Convert standard rear axle to limited slip?

[leggy]

Hey good folks of NPORA,

 

Frist Psot!

 

This should be an easy one. The vehicle in question is a 2002 SE with what Nissan calls "part-time 4WD", and I would generally call "regular 4WD". That is, I have a manual transfer case with 2H -> 4H -> N -> 4LO. Transmission is the standard 4-spd automatic.

 

I'd like to upgrade the rear axle to limited slip, which according to what I've read in the owner's and service manuals, was an option for this model.

 

1) Is this a Good Idea? I mean to say, are there any major issues with the Nissan LSD rear gears? Will I gain more than I lose?

 

2) What is involved? Is this as easy as pulling the rear gear and dropping-in an LSD gear set - or are there other changes to be made? Would I need to swap-in a complete LSD axle, for instance?

 

3) Are there good, reasonably-priced aftermarket clutch pack / spring sets, that I can use to rebuild / upgrade the LSD assembly before it goes in?

 

Ok, I guess that's all for now. Thanks in advance for any info, advice, etc etc!!

[leggy]

Oh, I forgot to mention that I live in Minnesnowta, and make regular but intermittent use of the 4WD for 5-6 months of the year.

 

And need I mention that this '02 Pathy is already the best dang snow vehicle I've ever owned? Throw the cables on the rear, shift it into 4LO, and the thing is pretty much UNSTOPPABLE - even in the worst (urban) snow "emergency" environments. Those 16" Michelin LTX M/S don't hurt the traction, either.. ;-)

 

No emergencies here, if you get my meaning.. lol.

[nunya]

If it's an open diff truck it's easier to shove a locker in

 

And feel free to stop in the new members area and put up an introduction thread (and post a couple pics, we like pics)

[Towncivilian]

I was also wondering if one could swap an LSD axle in... my R50 has an open diff. Of course, the challenge will be finding an identical geared LSD diff and then getting it out of a junkyard. Would there really be any benefits? I never go offroad (2WD, open diff, highway tires, worn suspension... bad combo), and the worst weather I drive in is rain.

[Timmons]

Stick with your open diff's if you never plan to off-Road. Otherwise, go ARB lockers all the way for the Rear. That's what I'm doing this week.

[leggy]

Stick with your open diff's if you never plan to off-Road. Otherwise, go ARB lockers all the way for the Rear. That's what I'm doing this week.

 

By 'open' diffs, you mean regular one-wheel wonders, plain differential gears, right? Sorry if that's a stupid q.

 

So what are "ARB" lockers, and how would they help me? I did a quick google, and it seems like you're talking about auto hubs with pneumatic actuation.

[Timmons]

By 'open' diffs, you mean regular one-wheel wonders, plain differential gears, right? Sorry if that's a stupid q.

 

So what are "ARB" lockers, and how would they help me? I did a quick google, and it seems like you're talking about auto hubs with pneumatic actuation.

 

 

Here is the link for the lockers. Watch the video.

https://www.4x4parts.com/nissan/arb-rd135-pathfinder-rear-air-locker-p-110.html

[Slartibartfast]

Yes, open diffs are one wheel wonders. LSD adds a friction clutch to sort of lock the two sides together, but still has enough slip to take a corner on dry pavement. A locked rear diff is like not having a differential at all, but a straight axle from one wheel to the other, like a slotcar. Some people just weld the gears in the open diff together, permanently locking it; you can turn a locker on and off, so it's either fully open, or fully locked.

 

I have LSD in mine (came that way). The only downside I've found is that it's a little tail happy in two wheel drive on ice (whole rear end drifts sideways due to both tires spinning), but that's my own damn fault for not having it in 4x4 on ice.

 

If LSD was an option for yours, check around any local junkyards for similar-vintage Pathfinders. If the rear axle has an orange sticker on it that says "LSD oil only," it's LSD. I don't know if the Pathy rear ends come with different gearing, but if so chances are a ) it wouldn't be the end of the world or b ) you could swap the ring gear from your open diff onto the LSD diff. I'm not an r50 guy though so don't quote me on that.

[Towncivilian]

If I recall correctly, the R50s came with two possible ratios: 4.363:1 or 4.636:1. The former was on LE/XE models, and the latter on SE models. I have an SE, so I have 4.636. Someone correct me if I'm wrong!

Edited September 14, 2011 by Towncivilian

[Simon]

I believe it has more to do with manual vs auto transmissions. Auto gets the 4.6, typically, while MT gets the 4.3

 

Pezzy's is an XE with 4.6 gears. As is my dad's 2002. Both have auto transmissions.

[adamzan]

And my dads 00 had 4.3 gears with a 5 speed and LSD.

