Flywheel fitment issue on a new Optimizer engine.

[Twisted Steel Performance]

If this is a new factory motor there won't be a pilot bushing in the crank..

 

[Goose57]

Looks like @Will L. post is accidentally confusing. There should be no "bearing" in the end of the crankshaft. The pilot bearing is for manual transmissions only, however, if it's put in by mistake or left in after a rebuild it's a problem with the automatic trans Torque Converter, TC. The converter does use the same area of the crankshaft and it's a tight fit.

I would call Yank Converters, as they know WTF they are talking about for converters, and just ask this question about spacing to them. Shameless plug: They make a nice TC even I can't tear up being a carnage thread winner some years...

What is the history on the transmission and TC? I assume the TC fit fine before the engine swap/replacement. Can you compare the new engine crank depth and diameter for the area in question from the old engine?

It's a tight fit for the converter to slide into the crankshaft. It's possible just the blue paint alone may be the problem. Note where the area isn't painted on the Yank red converter:
Yes I was wondering about a pilot bearing on an automatic trans. I talked to the trans. shop about a pilot bearing application on an automatic trans. and he told me that some times when they do a LS engine swap they do use a pilot bearing. He told me to take the washers and bolts out and slide the converter against the flex plate and see if there is a lot of play where the nose cone on the converter goes into the back of the crank. I did and it fit nicely with very little movement. I did tell him about the large gap between the converter and flex plate and also seeing the front pump seal and some of the converter shaft. He said to put just one washer between the converter and flex plate. I did mention in post #1 of my string of post that I also installed a rebuilt trans. And converter. I couldn’t compare the new crank depth w/ the old engine because it long gone. I’ve been at this build for awhile. Thanks for all the help. I’m sure I’ll be on here a lot with more questions.
View attachment 89107

 

[Goose57]

Looks like @Will L. post is accidentally confusing. There should be no "bearing" in the end of the crankshaft. The pilot bearing is for manual transmissions only, however, if it's put in by mistake or left in after a rebuild it's a problem with the automatic trans Torque Converter, TC. The converter does use the same area of the crankshaft and it's a tight fit.

I would call Yank Converters, as they know WTF they are talking about for converters, and just ask this question about spacing to them. Shameless plug: They make a nice TC even I can't tear up being a carnage thread winner some years...

What is the history on the transmission and TC? I assume the TC fit fine before the engine swap/replacement. Can you compare the new engine crank depth and diameter for the area in question from the old engine?

It's a tight fit for the converter to slide into the crankshaft. It's possible just the blue paint alone may be the problem. Note where the area isn't painted on the Yank red converter:

View attachment 89107

Yes I was wondering about a pilot bearing on an automatic trans. I talked to the trans. shop about a pilot bearing application on an automatic trans. and he told me that some times when they do a LS engine swap they do use a pilot bearing. He told me to take the washers and bolts out and slide the converter against the flex plate and see if there is a lot of play where the nose cone on the converter goes into the back of the crank. I did and it fit nicely with very little movement. I did tell him about the large gap between the converter and flex plate and also seeing the front pump seal and some of the converter shaft. He said to put just one washer between the converter and flex plate. I did mention in post #1 of my string of post that I also installed a rebuilt trans. And converter. I couldn’t compare the new crank depth w/ the old engine because it long gone. I’ve been at this build for awhile. Thanks for all the help. I’m sure I’ll be on here a lot with more questions

 

[Goose57]

Sorry about screwing up my rely post. I am on Medicare LOL

 

[Goose57]

If this is a new factory motor there won't be a pilot bushing in the crank..

Thanks TSP. I didn’t think I saw one.

 

[Will L.]

My apologies for the confusion in how I wrote it.

You do NOT want a pilot bearing in there. A pilot bearing was my guess as to what is wrong.

The torque converter should slide all the way forward touch the flex plate. The torque converter bolts should be a flanged bolt with thread locker applied and NO WASHER anywhere.

If the torque converter can not slide all the way to contacting the flex plate - SOMETHING IS WRONG.

