Limited Slip Differential - In My Dreams!!

[Archive]

I have a nice icy patch on my driveway that's only on the right side. Driving up the driveway, about a 10% grade, yesterday I got stuck halfway up. Left rear tire on dry pavement, not moving. Right rear tire on the ice, spinning away. Pushed in clutch and tried starting as slow as possible, same thing - right rear wheel spinning. Had to back up and get a running start to get over the ice patch.

What the heck is this about?? The whole purpose of the LSD is supposed to be to deliver torque to the rear wheel that has traction. Does not do the deal on my truck, that's for sure. #ad


Anybody else have the same results? Is mine just busted? This is bull-poop. #ad


------------------
2001. 5 2500 QC, SB, 4x4, ETH 6-sp, 3. 54 LSD, SLT++ (everything but cab lights), White over Silver, Tan leather. 4-wheel disk brakes. Delivered 8/31/00.

 

[Archive]

My LSD worked pretty good when my truck was brand new, but as soon as I changed the axle oil the first time it started slipping easily, even with the proper amount of friction modifier. Any time the left tire has traction and the right doesn't, it will spin easily even on the level #ad
. It does seem to work better than an open diff though since it goes in the snow pretty well for a 2wd with stock tires.

Vaughn

 

[Archive]

Try applying the parking brake slightly. This should cause the LS to engage. I DO agree you should not have to do this... My Trans Am LS from the 70s had no problem locking in these stiutations, don't know why Dodge can't make a better LS.

------------------
2001 HO 6 speed Regular Cab SLT 4x4 3. 54 anti spin 2500. Used for the daily grind and sneaking away to some secret Baja beaches toting a cabover

 

[Archive]

Sorry to hear this - Mine works great. I plan on changing over to a synthetic some and hope I don't loose the grip.

------------------
'99, 2500, QC, SLT, LWB, 4x4, ISB, 5sp, 3. 5xlsd, tow pac, HD tcase, tow mirrors, camper pac.

Alias: Martin Allen Bursell (posted per guidlines)

 

[Archive]

It sounds as though you have either too much friction modifier or you don't actually have the LSD. I would check it out either way. Irrespective, in my experience I've found it to be most beneficial to change the gear oil within the first 1k miles. From various differentials I've set up, I've discovered that most of the break-in wear takes place within the first 100 miles. Add only enough friction modifier to eliminate chattering when making a tight turn under LIGHT throttle. Too much friction modifier will diminish the LSDs effectiveness, to the point of acting like an open differential.

Ski Bum, try applying the brakes (lightly) while accelerating from a standstill on two surfaces with uneven friction coefficients (such as bare pavement and ice as you stated in your post). You should be able to obtain traction. If not, it's time to look further. Next test; jack up the rear end so both tires are off the ground (remember to chock. . not chaulk the front wheels for safety). In neutral, spin one rear tire, with an LSD, the other tire will also spin in the SAME direction. If not, you have an open differential. If so, Dana probably rewarded you with too much friction modifier. Just change out the gear oil and you should be fine. What ever you do, DO NOT add a whole bottle of friction modifier at once. If friction modifier is required, add it at one ounce increments... I usually sneak up on it a half ounce at a time.

I just changed the front and rear gear oil in my 4x4 Ram this weekend, switching to Amsoil's Series 2000 75W-90 synthetic. Without adding ANY ADDITIONAL friction modifier, I have not experienced any chattering while making turns. The marks left on my gravel driveway/road, from the inside wheel (while turning onto the "main" gravel road) signify that the ratio of friction modifier to gear oil is close to perfect. #ad


[This message has been edited by John (edited 12-04-2000). ]

 

[Archive]

John: Let me be sure I've got this right. The friction modifier makes the rear-end lube oil slicker, and the more you add the less the LSD clutch surfaces grab? What happens if you don't add any friction modifier to the lube oil? If the LSD does "chatter" is this something you hear, or feel, or both?

I am going to try the parking brake trick tonight - that ice patch seems to be there for the season. Next step - change rear-end lube and experiment with friction modifier. I still have the factory lube in it, and argee that I should have changed it by now anyway (due to break-in gunk).

