ARB grinding or ratchet Noise (updated title) (1 Viewer)

[Jetboy]

I've been swamped with work and regeared my 5th gen 4Runner. I did the front clamshell that's still sitting on my bench ready to swap in when I have a half day free to do it. I built a spare clamshell so I could just swap them in an afternoon. Glad I did on a spare. It was a HUGE PITA to setup correctly. It's so time consuming to get the pinion depth correct for a good pattern. I don't know ZUK at gearinstalls.com - his photo writeups are very helpful for me to learn from. What they don't really capture is the amount of work involved in a clamshell to get gear patterns as good as his. For a DIY - even with all the specialty tools, it is not an easy or fun job. The guy is as much artist as mechanic IMO.

With Cruise Moab coming up I decided to have a local shop do my rear diff so I could get it fully broken in before the trip. I didn't want to re-gear and then go straight to Moab. I have no prior history with the local shop. I have a few people I trust to do diffs, but none are local and I couldn't take the down time to ship and such. I know there are some good local shops on MUD here in Utah who I'd rather support (and trust more), but most aren't near downtown SLC where I work. I was hoping for easy drop off early, UBER to work, pickup after work and save a day of my own shop time. So... everything seemed to go normally as far as the install, but now I'm hearing some gear noise. It's not loud, but it is audible and about the same volume as AT tire noise, just a different pitch. And it only is making some noise on very light acceleration. Just past coasting.

On heavier acceleration or deceleration - no noise. Unfortunately I didn't ask to take a picture of the gear pattern. Not sure why I didn't ask for that.

As far as parts - I re-used the carrier bearings, they're low mile OEM and put new pinion bearings on - mostly because those are hard to swap without potential damage. Gears are Circle K from Korea (sold by Revolution), and 4.56 ratio.

How concerned should I be? Am I overthinking this or should I be pulling the diff and checking the pattern / resetting up the gears myself? Should I give it a few hundred miles? Or should I try to fix now? Thoughts?

 

[mr jits]

I've been swamped with work and regeared my 5th gen 4Runner. I did the front clamshell that's still sitting on my bench ready to swap in when I have a half day free to do it. I built a spare clamshell so I could just swap them in an afternoon. Glad I did on a spare. It was a HUGE PITA to setup correctly. It's so time consuming to get the pinion depth correct for a good pattern. I don't know ZUK at gearinstalls.com - his photo writeups are very helpful for me to learn from. What they don't really capture is the amount of work involved in a clamshell to get gear patterns as good as his. For a DIY - even with all the specialty tools, it is not an easy or fun job. The guy is as much artist as mechanic IMO.

With Cruise Moab coming up I decided to have a local shop do my rear diff so I could get it fully broken in before the trip. I didn't want to re-gear and then go straight to Moab. I have no prior history with the local shop. I have a few people I trust to do diffs, but none are local and I couldn't take the down time to ship and such. I know there are some good local shops on MUD here in Utah who I'd rather support (and trust more), but most aren't near downtown SLC where I work. I was hoping for easy drop off early, UBER to work, pickup after work and save a day of my own shop time. So... everything seemed to go normally as far as the install, but now I'm hearing some gear noise. It's not loud, but it is audible and about the same volume as AT tire noise, just a different pitch. And it only is making some noise on very light acceleration. Just past coasting.

On heavier acceleration or deceleration - no noise. Unfortunately I didn't ask to take a picture of the gear pattern. Not sure why I didn't ask for that.

As far as parts - I re-used the carrier bearings, they're low mile OEM and put new pinion bearings on - mostly because those are hard to swap without potential damage. Gears are Circle K from Korea (sold by Revolution), and 4.56 ratio.

How concerned should I be? Am I overthinking this or should I be pulling the diff and checking the pattern / resetting up the gears myself? Should I give it a few hundred miles? Or should I try to fix now? Thoughts?

Honestly, I'd bet it's the cheaper gears themselves that are the root cause of the noise. Typically the cheaper brands have a rougher cut, and as such are pretty noisy until broken in.

 

[Jetboy]

Honestly, I'd bet it's the cheaper gears themselves that are the root cause of the noise. Typically the cheaper brands have a rougher cut, and as such are pretty noisy until broken in.

Thanks. That was what I had initially thought was the problem. I just haven't ever had a noisy one that I could hear.

As it turned out the pinion bearing was loose. I could feel about .003 play in the flange vs the third member housing. So... I called the shop that set it up and they said they'd fix it. And then proceeded to close the shop a few days later. Leaving me with a bad diff setup a few days before Cruiser Moab. FML.

After reading a lot about gearing, in this case everything I can find suggests there's only one manufacturer of the 8.2 gears which is Circle K in Korea. There's only a few places that make them in the world outside of the OEM factories and only two tooling options to make them, so most gears should be pretty similar across brands anyway. In the case of the 8.2 I think they're all circle k regardless of what logo is in the box. I called Revolution to confirm that they were using Circle K sets before ordering. Toyota does make an OEM 4.56 8.2 diff, so there may be some better gears from Toyota that are possible to find somehwere. I think it's possible some brands do more polishing/lapping/ etc. although I really don't know. <- if anyone knows anything different I'd be interested to know about it. An extra $50 or $100 for a gearset is kind of a drop in the bucket in terms of the cost, but if they're all the same thing, there's no reason to pay more. ZUK is the best resource I'm aware of and he seems to like the Circle K gears.

I suspect one of the primary reasons OEM gears are quiet is the factory spec is .010-.020 backlash while aftermarket gears usually spec .006-.010. I'm not sure why the difference. The FSM also has a much wider range of pinion preload on the low end. Toyota sets 8-19 in/lb and aftermarket sets usually spec 12-15. A lot of guides will say something like 35 in/lb of preload for new bearings that would probably be far too high for a Toyota diff spec.

