pentiuman

Hey all. Need advice on mateing my flywheel to torque converter ("TC"). I installed a new 350 engine in my 91 GTA, auto trans of course, leaving the transmission in the car. My problem seems to be that my torque converter isn't mateing with my flywheel properly. When I installed the 3 bolts to join them, I apparently didn't do it right. The Pontiac factory manual and the Chilton's books (transmission section, NOT engine installation section) say that I should have made sure "the weld nuts on the converter are flush with the driveplate and that the converter can be turned freely by hand in this position".

BACKGROUND: Before removing my engine, I did mark both the flywheel and the torque converter's 3 bolt locations w/ a grease pencil. (Marked one-one, two-two, three-three). After removing the engine, I also marked the outside face of the flywheel, before I took it off the engine. Of course, the flywheel is keyed, but I have since examined a Firebird at the junkyard to make sure I've got my flywheel facing the right direction too, which it is - lipped side facing the engine.

While trying to put my engine in, I happened to notice that my transmission mount was split in half at the rubber. Don't know if it was already, or if I split it by raising the transmission / letting it sit without loosening the transmission mount nut first. Anyway, I installed a new transmission mount onto the transmission, leaving the nut off the stud. At the time, I thought I had it faced the right way. But have since looked at the books and noticed that I may have the front and back of the mount reversed. (Book pictures are poor). I don't know if this is my problem (or one of several problems). The design of the stud in the transmission mount, which faces downwards, is not in the center of the mount, forward to backwards, so perhaps I've got it wrong. But I don't see how that would make a difference, since the stud fits in a slot in the crossmember, and could be moved forward or backwards. Furthermore, since the transmission and engine bellhousing bolts are in and they are mated together, the torque converter should be independant, right?

After I lowered my engine in, with most of the weight off the hoist, I installed the motor mounts and bellhousing bolts, (which all went in great). I don't recall if I then installed the bolts to the flywheel and torque converter, or if I removed the wooden blocks holding up the transmission first. However, at some time after removing the wooden blocks under the transmission, the transmission / engine moved / fell. I did not see any damage to my flywheel / transmission / engine or bell housing from the fall, but this surprised me since:

A. I thought motor mounts held an engine firmly, and thus the transmission too, since they were joined, and
B. I assummed the transmission would go down / went down when I removed the wooden blocks under the transmission pan.

But now that I think about it, I think the transmission mount's stud got barely hung up on the crossmember slot, and it just took a minute for the weight of the transmission to overcome that. I say this because when I went to tighten the nut on the new transmission mount, the protective plastic cap on the stud was torn, evidence of the fall.

Since I never removed my torque converter, and it previously spun free, I went ahead and installed the 3 bolts, one by one, connecting it to the flywheel, tightening each one to the specified torque reading. That is, I tightened each bolt fully, before turning the engine by hand to get access to the next. Apparently this was wrong, as I should've installed the 3 bolts all finger tight, (turning the engine by a wrench to get to each bolt), and then tightened them.

When I did tighten the bolts individually, the flywheel and torque converter were close to each other, (about 1/2 inch) but not touching. I should have known something was wrong, because as I hand installed and wrench tightened each bolt, instead of pulling the entire torque converter forward to the flywheel, (as I thought it would), it made the flywheel flex towards the torque converter, at each bolt location. I went ahead and tightened all 3 bolts, but have not yet turned the engine over, except perhaps by hand to put the timing mark on top dead center.

What could be wrong? What could be keeping my torque converter back towards the rear of the car, away from the flywheel?

Others (perhaps inexperienced) have advised me to try to turn the engine over with the starter, to see if it turns fine, or makes any bad sounds, which I have decided not to do, until I get more opinions. Before writing this thread, I removed one of my torque converter bolts, and the flywheel moved away from the torque converter at that point. IS EVERYTHING NORMAL? IS THIS WHY SOME BOOKS CALL A FLYWHEEL, A "flexplate:?

