Removing bad AT... but flexplate rotates freely. Why?

[SkagitBoy]

Hey guys...
I am hoping for some opinions here. I thought I needed a new tranny, but now that it’s halfway removed, I’m not sure.
The catastrophic failure...
On the freeway, 70 mph and BANG! My engine revs high cuz I had cruise control on, but I lost momentum fast. All I could hear was loud metal on metal clanking and rattling. I got to the shoulder, put it in park and turned off ignition. I can’t remember now if the rattling continued as I was sitting idle or not. I had it towed home and haven’t started it since. I did check for codes and it gave me a P0761 with frequently reported fixes being: replace automatic transmission.
I wasn’t too surprised. My 96 Ranger XLT 4x4 4.0L has about 275,000 miles on it. A year ago I swapped out the original engine with a used one that had 97,000 miles on it. I’m not a mechanic, but did the swap myself with a lot of help from you guys and YouTube. I had a rough time making the final motor to tranny connection. It took me a couple weeks, but I finally got it together. They came together flush, I didn’t use the bolts to draw them close together, I torqued down the flexplate to TC bolts and I’ve been driving it daily ever since (over a year).
Anyway... just today while in the process of removing the tranny. I’m at the point where I’ve removed the starter to gain access to the 4 flexplate bolts. I remember very well from the last time I was down there, that it was a royal pain to turn the flexplate to get to each bolt. This time it is spinning freely, I have to use a vise grip to make it not spin so I can remove each bolt. With the bolts removed, the flexplate feels loose and sloppy.
Could I have busted the crankshaft? Can a flexplate fail/break? But if it’s not the tranny, why would it be giving me the code P0761?
Regardless, I’m gonna have to continue removing the tranny. What should I be looking for/be careful of?
I was so sure of what was wrong, now I’m so confused I don’t know whether to scratch my watch or wind my butt!
Any advice.... wisdom.... or tidbit would be awesome.
Thanks y’alls!

 

[Uncle Gump]

One of three things come to mind...

Broke Crankshaft

Sheared Flex Plate bolts

Broken Flex Plate

Might as well just keep pulling... gonna have to come apart regardless.

 

[adsm08]

Ignore the code for now.

You broke the flex plate, there is very little question about that.

Flex plates can and do break. It is particularly common on Cologne engines, which the 4.0 OHV is.

Your flex plate was not the start of the failure, it was the end of it. If you will recall from the last time you had it apart, there is a spacer between the crank and the flex plate. The spacer is what caused your failure. It is worn and did not keep the flex plate turning true, which stressed it and then broke it. You need to spend the extra $25 or so to replace the spacer as well, or this will happen again.

 

[Transman304]

As others have said, broken flex plate very common. Replace the crankshaft spacer at the same time.
Brad

 

[SkagitBoy]

You broke the flex plate, there is very little question about that.

Flex plates can and do break. It is particularly common on Cologne engines, which the 4.0 OHV is.

Thank you! You are completely right. So, where I'm at right now... exhaust is removed (took me way too long), transfer case is out, transmission is out. The flexplate is cracked 360 degrees, completely around the bolts to the crankshaft. And that's a problem, because I can't clamp the plate to anything to keep it from spinning (well, I can and it stays put... but the center where the bolts are spin just fine and that's the part I need to sit still). Therefore, I can't remove the bolts.

I referred to my trusty Haynes manual, and after reading what they say about flexplate removal... I'm more confused than before. I'm attaching a photo. They say to remove the transmission and they show the flexplate exposed. So, how can they then instruct you to wedge a screwdriver through the starter hole in order to keep the plate from spinning to remove the bolts??? Once you remove the transmission - the starter hole is gone... with the transmission! You're left with a big hole with no wedge-able holes anywhere. This must be a typo, however they explain it twice in 2 different areas of the manual. WTH? Am I missing something?

Can't I keep the crankshaft from rotating from the front end of the engine?

Also, the manual says to mark the flexplate and crankshaft before removing to mark exact alignment. Since I'm installing a new one, I assume that doesn't apply. But am I going to have an issue with balance/alignment at all, or are new parts just perfectly balanced already??? Probably a dumb question.

I did as you suggested and bought a new spacer when I bought the flexplate... only $16 from Amazon, Rockauto didn't have that part listed anywhere. I went ahead and bought a new exhaust manifold and Y pipe set, since I ended up cutting the old crap to get it out.

