am loving the site. Secondly, truck shudders under no load at 1500 or so RPM's. An example, driving along and it shifts through the gears fine. Then the torque converter goes to lock out I believe it is called. Anyway, the truck then shudders. If I coast, it goes away. If I let off the gas and go back on it lightly, the shudder goes away. If I let off and stomp on it, the shudder goes away. I can turn the OD off and at 1500 rpm is does it the same when the torque converter locks out.

There is some other feeling, maybe slippage but feels more like a surge at 70 or so. Not terrible noticeable but as I get more use to the truck the more I notice it.

What do you guys think? I was thinking that a new torques converter might do the trick but not sure. Again, I did the service. Fluid was not burned when I replaced it.

Stats: 2000 F-250, 5.4l, 4r100w (think that is right, at least the filter fit when I did the filter change) 4x4 196K

Thanks,
Jason

 

How much fluid did you replace?

 

I drained the transmission and refilled to where the dipstick shows right in the middle of the full range. I would have to count the missing bottles in the case. If you think it will help with your diagnoses then I will. I did not drain the converter. It shuddered before the service. I did not notice the surging/slipping at high speeds until after.

 

My 95 F150 does the exact same thing you described in the 1st paragraph. I'm not too familiar with the trans that's in my truck either, (4R70W) but I have rebuilt the C4 in my 79 and a few GM turbo 350s. Even though my check engine light is not on, I'm thinking it's the torque converter clutch solenoid. (TCC) I have some research to first before I go tackling the problem, but it's just a thought.

 

That answered my question.

You didn't change enough fluid to fix a shudder problem. Change it again and this time also drain the torque converter. That will probably fix the shudder. If not, you'll probably have to change the torque converter to fix it.

 

Mark,
So you are saying that the torque converter has to be filled seperately? I drained the pan, changed the filter, and put it all back together. Then I filled to where it shows full on the dipstick in the hot and park position just like it says on the dipstick. It still shows full.

I would love some more info. You are saying to replace the filter again? or just add fluid or drain and add back to full?

Thanks for the help Mark.

 

I've seen two other trucks with TorqShift automatics that had this similar shuddering sensation. In both cases when the transmission was removed the flywheel was found to be cracked. It may not be a transmission problem at all. If you decide to replace the torque converter be sure to tell them to check the flywheel very closely for cracks.

 

You can't fill the torque converter separately. It fills from the transmission pump, which gets it's fluid from the pan. It sounds like you only drained the fluid from the pan, not from the torque converter. That means you changed a bit less than half of the total transmission/torque converter fluid. That leaves enough old fluid that the torque converter can still shudder.

The new fluid you installed is now ruined by the old fluid. Either drain the pan again AND the torque converter, or follow this procedure:

https://www.ford-trucks.com/article/...nsmission.html

You don't need to change the filter again.

 

This truck does not have a TorqShift transmission.

 

and if i drained the torque converter and it still shudders then the t c is bad i take it .