Unlimited slip differential.

[Bad340fish]

What kind of responses have you guys gotten from your dealers about limited slip complaints. I have had it with this POS differential. I had about 5 or 6 situations in the ice sofar that i could have gotten out of with a halfway functional limited slip. And this weekend it went over the edge. I have to swing kinda wide to get into my driveway. Well my left front had to go partialy up the curb. I let the clutch out in first(dry pavement)and it sat there and spun one tire at idle. That is NOT anywhere near the way that thing should work IMO. I do have a very good dealer but i bought this truck used and not from them. So i wonder what they will say when i take it in. What have you guys run into.
Truck has only 23K on it.
Sorry for the long post, just venting #ad

Clark
PS. I know it does have the LSD because i got the window sticker with the truck

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Clark
1999 2500 QC SB 5spd Flowmaster 3 chamber
1968 Barracuda Formula S Viper Blue 11. 98@112

NHRA member for life

 

[RKohn]

Mine's going back to visit the dealer Thursday. I'll try to post the results by Friday.

It was fine till I had them fix a leak last month. I think they refilled it with too much additive. I'd rather have a little more chatter and a lot more traction. Right now I can't move the truck with one wheel jacked up and that ain't cool.

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Y2K Red Stealth Sport 2500 4X4 QC SLT+, 5-spd, 3. 54 anti-spin, 265-75-16 LTX’s (There ain’t no such thing as options, cause ya gotta have it all, including: DC’s dead cow/vinyl interior and don’t stop anti-lock brakes. ) Stock, but not for long. Oops, too late. What silencer ring? (More fun than my 98 SST)

 

[Chris N5CWM]

I agree. POS un-limited slip. The best LSD I
know of, for the money, is the Eaton "positive
Locking diff" that is optional on most GM
vehicles, mainly pickups etc. The diff has
the usual clutch pack and springs, and it
also has a flyweight assembly that will
engage a lockup (I'm not too sure as to how
it works, but it does! #ad
). I had one in my
'94 Chevy 3/4 ton 4x4. I could put one tire
on sand or pinestraw, the other on asphalt.
Once it starts spinning, about 2 seconds
later, clunk! You were off! Usually left a
long black mark on the asphalt as well.
There has to be a better setup for our Dana
70/80 rear axles.

In most situations, like slippery boat ramps
the LSD in our trucks works fine. Just under
high load situations like yours the are not
worth a darn.

Here is a link to the Eaton LSD. They used to
have some cool videos you could download that
demonstrated a standard diff, limited slip,
and their locker. Eaton Locking Diffs

-chris

 

[jkern]

i have always thought that mine has been a little "loose" as well, in most wet, or even dry off road conditions, i can make one rear wheel spin, but not the other, however on snow , if i goose the throttle, both will spin and put the truck into a slide very easily. it seems that it works when i don't want it to, and doesn't work when i really need it!

can anybody suggest a good test, or post the parameters for testing and diagnosing a bad LSD?

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Jeremy Kern
1999 2500HD 4x4 QC,SB, ISB, 5spd, 3. 54LSD, 33x12. 50 cooper STT's Denver off-road bumper with Ramsey RE12000, PIAA series 520, Rancho RS9000's, heavy ft. springs, JVD Torque Enhancer, DiPricol boost and pryo gauges, and a bunch of other little things! www.geocities.com/phrn30 for pics!

 

[LSMITH]

Mine works perfectly. If it didn't it would go back to the dealer until it did.

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99 2500 QC 4X4 AUTO SB 24V LARAMIE SLT 3. 5 LSD 285-75-16'S Everything but leather NRA Member

 

[Big-D]

Just visited my 5 star with this same problem last week. While looking me directly in the eye he stated, "LSD are just that, Limited Slip". I asked what does that mean? He said in so many words that the differental is not a "locked rear end" and will not always provide a transfer of energy to the wheel providing resistance. I couldn't believe what I was hearing. Stating my views about how I felt it should work ended in a test drive to a nearby gravel road. At that point he put the transmission selector in low, place one foot on the brake pedal and applied some torgue to the drive line. After releasing the brake both wheels spun. He then told me as we examined the marks in the gravel, "your LS is working just fine, see there both wheels were turning".

