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HOW TO: Access your front LSD without even removing the wheels


joshellis
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The R200 8" front diff swap makes an excellent upgrade for any diesel Terrano. What makes it even better is a superpacked 4-pin clutch type LSD. I am drip feeding a 4 cylinder turbodiesel to this front end on 33x10.5 KMs, it is intentionally a very overbuilt setup. The entire truck weighs 1800kg/3900lb. I realized that the C200 2-pin solid axle derivative of this differential was used as standard equipment as the MK Patrol, a much heavier vehicle with a bigger engine, and the outer CV joints share all the same dimensions/duties as the solid axle birfield. The IFS double offset joint looks remarkably similar too.

 

The Nissan LSD is known for being one of the best available and the capability increase is like night and day. Recently I wanted to superpack the LSD with more clutches. I realized that the front diff can be accessed without the need for removing the case and cross members, which shaved quite a bit of time off the job.

 

FYI I am running diff drop bushings but I doubt it would make any difference in terms of access

 

The 4 bolts in red - for some reason they installed 2 of them in reverse from the factory. Get a thin cutting disc and cut those ones out. Support diff, remove crossmember bolts and 2x bolts in green. Get your 3lb club hammer and knock the crossmember off.

 

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Now remove the shocks. Unbolt the CVs and push them to the side. Remove the short side stub axle and set aside. Pull the long axle about 2 inches and support it so the inner seal doesn't get damaged.

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Now you can pull the front cover off.

 

Unlike many Dana/Salisbury diffs, you don't need an expensive case spreader to remove/install the center:

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So mark bearing caps and remove:

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Now the fun part - split the case (8xbolts).
Note this is a 4-pin diff which is a nice thing to have in the front. In my case, preload rings were split. This was not helping.

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New clutches please. Instead of just jamming shims in there, I also put a thick stack of new clutches. These had much more material on the grooves than the old ones. The idea here is to obviously make it clamp hard but also to increase the breakaway torque (point at which it reverts to open).

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And then to reassemble the center, put it in the vice.

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Now you can reinstall the center, and put bearing caps/shims back in place exactly as they were. Put cover back on, reinstall CVs, fill with oil.

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Grease up every mating surface on the crossmember, grab your clubhammer and massage it back into place.

 

The front crossmember bolts can be replaced with new ones mounted the correct way around.

 

Even when lifting a wheel, the LSD will now continue to redirect some power. It is by far the best off road performance mod I have made to this vehicle. It may as well be locked. In conjunction I am running an H233B rear with Aussie locker, both geared to factory 4.875:1.

 

I have found the combo of superpacked front LSD, rear locker and 4.88s to be my most formidable offroad Pathy setup yet.

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Edited by joshellis
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Quite possibly, yes!

I've never pulled apart an R50 front diff but AKAIK they are the same 28 spline outer R200A, in which case your ring gear should bolt straight on to the LSD centre.

 

Donor LSDs can also be found in the solid axle C200 Navara/Hardbody. It is the same unit as used in the 87-89 300ZX turbo, and the same as the Calmini unit.

 

Basically my truck started life as R180 front/C200 rear. So I a diff drop + R200 swap and put the rear 4.88s in the front. They are running on the coast side of the tooth, not quite as strong as regular rotation but still a very stout setup for the weight of the truck/engine size/tire choice. The 4-pin centre is reputably very strong.

 

For the rear, I upgraded to an H233B centre from a Patrol in a WD21 case. 4.88s were used from the factory in some late model WD21 diesels.

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Very nice trick by the way. I thought I had heard somewhere that Terranos came with an R180 front Diff, but couldn't remember where. Sounds like a pretty tuff little rig.

 



Basically my truck started life as R180 front/C200 rear. So I a diff drop + R200 swap and put the rear 4.88s in the front. They are running on the coast side of the tooth, not quite as strong as regular rotation but still a very stout setup for the weight of the truck/engine size/tire choice. The 4-pin centre is reputably very strong.

 

 

When I did my diffs I also noticed that front / rear gear contact was opposite. I honestly thought that the H233B ran on the coast side, which seemed weird to me as they are notoriously a fairly strong axle. I might have coast / drive sides mixed up. Just to clarify, Isn't the drive side typically the cupped side of the ring gear? Below is the photos from when I swapped in LSD / Locker / Gears.

 

Here's the H233B Third Member.

RearDiffFullLabeled_zps48709eec.jpg

 

Here's the R200A

FrontFullLabeled_zps7f690714.jpg

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Thanks for the feedback, you have a sweet looking Pathy too! Enjoyed your build thread. I'm sure you have found the front LSD/rear locker combo to be a menacing offroad setup.

You are absolutely right, drive is the convex side of the tooth.

 

Yes sadly all the diesels, including the turbos, came with the R180 front, and the smaller FS5W71C manual transmission. Luckily I managed to find an FS5R30A 'big box' from a late model R50 diesel, which fit right in.

 

Its pretty common practice amongst 4x4 manufacturers to have the front diff running in reverse. And when you consider that the R200 is very overbuilt for its application (the front of a light-weight 140hp SUV), its quite possible that some came from the factory like that. Dont let the terms 'coast' and 'drive' put you off, they are designed to run on both sides. I have a spare set of C200 4.88s just in case, but when you consider drift guys are routinely putting 500hp through the R200 without worries, I'm pretty confident.

 

 

 

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In all honesty, I haven't wheeled it yet. It sat for the last 6 months while I worked on the house and took on other projects. I started it for the first time the other day. First time it's run since I started the build. I'm sure it will be quite capable, however I have a hard enough time finding time to work on my truck never mind keeping a build thread up to date LOL.

 

I wasn't so concerned with the R200A running on reverse cut gears. I assume this is the case with yours as they are from a C200 rear diff? Understandably that the amount of time the truck sees 4x4 is far less than the time you spend in 2WD. My biggest concern is the H233B running on the coast side of the gears as mine appears to be, and likely all other H233B as well. At first I thought maybe I got gears cut for a front axle, but these are the same cut as my factory gears. You can see from my photo above that for the ring gear to rotate clockwise (as would be normal for forward travel), the pinion has to push off of the coast side of the ring gear. My front diff appears to be running on the drive side as would be normal :shrug: . I guess as long as the gears are designed to run in either direction as you stated above, I shouldn't be too concerned with it. It just surprised me a little.

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Reverse cut is a different thing altogether and refers to the direction of the cut in the ring gear, it doesn't actually run in reverse...

 

What I have is standard cut gears from a C200 rear axle, running in reverse.

 

Very interesting about your rear end running in reverse. This has got me wondering... do they all do that? Let me get back to you...

Edited by joshellis
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