F-BIRD'88

The tork converter is not fully engaged with the trans pump. Remove the flywheel to tork converter bolts. Loosen but don't remove the transbell housing /engine bolts.
be sure the trans is square to the motor. Bump the starter over without spark until the tork converter engages with the trans pump fully. Retighten the trans/engine bolts. the tork converter should be able to move up and back and meet the flywheel with minimal force. Hopefully you have not cracked flexplate.

pentiuman

F-Bird'88 - Thanks. Just read your post and am still trying to get it clear that the torque converter is not fully engaged with the trans pump. Yeah, I had remotely heard of that problem before in years past, but never knew anything about it. I already removed one flywheel to T/C bolt, and will remove the other two, by turning motor over by hand. Guess I thought when the T/C was not fully engaged in the trans pump, the T/C would be sitting too far forward, as I read in another thread on another members car, not too far back, as in my case. (I don't dispute your wisdom, just trying to understand how the parts fit, as I've never had a TC out, to see a trans pump).

Why turn the engine over bit by bit, with the starter, (wouldn't by hand be safer, but harder)? (My spark plugs are in, and too hard to remove.) Will it be obvious when the T/C engages with the trans pump fully? How will I know?Noise? Resistance? By feel of TC turning freely or NOT turning freely by hand? Because T/C will pull forward against flywheel? ((I thought on auto transmissions, the torque converter should turn over freely when disconnected from flywheel. Right?)

I have always been a little concerned that the transmission was not square with the motor, because the front of the motor appears to be pointing slightly right (passenger side). However, I just summed it up that I'm a perfectionist and was imagining things, since all my bolts, including my bellhousing bolts and motor mounts, threaded in by hand. I wonder if maybe I should try to turn around my transmission mount, and once I do, perhaps leave the crossmember bolts a little loose to allow the transmission to move, before I re-tighten the bellhousing bolts?

Sorry for all the questions. I haven't done this in 20 years, and my experienced help never showed up to help.

Any comment on how I may know if I've cracked my flexplate (aka flywheel, right??)

FYI - I'm a computer technician, if I can return the favor in computer questions!

TexasSilhouette

iTrader: (4)

If I read your post right, you had a gap between the flex plate and torque converter with the belhousing butted up completely, that would be an indication that your torque converter is indexed corectly.

Just so we understand each other, engines to be bolted to automatics don't use flywheels per se, they use flex plates to connect to the torque converter. The mass of the torque converter serves the function of the flywheel.

Unbolt the torque converter from the flywheel and push the converter back toward the transmission. See if it spins freely, I suspect it will. If it does, then turn it slowly as you pull it (by hand) into the crankshaft until the torque converter touches the flex plate.

If you cannot get the torque converter to "walk" into the crankshaft, there are two possible causes that come to mind right off.

1.) The crankshaft has a ding that is preventing the converter pilot from pulling into the crank.

or

2.) there is a pilot bushing in the crankshaft that is not fully seated.




Oh too, of you don't have one already; I STRONGLY encourage you to get a flywheel turning tool. Lisle and a few other companies make them and life is so much a better place because of it.

Gluck Auf

pentiuman

Thanks TexasSilhouette,

Yes, I have a gap between my flexplate and torque converter, w/ bellhousing butted up completely, bellhousing bolts tightened, motor mounts in and tightened too. When I installed the engine, had to lift the front of the engine up the last inch, by hand, to make the bellhousing joint flush. The engine / transmission fell / moved after the installation, as I described. (Still trying to figure out what steps I did out of order, or did wrong that led to a slight fall / movement). Already removed one bolt from the flexplate to torque converter, before I stopped and started this thread.

FYI - Of course, when I removed and installed the motor mounts and bellhousing bolts, it was not up on jackstands. But all the other time, I usually just jack up the front left, real high with a hydraulic jack, and put 2 jackstands to hold up the left front. (I'm paranoid about the car falling on me, and feel safer with just one side off the ground). However, now I'm wondering, if it would be a mistake not to have the entire front end up on jackstands, if I'm concerned about proper transmission to engine alignment, while working on some of these types of issues?

I read, and re-read your post. I hope after I remove the other 2 bolts, that I will be able to pull the torque converter up towards the flexplate by hand. If not, I will then further investigate the 2 possible causes you list. (In that case, I will make another post with more questions, as I'm not familiar with everything, and this is a newly remanufactured engine that I just bought, and I'll need to try to determine who / what's at fault. Thanks

SpitotRs305

you will need a spanner wrench to turn the flexplate if you dont already have one... dont use the bolt in the crank snout.... or you will have another thread about repairing threads

sqzbox

If you have the bell housing bolts tight to the engine and still have a gap between the torque converter and flexplate then the converter is engauged to the trans pump, If it wasn't, you wouldn't be able to tighten the bell housing snug to the block. The converter bolts are the last thing you do after the bell housing bolts and you move the converter to the flexplate and rotate the converter to align the bolt holes (trans in neutral). If you move the converter towards the flexplate and the bosses on the converter don't touch the flexplate then the flexplate is on backwards.