 

[dbrannon79]

Also to add, the amount of TC shaft you see on the trans side should be normal. pull the washers and slide the TC up to the flex plate and post some pics of that and the area where the trans seal is that you were talking about. we all can tell you if it will be any issue or not.

questions: the trans and TC was rebuilt you say. is this a factory 4L80E and OEM TC that was rebuilt? some TC's are shaped differently if they are aftermarket. just thought I would pop that question so we are all on the same page.

 

[Goose57]

My apologies for the confusion in how I wrote it.

You do NOT want a pilot bearing in there. A pilot bearing was my guess as to what is wrong.

The torque converter should slide all the way forward touch the flex plate. The torque converter bolts should be a flanged bolt with thread locker applied and NO WASHER anywhere.

If the torque converter can not slide all the way to contacting the flex plate - SOMETHING IS WRONG.

no worries Will L. The converter does slide all the way up.

 

[Goose57]

Also to add, the amount of TC shaft you see on the trans side should be normal. pull the washers and slide the TC up to the flex plate and post some pics of that and the area where the trans seal is that you were talking about. we all can tell you if it will be any issue or not.

questions: the trans and TC was rebuilt you say. is this a factory 4L80E and OEM TC that was rebuilt? some TC's are shaped differently if they are aftermarket. just thought I would pop that question so we are all on the same page.

Yes it is a factory 4L8OE and a OEM TC. My trans. guy said it’s not uncommon to see that big of gap between TC and the flex plate when you do an engine swap. He told me to go ahead and just use one washer (maybe 60 thousands). I’ve had the TC bolts in and out a couple of times w/ loctite I’m afraid of messing the treads up. I think I’m going to leave it w/ one washer it looks pretty good.
Thanks guys for all your help. I love this site I learn a lot about these motors.

 

[Will L.]

Nopers. Setting aside my ase masters cert, not gonna set aside my training from GM and disagree as hard as possible with your guy’s misinformation.

Never add a washer. This is specifically taught in the classes.

I have ran 8 cylinder engines after removing a rod, piston, lifters, pushods, rocker arms.- when damage has occurred and no money exists but the rig has to roll.
There is a difference what you can do and what you should do.

If you’re stuck without options- fine. But tell people the difference between being duct taped and properly done.

 

[dbrannon79]

Will is right here. adding that washer reduces the amount of torque the TC bolts can handle before they snap and leave you in a pickle. also using washers that aren't exactly the same in weight and thickness can also throw off the balance of the engine and or breaking the flexplate from it constantly wobbling from this. Lord knows what happens when balance is off more than it is from factory. the guys will preach to have the rotating assembly balanced for a good reason.

having those washers in there might not cause you grief right away but can bite you in the arse down the road, even in an emergency situation where you have to feed it the onions to get out of the way.... snap followed by loud noises as bolt heads chew up everything below, combined with you and whoever is with you in the cab get run over by that semi speeding and plowing through!!

 

[WarWagon]

All I can think of is the crankshaft doesn't have the proper depth for the converter. I assume it wasn't like this before. You are only replacing the engine OR are you doing both the engine and transmission? I was assuming engine only being changed.

I see the bevel for the starter gear toward the engine so that is correct. You sure this is the proper flexplate not one off a 350 gasoline that will also clash the starter from wrong tooth count? You don't have a cracked and now broken flexplate as that would be really interesting odds.

Does the converter have a hard stop moving toward the engine?

By chance if you are doing both engine and trans than it's really bad odds on the converter. Wrong converter, bad rebuild on converter, etc.

Quit using locktight until you got this going together properly without the duct tape and bailing wire. "Test Fit" IMO if I was burning this kind of cash for a new engine I wouldn't accept the use washers answer. I already explained the risk when that converter balloons in normal operation. Warranty on engine from thrust bearing failure from improper install could be a problem.

It's time to split the transmission back off the engine and mount the converter only up on the engine to see where it's binding up. Can you obtain another 4L80E converter to compare measurements on?