Flex plate help

[RangRayy]

Not sure if this is the right place for posting but.....
I have my trans out and motor still in the truck. Trying to replace the flex plate bc teeth are missing.
Problem is... As I go to loosen the FP bolts it turns and turns the crank. I tried a breaker bar no avail, even tried a breaker bar on the front of the crank and it actually started loosing the crank pulley bolt.

How do you do this succefully? Any tricks would be greatly appreciated. I am at a loss right now.
Thought about hitting it with an impact but wasn't sure if it would help.
Dw-40 is sitting on the bolts now to help with rust but it still turns the crank...
Thanks
Ryan.

 

[DoubleDingo]

They make a tool that holds the flywheel/flex plate. It can also be used to turn the engine by the flywheel/flex plate.

http://www.amazon.com/Lisle-23800-Flywheel-Turner/dp/B000FN7JE2

I need to get one for situations like you're having so the engine won't turn, and for when/if the need to grab the flywheel/flex plate is required for turning the engine.

 

[RangRayy]

Thanks I just found out about that tool on google.

I also dug deeper found out on the 87 efi motors these flexplate bolts went directly into the crankcase and they put sealer on them to prevent leaks. So they're on there pretty good. So sealer must go back on to prevent leaks. FYI to people.

Also if like me you're replacing the flex plate use vice grips on the plate and spin it around till it hits the housing of the motor where the starter bolts up.

Or...
Use a 1/2 in impact with a six point socket(my bolts are 5/8) and it should spin right off. I am going to go get my compressor from my dad's tomorrow and give it a try. Will post my results.

 

[DoubleDingo]

I wouldn't recommend the impact method. Yeah it can be easier, but if the head of a bolt breaks off, you're into a huge project to extract the remaining part of the bolt and or drill and tap the threads.

 

[RangRayy]

Well what would make the head break off? Rust? I hit them with we-40 and PB blaster as well so it'll be well soaked. Well this project was supposed to be a weekend project and it's been three weeks....lol

 

[DoubleDingo]

Well what would make the head break off? Rust? I hit them with we-40 and PB blaster as well so it'll be well soaked. Well this project was supposed to be a weekend project and it's been three weeks....lol

If the sealant on the threads don't release, and the impact causes the bolthead to twist off, that could do it. I am just more cautious in my older years and tend to not make more work for myself if I can avoid it. If it were me I would secure the flex plate the best I could even if it meant tying rope through the holes to keep it from turning. A breaker bar with a slow tug is better than aggressive impact from a pneumatic tool.

I too had a weekend project that I just got to drive after about 2 months of issues needing to be addressed so i feel your pain there.

 

[mtnmankev]

Quote: "I also dug deeper found out on the 87 efi motors these flexplate bolts went directly into the crankcase and they put sealer on them to prevent leaks. So they're on there pretty good. So sealer must go back on to prevent leaks. FYI to people."

Sorry, but that statement goes against logic.
The flexplate is turned by the crankshaft.
The crankshaft turns within the confines of the block.
If the bolts that connect the flexplate to the crankshaft go into the crankcase, how does the crankshaft rotate?

 

[highdesertrange]

they are talking about the one piece rear main seal. they put thread locker on the bolts which you should do on the 2 piece seal also. on some of the one piece the thread penetrate into the crankcase. don't worry it will not stop the crank from turning. as far as breaking the bolts loose use an impact or stick a breaker bar through one of the big holes in the flex plate and let it rest on the starter pad. highdesertranger

 

[MadOgre]

if you have the correct size socket and the impact gun is correctly set to reverse and you hold the gun nice and snug and square with the socket fully seated on the head and use your trigger finger cautiously there is no way in hell that you will break off the bolt.

Do Not! use a swivel adapter

Most times than not the reason people brake off bolts with an impact gun is because they have it set to tighten instead of loosen and they don't notice because the bolt is not moving until it snaps in 2. and then they say to themselves, gee I guess that bolt was stuck pretty good!

 

[MadOgre]

The one piece seal set up that the flexplate bolts to is the rear of the crank shaft. The bolts thread into the crankshaft and the end of the bolts protruding from the crankshaft would technically be inside the crank case.

 

[MadOgre]

Quote: "I also dug deeper found out on the 87 efi motors these flexplate bolts went directly into the crankcase and they put sealer on them to prevent leaks. So they're on there pretty good. So sealer must go back on to prevent leaks. FYI to people."

Sorry, but that statement goes against logic.
The flexplate is turned by the crankshaft.
The crankshaft turns within the confines of the block.
If the bolts that connect the flexplate to the crankshaft go into the crankcase, how does the crankshaft rotate?

So if one of the bolts was missing from the flexplate to crankshaft you would have a crank case leak. open hole to the crank case.

 

[bucket]

if you have the correct size socket and the impact gun is correctly set to reverse and you hold the gun nice and snug and square with the socket fully seated on the head and use your trigger finger cautiously there is no way in hell that you will break off the bolt.

Exactly. I will also add, don't use a cheap socket that will crack easily. If it cracks, it then spins on the bolt head and rounds off the corners.

 

[RangRayy]

Freaking me out here not wanting to use an impact. Set to reverse? On the gun or the way the threads are on the bolts? I assumed these were standard lefty loosey righty tighty bolts.

 

[MadOgre]

Freaking me out here not wanting to use an impact. Set to reverse? On the gun or the way the threads are on the bolts? I assumed these were standard lefty loosey righty tighty bolts.

YEP righty tighty lefty loosy. I just took mine off on the weekend took me 2 min with 650 ft lb impact. just make sure the impact is spinning lefty/reverse before attempting to remove the bolt.

 

[350runner]

They are standard thread. Just do as you normally would... get err done

Sent from the dust in front of you!