[buccaneerbandit]

As the title says I believe I have a bad pinion bearing. I just completed the Elocker retro fit and after about 6 weeks of daily driving I have a slight whine at around 40 mph that is throttle input related. I have never dealt with a bad 3rd member so this is only my guess but the rest of the drive line is well lubed and the new 3rd member fluid lvl is good. Any input is welcome.

[Buckaroo]

I don't do the mods but have experience with T4R differential whine. Recently dealt with rebuild of open diff (not e-locker) so I have some thoughts. First question, is the whine constant or does it change between accel, coast or decel?

Buckaroo

[amalik]

97' 3rd gen here. I kept blowing rear pinion seals and had my bearings replaced in the diff. I was told by Toyota mechanic it was a bad pinion bearing.

After the bearings replacement, I had a very audible whine upon decel at basically highway speeds. On every single decel, it sounded like someone punched my rear 3rd in the stomach and she was crying.

I took it back to the mechanic and we took a quick test drive. Within just a few minutes, we turned around and he said he didn't set the backlash properly on the pinion/or other bearings (Don't remember). He tore it all apart again under warranty and reset the backlash properly. Very little/to no whine since.

My point is -- your initial thought of a problem with the pinion bearing is very likely correct. It may be the backlash though and not the bearing itself. This is a relatively complex area mechanically, I honestly had never heard of a bearing backlash 'setting' before my incident.

It really sucks you didn't get new bearings in the rear diff when you just had her cracked open for the elocker.

Even if it's just the backlash and not the bearing, if you are going to in there a 2nd time, I would buy a bearing set from Yukon or ECGS.

[buccaneerbandit]

The noise is only on acceleration and not until 40 mph. I can literally tap the skinny pedal on and off and the noise will come and go but only under load( acceleration)

[buccaneerbandit]

Yeah I was on the fence for weeks weather to just send it as a core to ECG and get a new one. I did new axel bearings and seals all new breaks and went cheap on the 3rd member. BAD call on my part. Anyone have an idea If I can run this for a bit as it is my daily and just sold my bike lol.

[mckennar]

Torque converter massacre: pics. Need advice

Transmission swapped: noise still the same

Both threads are the same guy, similar noise (first has links to video), went as far as replacing the transmission before pulling the rear end apart and discovering what he did on the 2nd link.

Hope this helps clarify your situation some. Not saying yours is as bad as his was, but it's an example of what can happen if it isn't properly set up on install.

[JZiggy]

I've driven a 3rd gen T4R with a bad pinion bearing and have spoken to others who have also... the symptoms you describe are spot on. Noise is only under load, and very load dependent, and the (high) pitch is speed related. It should also sound like its coming from the back storage area of the truck.

[pauldub]

To aid in diagnostics, you can pull the rear drive shaft and drive it in 4wd to see if that make your throttle dependant noise go away.

[Buckaroo]

Had pinion bearing wear/noise. I was concerned it was rear wheel bearing noise but confirmed it by jacking up the rear end and using a mechanics stethoscope while running it up to speed (be careful). If this is a pinion bearing, suggest you do the diff side bearings at the same time if they have not been done.

Buckaroo

[buccaneerbandit]

That's funny I just had it up on stands to check yesterday. Fairly confident its the pinion after my research and every ones responses. Just made a call to have it rebuilt.

[Buckaroo]

Originally Posted by buccaneerbandit

That's funny I just had it up on stands to check yesterday. Fairly confident its the pinion after my research and every ones responses. Just made a call to have it rebuilt.

Again, my experience is on the open diff but I found a bearing shop that specialized in diffs and had them rebuild mine. I pulled the third member and took it to the shop and provided all the new bearings/seals/crush sleeve,etc purchased from Camelback. I then reinstalled the rebuilt third member. Paying to have someone with experience set up the diff with correct backlash and pre-load on the pinion bearing is money well spent.

Interestingly, the side bearings looked/felt pretty good and only slight spalling on the pinion bearing which could be felt just a little bit when rotating - but it really made a noticeable whine. Over 220,000 miles, I suspect the diff fluid level had gotten a little low in the past and the nose of the diff housing angles up - the pinion bearing would likely be affected first.

Buckaroo

[eimkeith]

It's definitely a whine and not a whistle?

[buccaneerbandit]

It's definitely a whine and not a whistle? Yes sir. gonna pull the rear drive shaft and see if the noise goes away before I spend any $

[jsluse]

Originally Posted by Buckaroo

I don't do the mods but have experience with T4R differential whine. Recently dealt with rebuild of open diff (not e-locker) so I have some thoughts. First question, is the whine constant or does it change between accel, coast or decel?

Buckaroo

Mine is when I accelerate or decelerating

[brillo_76]

Originally Posted by jsluse

Mine is when I accelerate or decelerating

Did this 3rd member run low on gear gease?

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