 

If you can find an LSD 3rd member with the same gear ratio as your truck you can swap it in. I did that to my wd21, and it would be pretty much the same process on the r50.

 

Basically you:

 

Drain the diff oil

Unbolt driveshaft (I didn't have to remove mine, I just slid it all the way into the transmission and tied it out of the way)

Disconnect rear brake lines from the drums

You may have to unhook your parking brake cable (I didn't but this is on a 95)

Remove the 14 bolts holding the 3rd member on

Remove the 4 bolts at each drum holding the axle shafts in

 

Now this part is much easier (and safer) with 2 people:

 

Pull on the drums to pull the axle shafts out enough to disengage the 3rd member (you will hear it)

Gently work the 3rd member out of the housing. Be careful it is very heavy!

 

Put your new one in, bolt it up but not super tight yet, then slide the shafts in and put it all back together, then torque all bolts to the FSM specs.

 

There is a seal with holes for the bolts in it that came apart on mine. And since it was the weekend there was no way I was getting to the dealer so I used some rtv sealer magregor had and its been working fine for over a year now.

 

Hope this helps.

[leggy]

Hm, ok.. so I think I have a little conflicting info, here?

 

According to adamzan, it's a simple drop-in to convert open->LSD in my 2002.. whereas a previous poster said that my only option was to convert open->locker.

 

Of course, adamzan has almost 13K posts and I like his answer the best, so I guess that means he's right? =)

 

Also - we're having a terminology thing again. What you're calling the 'third member' is what I *think* I call the rear carrier. That is, the ball of drive gears inside the rear axle housing.

 

Anyway, I'm sure this will get settled sooner or later. In the meantime, any info on aftermarket / upgrade clutch & spring sets for the LSD gear? I figure if I've already got the assembly sitting on the bench, I might as well freshen it up a bit. I'd probably pull it apart for inspection anyway, unless it really looked super-duper clean & new.

[leggy]

Here is the link for the lockers. Watch the video.

https://www.4x4parts.com/nissan/arb-rd135-pathfinder-rear-air-locker-p-110.html

 

Watched the vid, read the info. Thanks!

 

But nah, I don't need anything that serious.. just looking to slightly (and simply) upgrade the stock setup, and a factory LSD set seems to be the most straightforward route.

 

Any sense of what a junkyard (oh, pardon me, automotive parts recycler) would get for the parts? It's just the contents of the rear pumpkin, eh? All my existing housing / axle shafts / etc will mate up?

[adamzan]

3rd member, rear carrier, yes it is the same thing.

 

What the others were saying is, that you can't put a locker into an LSD rear carrier. But you can put one in an open carrier. If you plan on getting a locker in the future I would just stick with the open, but the LSD is a nice upgrade. You can always just keep your open carrier in the garage for when the day comes that you get a locker. I gave mine away as another member was getting a locker and needed one .

[sewebster]

You should ensure that you get the same gearing as you already have... on WD21s it says in the engine compartment, I assume it's the same for R50s. Ours says something like HG43 (which means 4.3) on the plate on the passenger side rear of the engine compartment.

[rgallant]

I am considering this route myself, a couple of things you can get clutch packs etc but they are not cheap about 300.00 (In Canada) likely half that in the US.

 

You can check your gearing on a plate in the engine compartment, just to make sure they are the same.

 

And finally used LSD's in 4.6 are fairly common it the 4.3 standard version that are annoying to find.

 

And for the locker you need the locker plus a compressor and air lines run, and properly crimped and joined or it leaks like a sieve.

 

If you really don't plan on going off road, the LSD is cheaper BUT you need to adjust your driving style. The back end gets squirrelly in very slippery conditions rain, snow and ice. Once you are used to it is generally fine but it can bite you in the butt if you are not paying attention.

[leggy]

3rd member, rear carrier, yes it is the same thing.

 

What the others were saying is, that you can't put a locker into an LSD rear carrier. But you can put one in an open carrier.

 

Ah, OK - I get it. The LSD carrier won't accept the aftermarket (retrofit) locker because of the way the former is constructed; I suppose the area in the center of the ring gear is occupied by the LS clutch parts, and that's where the locker hardware would need to be.

 

If you plan on getting a locker in the future I would just stick with the open but the LSD is a nice upgrade.

 

I guess I just don't see myself ever wanting or needing a locker. This isn't for off-road use, just daily driving in a climate that can really make things difficult without a whole lot of warning. The LSD upgrade is just one more factor in my favor - though it may be almost gilding the lilly, as the PF already proved its worth this last winter. What a superb winter ride that thing is!

 

Thanks for the driving tips, I *think* this will be my first LS rear drive, if I manage to find and install it. Any sense of what I'll pay from a fair junkyard? (That's a "breakers" to you royal subjects, lol).