 

[Archive]

Johns got it right fellas!!! the friction modifier is to reduce the banging of the rear diff when making turns. the banging was the LSD unlocking in the turn, people complained so that was the cure. Just like the soft shifting autos, people complained about the harse shift so they lowered pressure and we all know what that did to the auto.
Anyway less modifier and the LSD will work a whole lot better!! Regards Pete

 

[Archive]

Hola Skibum, I installed a Dana PowerLoc LSD at 3000m, after discovering mine had an open diff from the factory. I now have close to 50k, I'm in the snow along with constant off-road conditions. It works like a charm. I've changed the fluid at 25k adding a minimal amount of friction fluid, no difference.

------------------
98 24v 2500HD SLT 4x4 auto, longbox/regcab, towpackage, slider, cab/fog-lights, PowerLoc, factory tow hooks, flaps, 265x75 Michelin A/S, Firestone Ride-Rite air springs, LeerShell, StarCraft-StarMate softside camper, bedmat, K40radio/firestik, real red rig. Unflashed
46k asmilin’

 

[Archive]

I had something similar happen to me.

I live on a narrow dirt road and the other day coming up a hill near my house I met the school bus coming down. I stopped and pulled off the side of the road to allow the bus to pass. The left rear wheels were on the road and the right off the road in loose dirt and leaves.

After the bus passed I put it in 2nd, let out the clutch, and didn't move. A check of the mirrors confirmed the right rear wheel was spinning and the one on road wasn't. I had to put it into 4-hi to get out.

Now, I'm certainly aware that a 3500 can get easily stuck since there isn't much weight in the back (although I do have 700 pounds of sandbags there at the moment) and the the stock LSD isn't the best in the world.

But this is a new truck (7500 miles) with 4. 10 gears and the LSD (so it says on the sticker). I'd expect better.

I'm beginning to wonder if DC didn't cut a few other corners. I'm gonna have to pull the rear cover sometime to check that the LSD unit was actually installed and fill it with proper fluid and friction modifier.

------------------
'01 ETH/DEE 4x4 QC SLT 3500 4. 10

 

[Archive]

i had the same thing happen last year with my 1 month old ram , i wheel on dry pavment , the other 3 in the snow/mud trying to back up , had to lock it into 4wd to get going . i had my rear cover gasket replaced a couple months ago , i noticed recently that it chatters when i go around a corner , i don't think they added any modifier , it doesn't say anything about it on the invoice , not surprised.

johnny winona , a dana power lock ? or was that a traction lock ? they are different animals , and i didn't think they made the power locks anymore , what do you have a 70 or an 80 , if i can get one this POS traction lock will be history .

 

[Archive]

Mopar Muscle:
I just had my rearend cover gasket replaced too (was leaking). On my invoice they listed two lubricant part numbers, so I assume one was the friction modifier. I haven't had a chance to check it out since, though. I don't hear any chatter.

------------------
2001 2500; SLT; 4x4; QC; LWB; Auto; 3. 54 LS; 265s; Camper; Tow; Sliding Rear Window; Travel Convenience Group; Cab Clearance Lamps; Forest Green

 

[Archive]

mrMoparMuscle
It is a PowerLoc, from WestCoast Diffs, installed 03/99. WestCoast Diff said that it is stronger, with a more postive lock then the OE, LSD. I don't have their p # handy, but they are ez to find searching the web. By the way, I only have a Dana 70, because of the auto, I spend time in stop and go city traffic as well as fairly heavy off-road stuff. If a 6sp was offered in 98 I would more then likely have a 80!

------------------
98 24v 2500HD SLT 4x4 auto, longbox/regcab, towpackage, slider, cab/fog-lights, PowerLoc, factory tow hooks, flaps, 265x75 Michelin A/S, Firestone Ride-Rite air springs, LeerShell, StarCraft-StarMate softside camper, bedmat, K40radio/firestik, real red rig. Unflashed
46k asmilin’

 

[Archive]

My LSD works super. I have Amsoil ser 2000 76W/90 Gear lube only in it. My only problem is rear tire wear, if I try to push on the go peddle at all in the corners it breaks the outside tire loose.

My I think LSD clutch have to be broke in to make it work effectively. For the first 30K(now have 95K) on my truck I always had 1600 - 2000 pounds in the bed, my tire life was better and it seemed to breakin the clutch packs. Give it some time and don't sit and spin the one tire and I'll bet the LSD will come to life.