I plan to change the oil myself and add the friction lube a little at a time until cornering is properly acquired. Wouldn't let the dealer do it for fear of what I might get back after his demo ride. Dave

 

[jkern]

dave,

does the addition of more than perscribed friction modifer make the LSD work better (lock up more) or worse. not sure i worded that right, but i want mine to be the next thing to a locker.

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Jeremy Kern
1999 2500HD 4x4 QC,SB, ISB, 5spd, 3. 54LSD, 33x12. 50 cooper STT's Denver off-road bumper with Ramsey RE12000, PIAA series 520, Rancho RS9000's, heavy ft. springs, JVD Torque Enhancer, DiPricol boost and pryo gauges, and a bunch of other little things! www.geocities.com/phrn30 for pics!

 

[Michael Hughes]

The more friction modifer, the more it will slip.

 

[Bad340fish]

One problem with the Eaton is if they catch to hard they spit the carrier right out of the back of the rearend. Saw a truck ata 4 wheel drive shop here in town that did that. He was carrying a load and one wheel dropped into a mud hole it started spinning the locked the eaton and chunked parts. My truck will go in next week if i get time so i will see what they say.


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Clark
1999 2500 QC SB 5spd Flowmaster 3 chamber
1968 Barracuda Formula S Viper Blue 11. 98@112

NHRA member for life

 

[One Old Dog]

I was at the boat ramp this summer and one tire was spining the other would not. I was told the next time put my foot on the brake and the other would lock in. on a 5 speed I guess you use the park bake. I don't no if thats works or not i have not been in that kind of trouble sence.

 

[BV]

Applying the brake is what the open diff guys used to transfer some torque to the tire with traction - Kind of like simulating a LSD.

My suggestion is to drain the fluid (probably due for a change anyeay) and refill using only 1/3 to 1/2 the required friction modifier to start then do the figure 8's and keep adding the friction modifier until you like the results. It's a very easy job for a DIYer. A little stinky and oily but easy.

 

[Ski Bum]

My LSD also seems to do plenty of slipping. Keep telling myself to change the differential lube and use less friction modifier, but been putting it off as its kind of a messy job. Would be real easy if there was a drain plug.

The "apply brake to get LSD to work" advice seems to be some fairy tale as far as I can tell. Besides, you need three feet to do this correctly with a manual transmission. Never helped me a bit.

Remember the old VW Manx dune buggies? They had a modification to the parking brake so you ended up with two levers, one for each rear wheel. If one of the rear wheels was spinning in the sand, you could apply the brake to that side and the torque would transfer to the other wheel. We used to call it the "Poor Man's Posi-Traction". It worked.

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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.

 

[RKohn]

I did my research in the mighty (as in mighty pricey) mopar manual last night. The test technique is jack up one side and bolt an adapter in place of the wheel(looks like a steering wheel puller) and a torque wrench. DC's high quality specs say... .

Are you ready for this? Anything from 30 to 200 ft. lbs. is acceptable. What a load of CRAP!!! If it checks below 100 I want them to change the fluid and try it without any modifier in there and see what it tests.


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Y2K Red Stealth Sport 2500 4X4 QC SLT+, 5-spd, 3. 54 anti-spin, 265-75-16 LTX’s (There ain’t no such thing as options, cause ya gotta have it all, including: DC’s dead cow/vinyl interior and don’t stop anti-lock brakes. ) Stock, but not for long. Oops, too late. What silencer ring? (More fun than my 98 SST)

 

[highland]

Mobil 1 Synthetic gear oil does not require any friction modifiers to be added. I use it and my limited slip works extremely well in slip situations. I do get a bit of chatter on slow speed turn under power, but I can live with it with the good performance otherwise. You might try it.

