LSD Troubles

[jlb]

How aggressive would you say your LSD is...?

I was out in the woods this weekend, and under LIGHT flexing my inside tire broke loose, and the outer one just sat there. No throttle required, just the loading from D was enough. It was slightly uphill, so the truck didn't move.

I have also noticed if I come around a corner on pavement, and get on the gas hard my truck tends to turn into a one tire frier. If traction is "similar" I leave two trails every time, but a little bit of a loading difference, and you would think I had an open diff. If I were to try the one wheel in the grass, one on the pavement trick I would rip up a lot of grass, but I wouldn't move much.

I have never opened the diff to check, or run any numbers. However, my truck is an outdoorsman which is supposed to have one as part of the package, and it is included on the features list from the window sticker.

Is the stock LSD just really weak, or should I do a little more digging?

 

[iam_canadian22]

sure doesn't sound like you have it, I was iffy about if I had just by looks when I opened it up but never experienced single tire spin in any similar situation
Ram Trucks - Recall
on the left hand side click on equipment listing, enter your vin, it will show everything your truck came with, another member posted the link in my thread when I questioned mine

 

[jlb]

It shows up on page 4 as having an anti-spin differential rear axle. I was also relieved to see the following on page 7:

Spring - Left Front
Spring - Left Rear
Spring - Right Front
Spring - Right Rear

I was really concerned that my truck may have been made with only 3 springs... lol.

I guess I should crack it open. Maybe I will buy a new cover, and do a fluid swap/visual inspection.

 

[jcat]

my 3.21 anti spin is pretty heavy. Low speed light throttle when turning I can hear the inside wheel (which wants to spin slower) chirping.

 

[iam_canadian22]

I guess I should crack it open. Maybe I will buy a new cover, and do a fluid swap/visual inspection.

The oem lsd looks alot like an open diff thats what made me worried i didnt have it, take a look on moes website theres a pic of one on there


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[loveracing1988]

The oem lsd looks alot like an open diff thats what made me worried i didnt have it, take a look on moes website theres a pic of one on there


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They look nothing alike... The LSD has helical gears, an open diff has spider gears.
To the OP, that is the Achilles heel of a helical lsd. When one tire doesn't have traction it is almost like an open diff. It requires torque to work so when one tire doesn't have traction it doesn't work so well. Next time try holding the brakes a little bit. It provides just enough torque to send power to the other side with traction.

 

[jlb]

loveracing1988, I wouldn't have the Torsen style limited slip as I have an '11, mine would be traditional in appearance like iam_canadian22 is referring to.

Also helical diffs are what HUMVEEs use because they can be much more aggressive depending on the shims and fluid used than traditional LSDs like would be in my truck.

Unfortunately like I said earlier in situations with differential traction (light flexing, grass/pavement, etc) I seem to have no LSD. Assuming I did have a helical diff, which I wouldn't, these types of situations would be the bread, and butter of the Torsen style LSD.

I did do a fair bit of city driving/towing in my first 30k miles (lots of tight corners, and hot operating conditions), and am due for a fluid swap anyway, so it is possible the friction modifier in my fluid has all dropped out at this point, which means I should do a swap SOON so I don't kill my diff.

 

[loveracing1988]

loveracing1988, I wouldn't have the Torsen style limited slip as I have an '11, mine would be traditional in appearance like iam_canadian22 is referring to.

Also helical diffs are what HUMVEEs use because they can be much more aggressive depending on the shims and fluid used than traditional LSDs like would be in my truck.

Unfortunately like I said earlier in situations with differential traction (light flexing, grass/pavement, etc) I seem to have no LSD. Assuming I did have a helical diff, which I wouldn't, these types of situations would be the bread, and butter of the Torsen style LSD.

I did do a fair bit of city driving/towing in my first 30k miles (lots of tight corners, and hot operating conditions), and am due for a fluid swap anyway, so it is possible the friction modifier in my fluid has all dropped out at this point, which means I should do a swap SOON so I don't kill my diff.

No, with ram's helical lsd those are the opposite of its bread and butter. Both my 1500 and 2500 do the same exact thing you describe. As soon as one wheel has very little reaction all of the power goes to that side.
If your friction modifier is worn out (which I highly doubt would ever happen in 30000 miles) you would have heard some chattering before it was worn out. My dad has a f150 that has had the fluid changed twice in 190000 miles and it still works fine.

 

[csuder99]

Ok, can anybody clear up the confusion about which type of LSD the Anti-Spin is ? This thread implies it is a helical gear type, however the differential shown here is clearly not a helical gear type: http://www.ramforum.com/f44/supposed_have_lsd_but_doesnt_look_like_i_do-54507/
It does look like a clutch plate type (carrier housing is 'wide' at the axle shafts).
Did anybody actually confirm a helical gear type in their rear axle ?

 

[TylerB]

It is indeed a clutch type LSD.

 

[loveracing1988]

In addition, an optional helical-gear, limited-slip rear axle is available. The limited-slip function instantaneously divides torque between the rear wheels in proportion to the traction available to each wheel. The system is consistently smooth when turning corners because it responds only to variations in traction.*
http://media.chrysler.com/newsrelease.do;jsessionid=DA25FCAEDEC229ABF0BD5990D65DCE11?&id=12166&mid=1

 

[csuder99]

That's what marketing wrote for the 2013 MY, it may well be one of those 'specifications subject to change' things. Hence my question if anybody has actually *seen* a helical LSD in their Ram.

Not to put salt into the wounds, but Ram also claimed the 4wd auto transfer case is locked in 4lock and it turned out it isn't.

 

[loveracing1988]

Not to put salt into the wounds, but Ram also claimed the 4wd auto transfer case is locked in 4lock and it turned out it isn't.

The irony in you saying that is the new transfer cases are in that same article. When I talked to Nick Cappa who is head of customer relations I told him that I read in the owners manual that both transfer cases act the same way in any mode but 4 auto, he called me a liar and said there is no way it says that anywhere out there. It says word for word in this article out out by Chrysler that the two transfer cases act the same in 4 lock and 4 low.
It is water under the bridge for me at this point, I am done with those issues.
If the 1500's do indeed have a clutch type lsd that would explain why the owners manual still calls for friction modifier, it doesn't explain though how it is so easily defeated. Every clutch type lsd I have ever seen takes a lot of torque for it to have 100% slip. My 1500 would have one wheel completely stopped at and the other one spinning freely at idle let alone with any real torque on it.