------------------
EAT'M UP
97 2500 Club 4X4 3. 54, Forrest Green/Driftwood, LSD 5 speed, & Psychotty Air System, TST #11, 370 HP injectors, timing at 16 deg. , 16CM2 housing, AFC spring kit, Geno's Exhaust Blanket, TST EGT gauge & 0-60 boost gauge in A Pillar, Cat-be-gone, 4" Dynomax Bullet muffler, Crome 4" turn down, AmsOil Through out, Geno's trans filter kit, AmsOil Bypass system, Lund Winter front, Leer Cab Level Shell Driftwood , 255/85R16, Dyno'd 342 HP pre injectors & turbo housing *NRA/USPSA member and proud of it*

 

[Archive]

Just remember folks. A limited slip is just that. A "limited" slip. Not a locker. If you want NO SLIP, you need to go to a locker.

 

[Archive]

Recently saw good evidence that the LSD on my '01 ETH DEE 4 X 4, works well. On an Elk hunt I was driving up hill on a narrow unpaved road with a buddy right behind, both in four wheel drive. There was about 6 inches of well packed snow.
Around a curve came a truck pulling a big 5th wheel horse trailer going way to fast. It was a simple choice--a head on collision or take to the uphill ditch,The other side was a LONG way down. Buddy and I both took the ditch (about 14 inches deep and fairly smooth. After the Idiots rig passed, I pulled out with no difficulty. My buddy with a 4 X 4 with out LSD tried and tried and could not get out. We had to winch him out. The only diff. we could see was the LSD.

Vaughn

 

[Archive]

It's my understanding with a LSD, when one wheel spins, you apply a little brake pressure and the LS engages the other wheel.

Just my 2c

------------------
2001 Ram 2500HD 4x4 Quad Cab, Slt, Auto, Long-bed, 354 Anti-Spin Differential, White Clear Coat / Light Driftwood Satin Glow, Trailer Tow Group, Snow Plow Prep, Camper Special, Brakes Pwr Disc/Drum, Rr Anti-Lock, every thing but leather.

 

[Archive]

Whatever happened to Thorsen differentials? These things were relatively fool proof and didn't require any snakeoil in the pumpkin.

*JE*

 

[Archive]

John, I changed my diff oil at 2500 miles (and was already very nasty looking!) and filled it with Mobil synthetic 75W90 since I had it on hand. The clutch packs were obvious, definitely LSD. I don't recall the brand of modifier but I added it and did the figure 8 thing and added it until it quit chattering. It still chatters very slightly, mainly when backing up. Another oddity, it seems to hook up MUCH better in reverse. A few weeks ago I was parking on a wet grassy incline. I put it in reverse and tried to back up it, certain I wouldn't make it with no weight in the back and a Cummins in the front. But it climbed it hiney first as if I were on dry asphalt!

I thought friction modifier was necessary because without it the lifespan of the clutch packs would be reduced considerably. If it doesn't really make a difference then I'll go with a lot less next time. John, does the Amsoil stuff you added already have friction modifier? It's time for another fluid change so guess I better order some.

Vaughn

 

[Archive]

I've never had the no-action problem on my Vette, but constantly had the banging problem until I switched to Amsoil racing gear oil. Now I don't use additive and have NO banging! I use it in my 89 Dodge too, but have no limited slip option.

------------------
http://coffeewithJesus. homestead.com/web1.html 89 1-ton, Amsoil System 3000 5-30,K&N air filter, cleaned-up exhaust, Dynomax straight-thru, rebuilt pump, 12cm wastegated turbo (not installed), thermostatically controlled twin 14" Permacool electric fans, intercooler (installed, not plumbed), modified 518 OD transmission, Gear vendors OD controler, R-134 refrigernt, louvered front fenders, 93 aftermarket smoothie grille, new Dupont Chroma-colr black, black-and-red rubber rubstrip, Cummins badges, black headlights; 78 35'Avion, 93 Lance 900 slide in with generator and power jacks. Jesus saves!

 

[Archive]

Vaughn, I can tell you from experience that not using friction modifier causes clutch pack problems. I have a pro street '41 Willys Coupe with 18" Mickey Thompsons on the rear. With the horsepower and torque, Currie 's (rear end guys) recommended an Auburn Posi. I somehow missed that there needed to be some modifier. I drove the car for awhile, and it sounded like I was snapping axles. I thought that the problem was in the trans, and by the time I figured out and called Currie's, damage was done. I drained the oil and it was a mess. The pod had to be sent to Currie's and it was expensive. To make a long story short, when I changed to synthetic gear oil on my truck, I added the modifier. I remembered what the oil from the car looked like. I figured out what the amount was (%) as recommended by the service manual. There doesn't seem to be any problem with the rear working the way it's suppose to. Just another opinion.