Ugh. Pinion bearings gone after using Lucas

[jeep_boy02]

So before my Moab trip last year I did diff service, installed rock crusher covers and swapped to Lucas oil.

Now just over a yr later I've been having a weird vibe and noise between 25-30 mph under light throttle.

Dealership just diagnosed pinion bearings are out. Rear more so than front.

Anyone else ran into or heard of Lucas causing issues? Guess I'll throw new bearings in and use Amsoil this time.

need mods... too little time and money

[Demon85z]

How many miles on the truck? I'm usually a believer in Lucas products but mainly their snake oils. I can't tell you how many times I've "saved" a transmission in a car and got another 20-30k miles out of an otherwise blown situation. Or their oil stabilizer and power steering fix. My 06 cummins has moaned the last 5 years. I Add some lucas each year and keeps on ticking and quiets it down..what weight oil did you go with? I'd also get a second opinion. I hope I don't offend anyone with this statement but dealership mechanics for the most part are nothing but part changers and code readers. The long lost art of diagnosising a problem the old school way. I have a hard time believing both front and rear are out. I've got 380k on my 06 and haven't had more than a rear leaking pinion seal due to a failed carrier bearing.

[jeep_boy02]

75 90 like manual states.

It's got 156k on it.

I just don't see a coincidence in all was fine, then once I used Lucas I started getting vibes and a drone.

First dealer said between tires and exhaust we can't tell what it is.
Today I described it and watched as they pulled it inviter a drive. The guy got a stethoscope, put it in air, another tech put it in gear and accelerated as he listened to end bearings, carrier, and pinion.

I'm pretty sure I could hear it across the shop too, wasn't anything I've heard before neither but I'm also always in the truck when driving.

On the second opinion, I agree too but not because I think they're trying to just sell me stuff. Although they said front and rear and he didn't have it in 4wd nor listen to front. But I can feel it in wheel and pedals so I was thinking hubs.

need mods... too little time and money

[jeep_boy02]

Rear pinion seal has been leaking and I've fought with warranty on it. In the end they pulled the "we'll do all we can to negate your warranty" so it's now not going to dealer for anything except to see if they can pinpoint something

need mods... too little time and money

[Demon85z]

Have you attempted to drain the oil and refill? I'm usually a valvoline guy but I like to run royal purple in my diffs. Have you checked all your axle u joints? I've had some odd noises and vibration when those go every 50k-75k miles or so. Usually when diffs go the sound and vibration increases with speed. It could be the torque converter as well. That would be something that would vary on tone and speed. I've had transmission bands create vibration and noise too until I shifted out of them.

[jeep_boy02]

Thought of trans. It doesn't change when I shift through gears. Always at 25-30, no change in pitch with RPMs or whatever gear it's in.

It literally could be anything, I'm still on all factory everything except brakes and balljoints.

need mods... too little time and money

[Retired BLM Rig]

My first suspicion would be U-joints if I was looking for a drivetrain vibration. The noise can telegraph up and down the driveshaft tube and make it sound like it's coming from somewhere else. You can't put a stethoscope on a spinning driveshaft. Look for rust stains coming out of the U-joint cups by the rubber seals. Jack up the axle and feel each joint for looseness, twist, push up and down and side to side. Any defect will cause runout and vibration in the spinning assembly.

A bad inner pinion bearing would make a whining noise on acceleration and just about go silent on deceleration, due to a change in thrust on the bearings. The opposite is true if it's the outer pinion bearing. The noise would get louder with speed. When Pinion bearings go bad, if it's not fixed early enough, it can destroy the ring and pinion gears due to changes in backlash between the gears.

Bad hubs can be determined by doing a slalom left and right, you'll hear a noise change with lateral force.

Since the front driveshaft is spinning all the time on a 2010 (unless you have free spinning hubs), you could remove the front shaft and drive the truck to see if anything changes. It could be a worn out centering ball in the double cardan joint. It's supposed to be greased at every oil change (quick lube places never address grease fittings, their attention to detail is shameful). Here's a link to a video with good animations and how-to: https://www.youtube.com/watch?v=yQANDDo-C8A

Here's another good video explanation: https://www.youtube.com/watch?v=lyctVMyjWk8

Since the front driveshaft is directly under the drivers floorboard, this could explain why you feel the vibration in the steering wheel and pedals.

Keep us posted.

[jeep_boy02]

Tore it apart to inspect as it did seem to have a tiny up down movement on the yoke...

Seems the pinion nut backed off some or maybe the snout stretched???

Tightened up the pinion nut and backlash measured 16!

Spinning with a drill it was a lot louder after tightening too so new R&P and install kit on way.



need mods... too little time and money

[jeep_boy02]

New Yukon R&P in... no noise/vibes or anything from like before but the shudder when turning from a standstill is actually worse now.

Think something got muffed up with the helical LSD???

need mods... too little time and money

[gtomike60]

Can you feel it in the steering wheel?
Check the front axle u-joints
If they are worn,will cause what you're describing when turning

[gtomike60]

Can you feel it in the steering wheel?
Check the front axle u-joints
If they are worn,will cause what you're describing when turning

[Retired BLM Rig]

They say that the helical LSD doesn't need friction modifier but after I did a fluid service on mine, I had a shudder as well. I added friction modifier and it went away. Give it a try.

[jeep_boy02]

Ok. I gotta change fluid after 500 Mike gear break in anyhow

need mods... too little time and money

[cb1987]

drained the factory oil at about 1k mi to get out any debris that may of been in there. refilled with regular 80w90 and its working fine after 13k. nothing strange at all.
many of the oils are predosed with friction modifiers so check the bottle

[JRHPWRWAGON06]

They say that the helical LSD doesn't need friction modifier but after I did a fluid service on mine, I had a shudder as well. I added friction modifier and it went away. Give it a try.

Interesting, I've always used redline without modifier. 75W90NS.
https://www.redlineoil.com/75w90-ns-gl-5-gear-oil

[jeep_boy02]

Small update. Changed fluid, cleaned and adjusted mag, refilled with Amsoil servers gear 75/90.

Felt a bit better but was still there. Took a 1k mile tow trip and on way back home I noticed it a lot less. Now , a couple weeks later, it's all back to normal as far as I can tell.

need mods... too little time and money

[Mule007]