 

[Ole Blue]

I know what you're talking about. I had my LSD replaced once and still if one wheel is on ice or mud it won't pull it's self. My dealer called DC they said if one wheel is on ice or snow or mud it will spin. I ask then what the *#&* good is a *%#*$# LSD if the wheel with the most traction won't pull. My dealers response was call the 800 number. So I did!They told me my dealer looked at my truck and nothings wrong with it. Don't that chap your back side! If someone comes up with a fix short of a detroit locker please post it..... Blue

 

[JJW_ND]

I must have a factory defective LSD in my 96. I have never been able to get just one wheel to spin. ALWAYS TWO. On ice, snow, dry pavement. Change fluid every 30 -40K. 75W90 and 2 bottles of Mopar fluid (Dana 80). Have just short of 190K on the factory original.

I have driven a dozen different Rams all with LSD from 1996 to 2001 models. They all have had the same tight LSD feel as my 96. Sharp turns on gravel surface leave marks from the inside wheel.

Your LSDs are not working correctly!

jjw
ND

 

[Vaughn MacKenzie]

highland, are you sure Mobil syn gear lube has friction modifier? When I put that in it popped and shuddered pretty bad with one tube of modifier, I ended up putting 2 tubes in to quiet it down but lost the LSD function at the same time.

I just changed to Amsoil 75W90 Series 2000 and the LSD seems to work better, and with no chatter at all. The Mobil stuff looked very nasty after 23,000 miles.

Vaughn
- - - - - - - -
'01 QC SB 2wd, ETH/DEE, 3. 54 lsd

 

[Dane]

I agree the thing should work better. It DOES work however. Try doing a burn out on dry cement and you'll see a black mark from one wheel about 2-3 feet long. look over where the other wheel would be and you'll see the beginnings of a second black mark. This means it's working.

The problem is related to how much friction modifier is added. If you don't add enough you'll get a clunking when you back up with the wheels turned or worse fry the LS clutches. thats why DC adds too much to be on the safe side.

The problem is with too much modifier the LS does not kick in when you need it most - ice, wet grass, etc...

You CAN over come that by applying the emergency brake. Also, when changing diff lube (you do change it on schedule right? #ad
)
only add enough modifier to keep the LS from clunking when backing up with the wheels turned. This is done by adding in increments and then waiting a few days to see if it clunks when backing up with the wheels turned. Even then you may have to use the emergency brake sometimes.

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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

 

[Big-D]

jkern, I believe your question about the modifier has been answered by a few of the guys since my post. If not, please feel free to ask again for this forum is the best way I know of for getting information.
Dave

 

[Scrmbld4X4]

The one thing that puzzles me about the whole deal is Why does the dealer call corporate??? Why not call the manufacturer. Dana Spicer? 30 to 200 ft lbs. What kind of a test is that? I bet Dana Spicer has other thoughts.

Mine doesn't work either. The 95's was awesome. Got the 99 stuck last weekend cause the LSD was doing anything. In knee deep snow pulling a trailer both wheels should spin period. There is no resistance to either tire (s) so both should spin.
I've overhauled numerous Pwr-Locs It is a very good design. One thing i've done in the past is to load the clutches. Put one extra steel in it to get the preload way up there. I always run synthetic no modifier. Going to try this in mine, it's about time for a oil change anyway.

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TOWER: '99 3500 4X4, White, 3. 54 LSD, 5spd, CMPR&TRL package. Glass shell or 9 1/2' Shadow Cruiser slide in. Geno's combo gauge. DynoMAX, K&N RE 0880, Jacob's E-Brake. PUTCO Max Boss boards and Flaps.
TOWEE: '82 CJ-8,Lime Light, Injected 440, 727 T flite, IH Dana 300, Dana 44 frt, Dans 60 rr 4. 88's & Detroits, 38. 5 X 14. 50 TSL/SX's, 15 X 10 Eagle 589's. Full soft top and full length cage.

BIGGER IS BETTER!! MO POWER