Buyer Beware...F P/Torque Conv Bolts

A couple of months ago I got the engine and trans together and put in the rat rod, along with the drive shaft. In the process I pulled the muscles in my back. At age 65 it takes that long for back injuries to heal...After a week of going slowly with the exhaust, gas line, and wiring, I fired it up...Cunkity, Clunkity, Clunk. Crap!!! My first thought was bad bearing in the engine. After some screw driver to the ear tests, I found it came from the bell housing area. Brand new flexplate and torque conv. Thinking I didn't get the bolts tight I pulled the trans away from the engine and checked. Bolts to the flexplate were tight on the crankshaft. Slid it back and made sure the bolts to the torque conv were tight. Fired it up...Clunkity, Clunkity, Clunk. Crap!!! I crawled back under with a screw driver to see if the torque conv had too much shaft play, I noticed it.
There was a paper thin gap between the flexplate and the torque conv. I used after market torque conv bolts and they were a smidgen too long and were bottoming out. Knowing the close tolerances between the flexplate and the back of the engine block I decided to slip a washer between the flexplate and the torque conv. No more clunking.

Buyer Beware....sometimes after market parts are not spec'd to OEM parts.

I've seen this on rear struts too, no recess after the end of the thread cut, and the nuts wont seat the top plate properly.... Grrrr... How frustrating to do a job twice...

My whole life I never knew you sometimes have to shim the convertor to the flex plate until we did the one on my Son's rpu. For years I simply pulled the convertor up to the flex plate and torqued the bolts down, but when we did that on his Olds engine it pulled the convertor out of the front pump so it wouldn't engage it.

I called Mondello and they told me to put enough grade 8 washers stacked between the convertor and flexplate so that we would only have to pull it forward just a tad after being seated. I asked if that was ok to do and they said "We do that on our 1200 hp drag car, so yes, it is ok !"

We did that and it has been working fine. You are right, Lakota, you really have to be careful. We were using a B & M convertor and B & M flex plate, and there still was a gap.

Don

Be careful you don't shim them too much. There's supposed to be some play. Like you Don I've always just pulled the converter up to the flex plate and bolted them up. Last year I pulled the target master 350 out of my plow truck for a rear main, reseal and timing chain when I noticed the guy before me had shimmed the gap between the converter and flex plate. Then I noticed there was about .100" end play on the crank. Both the crank and the thrust on the rear main bearing were worn bad. I had to send the crank out for a weld and regrind....200 bucks because it was shimmed to tight. My trans guy says 1/4 to 5/16 is about right.