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4L30E Reinstall After Rebuilt - Flex Plate Binding on Engine, TC Protruding Too Far

262 Views 7 Replies 3 Participants Last post by  DSUZU
Hey folks! I have a reinstall issue and I'm hoping y'all might be able to give some advice.

Finished a home rebuild of the transmission from my 2002 Trooper. Got everything to reassemble smoothly following the Verhoeven and ATSG guides, plopped on the new torque converter, and hoisted the transmission up into the car. Re-attached fuel lines, ATF lines, all my plugs, etc. I had just finger-tightened one of the torque-converter-to-flex-plate bolts so that I'd have them rotated correctly relative to one another. Got all my bell housing bolts in and was feeling great!

However, when I went to tighten that torque converter bolt and start rotating around to install the other 5, I found that I could not, even when applying maximum strength, get the trans/engine to rotate. Checked that I was in neutral, checked all sorts of stuff, and then realized that, upon tightening the bell housing bolts, my torque converter was actually flexing my flex-plate forward far enough that the flex plate is now binding on the engine.

By looking through that access spot where you access the torque converter bolts, I can actually see the spots where the flex plate gets flexed forward and binds. Basically, my torque converter seems to be protruding like 3mm or 4mm more than it's supposed to.

Has anybody else ever encountered this? What did I do wrong. I REALLY don't want to fully uninstall this thing if I can help it, but it seems that one of the following has happened.
1) I somehow have a torque converter with a different thickness from stock. I did not measure them when they were out, but I seriously doubt this. I ordered my new one from rock auto and the part number (both on the box and stamped) is correct.
2) My torque converter is somehow not seated all the way down on the splined output shafts. It doesn't seem like it's possible to do this wrong. It slides on, and it's not like I have an inch of extra length. Like I said, it's a few mm.
3) I've done something horrifically wrong in my rebuild in some other regard.

Is anybody familiar with this issue or has ever encountered this with a rebuild/reinstall? Also, should I be able to get the TC out without fully dropping the trans and screwing around with fuel lines and trans cooler lines again?
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Did your torque converter have the two notches in the hub for driving the front pump? Did you have them seated on the front pump correctly? Dennis
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Did your torque converter have the two notches in the hub for driving the front pump? Did you have them seated on the front pump correctly? Dennis
My torque converter does have those notches, but it didn't seem like there was any protrusion to fit up into those notches. If so, then that would be the obvious oopsie.
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Okay follow-up question. My understanding is that the depth of the overlapping splines between the torque converter and output shaft is roughly 1.5". As such, it seems I ought to be able to back off the torque converter and rotate it to re-seat it in the correct orientation without fully removing the trans (and screwing around with undoing fuel lines, trans cooler lines, and such underneath this incredibly corroded mess of a cheapo auction vehicle).

Thoughts? On this? Am I missing anything serious? I think I can remove my trans cross-member, grab my transmission jack, and get a 2 inch gap between the bell housing and engine and wedge some shims in there to hold it open while I finagle with this.
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My torque converter does have those notches, but it didn't seem like there was any protrusion to fit up into those notches. If so, then that would be the obvious oopsie.
The two notches in the "snout" of the TC case have to engage the two lugs marked in red on the transmission hydraulic pump. You can't see the lugs so you have to rotate the TC case and push until you feel the TC case engage.


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So I've been fiddling with this for the past half hour or so. I have enough space that I can rotate the TC independently of the rest of the trans, but I'm unable to tell if any of the orientations I've attempted are an improvement. Here's a photo of the current TC position (which is what it was beforehand). You can see the size of the gap between the TC mating surface and the 6 TC-to-flexplate mounting points. Does this look correct or would you expect the TC to sit deeper inside the bell housing?

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I can’t determine from looking at the photo if the Torque Converter is correct or not. Is this the original flex plate and Torque Converter?
1. Buster is the authority on automatic trannys.
2. Hard to tell from your picture, but I'm tempted to say it needs to go further back. However you can, mearure the distance from the rear engine face ot the outside of the flex plate. Measure the distance from the front face of the tranny housing to the torque converter mount pads. When the tranny measurement is a little greater than the engine measurement, you will be okay (maybe - hoping you didn't damage the T.C, or the pump drive tangs). Rotating the T.C. to align with the drive tangs can be difficult. It usually involves pulling the T. C. forward (probably best to wiggle it while moving forward maybe 1/4", then trial and error slight rotation until you can push it back further than where you started. Dennis
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