Symptoms of a bad rear diff

[JBurt]

So I've been chasing down a highway vibration for a long time. New u joint didn't fix it. New driveshaft didn't fix it. Without a rear drive shaft in it drives as smooth as butter.

It sometimes lurches going changing into P,R,D.

While I had the rear end jacked I noticed this rotational play while putting tires back on. The other tire is on the ground.



While I was messing with the driveshafts I could rotate the pinion 10 degrees or so back and forth by hand.

I'm pretty sure this is signs of a pretty worn gear set. With 7 PO's, 20 years, and 230k miles I wouldn't be surprised. I just wanted to hear opinions from people smarter than me.

Since I've got an e-locker should I have someone rebuild it or just go with east coast gear supply or someone similar? They've got e locker thirds for $665.

 

[JZiggy]

JBurt,

I'd suggest calling "Zuk" at GearInstalls.com. He does Toyota third members and is absolutely top notch. He installed a limited slip for me. His setups on his website are very fun to read about because he is so thorough and detail-oriented.

 

[diverscale]

look at the harmonic damper on the transfer case. I had the same symptoms and after changing the u-joint, driveshaft, wheel bearing, that was the culprit.

The rubber became too soft and the harmonic damper was hitting the ''stops''

 

[JBurt]

look at the harmonic damper on the transfer case. I had the same symptoms and after changing the u-joint, driveshaft, wheel bearing, that was the culprit.

The rubber became too soft and the harmonic damper was hitting the ''stops''

the harmonic dampener was causing rotational pinion play?

 

[UnderFire]

Should be plenty of local gear shops in your area. A fresh set of gears installed with new bearings and everything if you take your third in loose should be in the range of 400$.

 

[GrassFed]

If you have money to burn definitely throw some new gears in it. I don't know a whole lot but am I the only one that thinks all of this talk of new gears is premature?

I was chasing down rear differential problems in my Mom's car and I was reading as much as I could about them and I think a little rotational play in the pinion is ok, as long as the play isn't vertical. Although, that might pertain to the bearing only.

If it were me I would not replace the gears just yet. This might not seem too helpful, but I have also heard of people running thicker gear oil to see if it lessens the vibration further proving their suspicion of excess play.

Best of luck to you, chasing down vibrations is not too much fun.


Sent from my iPhone using Tapatalk

 

[thegipper]

You won't really know unless you open her up and check out the 3rd member. Check the backlash and see if it is within spec. Check the bearings for wear or damage but by what you said, it sounds like your 3rd member may need to be rebuilt.

I am no expert in this area so take it for what it is. I have worked on carriers on Jeeps a few times though...

 

[nissanh]

Yes, check the 3rd member. I think the backlash between the pinion and the ring gear should be 0.004 inches. It can be adjusted easily.
Take it down and post us some pictures. Use a dial gauge to measure the backlash. My cruiser has 0.016 of backlash in the front so I hear a "clunk" when doing between D and R. Do you hear it too?

If you are interested a shop in AZ near Phoenix is very famous to build toyota 3rd members.

 

[JZiggy]

Good input from nissanh -- you may be able to adjust the bearing preload yourself. Pop the third out and add some torque to the side bearing adjusters. Someone with more knowledge will be able to suggest how much would be appropriate.

 

[Buckaroo]

The wheel action in your video looks pretty normal to me. The primary symptom for diff wear or incorrect set-up (worn bearings/incorrect backlash) is noise typically described as a whine. You can hear it before you feel it.

Buckaroo

 

[JBurt]

Thanks for all the good points everybody.

One thing I forgot to add is that three is also an intermittent ringing coming from the rest of the vehicle most often while stopped in drive.

There is no whine coming from the rear end.

 

[diverscale]

the harmonic dampener was causing rotational pinion play?

I have a slight play in the pinion too, and even far from being a axle expert, a small play is normal afaik.

Again, just trying to help. Had the same symptoms, did check the pinion play too, and the culprit was the harmonic damper. Nothing was bad with it upon visual inspection only.

Oh and thanks for your smart ass response to my post attempting to help you.

 

[Buckaroo]

Would think it doubtful that it is diff issue based on your description. Will have to think more on the symptoms before I offer any suggestions.

Buckaroo

 

[mmendelscfi]

MY rear diff whines pretty bad. I'm getting ready to replace it.

what I was told is that when the gears start to wear you will get a whine when on the throttle and the whine will go away when you coast.

Thats what mine does.

 

[Buckaroo]

Thought about your symptoms.....maybe rear drive shaft balance? There are weights on the shaft that can come off plus if you drop the shaft and don't mark the correct location on the rear flange, you can reinstall it out of sync. Finally, try this free I-Phone app to check vibration associated with wheel balance and brake disc pulsation. Need to try it multiple times on different roads to get a good reading....lots of issues associated with wheel balance.

https://www.youtube.com/watch?v=SkiDVvs14ak

Buckaroo

 

[kolelt]

If its not clunking, and grinding, which would most likely be gears. Then its probably your bearings inside. If its your gears, YOU SHOULD BE ABLE TO TELL!

Get the truck of the ground, and put it in drive. Have someone listen underneath. Check if there is play on the pinion flange, driveshaft. I have a whine noise and its my rear diff bearings. Gears are fine. Also check your fluid

 

[JBurt]

I have a slight play in the pinion too, and even far from being a axle expert, a small play is normal afaik.

Again, just trying to help. Had the same symptoms, did check the pinion play too, and the culprit was the harmonic damper. Nothing was bad with it upon visual inspection only.

Oh and thanks for your smart ass response to my post attempting to help you.

No smart assness intended. I wondered if there was some relation. Too many times my ass has wound up being much too dumb.

Right now my dampener is off to clear the schrockworks skids that I have. The clunking/ringing/highway vibes have been there the whole 7 years and 50,000 miles I've had it. I'm not worried about it exploding.

It could be transsmission related (maybe a mount) or something with the t case.

I appreciate your help and willingness to input. Sorry the internet makes a poor medium for sarcasm and smart assness.

 

[johnbyebye]

MY rear diff whines pretty bad. I'm getting ready to replace it.

what I was told is that when the gears start to wear you will get a whine when on the throttle and the whine will go away when you coast.

Thats what mine does.

That sounds more like a pinion bearing whine actually. Unless you've visually inspected the gears and found them to be worn, I'd do some investigating beforehand.

 

[mmendelscfi]

That sounds more like a pinion bearing whine actually. Unless you've visually inspected the gears and found them to be worn, I'd do some investigating beforehand.

I should be able to check as soon as it warms up enough that I can stand being under the car for a couple of hours. How I envy those that live in a year round tinkering environment.

Here's the backstory. Had the cover start to leak due to rust and wasn't noticed until the gear oil ran low. Bought the Barnes 4WD diff cover and had a local welder install without disassembling and pulling the axle housing off the truck.

I didn't know any better. After a few thousand miles I could hear a faint whine on throttle. Only go worse over the next 10k. The gear oil is up but it immediately turns black after I change it

So I assumed some welding residue got in the housing but I also could have started it wearing prior.

I've got a used 3rd to try but I think in the end I might just get a rebuilt from east coast.

Unless I can just replace the pinion bearing easily? Not an area of expertise for me. Not much is actually.

Thanks for the tip.