Open dif to lsd.

I have 2017 2wd QC 5.7 with 3.21 gears and open dif. If I did a Mopar lsd swap from moe’s is it “plug and play” more like bolt and play? Should I upgrade gears at the same time as well? I don’t tow and don’t encounter any snow at all and very little rain, however there will be a day I move out of South west Arizona and will likely encounter more rain and snow. I will also more than likely have to tow a trailer to my next home so I’m more or less just trying to prepare for that. Much like others who didn’t go the 4wd with higher gears guys I got a decent deal on the 17 quad cab but I also didn’t look for a better one.


Sent from my iPhone using Tapatalk

Do you see yourself towing more than your truck is rated for ?

LSD is a nice upgrade, but if your moving into snow county, it won't sub as 4WD.

If you have a 2wd I'd do the gear swap and the LSD in a heartbeat. All parts can be purchased from Matt at Moe's for the swap. I think you will be much happier with the performance of your truck if that is a concern for you.
Jay

I'd do the LSD in a 3.92 gear ratio.

MADDOG said:

I'd do the LSD in a 3.92 gear ratio.

Click to expand...

Agreed

New to the ram work and I have an open diff. How do I know what I have for a rear now? I know it’s chrystler but not sure what’s in it. 2015 ram 1500 sportsman midnight. 2wd.

Jsavage said:

New to the ram work and I have an open diff. How do I know what I have for a rear now? I know it’s chrystler but not sure what’s in it. 2015 ram 1500 sportsman midnight. 2wd.

Click to expand...

Enter your vin on this site and you will get a "build sheet" which will tell you all the equipment on your truck
http://www.dodge.com/webselfservice/dodge/Recall.htm
Jay

Another way to see which gear you have is the next time your driving on the freeway if your turning more than 2K RPM at 80 MPH you have 3.92's, less than 3.21's. I would also consider looking for a junkyard LSD rearend with 3.92's already in it. Probably be a whole lot cheaper than buying the components separately especially if you're paying someone else to do the work.

I pulled the build sheet (Thanks Pull Ya) and found that I have the 9.25” with 3.25 ratio.

So looking at options for gearing with mpg in mind. 3.55? I should still see a decent torque gain and not kill myself at the pump. Thoughts?

Jsavage said:

I pulled the build sheet (Thanks Pull Ya) and found that I have the 9.25” with 3.25 ratio.

So looking at options for gearing with mpg in mind. 3.55? I should still see a decent torque gain and not kill myself at the pump. Thoughts?

Click to expand...

I went from 3.21 to 3.55's and noticed my oil temps went up by a good 5 degrees,and my milege went down by roughly 2mpg,but I run 30" tires. The difference in 1/4 mile track times was very minor between the 3.21'and 3.55's.If I didn't have a pile of money ******* in this diff i'd be going back to 3.21's.But the majority of my driving is on the freeway at 80+ mph,and that's where the 3.21's really shine.If the majority of my driving was at 60 mph,then the 3.55's wouldn't be at as big a disadvantage.If you're running a stock sized 33" tall tire and drive more in the 60 mph range,the 3.55's are probably the best all around gears though.My situation is a bit different as I run a shorter tire then most ,and the majority of my driving is on a 70mph freeway,where you have to be at 80+ mph just to stay with the little old ladies,lol.

Your oil temps going up 5 degrees doesn't make any sense. If that was true the guys with 3.92s would be up another 6-7 degrees above the 3.55.

If you are really losing 2 mpg, that's approximately $4 per week, if you drive 15,000 miles a year. I drive about half that much, and I don't cruise at 80. The interstate speed limit in Indiana is 65 for big trucks, and 70 for everybody else. I usually run 65-70. My 4.10s are worth it to me.

RLJ10X said:

Your oil temps going up 5 degrees doesn't make any sense. If that was true the guys with 3.92s would be up another 6-7 degrees above the 3.55.

Click to expand...

And just how do you figure that doesn't make sense,the rpms went up,so consequently the oil temps will also go up.I run a relocated filter set-up,and my oil temps at 80 mph went from roughly 196/198 with 3.21's to 203 or more with the 3.55's

It's a toy and doesn't see anywhere near 15,000 miles a year,my truck is a 14 bought brand new and is showing just a smidge over 36,000 miles now,and the majority of those miles are driving it to the track weekly to drag race it,which is 155 miles away,lol. I make the weekly drive up to the closest track every week-end the track is open in the summer,lol

Your truck is also a 5 speed truck,and they're absolutely gutless unless they have 3.92's or 4.10's,the 8 speed with it's 4.71:1 first gear doesn't need as much torque multiplication from the rear end gearing as the 5/6 speed trucks do.

