Torque converter...then what??

Call me an idiot...I have a question about installing my AW4. I've never put in an automatic trans. but I'm about half way through this swap.

Tranny >> Torque converter >> Flexplate >> dust covers >> ?? >> engine.

How does the crank end of the engine TURN the tranny? Where's the gear? spline? Is the whole thing turned by the flexplate. The torque converter is installed and seated...with flexplate ready to bolt on.

I'm a bit confused by your question. The crank is bolted to the flexplate. The flex plate is bolted to the TC housing. The TC housing turns the pump inside the tranny. The TC housing fills with fluid and due to centrifigul forces, passes through a bunch of vanes. The faster the speed, the closer to "stall" speed of the fluid. This transfer energy to the turbine and begins to spin it. The turbine is splined to the input shaft and away you go.

As you slow down, the fluid looses speed and energy and can no longer keep the turbine spinning so you slow down.

Take 2 fans and point them at each other at close range. Turn on one. It will spin the other

So it's just a big fluid coupler. No mechanical connection.

There are zillions of vids on Youtube.

I know HOW the TC works. It was just the connectioin from crank to TC that had me confused.

Saudade said:

.... The crank is bolted to the flexplate. The flex plate is bolted to the TC housing.

So it's just a big fluid coupler. No mechanical connection...

Click to expand...

...except for the crank bolted to the flexplate and the 4 bolts from flexplate to TC. So those 4 bolts run the whole drivetrain aft of that?

Ah. Yep. Flexplate bolts to the crank. The holes should be offset a bit to make sure it aligns correctly for the CPS. When you slide the tranny/TC on you should still have a small gap between the FP and the TC. Make sure you can spin the TC. If you can't, you may not have seated the TC completely. Once you've got that, you can spin the TC to align with the mounting holes on the flexplate and bolt 'er up.

Thanks for the explanation...too much thinking was killing me!!

My headache is miraculously gone...The TC does spin.

Another question while I'm here.

I've seen pictures of other TC's with a big "yoke" thing bolted to it (looks like a giant paper clip, kind of), is that just an installing tool or some extension of the TC itself.

I don't know what you're referring to now. Maybe it just keeps the TC from slipping off the shaft while carrying the trans around during install.

i think you are referring to the locking bar. basically there while you hoist the trans/transfer case up so the torque converter does not slip out of the splines/shaft and also helps keep the converter from resting to hard on the shaft and pump seal.
torque the flex plate to the crank and use locktite on the 4 bolts, then torque to spec. then hoist the trans and slip it in. the torque converter bolts are then installed but you need to install one then turn the flex plate to get to the next, and so on.

Saudade said:

I don't know what you're referring to now. Maybe it just keeps the TC from slipping off the shaft while carrying the trans around during install.

Click to expand...

That's what it is.

2stix said:

i think you are referring to the locking bar. basically there while you hoist the trans/transfer case up so the torque converter does not slip out of the splines/shaft and also helps keep the converter from resting to hard on the shaft and pump seal...

Click to expand...

Makes sense.

It all became clear when I got the BA/10 out and looked at the set up...with the clutch in...and with the clutch/flywheel out. Hopefully I can start the install tomorrow.
Got the loc-tite, flexplate bolts, new CPS etc. I may have questions about the positioning of the flexplate. The manual says it needs to put back in the "same" position.!?

I'd appreciate any tips or pictures on making the install easier.

Thanks.