mjwalfredo

Hi Yotatech,

Warning: this post is pretty long, you can skip the third paragraph if that means you might read the rest and give me some help

I am asking for some advice as to what to do with my rear axle now that I know there definitely some problems with it. I think probably multiple things in my rear axle have been F'd up for a long time because of the fact that I have been driving with a strong low frequency vibration/rubbing noise for a long time. The noise became noticeable at 30mph got really loud at right about 50 mph and then quited down a bit up until 70mph where it get so loud it's scary. I thought it was coming from the front but now I can pinpoint it to the rear axle after putting the rear up on jack stands and taking the truck up to those speeds. I can feel the vibs in the front even when the truck is not going anywhere.

I can't figure out exactly where the vib is coming from (probably because it is being compounded by multiple factors) but what I can tell you is that using a touch test with my hand on the axle housing near the driver's side bearing leads me to believe that is at least partly the culprit. The other thing I can tell you is that even though I don't know how much noise my gears should make, something is telling me that mine are way too loud. Also, by touching the pumpkin, the vibrations feel strong at that point to. The passenger side of the axle housing doesn't seem to vibrate as much when I touch my hand to it.

Now that I have told you the symptoms of my truck, let me tell you about an experience I had about 6 years ago in my senior year of high school... It was a cold night and I took my runner out to do a little bit of mudding. Against my better judgment, I let my friends convince me to try and drive through a deep water puddle in which I got stuck for a few hours with the water level probably above the diff. breather. When I finally got unstuck, I noticed that my parking brake lever would pull all the way up and not apply any force to the rear brakes. At this time, I had no idea about anything mechanical on the truck but I found out that I could tighten the cable by driving in reverse and yamming on the lever. I did that and things seemed okay for a while. After a while I noticed that the back brakes felt like they were not doing much work at all and my rotors were warping. I replaced the rotors, pads, shoes and drums by myself and now as I think back to the occasion, I believe there was diff oil on the inside of my tires but I could be wrong as this is six years later. Anyway, I had no idea what that meant at the time and I just went on replacing the brake parts and drove her all over the place. Anyway, to try and keep this story from getting any longer than it already is, the truck gradually got worse in regards to vibrations and rubbing noises. Here I am six years later, it is not my daily driver but I am getting ready to make it my girlfriend's daily driver and I need to fix this axle.

I have not noticed any gear oil leaking from the seals since that first time... Is that possible after 4-5 years of driving the truck with bad bearings? My diff seems real loud and I have what feels like slack in the driveline when I step on the gas sometimes. (The truck makes a thudding when I step on it) I am going to try and inspect the bearings this weekend but I don't really know what to look for.

I am looking to ya'll for any suggestions to what I should do with this axle. It is a 97 runner with 4.30 gears and an E-locker. Should I start with the bearings and then see if I can get someone to replace the gears? (Can I even do that easily with my E-locker?) Should I just go to a salvage yard for a complete replacement of the entire axle? Any help would greatly be appreciated. I want it fixed right but I don't want to spend an astronomical amount and I don't mind doing some work myself. Thanks Yotatach. (And thanks if you read all that!)

SteveO

The first thing I would do is to replace the u-joint on the driveshaft.

http://www.hunt4steve.com/OR/99_4Run...ff_oilseal.jpg

If that doesn't do it, Pull the axle shafts and then pull the 3rd member for inspection. Check to see if the Ring gear is coming loose (unlikely) or if there is too much play in the bearings.

You can see these online pages for reference:
http://www.hunt4steve.com/99RunLtdFsm.html

Then, I would check the axle houseing for a bent axle houseing. If you're able to get up to those speeds, without dog legging down the road, this is probably unlikely.