--- crank
___/ \___ Flexplate

correct

pentiuman

TexasSilhouette / Gluck: Did you mean to write that that would be an indication that your torque converter is indexed incorrectly? And what do you mean by "indexed"? Not in line, not right, out of order? Thanks

TexasSilhouette

iTrader: (4)

Indexing is the act of assuring all three components of the transmission are engaged into their respective components of the torque converter.

The three components are the input shaft, stator shaft and lastly the transmission pump. The pump being the last to engage and the most delicate, it is the one that gets broken when the converter is not correctly indexed. The pump is what engages those two notches in the torque converter snout. If you have not removed the converter, you have not seen them.

If you did not allow the converter to separate from the transmission at all, it will still be indexed.

If you were able to bolt the transmission and engine together and still retain a gap between the converter and flex plate, that too indicates proper indexing.

If the torque converter will spin freely before bolting up the flex plate, that too indicates a properly indexed converter. You verified that the converter will spin freely when unbolted from the flex plate, right?

Gear selection on an automatic transmission in this situation is irrelevant as automatics are all in neutral unless the pump is spinning (engine running) to provide the hydraulic pressure required to engage the clutches and/or bands required to engage a gear set. Just remember to assure it is in park or neutral before starting the engine. One of the worst snafu’s I have ever witnessed occurred when a technician started a fresh motor with gear selector in park but disconnected from the transmission which was in reverse. The car left the bay in a big hurry.

Glück Auf = Good Luck as seen in German Salt mines; an obscure reference but a relevant one.

pentiuman

Thanks all. I think I may have got it right finally, but would appreciate if you'd review where I'm at now.
1. I bought a flywheel turning tool for $33. Yeah, will only use it once, but it makes turning an engine over, to an exact position, so much easier, and w/out risking damage to the bolt on the crank). Had to go to 4 stores, as nobody had heard of one, much less stock on. Some questioned whether such a tool existed! Ordered from Napa, who had it in 2 hours.
2. Instead of just jacking up the drivers side of car, as I did when I installed the 3 bolts originally, I jacked up the entire front of car, and put 2 jackstands on each side. I'm wondering if this was the cause / or contributed to my stubborn TC to flexplate movement / alignment?
3. Removed the 3 bolts holding the flexplate to the torque converter, ("TC"), and flexplate did not retract back towards the front of the engine as much as it had flexed towards the converter when I originally installed it improperly, as now it was just about 3 millimeters away. (That is, when I originally put in the 3 bolts before the TC was against the flexplate, to pull the TC the 1/2 inch to the flexplate w/ the bolts, the TC must have come forward a little, as the flexplate flexed a little too). These bolts have had an orange colored sealant on them some time in the past, by previous owner. (I just bought the car w/ a bad motor 2 months ago). Don't know if it's a loctite or gasket product, or reason?
4. Spun the torque converter over by hand, which moved freely, (just as it did when I had the bad engine out of the car). Again, I never fully removed the torque converter or (auto) transmission. Initially, when I had trouble getting to the bellhousing bolts, I was going to remove the transmission and engine together, and I removed the driveshaft and loosened the (torque?) arm. Lost about 3 quarts of tranny fluid. Then decided to remove the distributor and windshield wiper motor, and had lots more room to get to those bellhousing bolts, to remove engine only, so I put the driveshaft back in.
5. Pushed the torque converter back towards the rear a little by hand, then tried to bring it forward towards the flexplate (by hand), but it first hit a rough spot / point where it binded slightly /wouldn't go forward. I almost panicked and thought about how I could use brute force to bring the TC and flexplate together. Then thought about another thread where the guy had the opposite trouble (TC too close to flexplate) and he used a sledgehammer, risking damage.
6. I remained calm and wiggled and turned the TC by hand, and it went over the point where it had stopped, and mated with the flexplate flat. Turned the TC over by hand, which rotated freely. I did this twice, pushing the TC back and bringing it forward by hand. IS THE TC SUPPOSSED TO BE ABLE TO GO UP AND DOWN (circular) A BIT BEFORE IT MOUNTS AGAINST THE FLEXPLATE PROPERLY?
7. I installed all 3 bolts hand tightness, then went back and tightened them to the specified torque (if I recall, 35 ft. lbs.).

