[steve25]

How deep is that groove in that plate?
It’s hard to tell exactly from your photo, but that metal went somewhere !

[chiphead]

Groove is 1 to 3 thou deep. I assume it's been self-clearancing. I dropped the oil and there is fine metal in the oil. Filter pleats show the same but no hunks.

I took a good look at the flexplate and its suspect. Reinforcing ring is missing. There are strange gouges near the bolts, but I can't tell if they are cracks or where some moron went after the flexplate bolts with a chisel.

Will a cracked flexplate make noise if I disconnect the converter? If I can prove its the flexplate, that's a good excuse to swap in the 10" Continental sitting on the shelf!

My plan is to fix the front of the engine, then dig into the back of the engine. Anybody got a lower radiator hose PN for a '67 GTO?

[72LuxuryLeMansLa.]

I would just pull the engine and tear it down. Find all of the issues out in the open instead of crawling around and under the car for days.

[chiphead]

Yeah, I know. I'm just trying to stretch this engine's lifespan. I know it's long in the tooth and deserves to be put out to pasture as a future builder. I'd like to do that before it comes completely unglued, LOL.

I've got a 4" stroker combo on the stand that needs a few things to finish. The plan is to sort the car and then swap the engine. I'm pretty close to sorting the car out, I need this 400 to last just a bit longer. One of those things is swapping the converter and proving the Conti and this TH400 are happy, prior to swapping the engine in front of that combination. I'd really like to get this 4" combo on an engine dyno prior to install to be sure it's happy.

[mgarblik]

Originally Posted by chiphead

Groove is 1 to 3 thou deep. I assume it's been self-clearancing. I dropped the oil and there is fine metal in the oil. Filter pleats show the same but no hunks.

I took a good look at the flexplate and its suspect. Reinforcing ring is missing. There are strange gouges near the bolts, but I can't tell if they are cracks or where some moron went after the flexplate bolts with a chisel.

Will a cracked flexplate make noise if I disconnect the converter? If I can prove its the flexplate, that's a good excuse to swap in the 10" Continental sitting on the shelf!

My plan is to fix the front of the engine, then dig into the back of the engine. Anybody got a lower radiator hose PN for a '67 GTO?

With the torque converter disconnected and pushed back, the noise should go away. If the flex plate is badly cracked or very loose, it may rattle. At any rate the noise will be different than if the converter were attached.

[johnta1]

When you put the cam gear back on make sure the cam sticks out a little bit for the eccentric to fit over. (the gear should bottom against the cam journal face)

I have seen the eccentric not seated fully (because gear wasn't bottomed out).
The cam bolt must be tight, should not bottom in cam.

That situation it did make some strange noise but can't remember what noise it was like if compared to this?

Then run it and see if noise is gone before doing the flexplate idea.

[chiphead]

Got it all back together. Cam endplay ended up about .011" with the .117" thick butler retainer plate. Fired right up. Ignition timing is the same, so I got the timing chain reinstalled properly.

Still making about the same noise. Oh well, at least I fixed the cam thing.

Next step is disconnecting the torque converter and see if the noise changes.
If that doesn't solve it, I'll try to capture the noise on video and see if you guys recognize it.

[mgarblik]

Originally Posted by chiphead

Got it all back together. Cam endplay ended up about .011" with the .117" thick butler retainer plate. Fired right up. Ignition timing is the same, so I got the timing chain reinstalled properly.

Still making about the same noise. Oh well, at least I fixed the cam thing.

Next step is disconnecting the torque converter and see if the noise changes.
If that doesn't solve it, I'll try to capture the noise on video and see if you guys recognize it.

That sounds like a good plan. Sure hope you find it.

[steve25]

Also just for S & G try disconnecting 1 plug at a time to see if what you hear changes .

[Formulas]

The cam retainer plate is sandwiched between the timing gear and cam face it is possible the step on the cam gear is to short and pinched the plate inducing extra wear...... you can measure the step and it should be taller than a good plate by whatever the stated cam end play is

[72LuxuryLeMansLa.]

Originally Posted by chiphead

Yeah, I know. I'm just trying to stretch this engine's lifespan. I know it's long in the tooth and deserves to be put out to pasture as a future builder. I'd like to do that before it comes completely unglued, LOL.