Either way, you have an issue that you should get resolved sooner than later, or the bill to fix it will only get bigger.

mjwalfredo

Steve-o,

Thanks for the prompt reply. I will start with the U-joint first. I am hoping that is where the slack is coming from. I know the vibs are not coming from there because a while back I dropped the driveshaft and drove in FWD and the vibs were just as bad. I'll go ahead and try to inspect everything I can this weekend and try to get some pics of all the hardware. If I pull the axle shafts, and decide to put it back together when I am done inspecting, do I have to replace the inner seals?

GSGALLANT

Was there any water in your gear oil when you drained it after being stuck in that water puddle? What was the condition of the gear oil the last few times you've changed it? Was there any sign of metal particles? It's time to pull out the axles and 3rd member, and check / change the bearings. You should also check that the gears are in good condition and properly set up.

SteveO

You won't have to replace them, if you don't damage them. Basically, be careful and support the axle shaft when you are pulling it out. I know, the whole chunk is heavy, but ya really got put your back into it when pulling it out and get it right.

Being that your diff sat in water for quite some time, I would question if you changed the fluid right away. If not, it may be that the oil has broken down, and as you know, water is not a very good lube.

Something that happend to me with my first 4x4.

I hada 82-83 Toyota pickup that was pretty much beat to snout, but it ran. so, I was happy. The 5 speed lost the centering pin for the stick shifter, so it would spin 360*. If you didn't know the shifting pattern, you wouldn't be able to drive it. The rear main seal was leaking oil onto the clutch, causing take-offs at lights to be somewhat slow. The 3rd member was leaking some oil at the pinion seal. The suspension was way to stiff for the weight of the vehicle, causing it to jump around on a rough road - kindy scary. Then, I really messed up. A friend of mine told me that I should drive around town with the front hubs locked so I could lube the front ring and pinion gears. I thought, yeah, the manual does say something about that, OK. So, I did, then I got onto the freeway. Big mistake. I'm cruising down the freeway about 60mph, and I start to feel the truck jerk, as if somebody is pulling on the back end of it with a strap. I quickly get to the side of the road, and just as I'm about to stop, the front wheels lock up. Not good. I unlocked the hubs, and went on my way, thinking I'll have to look at it later. At a later time, I locked in the hubs and tried to use 4 wheel drive. Needless to say, it didn't work very well. The grinding that came from the front diff was really bad. Without pulling it apart, I'm pretty sure the front ring gear attempted to weld itself to the pinion gear, or the bearings are shot, really shot. Of course, when you overdrive any gear, they get hot, and the parts either start to weld themeselves together, or the bearings these parts ride on, start to seize up. One of these two events happened.

In your case, if you had a bunch of water in the diff, instead of gear lube. You may be in that very same scenerio. Your bearings in the 3rd member may be shot. If they are, you will need to take the entire 3rd member (pulled from the vehicle, it'll be cheaper) and have it rebuilt. I would call around for the best prices and best service. When ORS messed up my gears in my rear 3rd on my current rig, I have a trusted Master mechanic at the dealership. I wanted them setup correct, with no howling, and with a good pattern. So, I paid the extra money for a good setup. I have not been dissapointed.

If its not the u-joint, sounds like it may be the 3rd member chunk. If you have another vehicle, you may have to have your Runner down for a day or two while the 3rd gets re-built. Water will replace the gear lube, then the bearings will get hot and grind themselves into fine powder. I've had it happen to my front 3rd in my first truck, and then on my '86 4Runner, I have had water get into the hubs, and destroy the bearings.

Get it take care of soon, you don't want those bearings to seize up at 65mph on the highway. No fun.

mjwalfredo

Thanks guys. I did not drain the diff after I had my little excursion so I don't know about any water. I think I had grease monkey do it and I think I remember them telling me they were concerened about the amount of metal they found. But, that was so long ago I don't really remember to well. I changed the lube a couple weeks ago and it look BLACK but not much metal on the magnet. I just called Carquest and I am going to try and replace my U-joint tonight with a Neapco part (only $21). I just want to see how that affects the vibs first and then I will start pulling the axles and third and call up a guy who I have heard is real good with gears and have him take a look. Thanks ya'll!