Guys, I don't know why I have a spot where the TC temporarily binds slightly when coming forward onto the crankshaft. Is this likely just the design, or could I have a small ding on it, or does it even matter, since it will come forward all the way, and spin freely?

I appreciate all your help, and your patience with my long posts. Installing this new engine in my "new" Trans Am is one of the most important tasks I've ever undertaken! It's also the hardest, and I don't want to do it twice, so please forgive my cautiousness and inexperience. I'm dying with anticipation to drive the car (having never done so, since I bought it w/ a bad engine). I haven't owned a Trans Am (or any 8 cylinder car) in about 15 years, so it should be sweet, if I ever get it finished. Now, how to pay for gas?

TexasSilhouette

iTrader: (4)

THe flywheel turner really makes a difference and while $33 may be a bit high I'm sure you agree now it was worth the investment.

The orange thread locker is from the factory and a good idea.

The torque converter pilot centers in the crankshaft so the slight wobble you feel before the pilot is in the crankshaft is normal.

The bind is probably a small spot in the hole in the crank you have to work past, probably the same one that bound it up in the first place. Turning the converter I suspect allowed it to get past the spot.

Enjoy

WhiteHawk

When the converter is fully engaged into the transmission, if you were to lay a straight edge across the bell housing surface, there should be a 1 inch gap to the bolt lands on the converter.

After you bolt the bell housing to the engine block, you need to work the converter out until that nose piece inserts into the crankshaft.

Sounds like you have an issue with that nose piece fitting into the crankshaft, as mentioned above.

Smith Guillen

I install my trans with the torque converter not in all the way. Never heard a pop but the engine wouldn't crank. I pulled the engine out and the converter was stuck. I managed to pull it out gently then popped it back in the splines and it went in all the way and spins freely. Whats the damage? Is there is any?

TexasSilhouette

iTrader: (4)

It is possible the front pump is damaged. I would recommend pulling the torque converter and inspecting the front pump drive ears. make sure the pump turns freely and that both ears are attached.

maroe624

Always pull and install trans and engine as one unit. Way easier to install and remove. Also lets you feel when the torque converter splines engage the input shaft then the pump. Should be able to turn it smoothly and hear some slack when its bottomed out. I had this same issue, thought I installed something wrong but all I simply had to do was pull the dam torque converter out till it touched the flexplate. The thing is heavy .

OrangeBird

iTrader: (1)

Smith Guillen , I have some bad news for you

Since you say you didn't have the torque converter in all the way (properly indexed to the transmission) , and you tightened it up to the point where the engine was jammed from turning (when you say "wouldn't crank" I presume this means the starter couldn't turn the engine) , it is a 101% certainty that you've damaged the transmission's pump . The top picture shows the two drive tangs that get sheared off of the pump's rotor when the torque converter isn't properly indexed during assembly .

NoEmissions84TA

iTrader: (1)

12 year old post but still relevant info and great explanation.

ASE doc

From reading this thread, it sounds like the TQ was engaged with the pump okay but wasn't going into the crankshaft smoothly. The problem was most likely rust in the hole where the TQ snout should slide in to align with the crank centerline. Have to make sure that hole is clean and smooth. A light coat of grease there doesn't hurt anything either.

OrangeBird

iTrader: (1)

ASE doc , from what I read of the post I responded to it sounds as if the torque converter was stuck in the transmission , and not on the crankshaft end . Maybe Smith will come back into the discussion and verify where , exactly , the torque converter was stuck .

And as to the thread itself , it was Smith who bumped the 12 year old thread with his question , so any post before Smith's is ancient history and I wasn't responding to any of the 2007 vintage posts , only to Smith's . Yes indeed the older posts were discussing a torque converter that wasn't all the way engaged to the crankshaft , but I believe Smith's problem is that it wasn't engaged into the pump .