09 tacoma, 4wd, MT thumping when shifting gears

Hey everyone! I'm having trouble diagnosing a thumping sound when I shift gears. I drive an 09 base tacoma with 1GR-FE (4.0L V6) engine, 4wd, manual transmission. Over the past few months, when I shift from 1st to 2nd, 2nd to 3rd gear, and less so with the higher gears, I get a loud thumping sound that appears to be coming from the rear end. I thought it might be an aftermarket hanger bearing I installed, but I've shot videos under the truck while shifting, and the hanger bearing looks okay. The engine block doesn't seem to move too much either. It appears to be the rear axle that is moving the most, but to be frank, I don't know what normal looks like. I wanted to see if anyone had some insight as to what this might be. I posted the video of the rear differential and axle on youtube:

https://youtu.be/VhLdaKKqI0M

Thanks for y'all's help.

 

I've never looked at mine like that but based on your video, the first thing I would look for is a busted leaf spring. It looks like that rear diff is rotating more than I would expect.

 

Unsure of the problem, but it is a great video!

I would be suspect of the spring area as well.

Loose u bolts? Have the springs been touched? Blocks? Add a leaf? Warranty replacement springs?

 

Ok, that makes sense. That's what I was thinking.

I'll take a look at the u bolts. I bought the truck with 164k and it's up to 209k. I think it's been lifted by the previous owner, but I haven't modified the suspension. I'll look at the warranty too. I remember seeing that.

 

I watched the video at .25% speed and between the 19 second mark and the 23 second mark it appears that the pinion gear shaft jumps like a tooth.

Slow it down and watch it. Maybe I'm old and crazy, but it looks that way to me.

 

Yea. Maybe.

Doesn't mean you don't know what you're doing though.

 

U-joints?

 

Lol, that's pretty much the same thought I had.

 

That's definitely when the thump is happening. Does that mean the diff needs rebuild if that's the case?

 

You would have to dig into it to find out. IMO there is something def going on. It shouldn't do that...

I would remove the drive shaft and inspect those universal joints also!

Put the rear end up on jack stands and rotate the pinion while the shaft is out and see what you feel when rotating the differential by hand. That may help you isolate the problem.

 

Ok. I'm going to check it out this weekend.

 

Please update the thread when you find anything.
Thanks!

 

I don't know much about differentials but it seems to have a ton of backlash (in the gears?... comparing how much the drive shaft rotates before the tires start to move) compared to what I would expect to see, but then again I never see mine in action to know if it is any different.

 

Yeah that's what I'm thinking. I'm hoping it's just the pinion nut that came loose and I can tighten it back up.

 

Really good video. I am experiencing something similar and trying to figure it out. Following!!!

 

Before you go messing with the u-joints you should check the torque on the U-Bolts holding the springs. I had a similar issue on my truck years ago and that's what it turned out to be. I think the proper torque spec is 73 ft/lbs but the service manual had it misprinted at 37 ft/lbs. It's worth a shot plus it's easy and free.

 

That's a good idea. I'll check it out.