Front Differential and Vibration

For a few years, I've had some vibration on my '02 Toyota Tacoma. Initially it was only at highway speeds (60+MPH) and only when braking. I had new brakes put in and the wheels balanced. The vibration was reduced but did not go away. Over the span of a couple of years, I had a change in life style which significantly cut back on my highway driving so the problem was mitigated by simply not driving at highway speeds.

Now a lifestyle change and I drive on the highway again and the vibration is.... bad. Scary bad. Most days, I can feel the vibration at speeds over 30MPH and it ramps up the faster I go. Applying the brakes amplifies the vibration. Some days are worse than others. I've driven 60+ and it just feels like wheel wobble. Other days, the the vibration feels like the truck is going to tear itself apart.

Fed up with the problem, I Googled around and it turns out this is a common symptom with a myriad of of problems. So I start walking down the list. Today I'm going to do the tests as highlighted at https://www.yotatech.com/forums/f2/front-end-vibration-troubleshooting-guide-231095/

I called around to find a mechanic and no one wants to even look at it outside of wheel balance and brakes. They all recommend the same shop that specializes in transmissions, differentials, and axle work. I describe the problem and he suggested looking at the front "pumpkin" (front differential) and the driver side axle. I do and it's covered in oil where it meets the differential. Grabbing the axle, I can move it around some measure and it makes a clacking sound of metal striking metal. The passenger side axle is clean (save for usual road dirt) and moving it around does not make the clacking sound.

$1,000 to bring the truck in and rebuild the front differential. Or I can remove the differential myself and bring it in for $600.

I've done minor repair work on the truck myself, mostly sensors, electrical, brakes, fluids, and bits and bobs. I never had the joy of doing this though. I'm the type that always read instruction manuals to avoid missing some important detail. So I got a hold of a copy of the Full Service Manual for my truck the first time I did my own repair and it seems reasonably easy to do, just a lot of work. I'm just missing a couple of tools (Torque Wrench) for the reinstall. How much of a rabbit hole am I diving in to remove the differential myself? The bit that concerns me most is if it seems reasonably easy to remove the differential myself why won't most garages even touch it? What detail am I missing?

 

Try momentarily putting it in 4wd. If the vibe goes away its almost certainly a bearing in the driver side of the diff. Don't panic the fix is fairly easy and cheap. The seal leak is likely a result.
Keep in mind when these OE bearings are new they have more play than one would think.

An outfit has come up with a better bearing, actually a bushing and step by step instructions to do the job. The diff stays in the truck and the seal can/should be replaced at the same time.

Read up here.
https://eastcoastgearsupply.com/c-1207128-toyota-clamshell-bushings-96-04-tacoma.html

 

Have the problem needle bearing

 

Have rotors / calipers ever been replaced? A caliper hanging up can cause the wobble too.

 

Never even heard such a thing. You mean the caliper getting stuck?

 

I have heard the phrase by many. That's where I learned it from. Must be a Northeast thing? Yes, getting stuck, sticking or...hanging up. Not completely closed on rotor but not completely released either. And yes, it can cause a wobble in your steering going at higher speeds.

 

Give this video and the one he does on removing and replacing the differential a look. Timmer is the man when it comes to a thorough review of what needs to be done and how to do it in your own garage!
https://www.youtube.com/watch?v=mh1BK5--KrU

I have done this, and if I can do it, so can the average shade tree mechanic!

Cheers!

 

curious because i have the same issue and beleive i saw 3 or 4 other threads just in the first 2 pages of 1st gen tacos!!! so many possibilties but im well over $1500 into my quest for a smooth ride (new tires that i feel started the issue, upper ball joints, outer tie rods, multiple balance and alignments, rear shocks) all these things reduced vibration but have not eliminated it, but this is first ive heard about the possibility of front differential. granted i am new to all this stuff and inherited the truck knowing it had issues

 

I too have this problem but only when i brake hard. If I let it slow down naturally and then start applying the brake lightly it does less vibration but it is scary whenever i have to slow down quick and the whole dashboard of my truck is shaking.

