Hey all. I'm the vehicle owner/driver, but not its mechanic. We installed a CJ7 motor into my 1977 Cherokee after I blew the original engine. It's developed a mysterious tick. It sounds like a Lifter - BUT - it disappears when I put the vehicle in reverse, is more pronounced at lower RPMs (almost disappears entirely at higher RPMs, in all 3 gears). The transmission is NOT slipping - so I've been told it's not the torque converter. Engine is holding oil. The sound is coming from the back of the engine - not the front. So I think we can eliminate the timing chain. Thoughts???

 

Sounds like it could be a cracked flexplate.

 

Oh my gosh, that's it! Watched this video just to learn more after your suggestion.... that's the sound. Intermittent, doesn't happen predictably, most pronounced under 2500 rpms. Thank you!!

 

check your flexplate bolts too.....they can cause a similar noise