I learned something new today.........

[Tarrbabe]

Maybe I'm stupid or slow but today after years of fooling with Mopars I learned something new. About a month ago I bought an 80 Step-side with 318/727. I have a rattle comming from the flex plate area and not having the time to change it myself, I took it to a local garage that does a lot of trans work. I explained I wanted him to change it out and since I had one that I knew was good I left it with him to swap out. He called and said I had brought him a flex plate from a 904. I got another flexplate, from another 727 and went down there. Both my flex plates were the same but the one on the Step-side was much bigger.
This I have never seen and had been told that all 727 flexplates were the same. NOT SO! This also means that the torque converter is the wrong patteren so I took him a 10 inch converter I had to use. He plans on putting it back together with the smaller converter and flex-plate.
Bye the way, the flex plate on the truck was not broke or cracked so I told him to go ahead and replace the front pump and inspect the rest of the trans for problems. I don't have a clue what is causing the noise.

Anyone have any ideas? Anyone know the flex-plates were different?

[dusterdon15]

Sometimes that rattle is just loose torque convertor to flexplate bolts.

don

[Tarrbabe]

I had already checked the bolts from the flex-plate to the torque converter and they were tight. The guy at the shop said the bolts to the crank were tight and to make sure I looked it over and it showed no signs of being loose/shiney or movement around the bolt surfaces.

[DAHEMIKOTA]

It could have been.....nah,you checked that already.

[Tarrbabe]

You must already have known I wondered what you thought.

[John Kunkel]

Mopar discontinued the 12" converter in '77 so all '78 and later 727's should have an 11" converter that uses a flexplate with a 10" bolt circle.

An '80 with the larger converter that uses an 11" bolt circle was retrofitted with a pre-'78 converter at some time in its past.

FWIW, there is no "727 flexplate" or "904 flexplate", in some installations the 727 and 904 use the same flexplate; they will swap among V8 motors.

[Tarrbabe]

The truck was a /6 w/3 speed on tree from the factory and changed later to the 318/727. The parts were taken from a 76 modle truck I beleive because that is the date on the trans. It is the correct short tailshaft and the steering colume was changed also but the hole with rubber boot for the clutch is still in the firewall.
Went down today to check on progress. Flex plate was not broke or cracked but torque converter had a small dent in it shaped like someone hit it with an axe. Can't find any other problems so I'm having him change it to the car type flex plate and the stock converter off my 340. It stalled at 2300 and was working well when removed. Time will tell.

[Tarrbabe]

The RATTLE was caused by the dent in the converter. I had it replaced with the 340 converter and no noise. The real switch was in stall speed. I'm so use to the Cordoba and the way the truck was, that I find myself wondering if the trans is slipping. God, I love stall. Haven't checked the rear out yet but I'm thinking 3:55's or 3:91's. This thing turns a lot of r's around town.
Wonder what it would feel like with the 340?
This stock Holley 2 bbl isn't cutting it.