So back in 2020 i bought a crate th400 from monster transmission cause nobody was working in Las Vegas, paid a lot of money, not as much as a gearstar but a close 2nd. Anyway after months of covid tyranny related delays finally got the monster in a box, with thor converter, etc. All was good till about a month or so ago and it started late shifting when cold like a bad modulator or vaccum leak, beat that dead horse to death and came with bupkis. Next in line was/is the governor. I ordered a new made in usa sonnax, and waited 6 weeks for it from jegs. Did not want to crack open/off the governor cover, lose a quart or so of fluid IF i did not have a new, not rebuilt governor in hand IF i needed it. So pulled the cover, governor today and found the nylon gear lost it's roll pin that holds it in. The governor had markings on it like monster probably put on when they rebuilt it, etc. So i imagine the roll pin was not installed & staked correctly by monster transmission and it fell out. it's out of warranty and the governor otherwise looks and works fine on the bench.

Anyway, my question for somebody who's been deep into one of these's th400's before is WTF would that pin go? The bottom of the pan? or?
I'm thinking IF it's in the bottom of the pan it's unlikey to cause any problems. Is that a safe bet?

thanks in advance.

 

It was never installed. It is almost impossible for the pin to fall out, if it was drilled correctly. Remove the gear and see if the hole was drilled. It should be .125".

 

the hole was drilled, i don't see how it could work fine for over a year and then stop working if it did not have a roll pin in it to begin with.

the closest i have for go - no-go gauge pin test is 7/64" & 1/8" drill bits. 7/64" goes through gear and governor together or separate. the 1/8" does not go through either gear or governor together or separate. I used the smooth part of the drill bits, not the twisted part of the drill bits for the go - no-go test and the drills caliper to the size they're marked.
There's 0.015625" difference between 7/64" and 1/8" so i guess i'd have to caliper a 1/8" roll pin from one of these governor kits out there to see if they run small or not.

So IF the roll pin fell out for whatever reason, do you think it would end up in the bottom of the tranny pan or the tailshaft housing? i can't really tell from the angle i'm able to see into governor housing with transmission installed.
I have a magnetic drain plug in tranny pan i was hoping IF it fell into pan the magnet would catch it.

thanks in advance.