Technical Chevy 350 flexplate install

Been chasing a slight vibration even in park with idle speed up. Previous owner installed new flex plate. I took inspection plate off and by what I have researched its a 350 plate but I think it my be on back words. Have a couple pictures from each side . First is from tranny, next engine. What I found was the bump on the plate should face the converter. Any one with first hand information on this?

 

yes, that is backwards.

Removing it might be "fun", at least the one I had to fix many years ago was. There's a little lip on the "rear" side of the plate that gets bent into a groove on the crankshaft, when you install it backwards.

 

What he said ^^^^^^^^^^^

 

Thanks for confirming, I think I may have to pull the motor. The original transmission cross member is still in, so there's no room to slide the tranny back, unless I cut the cross member out and put a Walton cross member or other one in.

 

Had the same problem , HAMBers straightened me out.

https://www.jalopyjournal.com/forum/threads/th350-need-more-help.1128020/

Don't just flip the old plate, get a new one. And new bolts
good luck

 

Not absolutely necessary to remove either engine or transmission. First remove convertor bolts an slide convertor back, next remove trans. bolts to engine, pry trans. back off of dowel pins, engine and trans. will drop down kinda wedged against each other at top (picture opening a double barrel shotgun while holding upside down, will be open at bottom and tight at top) this will leave you just enough room to get your hands/fingers held flat to reach the flexplate bolts, using a long box end wrench on flywheel bolts one at a time held by finger, hit the end of wrench with hammer to break it loose, use one finger from each hand to unscrew each bolt rotating flywheel as necessary, before removing last bolt mark flywheel at the 6 o'clock position with chalk, this gives you the orientation of crank position, place new flexplate over the old one, match the bolt holes and mark new flexplate, slide it into place in correct position, finger tighten all bolts to be sure position is correct, tighten with wrench/ hammer. Not sure what motor/trans. mounts you have so look over carefully before trying this, be safe. You will probably need tall stand to support engine and a long prybar to re-position trans. back on the dowel pins. Bolt it all back up.
I've done this many times without even removing cooler lines, exhaust, driveshaft, etc. Takes about 60-90 minutes if you've done it before.
NOTE! replace rather than re-use flexplate, use loctite on flexplate bolts, be sure that dist. cap will not hit firewall and that fan will not puncture radiator.

 

Like I replied to squirrel there's about a inch of room to move back before the transmission pan will hit the transmission cross member, unless there would be more room if I would take the transmission pan off. That's why I was wondering about taking cross member out and replacing with Walton or similar cross member. Yep that flex plate will be trashed.

 

Thanks for the information. How far will the tranny need to move back doing it like you say. I have 1 to 1 1/2" to the cross member where the back of transmission mounts. Thinking it might not be enough was going to take cross member out and put in a new one after. Have read where some use couple bolts in bottom of bell housing to slide back and keep aliment.

 

Thanks for the post. Did you find the flex plate hard get off like squirrel said

 

I've not come across that before, but even if backwards, why would there be a vibration?

2nd question, not having a flexplate on hand, would the starter still engage correctly?

Just curious.

 

Take the trans out and do it right. Replace the flex plate as well. Once and done! Check everything out carefully .

 

I had an experience where the torque converter re-builder failed to balance the converter and there was a vibration that we chased for weeks.. In the end I pulled the converter back and started the motor. It reved like a sprint car, but the vibration was gone. You may want to check and see if there is a "new" converter installed.

 

Yes in the planning stage, Has original transmission cross member with rivets, cut with tranny mount welded in , so will have to remove it or pull engine& tranny together, to get out with the cross member in the way.

 

If it will move back an inch, that would be enough room to replace it.

 

Thanks going to give it a good look over today

 

No, came off easy.

 

2nd question, not having a flexplate on hand, would the starter still engage correctly?

Mine engaged enough to start the engine, but the teeth were only 3/4 of the way lined up.

 

OK maybe I will be lucky to come off. The starter is what I noticed first you could see it would only in gauge about a 1/2 on the teeth. It started ok except once and while when it was hot.

 

Pull the mount and it may give you more room to pull it back. I use guide bolts all the time to line up transmissions. You may need more than 1" to get the flywheel bolts out.

 

Drilled out the rivets, took out the cross member, transmission pulled back, flex plate out , have the new one ready to install. I know you have to Loctite everything, does it matter which way the 3 torque converter bolts/ nuts go in?

 

Dis regard, I found the information on a search, nuts go on the torque converter side. bolts go in from front

 

Usually nut to convertor side. Be sure the bolt is not to long and hit the back of the convertor.if too long it will distort the flexplate.

 

Thanks I have the flex plate and converter bolt kits. Converter bolts are 3/8x24x1/2 "