Help newbie understand lsd swap

[RustyRamFan]

I'd like to take my rear end's open differential and somehow turn it into a limited slip. Problem is, I have no idea how to understand this.

Is it as simple as adding a few parts?

What is an axle ratio and why does this matter so much?? How to know your axle ratio??

Didnt Dodge offer this factory as "Sure-Grip" and you can swap into these diffs easily?

How do you swap a diff?

Am I supposed to go with a Sure Grip LSD or some other forum of LSD?

All advice appreciated,
I cannot have the fords pass me up while I'm stuck in the mudd!!

 

[reek]

You need to change the carrier to go from open to LSD, more than adding some parts. Some of the old Mopar sure grips were not rebuildable and some were. I forget what the cut off year for that was. having said that, you're probably better off going with a new part, my personal favorite is the Detroit truetrac. they're durable, low maintenance and don't need additive. how ever this can get spendy. You would have to rebuild the rear end and in reality, it's not that difficult but can be frustrating your first time around. you have to remove the rear end/live axle and disassemble the thing. the old mopar 8.75 rear ends were relatively easy but not sure how involved with shims the newer rear ends are. on the plus side, newer crush sleeve eliminator kits do make most rebuilds a lot easier now days. there are some pretty good bench books/manuals that go step by step that help.

try looking at this link

https://www.matfoundrygroup.com/News and Blog/Types_of_Differential_and_How_They_Work

gear ratio comes down to how much 'leverage' you want out of the rear end. gear ratio in the low 3's such as 3.09:1 will get you a little better gas mileage and lower RPM on highway. 4.10 will get you a bit more pep and tire spin-ability but lower gas mileage and higher RPM on highway. If you have an overdrive trans, the highway issue is generally a non-issue. I put a 3.73 in the rear, up from a 2.76 when I swapped my 727 for an a518 transmission. My old El Camino had a 4.56 but with a 3 speed TH350 in it. that was pretty much good for burn outs but I hated going on the highway.

lots of stuff to research so you make an informed decision, then drive the truck, regret the decision, then change to ration one or two more times to be happy. JK, kinda.

 

[crazzywolfie]

if your worried about traction in the mud and want cheap you could do a lunchbox locker. they are cheaper than a new carrier. if you are re-gearing minus well just buy a new carrier but if you got 3.55 gears which were pretty common in 91 you would likely be ok.

 

[RustyRamFan]

Thanks for the info guys. I look forward to learning even more about this! The Detriot truetrac sounds pretty awesome.

I'm not sure about my gearing in my rear end but hopfully I can keep the same ratio. It does have the overdrive option but, the truck sounds like its gonna gernade at around 80mph on the highway!