Limited Slip Differential clutch chatter??

[btanchors]

Hello everyone,

I have a 2006 Toyota Tundra Double-Cab Limited 4WD with Limited Slip Differential. At around 5,000 miles, I replaced the lubricant in the Limited Slip Differential, Transfer Case, and Front Differential with Amsoil Severe Gear 75W-90.

At around 6-7000 miles, I began to notice my passenger side front tire was wearing too much on the outer edge. At the same time, I experienced what *felt* like a "scrubbing/rumble/vibration", when accelerating from a stop with the steering wheel turned. It was as though the truck was in 4WD mode on dry pavement, only I was not in 4WD mode.

So I took it in for an alignment...The alignment guy said my alignment was way out. I told him about the vibration and he told me it's quite possible it was due to the alignment being out, hence the "scrubbing" sensation. I thought initially I had the problem solved. But I soon realized that was not the case.

The problem is still happening - It happens when I begin at a dead stop, with the steering wheel turned, and step on the gas. The sensation only happens for about a second or less, and doesn't happen once I am above 5-10 mph.

If I accelerated from a dead stop with the steering wheel straight ahead, the sensation doesn't happen.

I tried going to an empty parking lot and doing lots of tight figure-8 turns, at both 5 mph and 10 mph, but cannot get the sound to happen.

Am I experiencing LSD clutch chatter? Assuming the problem IS LSD chatter, is this how that problem would normally manifest itself? If I go ahead and add the LSD additive, and that turns out NOT to be the problem, will the fact that I used the LSD additive cause any problems, even if it was unneeded?

 

[btanchors]

I meant to add in my above post that I did NOT put in the Amsoil "Slip Lock" additive...The instructions on the Amsoil SVG 75W-90 indicates it is compatible with most LSDs, and to use the additive only if clutch chatter occurs. I have read that others in this forum are using this gear lube without any signs of chatter, on the exact same model of truck and LSD. So I guess my bottom line question is, how do I recognize LSD clutch chatter?

 

[Steve S]

Toyota may have some differential problems ,do a search or ask the dealer, if there is a good one close to you.

 

[Pablo]

Doesn't sound like a LS problem to me, particularly since it's not in 4WD when it happens. Only on the outer edge of the tire? Strange.

BTW Putting the LS additive in won't hurt anything.

 

[PineMountain]

2003 4wd Tundra w/LSD owner here..
Potentially two seperate issues-
If there's something wrong with your front end - as evidenced by the tire wear problem- then the differential or axles/hubs could be faulty.
However, a common problem with Tundra rear-ends is dragging brake shoes- feels like differential chatter when making a moderate turn. It's usually most pronouced on a cold (as in first thing in the morning)start. Causes include stuck(corroded) parking brake pivot arms and inadequate lubrication of the backing plate/brake shoe contact points.
You might want to check your rear brakes first.
As an aside, my '03 has an Eaton LSD... not sure about yours... there's been many discussions on one particular Tundra website regarding lube/chatter problems. Eaton only recommends a GL5 mineral gear oil (I'll duck now....)

 

[unDummy]

The Tundra diff is stiff. Definitely add a bottle of LSD additive to it NOW. If the problem doesn't go away, then it isn't the diff. Check tire PSI, lug nut torque, and for any suspension looseness.

Tundras tend to chew up front tires. Only lead footed drivers have rear tire issues.

Are you rotating regularly?
Any mods?

 

[Andrew]

My experience with LSD chatter:

When I bought a car with an LSD for the first time, the diff fluid was changed but no friction modifier was added. The car would behave normally until 2 or 3 mins at continuous high speed (eg. on highway/motorway). After stopping at the first set of lights off the highway/motorway, pulling away would result in a hideous noise that sounded like I was dragging a steel toolbox behind the car. I could never reproduce the problem unless I drove at medium - high speed for a while. If I stopped for 5 mins the noise would go away.

Diff specialist told me to add the friction modifier, problem solved.

The friction modifier does as its name suggests. Without the modifier, the LSD overheats and "chatters". Live and learn.

 

[Doc8404]

can you put too much friction modifier in it?
i had/have a slight rear diff leak and thought about "topping off" with my Amsoil FM....however, i did add a bottle when i filled the rear with Amsoil

 

[Craig in Canada]

LSDs can be built several different ways, some don't need any additives at all because they don't even have traditional clutches. That may be why some people report not needing any.

I'd say that you're definitely looking at a diff issue - get that additive in there NOW, you're wearing out your diff and all kinds of other things.

Your alignment was probably way out and the diff locking accelerated your wear by thousands of miles. Also, it was only accelerating wear when turning and perhaps your suspension geometry rides on the outside edges during turns. Not sure how you couldn't feel an alignment being that far out ???

 

[btanchors]

All,

Many thanks for your comments. I have a 4-ounce bottle of Amsoil Slip-Lock Additive and I am going to add it tonight. The bottle says it treats 2-4 quarts of gear lube. My Diff has exactly 4 quarts in it, so hopefully, one bottle will be enough. I will report this time tomorrow to tell everyone whether this affected the problem...

Pine Mountain - interesting you should mention a dragging rear brake as a possible cause of this problem. That's the way my wife describes the sound - Like a brake that is dragging slightly. The reason why I am leaning against this being a possible cause - 1) If it was a brake issue, why doesn't the problem happen when the steering wheel is straight, and 2) Given the truck is new, and we started noticing the problem at only 6-7000 miles, I would tend to doubt corrosion would already be at a point to inhibit proper operation of the brakes. However, the sound could well be caused by this. If the friction modifier doesn't solve the problem, I will look at the brakes next.

 

[Hirev]

My 06 Tundra was recalled because of bad lower ball joints has yours been checked or fixed???