I've got a 4" stroker combo on the stand that needs a few things to finish. The plan is to sort the car and then swap the engine. I'm pretty close to sorting the car out, I need this 400 to last just a bit longer. One of those things is swapping the converter and proving the Conti and this TH400 are happy, prior to swapping the engine in front of that combination. I'd really like to get this 4" combo on an engine dyno prior to install to be sure it's happy.

I hear you! I found that 53yrs and approx. 280,000 miles was the absolute limit for my cars original 350. It survived over 65000 miles with a dead cylinder.

[chiphead]

Played hookey this morning to crank the engine and listen. With the converter disconnected, I'm not hearing the rattle crunchy noises from the engine. All I hear is valve ticking and fan noise. Sounds more normal, at least to me. A new metallic rattle noise is randomly coming from behind the engine.

I got under the car and I can't see a crack in the flexplate. It does look suspicious, like somebody chiseled or beat on it at some point.

What does this tell us? What else should I do before I pull the trans?

[steve25]

You should not have to pull the trans to remove the flywheel, if anything just back the trans off some.

Once removed fire the motor again and see if you hear anything.

If so are you running exh manifolds and maybe your hearing the heat riser flap kicking back & forth?

[chiphead]

Hooker SC headers and 2.5 exhaust, no heat riser. Last night I crawled around under the car and looked for anything that could be rattling against the exhaust or drivetrain. All I found was one front steel brake line that I moved away from a header tube. I also made sure the converter was pulled back from the flexplate.

This morning the engine sounds great (once I got it warmed up). If I have to swap the flexplate, I'd like to swap converters. I did find an ID on the existing converter, it's got a "Transmission Specialties" sticker on the front. Looks like an expensive converter. Still rather run the Continental.

https://www.tsirace.com/?srsltid=Afm...tnh_GWnRIptL06

[chiphead]

Starting pulling it apart tonight to drop the TH400, and need some advise so it goes smooth. The plan is to put the car up on 18" tall 2x4 wooden cribs and use a trans jack to lower it enough to change the flexplate and swap the converter.

How far back does the trans need to go before it will drop straight down? How far back can I tilt the engine before breaking something?

If I cut the dust cover ears off the case, will the trans drop down between the headers? The driver's ear is already cut, but the passenger ear could take a trim.

How long are the TH400 bellhousing to engine bolts supposed to be?

[mgarblik]

The bellhousing bolts to the engine block bolts engage the block 1/2-3/4" deep. If you remove the cooling fan blade and the distributor cap, the engine can tilt way back. Make sure the distributor body doesn't hit the firewall. It could break it. Not sure what it will take to clear the headers. May need to take the cooler lines loose from the radiator or trans.

[tstroud]

Keep the torque converter with the transmission. You might want to fabricate a strap to go across the converter to keep it from falling out. Moving the tail of the transmission to one side or the other may help in getting it to clear the headers.

[grivera]

If you have a transmission jack, you can tilt the table laterally to give you the clearance needed between the headers.

[chiphead]

So I got the flexplate out this weekend. Its what I expected. Neanderthals.

Look at this thing. LOOK AT IT.

What in the Sunday evening desperation michigan methamphetamine hell is this?

Look at the chisel marks. Look at the deep grinding gouges under the bolt heads. Look how they enlarged the center hole. Its not even concentric with the crank register.

It looks like somebody took a late '70s small register flexplate and molested it until it fit the larger crank register. I took the bolts out with an electric impact. They weren't that tight. I added a picture of the stock replacement for comparison.

WTF, over?

[steve25]

Never underestimate someone’s stupidity or determination to get mismatched parts to fit!

Way back when I worked at an auto parts store I sold a guy a set of file fit rings for his rebuild and wrote such on the box so that a blind man could see it.

A week later he calls up and says that the motor will not turn over, yet the crank had spun fine before the pistons got put in.

He brings the motor by to our shop and we had to beat it apart because he never fit the rings!

Once we got it apart and the rings off the pistons we could not even get a ring back into a bore!!

It was a jaw dropping mystery how he ever got the darn short block together.

You would think that after he got 4 pistons in he would think something must not be right because it took 65 ft lbs to get the thing to spin.