 

[Jetboy]

Long story short - the gears should be silent. I had to pull out, fix, reinstall. Everything was fawked up. Pinion was about .020 too deep. Back lash was way to high to compensate. Zero preload on the bearings - wouldn't even measure 1 in/lb on my wrench. Pinion flange filled with gray RTV - like down in the splines and on the inside - I've never seen that one before? They even routed the brake lines wrong putting it back together. It's easier to do them right than screw them up. They routed the soft line the wrong way around the hard line. Used red loctite on 2 of the diff mounting studs - but only 2. Why? I have no idea. Just all around a poor quality job. I'm very disappointed in my own decision making. I feel bad for the poor lc80 owner they were doing the R2.8 install on sitting there. My job was simple and done wrong. Not sure if this was the unfortunate timing of being one of the last jobs of a failing business or just a sign of the quality of work.

Setting up the 8.2 is really easy as far as diff setups go. Moved into a nice pattern. Now runs silent!

I was really impressed by how much improved the 8.2 really is. It's a LOT stronger than the 8" diff in a few critical ways. Toyota did a great job as far as making the pinion bearing huge and very tight to the pinion head.

It does take some specialty tools, but nothing magic. It just takes some patience to do it right. That shouldn't be beyond the skill set of any professional mechanic or advanced DIY home mechanic. It's MUCH easier than the clamshell. As I used to say when I worked in construction when something was built out of spec: if it's worth doing - it's worth doing twice... tear it apart. Sometimes you make bad choices. I took my 4Runner to the wrong shop assuming they had a good reputation for setup on jeep axles and they could manage to do this work correctly. I was wrong. At least now it's done right. Now let's go see if I can break it...

 

[Jetboy]

I can't win...

after fixing the rear I started getting some grinding noise on the highway on my way to Moab. Tried a few things and it was silent in 4wd, but noisy in 2wd. That pointed to the front diff with a new ARB and new gears in it. I finally had time to pull that front diff back out this weekend. Spinning the side gear of the ARB sounds like a ratchet. I assume now that there's something wrong internally with the ARB. I was pretty sure this was the case before I pulled it out. Noisy in 2wd, but quiet in 4wd means spider gear noise or locking mechanism noise. In 2wd the ADD is open so the only thing spinning should be the spider gears inside. My bet is that the ARB engagement teeth are hitting eachother in the "open" position, but I have no idea what's going on internally. So now I'll probably have to send the ARB back to get it replaced/repaired. And now I have mis-matched front / rear diffs, so I'm going to have to swap rear diffs... again to match the front 3.73 I swapped back in so I can use 4wd while I decide where to go from here.

I'm at the end of my limit of frustration, time, and money to spend doing this. We'll see what happens with the ARB. I didn't have the serial number today for customer support so I'll find out tomorrow what they want me to do with it. Of course it's very frustrating to deal with a defective part that requires so much work to install. Unless ARB wants to pay for a shop to swap it back in and warranty it - I don't think I'm willing to roll the dice with installing an ARB again. I assume the warranty will be "here's a new one, go spend $1000 to have it installed again and enjoy". But we'll see tomorrow.

I guess the only silver lining is that I kept the OEM front and a spare OEM rear diff as backups. Otherwise I'd have my 4Runner sitting for probably weeks at a shop waiting to be fixed.

 

[Jetboy]

Here's a video of the issue. If anyone has any ideas of how I could have caused this by an improper install of some sort, please feel free to let me know. I can't think of anything other than the engagement mechanism not disengaging. Kinda sounds a lot like Detroit in there or something. The string you see on the stub shaft is a little string of RTV.

ARB air locker noise - YouTube

 

[Jetboy]

Minor update on this - I pulled the unit out. It wasn't install related or related to any bearings in the diff. It's internal to the ARB. We'll see how good ARB's warranty is now. Edit: they did send a return shipping label. IMO they shipped a broken product sold as the premier product in the market, they should at least bench test them before packaging, and they should cover the cost of labor plus the replacement of the ARB. We'll see how it goes from here.

Warranty says "For total peace of mind, all ARB Air Lockers® are backed by a comprehensive, five-year, unlimited miles warranty. Coupled with ARB’s extensive dealer network, you can be sure we’ll be there to support you in the unlikely event of an issue. " If that means - you ship to us on your dime, pay for all the labor, and we'll fix and ship back - I think that's a bit disappointing. Hopefully if that's the case they at least send a full new retail package set so I can sell it and buy a Harrop.

Here's a video of the carrier noise removed from the diff.
June 22, 2019 - YouTube

 

[Jetboy]

So... the diff has been at ARB since June 26th. It's 3 weeks later and so far no response from ARB. I asked for an update last week. No response yet. How long should this take? How long are people waiting with their vehicles apart to get a fix? Or are most people buying a replacement then sending the broken parts back to ARB for warranty?

Am I being unreasonable expecting a quicker turn around?

 

[Jetboy]

Spoke with ARB middle of last week. They say they looked at it (the carrier and the video) and it's normal to be that noisy. They said it's only making noise because it doesn't have oil in it. Video link below. Can someone confirm that ARB lockers are normally this noisy unlocked? In an ADD front one side spins full speed - lots of noise at highway speeds. Is this really normal operation?

 

[mrmumbels]

Spoke with ARB middle of last week. They say they looked at it (the carrier and the video) and it's normal to be that noisy. They said it's only making noise because it doesn't have oil in it. Video link below. Can someone confirm that ARB lockers are normally this noisy unlocked? In an ADD front one side spins full speed - lots of noise at highway speeds. Is this really normal operation?

Did you ever get an answer to this? My OX does the same thing after 1000 miles. I don't remember hearing it before the install.