Your oil temp went up when your rpm went up,correct?

Threrefor, using your analogy, your rpm goes up further with 3.92s, the temp would go up further also. Theoretically.

But if your truck has a functioning thermostat, that should all go out the window.

3.21 to 3.92 wouldn't have cost any more that going to 3.55s. If fast times are what you're after, it would also stand to reason, that the 3.92s would have been the way to go. 3.21 to 3.55 really isn't that much of a change. As for gas mileage, if it's a low mileage toy, who cares? The easiest way to get good gas mileage is slow down. I'll bet if you drive 65, instead of 80, you'll get your 2 mpg back.

I will agree with you tho, of your assessment the the 5/6 is gutless with out 3.92, or 4.10. But the 8 wasn't out in 11.

If you are going to upgrade to a limited slip do a Torsen based over a clutch based. It might be more money but the difference is night and day when it kicks in. 3.21 to 3.92 is a great upgrade for the initial launch but wont do much for highway passing, unless you have the 6 speed auto, then the 3.92 is a no question.

The thermostat doesn't have as much to do with oil temps as you're trying to imply.The crankshaft/bearings /valve springs etc. are all aways away from a cooling jacket,with the crankshaft being the biggest oil heat creator,and it's not anywhere close to a water jacket for cooling. There isn't any late model Ram built that doesn't run hotter oil temps then coolent temps when cruising down the road. You're analogy of "slow down" doesn't work on a 70mph freeway,not unless you want to get involved in a "road rage" incident,lol. I'm comparing the milege to the same drive and same speed ,so my assessment of the milege drop is accurate,if I slowed down it wouldn't be an accurate comparision would it. At 65 the 3.21's would still get better milege then the 3.55's would at the same 65mph,takes fuel to create rpm,and the 3.21's require less rpm then the 3.55's to maintain a set speed.I'm not sure how you figure you're going to spin the engine faster and not burn more fuel,you'll have to explain that one to me,lol. Truck runs DA corrected 11.90's with either 3.21's or 3.55's so going to 3.92's would probably slow it down,as it'd have to make one more gear change to pull the 3.92's out the back door[/QUOTE]

Where do you live that driving 70 gets you into a road rage incident?

RLJ10X said:

Where do you live that driving 70 gets you into a road rage incident?

Click to expand...

The speed limit is 70 mph on the road ,if you're driving at it,you're tying up friday afternoon traffic,and you'll get cut off and brake checked ,lol. Not really important where the road is,but it's the QE2 between Calgary and Edmonton


http://yagotta.ca/alberta-destinations/queen-elizabeth-ii-highway-calgary-to-edmonton/

If the load is lighter, it takes less gas to spin an engine the same rpm.

RLJ10X said:

If the load is lighter, it takes less gas to spin an engine the same rpm.

Click to expand...

Good theory,but it's out to lunch in this scenario. I will agree though if the engine stays at the same rpm and the load on it lessens,it will burn less gas,but we're not talking about that here.Since when does the engine spin at the same rpm at 65mph if you have 3.21's or 3.55's .That's another one you're gonna have to s'plain to me,i could of swore the 3.21's would be spinning the engine roughly 10% less rpm then the 3.55's would be at 65mph. I give up,you seem bound and determined not to believe my real world experiences as they seem not to jive with your theories,lol.Look up closed loop operation.

WilliamS said:

If you are going to upgrade to a limited slip do a Torsen based over a clutch based. It might be more money but the difference is night and day when it kicks in. 3.21 to 3.92 is a great upgrade for the initial launch but wont do much for highway passing, unless you have the 6 speed auto, then the 3.92 is a no question.

Click to expand...

Detroit locker or truetrac. Fully locks, and will last a heck of a lot longer than the factory LSD.
But honestly if your going to move to a state where you will be driving in the snow, save your money, and buy a 4x4.
A LSD in a two wheel drive truck in the snow around a bend is asking for trouble.