Torque Converter question Competitor

[Mad_Trbo]

I've been trolling the old supra boards, but I am honestly coming to realize the knowledge level just isn't there.

Anywho I decided to have a look at the internals of my supra tranny and found the following. The face of the torque converter has witness marks where the bolts from the flex plate have been contacting it. I am wondering if this a balooning converter or what it could be.

I figured someone on my trusty buick forum would have an idae or maybe even some experience.



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Any assistance appreciated..

 

[Dusty Bradford]

Can you see any air gap between the converter and bolts?

It could be the converter is thrusting forward under WOT.

Either way you need to look at how much pilot engagement you have and get some shims between the flexplate and the converter. If you get some shims in it and then don't have enough pilot engagement into the crank, the pilot height needs to be increased. That means the converter would have to be rebuilt with a taller pilot.

 

[Mad_Trbo]

Shim

I can measure pilot engagement with the TC off the trans.

Couple of questions

How much pilot engagement do I need to have?

Also if I have the requisite 3/16" between the mounting pad and the flex plate can I shim that to zero without harm to the T/C or pump. I know if you have more than 3/16" and you bolt up the converter you risk the converter disengaging the tranny pump. But can you have the converter mounted to far onto the pump?

And this thrusting seems like it would be bad for the thrust on the crank??? Should it be doing that, thrusting / walking forward and will shimming stop it or is the flex plate going to do just that and flex and I end up with the same issue.

Dusty thanks for the feed back, I sent you a PM ..

 

[Dusty Bradford]

I can measure pilot engagement with the TC off the trans.

Couple of questions

How much pilot engagement do I need to have?

Also if I have the requisite 3/16" between the mounting pad and the flex plate can I shim that to zero without harm to the T/C or pump. I know if you have more than 3/16" and you bolt up the converter you risk the converter disengaging the tranny pump. But can you have the converter mounted to far onto the pump?

And this thrusting seems like it would be bad for the thrust on the crank??? Should it be doing that, thrusting / walking forward and will shimming stop it or is the flex plate going to do just that and flex and I end up with the same issue.

Dusty thanks for the feed back, I sent you a PM ..

As long as the pilot is inside the crank enough to fully center the converter, your good.

The 1/8 min is the least amount you should see between the converter and flexplate with the converter fully seated in the trans. You do not want to push the converter fully into the trans and shim it to "0". It can and will damage the pump.

If you can see a gap between the converter and the flexplate bolts when the engine is at rest but you are getting those marks..... it has to be thrust. The purpose of the flexplate is to be a cushion for the crank thrust bearing. If it's flexing enough for the converter to contact the bolts you have an issue than can cause thrust bearing failure. This means that the converter is shoving directly on the crank via those bolts.

What you want to do is get the converter away from the flexplate enough that you have .125 between the converter and flexplate and .125 from the converter being bottomed out in the pump AND still have enough pilot engagement. This will allow movement both ways and the flexplate can do it's job. If you can't get these distances the converter needs to be fixed because it's build height is off.

 

[Mad_Trbo]

Exactly what I was thinking

Thanks for the feedback Dusty. Still curious to know what PTC can do with this platform. The Toyota group is completely smitten over their six speed manual tranny and I can't get any reputable support on the automatic.

Sucks!