Cracked Flywheel

I have to ask …is the flywheel on in the proper direction ? Have you compared the new flywheel to the old one ? Here is a good write up on the differences. novak-adapt​.​com/knowledge/gm-c…

Read the first 2 paragraphs while on break. Will definitely broaden my knowledge further later this evening. Thanks for posting the write up. Any and everything helps one go further in this field!

Sounds like you might have the dished flywheel which takes the place of the spacer ?

parts were ordered from World Pac. Part numbers have been verified with GM dealer . Flywheel is marked “engine side” Supposedly, this is a one year engine? that requires the spacer

If you remove the spacer, the flywheel, hit the nose of the starter

Does the flywheel look the same as the old one ? What brand is the new flywheel ? What part number ? Was anything else changed while the trans was out ? I wonder if your customer is not telling you the entire story and somebody else has been in there maybe even causing the original flywheel to crack ? There is obviously a mismatch of parts, you jut need to figure out where. Pictures would really…

My lookup shows … Is this what yours looks like ? gmpartsdirect​.​com/oem-parts/gm-d…

Attached images. Flywheel

That new flywheel picture shows that the flywheel IS backwards!

On you third picture, is that the way it goes on the engine or is that just to show the wrong way ? How far does your crankshaft stick out of the back of the engine ? It sounds like there is a short and a tall converter, whats chance that the wrong converter was in there originally ? How does everything sit with all of the original parts ? Original converter and flexplate. I think you…

that is installed the wrong way, just to see mounting. installed backwards, the flywheel will NOT sit flush, on the converter He's owned the truck 8 years. unknown history before. original flywheel installed correctly{engine side to engine } cant really tell original mounting, as with the cracks, but the offset old to new seems identical flywheel and converter have bar codes on them. making…

Did the original one have the spacer ? Reading the article I linked to it sounds like you have the wrong flywheel or are using the spacer where it is not needed. Does the new flywheel match the old one ? Picture maybe ?? The pictures make it look pretty obvious which cranks need the spacer and which do not. You should be able to tell by looking at it.

Yes there was a spacer. We ordered one because world pac says this flywheel required that and new bolts

Photos that was the part number we received

Spacer was there. Checked with caliper for thickness against the new spacer

In the first picture it almost looks like the converter hub is not long enough to go into the crankshaft hardly at all ? Just thinking out loud. Do you still have the original converter ? Was the only problem with this thing the broken flexplate ?

How thick is the “spacer”, or is it a clamp ring that goes on the outside of the flexpate?

Identical to the original. Checked with vernier caliper it is a spacer

Thinking a little out of the box. How much history do YOU have on this vehicle? Have you checked to see if this is the original engine, transmission and starter for this vehicle? Maybe somebody swapped one of these items from an incorrect application vehicle, knowingly or unknowingly? I've had issues like this with people trying to save a buck to either make it work as cheaply as possible…

Supposed to have bought it from the original owner, 8 years back I have 2 aftermarket flex plates coming tomorrow posed this 2 our local trans shop, and he suggested we try another flex plate

The blue converter, is the one we got to try, that made no difference thinking of a “ballooning” converter

You bring up a good point on “swapping parts to save a buck”. I see rebuilders alot take a fairly new engine transmission from a totaled rollover then put it in another similar vehicle, reprogram, relearn and send it. These engines, transmissions they're swapping still have the factory barcodes, etc. It's almost as if you start not believing anything is original as a few have made you…

Check the VIN# with dealer to see what engine/trans should be in the vehicle. I'm not sure the 6.0L used a 4L80E, most of the ones I've seen are 4L60E or 4L80E.

@Steve could you give a little more clarification as you said not sure a 4L80E & said you'd seen 4L60E or 4L80E. Not sure if there was a typo or auto correct that repeated itself on what you were typing?

Sorry meant 6L80E

A couple things that come to mind: If you could edit your post and add the vin that would be helpful. I would want to see if you can find any numbers on the engine block as well as the transmission to verify they are correct. I suspect something has been changed, either the trans is not correct or the engine. You need to get on repairlink and look up your vehicle by vin and verify the…

1GCGG29U… vin # added

Is it only me ? I dont see the vin anywhere ?

Here are the OE part numbers … SPACER,FLYWHEEL … FLYWHEEL,ENGINE … STARTER

That's what I have received as well as #… bolts starter isn't the issue though

You put previously “If you remove the spacer ,the flywheel, hits the nose of the starter” I think that is what he is referring to

I know you said that you think the converter is into the trans all of the way but the rest of the parts all look to be correct. I had a TH400 in a race car years ago and the only way I could ever get the converter in all the way was to stand the trans on its tail and then spin the converter until it fell in all of the way. Its certainly worth a try isnt it ? Either that or put the trans and…

I have replace lot of those flywheel always with gm ones. Tray to install converter without trans. The converter goes deep in trans , basically mating trans and engine without forcing converter into crank shaft. Hth good luck

I forgot to add you can easily check it fit by measuring the depth of converter against bell housing​.​Then you can measure the hights od the flex plate.

Any updates ??