Need Powerglide Experts

[68rs327conv]

I have a 68 Camaro Convertible 327/210hp base engine that is currently undergoing a rotisserie restoration.  While in the body shop I had the engine sent out to be rebuilt and I took the original powerglide to a local transmission shop.  While the trans was being rebuilt we decided to go ahead an replace the torque convertor.  I picked up trans and new torque converter (PG4) and they sat in my garage for the last 6 months.  Well the time finally arrived to install the engine & trans back in the car before the front end is bolted  on.  Low and behold, the torque convertor will not mate up to the flex plate properly.  It appears the button on the end that mates to the crank shaft is too short and dosnt let the converter fit flat against the flex plate.  Flex plate was not changed and the previous convertor was sent back as a core so I cannot visually compare.  Trans shop said all the PG converters, especially the flex plate side were the same.  They even ordered another converter and the trans shop owner came to install and had the same problem and now says the flex plate must be wrong.  I am not buying that one as it worked before for 20 years.  According to the parts book the 68 PG part number 3852880 and the 350 version was different.  What am I missing here, any advice would be greatly appreciated.

Mike

[Everett#2390]

All flexplates are the same except the 400CID, whether 153 tooth or 168 tooth.
Could flexplate be installed backwards?
As long as the button fits into the crankshaft and flexplate is within 1/16 inch , should be good to go unless t/conv has to be slide out from the trans which might disengage the body from the oil pump.

[68rs327conv]

Not on backwards.  Transmission shop owner is stumped.  Doesn't think flex plate is correct, and he is suggesting I try a new flex plate.  New converter will not set flush against the flex plate.  I think button on the converter is too short but I do not have the original to compare too.  Does this look like an original flex plate?

[BlackoutSteve]

My flexplate (ext balanced 454) has raised bosses where the converter bolts up. I guess they are offset rearward about 1/4-3/8"..
 Yours doesn't appear to have them. ..or is the entire outer rim offset?

[rich69rs]

Not sure if these pics will help - but.....

two pics showing my Powerglide bolted up to my '69 327/210 engine before going back into the car.

Richard

[Everett#2390]

Mike, yours is not an OE flexplate, should look more like Steve's flexplate.
At this point, I would try another t/conv and/or flexplate just for giggles.

[68rs327conv]

Yup, next step is to try a different 153 tooth flex plate.  Thanks

[67 RS Ragtop]

The flex plate shown on the engine is exactly like the one on my 10B '67. I would suggest you be sure the bore in the crankshaft is "round", and the correct size as compared to the nose of the torque converter, as it sounds as though the TC is not going into the end of the crankshaft, and since you have swapped convertors, the problem may be at the CS, as you mentioned you had the engine rebuilt - JMO          If you need, I can take pics and measurements, but again this is a '67 327 with a powerglide, but they should be the same at the area in question.

[68rs327conv]

Pictures would be greatly appreciated, especially if you also have a picture of the button on the flex plate side of torque converter.  If this is an OEM flex plate than I prefer to keep it.   Problem was the TC would go into the end of the crank but seemed to bottom out at the base of the TC band would not sit square against the flex plate.  We couldn't bolt up the trans completely due to the TC.  I know where I can get an NOS GM converter but expensive plus I will be out of the converter I already purchased with the rebuild.

Mike

[BlackoutSteve]

Not sit square? Do you mean the converter is actually skewed against the flexplate?

When my converter's center pilot lines up with the crank and is all the way in, there is still a small gap between the mounting lugs and the flexplate, but all three of the mounting lugs are an equal distance from the flexplate before bolting it up.. I do use 1/8" hardened washers to make up the difference, but this is normal in many cases from enquiries I have made.
You would have issues if the converter is not square and the lugs were varying distances from the flexplate before bolting..
I'm a little confused with your description.

[68rs327conv]

When I took the transmission back to the shop that rebuilt it, I noticed when they tried to remove the converter, the transmission shaft pull out.  It looks like the shaft must have moved somehow when we attempted to mate the transmission to the engine.  They put the transmission back together and we will make another attempt to mate the trans with the engine.  I did find another picture of the same engine and it had the exact flex plate, so I know mine is original.

This has been very frustrating as I did this same replacement 25 years agon in my garage with no problems.


See the link in my profile for pictures of the restoration and a link to my picasa web pictures


Mike

[67 RS Ragtop]

My memory may not be 100%, but I remember when I was rebuilding automatics that some of the input shafts had different length splines on the shafts, and if they were installed 180 degrees out (backwards), you could also experience this type of issue - just don't remember if this applies to the Powerglides. Just something to check, if this shaft can be removed while the trans is still assembled. If you want, I can measure the depth the TC mounting ears are below the case mounting flange, when it is fully seated in the rearward position, as my trans is currently "out".