Front Differential Cyclical Groaning/Grinding Noise

hmmm. Will probably keep an eye on it and take it to get inspected by the shop I go to every 40-50k or so.
I did have them do a master kit + solid spacer as well as replace the shims. Pretty cheap insurance in my opinion. They did it right the first time and removed the front and rear diff/axle completely and worked on the bench which was why it took them a while to do. They also cleaned everything up and inspected it using borescopes and some type of handheld microscope.

 

Most diffs I can reuse the old bearings as long as they are in good shape. Ive got a special tool that can pull the pinion bearing up enough to get a separator on it. If a shop is throwing the old shims back in a regeared diff, then they're not checking backlash, pre load, or a pattern check. There's not a single regear where the shims went back in the same spot.

 

Yeah. I don't do enough to warrant that. I just use a screw down separator and kind of mash it on and replace the bearings on the pinion. I would be upset if I had a shop do it and they didn't do a full set up on new gears.

 

Very upset to say the least.

 

alright, so to fill u guys in. I regeared the truck my self. All the preloads/backlash/contact patch were checked and rechecked like 5 times and within spec at the time. It was my first gear install, sure, but I did a solid month of reading on how to setup gears, and had a friend who sets up Dana diffs for Jeeps recheck all my work and he said everything was within spec as well.

I regeared the truck about 4 years ago. It's been doing it for the past 2-3 years. At this time, it does it whether I'm in 4WD or RWD. It's only present between 51-59mph. I've also noticed that it only does it when the ambient temp is higher. In the winter it's silent, but now that temps have gotten up for the past month or two in Maryland the sucker is whining.

It's definitely not wheel bearings. Aside from the fact they never failed the wheel bearing load test while driving, I did replace them anyways because of how bad this annoys me. Also definitely not the CV. It's not that CV clicking noise, but I had also read a few posts years back where people said toyota replaced their drivers side CV and it fixed the issue. I coughed up the $400 and bought a new OEM CV from Toyota. Not a huge deal because I typically like to have an extra CV since one will inevitably break on the trails. I dont work at a shop anymore, so I'm not looking forward to dropping the front axle in my driveway but it seems like this is what it's looking like I might have to do? I might pull the fill plug to see if theres anything unusual on the pinion teeth. If you guys are saying the carrier can be loose then I'd assume it would show in the teeth. I can also pull the drivers CV to see if I can push the carrier left to right or if the shim is loose.

 

What is the ambient temperature when it's silent?
First thing I would do is pop the plug and look at the teeth for improper wear, replace the oil for higher weight (like I first mentioned) then drive it around to see if it solves the issue. If it doesn't then dissemble everything and check what the issue is. You shouldn't be driving with it like that.
My reasoning behind this is because the oil is thicker when it is colder which is probably why you don't hear it when it's cold.

Edit/Disclaimer: I haven't done a re-gear myself, but I am always at an offroading shop that builds rock bouncers. I just watch and mess around with the techs there. I am an Aircraft Technician by trade though so know a thing or two about turning wrenches.

 

If all your bearimg pre loads were good, backlash good, and good pattern check, I would eliminate a diff problem. How did you check backlash? How did you check pre load?

 

I bought a special tool that connect to check the backlash.

$76 Starrett Indicator Hole Attachment, AGD Standard, Versatile Measurement, Secure Clamping, Durable Design - 670B

https://www.amazon.com/Starrett-670...0104069&sprefix=starrett+attac,aps,155&sr=8-1

For preload, I checked the pinion, first. This took several tries to get right since I did a solid spacer conversion, once this was done I checked the preload on the whole assembly by putting the pumpkin together.

 

40F or below. I was thinking the same.

 

Interesting. I'm sure it was accurate. I use a test indicator.

 

Haha yeah, I didnt know about those until recently to be quite frank. But I guess this is a dial indicator conversion accessory.