 

[scotts90ranger]

If the flex plate is spinning on you you can use some vise grips to clamp onto the ring gear to keep it from spinning. But if it is spinning the flex plate might come off with the torque converter so you might not need to worry about separating them assuming the spacer isn't holding everything together. If the flex plate comes off with the torque converter you can take the nuts off with an impact or something while it's more convenient.

 

[SkagitBoy]

If the flex plate is spinning on you you can use some vise grips to clamp onto the ring gear to keep it from spinning. But if it is spinning the flex plate might come off with the torque converter so you might not need to worry about separating them assuming the spacer isn't holding everything together. If the flex plate comes off with the torque converter you can take the nuts off with an impact or something while it's more convenient.

I think I'll add a picture, to be more clear. I already have the torque converter and flexplate separated. I can't clamp the flexplate to anything because it's no longer one piece. It's like a donut (the part with the gears and holes for TC bolts) with a donut hole (being the middle with the crankshaft bolts). It cracked all the way around.

 

[adsm08]

Normally you would be able to stick a screw driver through any of the flex plate holes from the back side and have the blade end up wedged against the block. That's not an option for you at the moment since the flex plate is broken.

You can hold the crank still from the front of the engine to remove the bolts. Try doing that when installing them and you will loosen the crank damper bolt.

Ideally you would have access to an impact wrench, which applies the torque in a manner that will turn the bolt, but not the crank shaft.

Do not worry about your inability to mark things. You are correct that it doesn't apply in your situation because you are replacing parts. If the orientation of the flex plate to the crank is critical for engine balance the pattern of the bolt holes will be asymmetrical so that you can only install it one way.

 

[pjtoledo]

you have 3 options

use an impact wrench, either air or battery.

use the "poor mans impact" that's where you put a WRENCH on a bolt and whap it with a hammer.
BE CAREFUL!!! HOLD THE WRENCH FIRMLY at the bolt,,,IT WILL TRY TO HIT YOU

there is a trick to holding the bolts, couple options here

put a socket in the center hole (yes, I know there is nothing there) with a long bar or ratchet pointing to the left.
hold that wrench there.
put a socket on another bolt, preferable a top one, rotate it until that socket contacts the first bar/ratchet

hold firm on the first bar, don't let it move, that keeps the crank from rotating

pull on the second to loosen the bolt


there is another way, only works on bolts at 9 o'clock position.
place socket on bolt, place jack, jack stand, board, pipe, or whatever between ground and the SOCKET so socket cannot move downwards. remove bolt.

go to next bolt, pull on it to rotate the crankshaft until you're at 9 o'clock again.

 

[SkagitBoy]

Normally you would be able to stick a screw driver through any of the flex plate holes from the back side and have the blade end up wedged against the block. That's not an option for you at the moment since the flex plate is broken.

You can hold the crank still from the front of the engine to remove the bolts. Try doing that when installing them and you will loosen the crank damper bolt.

Ideally you would have access to an impact wrench, which applies the torque in a manner that will turn the bolt, but not the crank shaft.

Do not worry about your inability to mark things. You are correct that it doesn't apply in your situation because you are replacing parts. If the orientation of the flex plate to the crank is critical for engine balance the pattern of the bolt holes will be asymmetrical so that you can only install it one way.

Just one thing...
Now, to hold the crank still... I do what exactly?

 

[SkagitBoy]

put a socket in the center hole (yes, I know there is nothing there) with a long bar or ratchet pointing to the left.
hold that wrench there.
put a socket on another bolt, preferable a top one, rotate it until that socket contacts the first bar/ratchet

I'm gonna go try that right now.
Thanks man!

 

[pjtoledo]

did it work?

 

[adsm08]

Just one thing...
Now, to hold the crank still... I do what exactly?

You stick a socket on a breaker bar on the damper bolt and hold the crank still.

 

[SkagitBoy]

did it work?

I ended up buying an impact wrench from Harbor Freight. It was worth every dollar! The bolts came out no problem. Thanks for your advice. I wish I could say that I'm done, but I'm fighting with the exhaust. It was a pain to get out and it's a pain to get back in.

 

[SkagitBoy]

Here's the bad flex plate.