Ran transmission 2 1/2 quarts low

[Jjbiskup]

The transmission now jerks when cruising at 50mph and has an intermittent knocking sound from somewhere in the transmission area. What could be the cause of knocking?

 

[Erik the Awful]

I think you have multiple problems, and the jerking is an engine performance problem.

 

[Jjbiskup]

I think you have multiple problems, and the jerking is an engine performance problem.

Its a shutter. Could it possibly be caused by the torque converter not being spaced right?

 

[Schurkey]

Its a shutter.

Cameras have shutters. Do you mean "shudder"?

Could it possibly be caused by the torque converter not being spaced right?

"Spaced" from what? The flexplate? The transmission?

MAYBE there's an issue with the converter clutch. A scan tool would be a significant help.

 

[Jjbiskup]

Cameras have shutters. Do you mean "shudder"?


"Spaced" from what? The flexplate? The transmission?

MAYBE there's an issue with the converter clutch. A scan tool would be a significant help.

Yeah it started to shudder at like 50 and then it seemed like it lost power. And yes spaced from the flexplate. Somebody else installed this trans and i dont think they did it right.

 

[Schurkey]

I'd expect a torque converter clutch to engage somewhere around 40--50 mph, depending on gearing and throttle position. So converter clutch seems very reasonable as a cause. But there's still more diagnosis to be done.

 

[NickTransmissions]

Yeah it started to shudder at like 50 and then it seemed like it lost power. And yes spaced from the flexplate. Somebody else installed this trans and i dont think they did it right.

Do you have a bi-directional scan tool that can render live data?

If not go buy or borrow one, plug it in and drive around with the scan tool displaying transmission and tc activity data. Pay attention to shift speeds, whst gear you're in vs what the pcm thinks and tc duty cycle/efficiency. Will tell you if you have an issue with the trans and/or torque converter or not...

Shuddering at higher speeds is usually tcc slipping and id expect p1870 to set/store. Id also expect to see a "trans temp" warning as slipping tccs will generate lots heat.

Also, what do you mean when you say the torque converter was "spaced"?

There should have been between 1/8" and 3/16" of an inch between the tc's mounting pads when all they way in on the pump and the bolt holes in the flexplate.

Is it still shifting weird and making noise or have you resolved those issues?

 

[Jjbiskup]

Do you have a bi-directional scan tool that can render live data?

If not go buy or borrow one, plug it in and drive around with the scan tool displaying transmission and tc activity data. Pay attention to shift speeds, whst gear you're in vs what the pcm thinks and tc duty cycle/efficiency. Will tell you if you have an issue with the trans and/or torque converter or not...

Shuddering at higher speeds is usually tcc slipping and id expect p1870 to set/store. Id also expect to see a "trans temp" warning as slipping tccs will generate lots heat.

Also, what do you mean when you say the torque converter was "spaced"?

There should have been between 1/8" and 3/16" of an inch between the tc's mounting pads when all they way in on the pump and the bolt holes in the flexplate.

Is it still shifting weird and making noise or have you resolved those issues?

Obd1 has that? I thought that was only obd2

 

[Jjbiskup]

Do you have a bi-directional scan tool that can render live data?

If not go buy or borrow one, plug it in and drive around with the scan tool displaying transmission and tc activity data. Pay attention to shift speeds, whst gear you're in vs what the pcm thinks and tc duty cycle/efficiency. Will tell you if you have an issue with the trans and/or torque converter or not...

Shuddering at higher speeds is usually tcc slipping and id expect p1870 to set/store. Id also expect to see a "trans temp" warning as slipping tccs will generate lots heat.

Also, what do you mean when you say the torque converter was "spaced"?

There should have been between 1/8" and 3/16" of an inch between the tc's mounting pads when all they way in on the pump and the bolt holes in the flexplate.

Is it still shifting weird and making noise or have you resolved those issues?

I also have not driven it at that high of a speed again. I will do and see if the problem persists. It made a very apparent knocking sound. Similar to that of an engine knocking. Dont know if it was coming from the trans or transfer case.
I will have to take off the inspection plate to see if the bolts are loose or if the spacing is off. If the tc wasnt spaced correctly the transmission wouldve burned up by then surely right? Ive driven it around 30 miles so far.

 

[Schurkey]

Obd1 has that? I thought that was only obd2

Posts 14 and 15, particularly, but the whole thread is interesting.
www.automotiveforums.com/vbulletin/showthread.php?t=1146067

Automotive Forums .com Car Chat

94 k2500 no low end power and horrible fuel mileage C/K

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It made a very apparent knocking sound. Similar to that of an engine knocking. Dont know if it was coming from the trans or transfer case.

Or cracked/broken flexplate. Common on one-piece-rear-main-seal smallblocks. Possible on anything else.

I will have to take off the inspection plate to see if the bolts are loose or if the spacing is off. If the tc wasnt spaced correctly the transmission wouldve burned up

WHAT "spacing"? The converter bolts to the flexplate. There's no space between them.