4.0 l SOHC flex plate to converter install issue

[ICoull]

Finished the timing chain rebuild of the 4.0 and tried to re-install engine to automatic trans. Torque converter stayed in transmission and WAS pushed all the way back so that it rubbed the inside of the bell housing. I thought that would create enough clearance to bolt engine and trans together; after that I thought I would be able to spin TC into alignment with flexplate - nope. TC was jammed against the bell housing and the studs were jammed into back of the flexplate - many choice words about that design feature. I had to loosen the tranny bolts and separate the engine by about 3/8 in to get the TC to turn and align the studs with the flex plate holes. So now the ends of the studs are just flush with the front of flex plate but won't coax forward enough to start a nut on them. It is as if the pilot shaft on the TC will not enter the alignment bore on the flex plate, and I can't seem to get enough grip on the TC through the starter hole to yank it forward. So far no bent screwdriver or other tool seems willing to shove the TC and its studs forward enough to engage the nuts.

Any suggestions here would be appreciated. I can't imagine having to pull this all apart again to resolve this issue!

 

[imp]

Finished the timing chain rebuild of the 4.0 and tried to re-install engine to automatic trans. Torque converter stayed in transmission and WAS pushed all the way back so that it rubbed the inside of the bell housing. I thought that would create enough clearance to bolt engine and trans together; after that I thought I would be able to spin TC into alignment with flexplate - nope. TC was jammed against the bell housing and the studs were jammed into back of the flexplate - many choice words about that design feature. I had to loosen the tranny bolts and separate the engine by about 3/8 in to get the TC to turn and align the studs with the flex plate holes. So now the ends of the studs are just flush with the front of flex plate but won't coax forward enough to start a nut on them. It is as if the pilot shaft on the TC will not enter the alignment bore on the flex plate, and I can't seem to get enough grip on the TC through the starter hole to yank it forward. So far no bent screwdriver or other tool seems willing to shove the TC and its studs forward enough to engage the nuts.

Any suggestions here would be appreciated. I can't imagine having to pull this all apart again to resolve this issue!

First, it sounds as though you DID fully seat the TC in the oil pump, that being the usual cause for a problem getting things back together.

Often, the TC slips forward while maneuvering the trans. back into location, then "misses" engagement with the pump when squeezing things back together. imp

 

[ICoull]

Torque converter position at re-assembly

Thanks for the suggestion imp, but... I can't understand how the TC can be so far seated that it contacts the inside (back) of the bell housing AND be mis-located too far forward at the same time? All the evidence seems to show that the TC is 'still' fully inserted - so much so that the back of it continues to contact the inside of the back of the bellhousing. Even with the TC studs located in the flexplate holes, bolting the engine and transmission fully together causes the TC to jam/contact the back of the bellhousing and prevents engine rotation. By separating them by a little over 1/4 inch the TC is again free to rotate freely [except now it can only rock a degree or two in either direction as the studs move inside the flexplate holes].

If I have damaged something it was due to my belief that a fully seated TC would clear the flexplate and its studs, and the studs and holes would not need to be aligned as the engine and tranny were bolted together. Maybe someone can comment on that assumption.

 

[Tech By Trade]

If the TC is in all the way, when the bell housing is bolted up you should still be able to reach in the starter hole and spin the TC. There is about 1/4 inch of room between the TC and the flex plate. If there isnt the TC is not all the way in.

 

[Stick4503]

Hope you have already got this taken care of but if not, I was doing mine last week and ran into the same thing. Turns out that the hole in the flex plate i was trying to line up was the wrong one. Check to make sure that you are lining up with the correct holes.

Otherwise when I was lined up on the one hole I could see in the starter access it was not lined up with the other 3 holes. Rotate the engine while watching for the next hole.

As far as the TC turning with clearance, when I took my transmission out last year and reinstalled I had a little clearance to turn it but this time I replaced the TC while the engine was out and did not have clearance with the engine and transmission seated.

 

[ICoull]

AHA... that may explain the Torque converter misfit issue.

Hope you have already got this taken care of but if not, I was doing mine last week and ran into the same thing. Turns out that the hole in the flex plate i was trying to line up was the wrong one. Check to make sure that you are lining up with the correct holes.

Otherwise when I was lined up on the one hole I could see in the starter access it was not lined up with the other 3 holes. Rotate the engine while watching for the next hole.

As far as the TC turning with clearance, when I took my transmission out last year and reinstalled I had a little clearance to turn it but this time I replaced the TC while the engine was out and did not have clearance with the engine and transmission seated.

Aha...I was assuming the holes were equidistant and if the one stud I could see was lined up they all would be. Sounds like that assumption is not correct, and I need to try a different combination of stud and hole alignment. Thanks very much for this tip. I was tearing my hair out [what little was left] trying otherwise to understand what appeared to be happening.

Thanks a bunch to all who took the time to make a suggestion..

UPDATE - Had to remove and re-install transmission [long story] but the converter studs are all equidistant from each other and not the issue. My recent theory is that the converter hangs just slightly off parallel with the trans input shaft, and that perfectly aligning the front of the trans and engine block will actually mis-align the converter and its locating points [studs and center bushing]. Dropping the back of trans slightly [a couple of degrees] before pushing them together allowed the studs to fully insert. You may want to try this if you are having trouble getting the converter studs to fully insert into the flex plate.

 

[07gtman]

i know this is an old post just thought this may shed light on the flex plate alignment issues

 

[ICoull]

i know this is an old post just thought this may shed light on the flex plate alignment issues

Just to be clear... The 'extra' bolted on adapter that is pictured is only present in the 4.6 l V8 versions. I believe the 'alignment' issue with it is all about radial alignment [ie. proper centering] of the adapter on the Torque converter. The 4.0 l V6 does not have the adapter plate, but has 4 studs welded straight to the TC body. In either case, the 'droop' of the TC sitting on the input shaft would tend to very slightly mis-align the studs [either on the adapter plate, or the TC] relative to the center line of the transmisiion/engine.

 

[07gtman]

sorry you are correct