Seating the Torque Converter Properly

[mnwolftrack]

If you've been following any of my threads regarding a noisy auto transmission in a '98 OBW, I'm going to replace the transmission (myself). There's one thing I'm not quite clear on. People are referring to making sure the torque converter is seated properly the last 1/4 to 1/8" otherwise if you use the bolts between the transmission and engine to pull it together, the torque converter will ruin the oil pump (aka front pump??). What I'm not understanding is, is the process of seating the torque converter done while the transmission is still out? I'm used to manual transmissions and clutch jobs, so please forgive me. For what it's worth, I've been searching for an answer here on this gap, and after a few hours of reading posts, I'm still reading through the posts that tell other people to search and read the older posts. I'm on dialup internet access and haven't gotten to those older posts yet.... Not sure how far back they are.

 

Is the whole reason the torque converter needs to be seated properly becuase it may have slid out a bit on it's shaft when the trans was seperated from the engine (or because you pulled the TC out to replace a seal?).

 

Otherwise, I'm thinking the 1/4 to 1/8" gap is when you try to bring the bellhousing surface to the engine block surface, and they won't quite go together (thus you incorrectly try to use the bolts to bring them together and wreck the pump).

 

Lastly, is the oil pump in the transmission also referred to as the front pump? And, if you damage the pump by not properly seating the TC, what are the symptoms? I'm kinda wondering if the previous owner of my new car who swapped in a 2.2 in place of the original 2.5 may have made this fatal mistake thus causing the noisy front pump?

 

background info covered in other threads (if you haven't read them):

 

I originally bought this car thinking it had a noisy alternator or other pulley. I have plenty of auto experience on Toyotas for 15 years, but this is my first subi (obviously my experience didn't help me buy this car very wisely). I removed the belts and the noise remained. The noise only occurs while moving in gear, unless it's well below 0F air temp then it does it for a minute or two at idle in park. Then, with my foot on the brake, i can move the shifter slowly through the gears (change gear every 5 seconds) and the noise is present once the vehicle has changed gears, but goes away during the shifting of gears. The difference in noise between D and the other forward gears is minimal, but the biggest change is from R to a forward gear, or to/from neutral. When cold, the noise is most audible with a stethescope pointed on the bell housing. The noise changed a little bit and quieted down a little when I put some Lucas Oil TrannyFix in. Now it sounds like a ticked off sputtering bumble bee. The noise quiets or goes away when the tranny is upshifting, then comes back once it's done fully shifting gears. At idle (when warmed up) or coasting, the noise is absent. The tranny otherwise shifts perfectly fine.

[Reveeen]

Well I'm not quite sure what you are talking about.

You take the torque converter and hang it on the input shaft of the transmission, pushing it in (by hand), now if you had it out and looked at it you would notice that there are tabs on the leading edge of the transmission side just past the area where the front seal rides, these tabs MUST index into the oil pump (front pump), so you push it in and turm (or rock) it until these tabs fit (travelling inwards maybe an inch) and the torque converter "clicks" into place (or into the pump). Now hang the transmission on the engine (or engine on the transmission), but chances are if you are hanging the transmission on the engine without a proper transmission jack the damm torque converter will fall out, so be careful and gentle. When the transmission and engine are mated (bellhousing to engine block, no gaps) and the torque converter still engaged into the front pump, there will be a small gap between the torque converter and the flex plate (you should be able to freely spin the torque converter with the engine/transmission bolted up tight) if you can't you have trouble, probably the torque converter fell out and you must unbolt the transmission from the engine evenly until you can spin the torque converter and "click" it back into the pump, I say "evenly" here because if it isn't even the torque converter will bind on the front stub that indexes it into the center of the crankshaft, and you will never spin it. Bolting the flex plate to the torque converter actually draws the torque converter out of the transmission (about 1/4") and completes the mechanical attatchment.

[mnwolftrack]

Hello,

 

Actually, I think you answered my question. I was confused if this 1/4" of travel had to do with putting the torque converter on the input shaft of the transmission. I was not understanding why the converter was pulled out of the transmission to begin with. As I am learning, the torque converter can fall out or stick to the flex plate and come out.

 

I was confusing all of this with some sort of a gap that may occur between the bellhousing and the engine block, as if the torque converter was preventing the engine and transmission from mounting together.

 

In my case, it sounds like the torque converter may pull out a little bit when I remove the tranmission. And, on the transmission that is being shipped to me, the torque converter may have already been pulled or or wiggled out.

 

Knowing that the torque converter should spin freely when the tranmission is re-attached to the motor, and before the flex plate bolts are put in, helps a lot.

[mnwolftrack]

I have to admit though, I'm getting paranoid reading through older posts. I just finished reading all posts that came up in a search for "torque converter." I didin't find anything regarding my quest for info regarding this 1/4" last bit of travel, but I found info referring to bad torque converters themselves and cracked flex plates. My car shifts up/down just fine and smooth, and if the TC was bad I'd think it wouldn't. But the flex plate has me wondering.... I guess I'll find out when I pull the transmission. I'm not sure what a cracked flex plate sounds like much less have too much experience with front pump noises. I'm used to manual transmissions!

[Hocrest]

A cracked flexplate sounds like a loud metal on metal clanging at certain engine speeds, often when NOT under load. Most of them that I've seen are cracked in a circle around the support ring that the bolts go through.

 

A tip to make sure the TC is seated is to measure the distance from the face of the bellhousing to the TC tabs and match it to the distance from the flexplate to the engine block where it meets the bellhousing.

 

Since there are multiple splines that need to get lined up to fully seat the TC, push in in as far as it will go, then spin it clockwise a few times, stop and push in whil slowly turning CCW. Repeat a second time to be sure. Once you do a few, you can tell if it's seated properly by the way it feels...

 

Once it is in, use a long small wire to help hold the TC from slipping out while you maneuver the trans around, make sure to remove the wire once you get the trans into place, before you push it tight against the engine.

[john in KY]

The transmission will not shift in any gear when the front pump is damaged. Also if you remove either line to the radiator, there will be no flow.

[Reveeen]

Ok.................

 

When a junkyard (or whoever) ships you a used transmission they usually put wire(s) accross the belhousing (through the mounting bolts) to hold the torque converter in. Whenever installing an unknown/used transmission it's a good idea to replace the front seal because if it leaks after the fact you will be pulling the transmission and doing it anyway. Check the flex plate for cracks, as was mentioned, they crack at the crank mount. If you put a yardstick accross the belhousing and measure from the inner edge of that yardstick to the flex plate bolt holes and compare that measurement to how far the flex plate sticks out from the belhousing surface on the engine, that will tell you if it is seated.

A few "cold ones" in your fridge should be more than enough to tempt a mechanic to drop by on a Saturday and give you a hand with this, it is not difficult, every auto transmission is the same in this respect, your difficulty lies in not having done this before, make him/her show you what he/she is doing, watch carefully, it will be over before you know it.