Thread: Can You Say CARNAGE?

Originally Posted by Toasty

get yourself a good stack of 2x12's and make yourself a HUGE sawhorse, then you can get a pulley type apparatus and pull the engine out... though if you want to pull both out together, better to drop out from below.


you laugh, i know... but i've seen it done.

Crap, why didnt I think of this. Thats perfect. A few carriage bolts to hold the pulley and we got ourselves a lift.

Give me the pro's and cons of going out the top or bottom. You know what, belay that, I'll start another thread instead of hijacking my own so this one can stay on track about the actual damage.

CHAMPION breakage!

If its gotta blow, blow it good, it makes for better pictures

Here Scotty, maybe this will make you feel better! This diff was an aftermarket LSD unit that was street driven for 2 years in a customers car. I got a call one night saying the car was leaking a ton of trans fluid and it quit moving. I knew right away what it was but didnt expect to find this! His trans had a lot more metal in the pan than yours but luckily didnt get into the ring gear or planet and sun gears. He was in a pinch and needed the car so I put a stock HD diff back in and that was probably 8 months ago and luck is definately on his side as it is still running strong! Maybe its because I worked my majic on the trans 4 years ago lol.

WOW!!!! talk about a big Diff......

HA!!! I made a funny!! HAHAHAHAHAHHA!

Man, how in the world do you shear off a pin like that? That just blows my mind really.

If only my differential had looked that good when it came out, LOL. UR LOSN, UR A GOOBER, LOL.

That is the result of clutch plates on the side gears putting a ton of stress on the two center/spider gears. I believe this was an Intense Stage 2 diff and they used bronze bushings on the spider gears and would make a mess out of anyones fluid after a few miles. Once the bushings wear away to nothing you have tons of slop and bad metal on metal contact chewing into the cross pin until it is no more. Again this is 2 years of every day street driving on street tires, it may have gone to the track one or two times right after it was installed.

I decided after getting home today that I would dismantle my bad differential just to see what it would take. It was surprisingly easy until all the needle roller bearings start to fall out of the planetary gears. I could see where one would easily panic upon this happening. Fortunately the ATSG book I have kinda goes over reassembly.

Anyway, I thought these pictures would give one the full extent of the damage. Perhaps Trannyman can comment, but I remember there being or reading about an issue with the thrust bearings or something along that line, particularly during burn outs. It will make sense in a bit.

First, my sun gear:







In this pic you get a good sense of just how much of the gear is missing and how badly rolled over the splines are:




Okay, here is kinda sorta what the thrust bearing should look like under normal conditions:




Well, here is how mine came out of the differential:



I have never done a burn out in my car and while I can be a spirited driver at times and do make wot runs on occasion I dont abuse my car. So it was a mystery to me as to why the thrust bearing would be torn up like this and got me to thinking if this was perhaps the source of the whole issue.

Then I remembered the two track passes I made last year in Tulsa. I had my laptop hooked up and was measuring traction. I had lousy 60ft times (2.4s) because I was just flooring it instead of rolling into the throttle. I had never had a car that had such down low torque so I had to learn how to launch it. So my tires just sat there and spun until I hit second it seemed or close to it. I made two passes like that and still took out a Camaro RS and turned in a 15s ET.

But I am willing to bet my upcoming bonus that is where the damage started because the wheel spin was long and drawn out. Whether it would have helped out or not, I dont know, but I want a differential squirter now.

Anyway, I thought I would share.

That thrust bearing was probably damaged as result of all the metal floating around. Even destroyed its not going to allow the diff to walk around enough to cause your gear failure. The IS2 diff I pictured above had a bearing that was fine, I took it apart and it has some rollers that were worn so I replaced it anyways but I have never heard of that bearing failing from burnouts. I was kinda shocked to see what you had happen given your symptoms as that is not very common. Normall the cross pin and spider gears are junk. Doing one wheel burnouts puts tons of stress on the gears and since our great 7w trans fluid doesnt hold up well under extreme conditions like this the spider gear will actually get so hot on the pin they try to weld themselves together! Normally a bad diff only shows signs of wear on the pin and the two spider gears, everything else in good shape. This is a really big reason I prefer using the fluid blend that I do as it sticks to the parts better under such conditions and I am yet to see a diff failure to date since using my brew in these transmissions. When only one wheel is spinning then the diff spins at TWICE the speed of the speedo! So if the speedo climbs to 40 or 50 mph when doing a burnout with one wheel, the diff is really spinning the equivilant of 80-100 mph, but in addition to that speed the poor little spider gears are spinning fast as well and the ATF just gets flung off and there is no lube oil to prevent the carnage, well not for long anyways!

Dave, you amaze me. I dont know why it did not occur to me that the tranny fluid would actually get slung off the differential at those rotational rates. Makes perfect sense now.

As for the damage to the thrust bearing, I thought I had read somewhere, God only knows where, but that it was the source of issues during burnouts, however I far more trust your expertise than what I read in general on forums.

That said, I do wish to point something out if I may. Standard ATF is a bit thicker than a 7 weight fluid. Now there are some manufacturer and blending variances but I havent seen a standard off the shelf ATF that thin.

The Amsoil ATF I used has a Kinematic Viscosity @ 100*C of 6.8 cSt, which is equivelent to a 20 weight engine oil. The new Dexron VI, according to Mobil 1's blending anyway, comes in at a 5.83 cSt which put its very low on the 20 weight side, very close to dipping into the 10 weight viscosity. Depending on what numbers you are using though we may be talking apples and oranges.

Is there a particular weight you recommend? I can get 30 and 50 weight tranny fluids, Im just not 100% sure they are Dexron III compatible.

Very well could be. I never saved the info cause Differential damage was the furthest thing from my mind with the symptoms I had.

On the trans fluid weight that is just the number I was told a long time ago from the guy that pushed me onto the fluid mix I use and he said he preferred mixing it with Mobil NON synthetic Dex 3 fluid. I would believe 7 as it runs like water but I am always game for learning new facts! The fluid I use is a 30 weight fluid and comparing its thickness with trans fluid is huge. He told me some guys where having issues with corvette builds running in the 150+ mph ranges and melting down the geartrains in the 4L60E transmissions and switched to this fluid and it never happened again. He specializes with 4L60Es and 700R4 transmissions and his knowledge of them is awesome and I have learned a LOT from him over the years and is one of the most respected transmission specialists to me. Its thicker which helps keep it in place, lubricates better, and keeps parts cooler under load. Also if you think about it the center of these differentials is just a smaller version of what is in a rwd car, and they get at least 80w90 gear lube, we get water lol. Chrysler had the right idea on a few fwd models at there were seals seperating the diff from the rest of the trans and they used gear lube for the diff and atf for the trans, but because of the arrangement inside they had the room to do that.

You are bringing so many thing together for me Dave and tying in so many odds and ends now its not even funny. I am indebted to you for sharing the information you have. I havent even really tore into the transmission and Im learning a ton. How about that!

knowledge is power!

Originally Posted by UR LOSN

knowledge is power!

Now if only my car was as smart as Dave.

You guys are toooo much!

Originally Posted by Trannyman95

You guys are toooo much!

You so deserve it!!! And you know it sir