DODGE RAM FORUM banner

"Anti spin differential" - Why do I need one?

40K views 37 replies 27 participants last post by  wvcoolvinilla 
#1 ·
So I had a couple of deals fall through on me yesterday, so I am still in the market for a 2011 Ram.

My 03' had the posi rear end...now 8 years later it is an option?

Why is something like this good to have? I know it sounds like a dumb question but help me out here. To me its a non issue but the father in law who is a mechanic says its a must have.

Thanks
 
#2 ·
In my opinion it's a must have as well...and you'll know it the first time you have to step down when the roads are damp.....With the power of the Hemi and only a one legger, that rear tire is going to spin, you'll have no grip and won't be able to merge into traffic....with my 08 I always had to put it in 4x4 for those situations.

Now granted, you can't pounded it even with the posi because then you'll spin both tires but you certianly have 90% better traction with it.

And of course if your ever going to go 4 wheelin, without a posi you won't be able to do half as much.
 
#4 ·
So in 4X4 without the limited slip I'll only have 2 opposite corners grabbing? With limited slip I'd have both rear wheels working for me as well as 1/2 front ones?

I had absolutely 0 traction problems with my 03, I mean 0. I couldn't spin the wheels without a brake torque. Not as much fun to drive. I don't mind the rear end breaking loose once in a while, know what I mean?
 
#3 ·
If I had it to do all over again, I would have DEFINITELY picked a Ram with the limited slip gearset. I didn't realize that my 3.55's didn't have limited slip until well after I bought the trunk (I made an ASSumption there that it had limited slip).

I personally don't care for the intervention of traction systems as I find they are too intrusive and hamper driving in certain situations. Not saying they're bad all around, but I'd prefer to have the LSP kick in and then have the traction control engage at a higher threshold.

Basically, you're running around with two open diffs on these if you buy the 3.55's, and I personally think it's stupid that Dodge didn't include the lsp on the 3.55's - I guess it's a cost-savings opportunity for them, and they figure that most folks nowadays are happy with the electronic traction control.

Just my opinion natch -
 
#5 ·
I did a little test with my 2011 Sport, 3.55 rear, did a power brake and left two black marks on my drive way. Others who have taken there 3.55 rear trucks to the track are stating smoking both back wheels.
 
#6 ·
I really wish I joined this forum a month BEFORE i purchased my Ram. Some very good information on here that would have been nice to know before hand.
 
#19 ·
Agree with you, I joined the forum after i bought my RAM. I could pick a better truck especially with 3.92 gears. My is 3.55's.
 
#7 ·
My 3:55s haven't caused me any problems as far as getting around even though we've had lots of snow this winter. I didn't join the forum untill after getting the truck either.I would have made sure I had LS if I knew my truck didn't have it.
You'de think it would be standard on a 390 HP vehicle.

Jeff
 
#8 · (Edited)
It's a misconception to think of an open diff as only powering one side. No one directly said that here, but I know lots of folks think that from conversations I've had.

In an open diff, each side gets exactly the same amount of torque, no more or no less (not including a tiny fraction caused by the gearing geometry itself). Also, for a given input (drive-shaft) speed, the COMBINED speed of the two sides will be the same. So, during normal driving down the highway, both wheels are equally powered, at the same speed.

The problem is that since neither wheel can get MORE torque than the other, and since a free-spinning wheel can't accept any torque, the non-spinning wheel doesn't get any either. The free-spinner's speed just increases to twice the speed as would be if both could turn. With the LS, the spinning side uses some technique to grab onto the other side and pull it along, thus transferring EXTRA torque to the side that actually has more traction. For anyone that's into learning about stuff like this, the howstuffworks.com website has TONs of info.

I don't have any scientific testing evidence, but I would think that without an LS, if you could punch hard enough to break both wheels loose at the same time, they would both continue to spin. As one gets more traction than the other, it would start to slow down, speeding the other up. As long as the vehicle started moving enough while both were still spinning, you might be able to lay a good double patch. I'd suspect though that one stripe would be longer than the other.

I too am in the camp of "wish I had it", but I couldn't resist everything else about the 2011 I found on my dealer's lot, but it has the 3:55s. I'm not TOO worried about it though. My '98 didn't have it either, and I even plowed with that. The only real issues I had were when starting on wet or slippery pavement in 2WD. I figure all of the problem cases I had with the old one will be dealt with fine on the new one with the traction control.

For me, it's way better to have it, but certainly not a deal-killer.
 
#15 ·
i hear ya there. my 06 had the same bs. the only time an open dif is good is in the sand. i got stuck a few time in the snow and had i had some type of rear lock i probably would have gotten out. i the rain even with my 35's i could spin the rear very easily. they shouldn't make a truck without it as standard equipment.
 
#14 · (Edited)
Here's what's new for 2011
Got to http://www.ramtrucks.com/en/, buyer's tools, Build Your Own

...."Anti-Spin" is an option for ALL Rams with 3.21, 3.55 and 3.92 gear ratios now for $325 ;)



I've got a 2010 with open rear, 3.55's

It's not a problem for me,
Can even spin BOTH my Heavy 305/50R20 Grappler's on clean dry pavement...

<click for video>


there ya go, just as herc said...one side slightly longer ;)



I can spin just one wheel if the passenger side is in the gravel/dirt and the left one's on dry pavement.

...or if I mount up my little 27" drag radials just before heading to the track
(effective gear ratio drops to 4.30:1) and if there's a little dust on the road full throttle is almost impossible
...even trying to baby it off the line wont help once the massive torque kicks in ...Thanks to my Diablo Trinity :D



No problem for me on a prepped track though after a short burnout,
and yes both spin out of the water box sending me sideways.
Full throttle launches never spin after that!

