Knocking Sound in 4H

Hey everyone, I was wondering if anybody had any ideas on why my 2009 Tacoma knocks in 4H when I reach 35 mph? I have not yet tried 4L and it doesn't happen in 2H. I am thinking U joints. Thoughts? Thanks, Pepper

 

For one thing you are going to have a hard time reaching 35mph in 4low. The gearing is too low to go much faster than that.

Ujoints would be the first guess. Can you crawl under there and grab both sides and check for slop in the ujoints?

 

Is this what you're hearing?

http://www.tacomaworld.com/forum/2nd-gen-tacomas/308974-front-end-noise-4wd-video.html

It drives me batty sometimes

 

Thanks for the response guys. I watched the video you put on here and it does not sound like that. It's more of a knocking noise in which i can feel at my feet when driving and hitting 35 mph in 4H. Its loud as hell too. I plan on taking him into base this week and getting him raised up on the lift and seeing what I can find. If there is any troubleshooting techniques you can think of for me to try in the meantime, please let me know and I will give them a shot.

 

I figured it out. It was neither the ujoints or drive shafts. Some tube with a metal cap was hanging off the top of the transmission and was never resecured. I zip tied it up and no more sound. I got lucky.