Front Diff Swap - R180 to R200

[Dieselboy]

OK, a few newbie type questions so please bear with me. I've been using the ol' search function but getting a little confused.

 

Firstly, am I right in thinking that the ring gear in the R200a front diff is 200mm and the R180a is 180mm? So the R200a is that much beefier and can handle more abuse?

 

Secondly, can I swap out an R180a for an R200a? I have the R180a on my Terrano (after doing a lot of net research to find out!) but I have a complete hub-to-hub R200a assembly on my V6 WD21 Pathy parts truck. How easy is the swap over - just a straight replacement? All bolts on in the same place?

 

Really want the heavier duty diff if I'm going to be putting 33s under there. Plus, I want to install air lockers and there isn't an ARB locker option for the R180a as far as I can find.

 

Lastly, as far as the ARB air locker option goes, can I instal an air locker in a rear H233b axle that's factory fitted with an LSD? Would the ARB locker just replace the LSD differential case assembly and its contents of disks, plates, and gears? Or would I need an entire open-diff third member? I've heard conflicting things from different people on this.

 

Many thanks

Mark

[Heloflyboy]

Hi Mark, I am not to sure on R 180 to R200.Why don't you SAS ? It would be better in the long run. You will need to do a body lift and have your arms cranked all the way down for 33" not to rub. It also puts a lot of strain on the steering, C.V.s and boots.The only reason I mention this is I also had 33" with IFS. I finally did SAS.It would of saved some money in long run doing SAS to begin with.

The rear third member does not matter if you are going with ARB or detroit locker.I just did detroit swap into L.S.D. went just fine. You unbolt ring gear from L.S.D. and bolt it to D.L. or ARB. Make sure you get back lash set correctly.You want to make sure you get new bearings and seals before you start. You might want to get axle seals at same time.Mine was leaking onto parking brake just enough to where I could never get it to work properly.Axle seals are a bit of a pain to change also. Good luck hopefully this helps.

[silverton]

You will need to do a body lift and have your arms cranked all the way down for 33" not to rub. It also puts a lot of strain on the steering, C.V.s and boots.The only reason I mention this is I also had 33" with IFS.

 

that's only if you get stupid and try to run 33x12.50's.

 

33x10.50R15 is just fine on a stock height pathfinder, just need to massage the quarters and fenders a little. I know from experience on two rigs.

[Dieselboy]

Yeah, I've got a 3" SL in my parts truck that I'll be refurbing and swapping into the Terrano, plus a 3" BL as well. And no, it will not be 12.50s. 33x10.50s is what I want to run. And I'm happy to trim the body a bit if need be too. Will be dropping the front diff by 0.5 to an inch to help with CV angles. I got pretty adept at quickly swapping CV axles and steering linkages in my old Pathy, so will be beefing up the steering on this new rig too.

 

Just need to find out if I can swap the R180 with the R200. Don't need the PITA getting that R200 out of my parts truck only to find it doesn't fit.

Edited November 28, 2011 by Dieselboy

[1994SEV6]

Hey take a look at this real quick. This guy is asking a very similar question. He went on another Nissan site and copied and good info about the differentials and stuff. I think I've seen it before. It looks very familiar and it's good stuff

 

http://www.nissanpathfinders.net/forum/index.php?showtopic=31733&view=findpost&p=598454

[Dieselboy]

Thanks for that. There's a lot of interesting info there!

I had actually seen that earlier though and used it as a start point for my research. The diesel Terrano is a strange beast. In some ways its just a diesel-engined Pathfinder, but the drive train has a lot more in common with an HB.

 

After doing a lot of part numbers comparisons between different websites, seems I've got the H233b rear diff, a R180a front diff at 4.625:1, a RE4R01A tranny, and a TX10 transfer case. That diff combo is much more like some HBs that the Pathies.

 

From the schematics it looks like the R200a could swap in for the R180a. But that's just how it looks. Would probably need to run the R200 CV axles as I think the mounting flange on the diff is different to that on the R180.

 

The questions is . . . will it fit!?

[bmcgawain]

Thanks for that. There's a lot of interesting info there!

I had actually seen that earlier though and used it as a start point for my research. The diesel Terrano is a strange beast. In some ways its just a diesel-engined Pathfinder, but the drive train has a lot more in common with an HB.

 

After doing a lot of part numbers comparisons between different websites, seems I've got the H233b rear diff, a R180a front diff at 4.625:1, a RE4R01A tranny, and a TX10 transfer case. That diff combo is much more like some HBs that the Pathies.

 

From the schematics it looks like the R200a could swap in for the R180a. But that's just how it looks. Would probably need to run the R200 CV axles as I think the mounting flange on the diff is different to that on the R180.

 

The questions is . . . will it fit!?

 

You should be able to get it to swap. I believe you are correct on the axles needing to be swapped too. From what I can tell, the bolt patterns are different. I have also been reading more on Nissan difs just so i know what crowd to market my H/B parts too. These guys are using the R180 and the R200 interchangeably. Although they are using them in different applications, its all the same because Nissan is so smart!

http://www.zcar.com/70-83_tech_discussion_forum/r200_r180_swap_help_632628.0.html

[MY1PATH]

I think You can swap the entire R200 Carrier. I recommend using Diff drop bushings when you do the swap (4x4 parts advertises them as making 180 to r200 conversions easier) . You may need the R200 front and rear cross member to go with it.