SteveO

If the u-joint doesn't do it, be sure and pull the 3rd yourself. You'll save labor costs. Taking a 3rd member to them and have them work on it, while its on the bench is much easier than having them pull the axles themselves. Plus, you will know your seals will be good when you put all back together. If, the 3rd is shot. While the 3rd is being rebuilt, you should take this time to replace the inner axle seals as well. Since the rig will be done for a day to so. With metal coming from the 3rd, I'm thinking the bearings are not doing too well.

mjwalfredo

Update:

I finished pulling the rear end apart tonight. Pics coming soon when I get ahold of a digital camera. Boy that was fun, haha. I am no mechanic but immediately I could tell there is a problem with the driver's side axle bearing. When I spin the backing plate around on it, it makes nice grinding noises and there is a heck of a lot of play between the bearing and it's house (I guess). The other backing plate spins around smoothly and quietly on its axle. There is black residue on the inside wall of the bearing and there was a pretty good amount of metal flakes in the gear oil that puddled up in it's axle housing Also, the surface of the shaft of the axle seems like it is flaking off, does this tell anyone anything? It might be caked on dirt/metal residue I think. I think I will go ahead and replace both bearings while I am at this.

I also pulled out the third member so I can have someone inspect it. There are no chipped gears or anything like that. Just a little bit of the black residue I mentioned earlier on a few spots of the gears. I am concerned about it a little bit because when I spin the pinion flange with my hand back and forth, there feels like a little bit of play there and it makes a metal knocking noise. Also, If I spin it one direction and then try and go back the other, I have to apply a little more torque before it breaks free and then spins smoothly. This is different from the time I pulled out my front diff. It spins back and forth nice and smoothly.

All around, not that hard of a job. I did get frustrated near the end when I was trying to pull out the pig and it got stuck on the sway bar. Unbolted it and thought I was good to go but no, it couldn't clear the gas tank skid plate. After unbolting it, I yanked it right out onto a bag of grass seed. I'll post pics as soon as I can. Thanks for the help guys.

mjwalfredo

Called the dealership about having the bearings replaced and the dummy on the phone told me not to bring the axles in to them because I could have it done much cheaper at an independent shop.

Does anyone have any experience with bearings from Carquest? Is there a big difference in quality vs. OEM Toyota bearings? I hear the Toyota seals are better.

As a side note, a mechanic friend said he did not like the wear pattern on the ring gear. He said it was flat all the way across the teeth and that was not a good sign. He thought the ring gear was a little loose and the backlash should be reset. I asked him how that may have happened and he said maybe some dirt got in there, which is likely. He said having it worked on may not totally fix the gears but it is worth a shot before I go out and buy a replacement locking carrier assembly. The dealership wanted nothing to do with that either so I am gonna try a guy I hear is really good with gears. Wish me luck!

SteveO

good luck

mjwalfredo

When I was listening for vibrations in the axle with the truck on jackstands a CEL was thrown. Is this probably just a coincidence or will spinning the wheels with no load trick the computer? I won't be able to have it checked out for a while as I don't have a rear end right now

BTW, tech said the gears looked good to him and he wouldn't do any work on them. He lubed the carrier up, adjusted the tolerances, loosened my pinion nut that was too tight (my fault) and didn't even charge a dime for it. What a good guy!

mjwalfredo

Well, after having the backlash set with very low tolerance, my pinion nut loosened, new bearings and seals on the rear axle, I took the truck out for a quick test drive. Vibrations are gone! I havn't put the rear driveshaft back on yet because I want to replace the rear u-joint but in FWD it felt like a new truck. Thanks for your help Steve-O. Now I've just got to fix the swaybar axle mount bolts I sheared off on the passanger side and bleed the brakes and I am going to be loving my truck again. I am having second thoughts about letting the girl friend drive it!

SteveO

Glad to hear you are getting closer to getting your truck back in top condition.