Edited September 14, 2011 by leggy

[leggy]

Oh hey, one more question just came up.

 

What models / years will interchange with my 2002? Was the LSD more common in the QX4 models, or the PF SE models, or what should I be looking for?

[XPLORx4]

I've been a bit of a lurker in this thread, but I figured I should step in and clear up some confusion about the terminology here.

 

A "third member" is usually the entire center section of a rear axle, including the front of the differential housing, the ring and pinion, the differential carrier, and its bearings. "Third member" straight axles are constructed differently than straight axles with a differential cover. R&R of a third member into the axle tube is often much easier than the other type because you don't have to set bearing preload, backlash, and other more complicated setups during reinstallation. Therefore, third members can be more "plug and play" and don't require expertise in gear setup. For example, if you want to replace a 4.36:1 open diff with a 4.63:1 LSD, to upgrade the diff and R/P ratio simultaneously, all you need to do is pull the old third member off the axle tube and swap in the LSD unit.

 

The "differential carrier" is the housing that encases the side gears and spider gears of the differential. The differential carrier bolts to the ring gear. LSD carriers and open diff carriers are different, but once they're bolted to the ring gear, installing the ring+carrier combo into the third member housing and setting the gear mesh is pretty much the same.

 

An ARB air-locker is a complete differential carrier that replaces the original carrier, whether that original is an LSD or an open diff. The ARB carrier bolts to the ring gear, and then the ring gear/ARB carrier is installed into the third member housing (which is then mounted onto the rear axle tube). When not engaged, the air locker behaves just like an open diff. When engaged (or "locked"), the left and right axleshafts are mechanically locked together so that there is no differential action between them, for maximum traction off-road.

 

Finally, the stock LSD in the R50 is very weak compared to the WD21 LSD. It's a marginal upgrade that in my opinion is not really worth the expense and effort, unless it is further modified. The R50 LSD is not strong enough to move the truck if a rear wheel is off the ground. An H233B third member from any year, any model R50, will fit into any other R50. The only differences will be gear ratio (4.636 or 4.363) and open vs LSD.

 

The following threads can be followed if you want to improve the stock LSD performance:

 

97 LSD Rebuild to 94 Specs

 

Laxman's 2001 R50 LSD Modification and Install

 

Whether you simply swap in a stock LSD, or modify the clutch packs of a stock LSD (and deal with resetting the gear backlash and bearing preload), or replace an open diff with an air-locker is primarily a matter of what kind of performance you want to get from your rig, and how much time and/or money you have.

 

My '97 LE originally came equipped with 4.363:1 front open diff and 4.363:1 rear LSD. I purchased from a local wrecking yard a front entire diff case with 4.636:1 gears, and a 4.636:1 open rear third member for $250 each. (They were relatively new, roughly 37,000 miles on 'em). I had a shop swap out the open rear for an ARB locker, then replace the stock third member, which I then sold for $100 to a guy who wanted a stock LSD. A few years later, I had that same shop install a front ARB locker. I still have the stock front open carrier boxed up on a shelf in my garage.

Edited September 14, 2011 by XPLORx4

[sewebster]

Apparently, at least for wd21s, the arb locker is incompatible with an oem LSD diff. Why is that? Different attachment mechanism of the carrier to the ring gear?

[XPLORx4]

Apparently, at least for wd21s, the arb locker is incompatible with an oem LSD diff. Why is that? Different attachment mechanism of the carrier to the ring gear?

 

Where did you read that? The ARB RD136 for the 31-spline H233B doesn't seem to indicate such a restriction.

[sewebster]

Where did you read that? The ARB RD136 for the 31-spline H233B doesn't seem to indicate such a restriction.

 

I've just seen it posted on this board a million times. Hopefully someone else will chime in...

[leggy]

I've just seen it posted on this board a million times.

 

Funny how that works..

[sewebster]

In another thread I made on this topic in the garage section, it was explained that apparently the differential case for the LSD has a smaller interior than the open version so the locker won't fit. By differential case what I mean is the "container" that attaches to the ring gear that contains the spider gears... Pics in FSM... but FSM doesn't mention the relative size. Shrug.

[Rick13]

I'm NOT suggesting that the LSD is worth changing to, but I can attest to being able to roll out of a flexed out position (driver's rear wheel completely dangling) because of the limited slip. I've had to practice how much brake I use while giving a little gas. I've now done it a handful of times and think I can make it work quite regularly now. Thunderbolt watched me do this on Red Cone Pass about 2 weeks ago and honestly it's feels pretty cool to pull off when it looks like a new line is in order.

 

Again, not trying to sway you either way, just my

Edited September 17, 2011 by Rick13