Imagine CV's and maybe even hubs may need to swap with to match splines.

 

That being said, I think the r180 is plenty strong. The gear sets come from the same place and R200 Diffs have withstand 450 HP every day in the back typical High boost Import racers...

So is 20mm larger really worth all that work for an engine that puts out 160hp tops?

Maybe it is, maybe you plan to boost one day or drop in a 350. Or maybe you just feel like doing it anyway. That's fine, I just wanted you to consider the above first.

[1994SEV6]

Thanks for that. There's a lot of interesting info there!

I had actually seen that earlier though and used it as a start point for my research. The diesel Terrano is a strange beast. In some ways its just a diesel-engined Pathfinder, but the drive train has a lot more in common with an HB.

 

After doing a lot of part numbers comparisons between different websites, seems I've got the H233b rear diff, a R180a front diff at 4.625:1, a RE4R01A tranny, and a TX10 transfer case. That diff combo is much more like some HBs that the Pathies.

 

From the schematics it looks like the R200a could swap in for the R180a. But that's just how it looks. Would probably need to run the R200 CV axles as I think the mounting flange on the diff is different to that on the R180.

 

The questions is . . . will it fit!?

The H233b and the R200 are paired because they have a certain gear ratio. And it's the same. I didn't think the r180a had the same gear ratio, but obviously it must since it's on your truck.

I'm stuck here wondering what the difference is?

According to the link bmcgawain supplied, they are very similar with little swapping to do..What's the point of putting one or the other in? You have a heavy duty diesel engine, the bullet proof rear end, the trans isn't bad, so what's up with the r180a? Is it just a little bit weaker or more prone to failing or what?

 

You should be able to get it to swap. I believe you are correct on the axles needing to be swapped too. From what I can tell, the bolt patterns are different. I have also been reading more on Nissan difs just so i know what crowd to market my H/B parts too. These guys are using the R180 and the R200 interchangeably. Although they are using them in different applications, its all the same because Nissan is so smart!

http://www.zcar.com/70-83_tech_discussion_forum/r200_r180_swap_help_632628.0.html

LOL "the r200 is illegal" wtf is that bs? How can you make a factory diff illegal?

[Dieselboy]

The main reason for swapping is to be able to install an air locker in the front and re-gear to 5.142.

 

Now, as far as I have found out so far, there is no ARB air locker available for the R180 diff. Not sure about a 5.142 ring and pinion set.

 

So if anyone here can tell me (truthfully, lol) that an air locker for an R200 will fit with no problems in an R180 and that there are 5.142 gear sets available - well, I'll not need to swap!!! I'd rather not as I've got better things to do with my time!

 

As for drop down bushings, I got a set that'll go on what ever front diff when the SL goes in. A PITA to do from what I've read, but hey, if it adds life to my CV axles, probably worth it in my book.

[pakoe]

Hello Dieselboy, i have a terrano td2t too, and i swap the r180 to r200, and i replace the original 4.625, to 5,14 gears, i run with 285/75r16 perfectly. The swap is very easy, but you need change the all the drive shaft, and the hub, because, your original drive have 6 bolts, and the r200 5 bolts, and the axle of the r180 carry 27 splines, to 28 for the r200 axle, the knuckle spindle is not the same too .The crossmember to the r180 is good for the r200. Just one more thing, you need, raise a little the engine, because the oil pan is touch with the differential. Ah!, i have a front lsd and lockright locker in the rear.Excuse me for my english, but the translator isn't very good.

Edited November 28, 2011 by pakoe

[pakoe]

my car

http://www.hiboox.es/go/imagenes/auto-moto/dsci0018,38680054310669ba66140ddf447d8434.jpg.html

 

http://www.hiboox.es/go/imagenes/auto-moto/dsci0019,c1bb536998b74edfbb7900d0c5c75684.jpg.html

 

my swap

 

http://www.hiboox.es/go/imagenes/auto-moto/imagen000,05d0f93a190af96c7abe86ee15f18d84.jpg.html

[1994SEV6]

Hello Dieselboy, i have a terrano td2t too, and i swap the r180 to r200, and i replace the original 4.625, to 5,14 gears, i run with 285/75r16 perfectly. The swap is very easy, but you need change the all the drive shaft, and the hub, because, your original drive have 6 bolts, and the r200 5 bolts, and the axle of the r180 carry 27 splines, to 28 for the r200 axle, the knuckle spindle is not the same too .The crossmember to the r180 is good for the r200. Just one more thing, you need, raise a little the engine, because the oil pan is touch with the differential. Ah!, i have a front lsd and lockright locker in the rear.Excuse me for my english, but the translator isn't very good.

 

Wow. That's a pretty good write up. Short and simple. My r200 has 4 bolts though (I did see that yours is 5). The drive shaft is 4 14mm bolts and I'm pretty sure the CV axles are 4 bolts also, but it could be 5 since they are at weird angles. Other than that, I think it's perfect.

[pakoe]

Sorry but i have a mistake, the word doesn't drive shaft,yes 1994sev6 this part have 4 bolts too in the mine, i want tell cv axle. Excuse me again, i need more practice in automotive words.