Rear end noises only in reverse

I have a rear end noise and it only happens in reverse. I tried in neutral and no sound. Any thoughts on what it could be?

 

What sort of noises? Squealing, cricket like noises? If so, check your u-joints, most likely the one at the rear diff.

 

It is a cricket like noise, did grease all 3 u-joint but no luck.. I will regrease and get someone else to drive the truck while I am next to it to see where it is coming from.

 

With the engine off, put the truck in neutral and engage the parking brake. Twist the driveshafts to check the U-joints for backlash. Check the carrier bearing for slop.

 

Did all four caps of each u joint purge grease? If unsure, grease them again and watch closely. Any joint with a cap that won't purge should be replaced.

 

DId the 3 again and grease came out of the four caps. Still has the sound... not sure what else it could be.

 

I'm having a similar problem w my 2000 taco. Squeaks in reverse, and just started to do it when I go forward. I have lubed all the zerks and purged (assuming that means sees grease come from the fitting, not a mechanic) but the noise actually started AFTER I lubed... It is louder in reverse, sounds like some one jumping on a squeaky mattress.... U-joints? Hanger bearing? The noise seems to be coming from the aft section.

 

All the grease in the world will not fix a bad joint once it gone. Squeaking in reverse is a common noise when a joint goes bad and when they bind up usually from lack of service they will have no play so you can twist the joint all you want when you should be using the time to drop the drive shaft.

 

I'm not noticing any play in any of the u-joints. How would I know which is bad?

 

You got to take the shaft out and turn the joint by hand if is tight it's bad and when you take it a part it will be full of rust and ground up parts. More than likely it will be the rear one. A U joint with play in it won't squeak it might clunk but it won't squeak.