I'm trying to get the torque converter into my freshly rebuilt trans and I've got to the point where the converter is slightly hopping on an off the pump lugs, or so it appears. Every half a revolution the converter drops about 1/16, then pops right back up again as I rotate. I've been at it for an hour... any ideas on what to look for?

 

Sounds like maybe a wrong converter LT trying to install in and LS trans just barely touching the pump tangs? I would also take a small pick and use to make sure pump rotor is free and can move.
Frank

 

The torque converter looked identical to the one that came out and the pump seemed good. I have to admit that I lined up the converter where it seemed to be sitting on the pump lugs and tapped it in with a rubber mallet. It went straight down and bottomed out. I measured the depth of the converter bolt bosses to the edge of the bellhousing at 1-1/16". We'll see how it goes.

 

possible the builder didn't seat the pump bushing on a TC after driving the bushing into the pump half. this is why it's a good idea to buy your TC first and give it to the builder so they can make sure it fits the pump.

make sure to check and shim your TC pull out when installing.

 

Well, I can tell you for sure that the builder didn't seat the TC onto the pump bushing because the builder is me! This was my first transmission build, I put in a transgo shift kit at the same time. I got it in last night. It started up, no codes, and seemed to shift fine on the lift. I took it for a 12 mile run and it seemed to work great. So far the worst I'm finding is an exhaust leak.

 

Hey, I'm having this exact issue. Did you get it figured out?

 

First, welcome to the forum!

Unfortunately the Op hasn't posted an update; we will assume he figured it out.

Why not give us all the details - what trans and year is it, did someone just rebuild it, where is the converter from, what are the measurement?

 

Hello,
It has been a few years now, but when I tried to install a new convertor it would not go on the pump. It was from a good brand name, but the inside of the "neck" that engage the pump was not turned -lathed to clean up the weld. Called the builder and they said the buy that part and sent out a different one that worked. Looking down the inside of the pump I could see the ridge that was hitting the input shaft.
Something to check, hope that helps. The convertor has been great, no reason to name names.