For Winter driving my 4x4 is actually as good or better than my old 04' Sport 4x4 Hemi Ram with 3.92/LSD.
The ESP always keeps me going were ever I point her. Good tires make more difference than anything for winter driving.
Terra Grappler's > Good-for-a-Years HP's.

If you can get the anti-spin for $325, its a not a bad deal for the money.
I plan to eventually re-gear to 4.56's and a Detroit True Trac anyways so its' not a deal breaker for me.







Here's a good example of what "can" happen at the track without doing a short burnout to heat the tires up

Left Lane 10' QC Ram Open diff 3.55's stock tires... excessive spinning at launch
Right Lane 10' RC Ram Open diff 3.55's drag tires... (Me) Hooked and Gone!

http://www.youtube.com/watch?v=ZWsIASP8FNA
 
#13 · (Edited)
LSD is great to have in mud, snow, slippery boat ramps, as well as the drag strip

for open differentials you have to think about how to get traction, if you have one wheel spinning its harder to get moving, so you have to apply a certain amount of brake pedal to slow the spinning tire & at the same time evenly add just enough throttle for the non spinning axle to get some traction, it is a delicate balance. It is a poor mans LSD.

I believe that you can get 3.55 with LSD, i know that they make a Locker for them,
Randys ring & Pinion sells a lot of YUKON brand
http://www.ringpinion.com/

http://www.drivetrain.com/parts_catalog/positraction/

--------------------------------------------------
don't take this as GOSPEL, it is something that i saw on another site

Latest RAM production updates:

1500
Production scheduled to begin:
AM/FM/CD/DVD/HDD/MP3/NAV (RHR) - 02/14/11
Midnight Blue Pearl Coat (PB8) - 03/21/11
3.55 Axle Ratio (DMD) w/LSD - 04/04/11
3.92 Axle Ratio (DMA) w/LSD - 04/04/11 Discontinued

Power Folding Black TRL Tow Mirrors (GP1) - 04/18/11
Power Folding Chrome TRL Tow Mirrors (GP2) - 04/18/11
P275/60R20 OWL All Season Tires (TUB) - 07/08/11
Chrome Accents Group (AEE) - 08/01/11

more rumors or just all BS
looks like the anti spin will now be available as a separate option for $350.00,and the 3.92s are being discontinued because dodge is going to a 3.99:1 ratio as an option for $25 over the standard 3.55s
the Adventurer is suppose to start this trend, is that what the call the EXPRESS??

the 2011 Ram will end production in 30 days, June 20th the factories will be closed for at least 2 weeks
 
#16 ·
I really wanted the 392 with the lsd, but i got a really great deal on this truck' I could not pass up for just the rear. I can live with the 3.55, this truck is fast already and I did not even start to bolt stuff on yet.
 
#20 ·
For the average person that doesn't go off road or to the drag strip, which is probably 95% of us, the 3.55 is great. I just towed a 56 Plymouth on a U-Haul trailer which was about 6,000lbs. total. I went from Vancouver BC. to Denver Co. empty and back with the trailer and the car. 22 MPG. down and 14 MPG. loaded. That is US. gallons. More power and control than needed. I previously had a 04 Dakota with anti spin but never noticed it's worth, but I stay on pavement.
 
#21 ·
We also do have a great 4wd auto, that can be used any time. I have used mine in the rain and did not get any slipage at all. If I did drag race I would just put it 4 auto and have a great launch.
 
#25 · (Edited)
I've had my 10' 4x4 Sport 3.92 LSD for a couple of weeks now. Took it into the back hills over the weekend and found a Massive mud pit about 50ft across that was a good foot deep of sticky, tacky mud and never had a problem playing in it. The truck did great pulling me through it in 4Hi over and over again. I did have a factory locker in my 02 Silverado though and I had it in some wickedly bad places and it never failed to pull me out. Wish Dodge would offer it. The LSD should be standard and the locker should be the option IMO.

 
#26 ·
I think for $325 most people would rather have this option if they know what it is. Unfortunately most of them come without it, the dealers don't order it.

I guess it's less of an issue with the traction control. But I know my 2007 2 wheel drive ram 1500 was like a 1 wheel drive. I think it's even more critical to have on a truck that doesn't have 4 wheel drive. My current 2011 has the 3.92 (probably cause its got the 3.7) but no lsd.
 
#28 ·
I helped my brother when he was ordering his express, and I think the "standard" was 3.55 with open differential, then you had the option of either 3.21 or 3.92 gearing for an additional $50 and the option of "anti spin" differential for what I thought was $150....but now after reading a couple posts up I do recall it actually being $325 or so.....A shame that I'll have to spend over $1,000 for what could have been had directly for less than half....
 
#29 ·
Im glad mine came with an LSD, i have big drag truck plans in the future. If it was just a pavement princess an "open" diff would be just fine.

AZHunter, nice pic!
 
#32 ·
I've been looking at getting a new Ram and I've noticed on the Ram "build your own" site it has 3 options. 3.55 gear, 3.92 (with anti-spin rear differential) and Anti-Spin Differential. If the 3.92 gear comes with an Anti-Spin Differential then what is the 3rd separate option for? There is a difference of about $300 between the 3.92 and the Anti-Spin Differential Option.
 
#33 ·
I don't know if they changed it but it used to be that standard ratio was 3.55 and you could pay for 3.21 or 3.92 as an option, and as a SEPARATE option you could pay for LSD (I don't think LSD was available with 3.21 though...).
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top