Loud thud on front driver side

I just replaced the engine with a jdm 60k mile engine. This came with it's own set of issues but its been on the road for a day now and now there's a loud thudding coming from the front left tire. There is no grinding noise like a bad bearing, but a thud every wheel rotation so it gets faster with speed. The wheel has no play and I'm still trying to rule out of its a bushing, my main worry is if its in the tranny or transfer case? If anybody has experienced this I would love to know where to look!

 

Update: I've looked deeper into the whole front end assembly and my biggest note is fluid leaving from where the driver side axel meets the transmission. I feel like its most likely a torn bool leaking grease but it also could be transmission fluid. I'm going to pull the axel out and update on what I see.

 

Could be an axle seal. Also that jdm engine....oh boy. I would not turn up the power on it.

 

Yeah the engine was in rough shape, turbo was shot and had to transfer the old one. In other news I am replacing the axel seal, axel, and bearing. The left engine mount wasn't fully tightened which caused it to drop ruining the front left driveline components

 

OOF. That has happened. OEM mounts suck. Red loctite and proper torque gave me no issues.

 

One new oil seal, axel and bearing later the problems solved! learned a lesson on taking my time, this was completely avoidable. This ended up ripping the cv boot on the front of the driveshaft as well… luckily there’s a thread here on replacing that boot, though it was an annoying job to do