Flexplate hitting starter
 

I'll be as thorough as possible.
A year ago I had the starter replaced. The it developed a knocking sound, turns out the Flexplate was hitting the starter because the whole Flexplate/torque converter was wobbling.
Ended up not driving it much for the past year, then had the Flexplate and torque converter replaced. Found the snout on the torque converter was broken. Probably causinfpg the wobble.
Once everything was back together and started, it still knocked even though nothing wobbled. Even after hours of shimming the weight hits the starter every RPM.

I have worked as a service advisor for 14 years and any pretty competent when working on cars. I'm having the techs at work do it for me though, I know when to let the pros do something I'm not comfortable with.

Any ideas?
Please ask more questions if needed,

Re: Flexplate hitting starter
 

There's to different starters depending on how many teeth the flex plate has. Make sure they put the right flexplate pre 86 shouldn't have weights.

Re: Flexplate hitting starter
 

Mine is an 87 R20 454 TH400.
The Flexplate that was removed had a weight also and had the same number of teeth.

Re: Flexplate hitting starter
 

Do you think the flex plate could be back wards? I've done it.

Re: Flexplate hitting starter
 

Thought about that. The weight is facing the engine.
Which I understand, is the correct way.

Re: Flexplate hitting starter
 

Are there shims between the torque converter and the flex plate? Sometimes a couple shims or washers are needed so the converter engages properly with the oil pump in the transmission. Too many could be putting pressure on the pump and the flex plate, causing it to flex.

Re: Flexplate hitting starter
 

Is the starter staying engaged? Is the truck properly timed?

Re: Flexplate hitting starter
 

Are they sure the torque converter is lined up and fully installed into the tranny? I have seen them not seated on to the pump ears completely and still get the trans bolted to the block. That will cause the converter to push the flywheel toward the starter. Try removing the three converter bolts and see if the converter will spin freely.

Re: Flexplate hitting starter
 

Not sure how to refer to my idea but maybe crankshaft end play, the crank is/has walked in the bores causing the problem. I only say this because when I bought my 88 burb the flex plate was cracked around the crank and rubbed the dust cover. Of course I didn't know until I pulled the trans and t-case out where I could see it. But anyway I noticed that the crank shaft could move front to back pretty far as I was trying to pry the broken out center off the crank. I was worried that maybe the motor was junk but I fixed it and ran it another 4 years with not major problems. It was the original 350 as far as I know with 150k maybe at the time. So not sure how to check that out other than trying to push/pull on the balancer or flex plate.

Re: Flexplate hitting starter
 

The weight is facing the motor and still hitting the starter.

buddy1: the truck was driving fine for a week until the starter fell apart. Would the truck be drivable if it wasn't lined up and installed correctly? we took the busted starter that was ground down a bit from hitting the flexplate and had it rebuilt. When they rebuilt it, they replaced the nose cone with a new one and the problem is back because it's not worn down like the one before if that helps.

mattybilt79:
We put a prybar between the motor and flexplate and did not see any movement.

Thanks for the help guys!

Re: Flexplate hitting starter
 

Think I may try a different starter today:
http://www.autozone.com/starting-and...35927_23521_0/

The nose on this one seems to not have the large metal piece where the pinion gear comes out.

Re: Flexplate hitting starter
 

Swapped for an AC Delco starter problem solved. Turns out there are different nosecones.

Re: Flexplate hitting starter
 

thank you for posting the solution, glad you figured it out, often times we make suggestions and recommendations and never hear back from the original poster so we have no idea what fixed it

Re: Flexplate hitting starter
 

Your welcome. I hope someone else can benefit from what I learned!
This board is the best!