Is this a mechanical LSD or a electronic LSD? The 06 Tundra used a mechanical LSD if it does not have the VSC option.

If your 06 Tundra has VSC as an option than its is a electronic activated LSD.

Have you tried putting all 4 wheels off the ground on jack stands in 2 WD mode spinning each front tire by hand to physically check and see if your front drive line is not spinning? You may want to do so. I would also do this from what you are describing.

The best way to tell if you have enough LSD additive on a wet clutch type mechanical LS is to pull up to a stop sign (straight on) with good dry pavement at a dead stop with window down. Make a sharp turn 90 degrees to your right. Do this test with the gear oil cold and also well warmed up. If you can hear your tire chirp going around the corner or get real harsh feed back than you should add LS additive in small increments at a time. No more than 2 oz at a time before retesting.

If you add to much LS additive it will result in accelerated to rapid wear on the wet clutch used in the mechanical LS used in your unit. Also the clutch pack needs to stay locked up for the most part to keep gear oil temperature from getting out of hand.

I've had very good results on my Toyota LSD just using plain old $3.79 a qt Valvoline 85w-140 "high performance" dino gear oil with no extra LS additives. It already has it mixed in. Toyota recommends changing out LSD gear oil every 15K to flush out clutch and iron debris so I can't see using a synthetic for such short OCI.

I will probably get flamed for this but.... Most LSD to their best with dino and synthetic blend gear oils rather than full synthetics from my experience with them.

 

[btanchors]

Hirey,

My 2006 Tundra was not included in the ball joint recall. It has a manufacture date of December, 2006, so it was among the last Tundras made for that model year. By that time, corrections had already been made on the production line.

Tire pressure on all four tires is at 35 psi - a bit higher than the specs call for. The tires are the stock 265/70R17s that came with the vehicle. No mods have been made to it.

I am planning on having the drive train fluids (Diffs, front and rear, as well as the transfer case) analyzed at 15K miles...Since I changed it at 5,000 vehicle miles, the gear lube will have been in service for 10K miles at that time. If there is a problem in any of the units, hopefully it will show up in the UOA.

Also - My Tundra does NOT have VSC - only a "mechanical" LSD....

 

[sharp spurs]

I have had recent experience with this. Vehicle is a 2006 Toyota Tacoma with LSD. The 30K maintance was performed, and the rear diff. fluid was changed. At the time I informed the service department that it required 75-90 gear oil for LSD rear ends.

On about the 3rd day after the service was performed the clutch packs would "rumble" in a turn while cold. Once warmed up the vibration would subside. Vehicle was returned to the dealer to be checked out. I speculated to the service dept that they may have put non LSD fluid in the rear, resulting in the rumble.

Dealer replaced the fluid with Royal Purple, (not sure of the weight) and the problem went away. At 35K miles the rear was acting up worse than before.

Back to the dealer to be checked. They were unable to duplicate. I informed them to hold it overnight and I would drive with technican the next morning. Result, I could reproduce the rumble at will.

For what ever reason, Toyota replaced the rear pumpkin gears, clutches, and seals. I got the truck back on 10/30/07 and as of today problem has been resolved

 

[btanchors]

Ok guys,

I just added 4 ounces of the Amsoil Slip-Lock additive - Note that the Diff had 4 quarts of gear lube already in it, so this is a ratio of 1 ounce of additive to each quart of gear lube. I then drove all over, making lots of turns, and a couple of figure-8s, and some 360-degree turns in each direction.

So far, I have been unable to duplicate the problem. However, as sharp spurs notes above, my problem also tends to be intermittent, and worse when cold. We'll see tomorrow morning, after a cold Halloween night soak, how it performs...I will keep you all posted.

 

[btanchors]

Sharp Spurs -

Another point - It's interesting that your dealer used Royal Purple...I noted that when I drained the factory fill of gear lube out, it had a definite purple hue/color to it. Makes me wonder if they filled it with Royal Purple at the factory...Is any other vendor's gear lube purple in color?

 

[craigaz]

I had the same problem on my '05 tundra after switching to Amsoil without adding the modifier. I ended up getting a 4oz bottle of modifier from the dealer and now she's quiet as a mouse!

 

[sharp spurs]

btanchors,
I am not sure the color of the OEM fluid. Dealer said that they replace with RP on all LSD diff's. I really don't have a clue if the Syn RP just masked the existing problem or not.

From the 30K service until I returned the truck, it was driven approx 500 miles. Was damage done from the possibility of using non LSD fluid in that time frame? I would speculate yes.

Again, it would only act up when cold for a very short period of time.

As a side note, I am looking at the invoice from yesterday and the oil used for the new rear pumkin gears states "Royal Purple 75-90". Time will tell.

 

[Doc8404]

Quote:

---

Ok guys,

I just added 4 ounces of the Amsoil Slip-Lock additive - Note that the Diff had 4 quarts of gear lube already in it, so this is a ratio of 1 ounce of additive to each quart of gear lube. I then drove all over, making lots of turns, and a couple of figure-8s, and some 360-degree turns in each direction.

So far, I have been unable to duplicate the problem. However, as sharp spurs notes above, my problem also tends to be intermittent, and worse when cold. We'll see tomorrow morning, after a cold Halloween night soak, how it performs...I will keep you all posted.

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FOUR qts? wow....my F150 takes 2.2

 

[Craig in Canada]

Quote:

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I then drove all over, making lots of turns, and a couple of figure-8s, and some 360-degree turns in each direction.

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...and now that you're done looking goofy, I hope your diff will behave

 

[widman]

Limited slip clutch chatter happens on U-turns and similar turns. Not straight roads. listen on a u-turn on asphalt. My 95 4Runner does not need extra additives, but my 99 4Runner needs it. I've never taken them apart to see the differences, but they behave differently.