 

I agree, it could be the needle bearing problem on the driver side of the front differential. Check out this video and also click on the East Coast Gear Supply link we provide in the video description. If you scroll down the page, you'll see the video they made discussing the problem with the Toyota differential housings.

https://www.youtube.com/embed/sXIfHArtvF8

 

Mine is the needle bearing 100% under my drivers foot. Pulsating between various speeds. It’s annoying for sure but I’m gonna send it. Stupid that this issue arises when you lift it. I’ll do that bearing soon but idk if I wanna mess with it lol

 

I just installed the OME kit on my truck a couple weeks ago. I think I have the beginnings of the needle bearing problem, based on the vibrations I'm feeling (very minor) and the description in this thread. My question to y'all is, is this something I need to get fixed asap or can it wait for bit?

 

I’ve been running mine for 10k miles now since I’ve lifted it. I wouldn’t stress so much about it. My question is will the needle bearing grenade in the diff if this isn’t looked at? I’ve never heard of the bearing doing that soooooooooo

 

The bearing will fall apart but it's contained in the end of the differential because it's got nowhere to go due to the shaft of the CV axle. But, run it long enough like that and you may cause damage to your differential housing or you're going to cause a gear oil leak because a lot of pressure is being put onto that outer seal.

 

The the inner end of the CV shaft also serves as the inner race for said bearing. It can be worn/scored by long time running with a geriatric bearing.

 

Seems like I’m gonna have to change it out then lol boy oh boy.

 

Cross post from another thread, but this happened to me today. I know I'm reviving a year old post, but I wanted to record it for posterity in case someone else is researching this problem.

I changed all my fluids two weeks ago, including my ATF, Front Diff, Transfer case, Rear Diff, and brake bleed. I filled all diffs and transfer case until oil was pouring out of the fill hole and then I plugged them.

This week, I installed a 3" lift kit and 1" diff drop kit.

Yesterday, I installed a new CV axle on the passenger side. When I removed the axle, diff fluid came pouring out. Well, I didn't bother to remove the diff drop kit and just refilled with oil until it came pouring out.

Today, I went to take it to get an alignment 20 miles away, and I started to get a grinding, moaning, buzzing sound by the time I got to the shop. The technician thought it was a wheel bearing going bad due and exacerbated by the new lift kit. So, I took it home and jacked it up,and prepared to take off the wheel hub out get a new bearing installed. Well, when I went to turn the hub to check the bearing, I noticed it was hard to turn. So I grabbed a screwdriver and jammed it into the disk brake and gave it push, and it turned the front 4WD propeller shaft! I had it in 2WD mode so it shouldn't have moved the shaft at all. So that was what was causing the vibration. The only thing I could think of next was to remove the diff drop and put it back to stock. I did that... but it didn't change anything. So then I thought about how fluid poured out of the CV Axle, and I refilled the diff with the drop kit installed. So, I decided to double check and take the fill bolt off and see if there was enough or too much diff fluid. No fluid came out. So I filled almost 0.25 of a quart before it came pouring out again, then capped it. Took it for a drive... no vibration. All fixed. Hopefully, I didn't cause any lasting damage to the front diff from the 50 miles I drove with the diff drop and with the low fluid.

TLDR; Make sure you have enough diff fluid in your front diff (and all your parts really) or else your front CV axles will catch the diff gears and spin the propeller shaft causing vibration.

 

So I need to take my diff drop off when I do my diff fluid change

 

No, I don't believe so. I've have a 1" diff drop on my 3rd Gen 4runner and I've drained and refilled my diff with the diff drop installed and I've had zero issues. I've never heard of the issue @Takomasak reported. Now with that said, I recently pulled my front diff for a regear and e-locker install video I shot with East Coast Gear Supply. When I reinstalled it, I started thinking about what Chase Perry (CEO of ECGS) said in the video about the amount of fluid the front diff holds and how it is affected by the size of the ring gear and whether the rig has a diff drop. I filled the diff until gear oil started spilling out but then I thought what if I jacked up the rig raising it by 1 inch to offset the diff drop to see how much more oil I could get in. So, I took a measurement from the ground to the bottom of one of my differential support arms. Then I got a jack under the center of the front cross member and jacked up the rig until I raised the support arm 1" higher than the previous measurement. I pumped more oil in and it didn't take much before it started spilling out again. It didn't seem like a significant amount, but who knows, maybe it could make a difference.

 

Good check Timmy! I've had a 1" front diff. drop kit on for well over a decade and have not had any obvious gear oil starvation problems that I was aware of. But I will fill the front diff after raising the support arm by 1" just to get that little bit of extra fluid in it. A few ounces of prevention may be worth a pound of cure.