Rebuilding R200 Diff

[Proximity Motorsport]

Hey.

I put a nismo centre into my r200 from r33 the other day, and when I put it back together, there was shitloads of backlash. I didn't check before I pulled it apart but im assuming the centre is maybe machined slighlty thinner on one side, causing the shims I re-used not so effective.

I haven't had huge exposure to diffs, but I know in a Patrol diff, there is nuts on either side that you can adjust to set preload and backlash.. and what an easy, effective way of doing it. The R200 diffs though use shims to get preload and backlash though. My diff only had 2 shims on one side and 1 on the other.. I haven't measured them, but how close to perfect could it be, the shims are at thinnest, 1mm thick. So Im wondering can anyone tell me, if I need to add 0.25mm on one side or something how am I supposed to get such a thin shim in there, considering I had the use a soft hammer to tap the others in there in the first place. Or do nissan sell a HUGE variety of shims in steps of 0.05mm or something? (1, 1.05, 1.1, 1.15 etc)

Can anyone please do a bit of a spiel on how to setup the backlash properly with these diffs, and what specs I should be aiming at. for preload on side bearings, I've been told with the patrols they tighten them until you can feel load on the diff when turning it by hand, then back it off 2 notches on the diff. Is this pretty much the same principal with the R200?

Ill try get some photos and do a HOW-TO right up, because I can't find anything on the net about this, and there has been a few diff questions asked on here before.

ps. just for knowledge.. do the R200 have a crush tube under the pinion or just shims?

Cheers

[Dobz]

Measure them with a micrometer to make sure they're not too different in thickness. Even though they might look the same it's hard to tell the difference by eye when it might only be 0.1-0.2mm thicker than the other.

[Proximity Motorsport]

Yeah I know. I was just asking in advance on that question, wondering if they are only set sizes, 1mm, 2mm etc, then the diff wouldn't be setup accurately at all! And how am I supposed to add a 0.25mm shim to the diff, I would destroy it trying to squeeze it in.

[bubba]

When I put new centres in old housings, I pay my diff guy a couple of hundred bucks to set it up.

[Proximity Motorsport]

yeah well I have the tools and mechanical knowledge to do it, I just need to know the procedure and how its done.. then I know its done properly, and I know I did it myself.

[skylinegtts]

check out the r32 gtr workshop manual,

should be pretty much the same procedure for the rear diffs. and it will give you a step-by-step guide

[wlspn]

There is a bit of an art to properly setting up a diff. If you are happy with the carrier preload (how tight the centre slots into the housing then what you need to do is leave the total thickness of shims the same but adjust your backlash by adding to one side & removing from the other.

e.g If you had a 1.0mm shim each side of the carrier you would change the crown-wheel side shim to .95 & the other side shim to 1.05. There is no set rule with sizes, you just need to keep checking.

As you can tell to get things perfect you need a large collection of different sized shims which is why a lot of people would just go to a diff specialist. Pinion preload (crush on spacer) can also affect backlash.

Most people dont realise but there is a lot involved in correctly setting up a diff, like pinion preload, carrier preload, backlash, mesh pattern, etc

[wlspn]

So basically every time you install the center & dont get the correct backlash readings the centre must come out, you slightly adjust shims then start again. Also how are you measuring backlash? The proper way is with a dial-indicator which measures in 0.01mm increments. As a general rule, dependant on gear size, you want 0.10-0.20mm backlash.it is very hard to judge this by feel unless you have built a shitload of diffs...

Are you going to paint the gears & check meshing pattern?

Honestly if you dont have the tools or knowledge mentioned & really want this diff to last it is quite often better (& easier) to go to a specialist.

[Proximity Motorsport]

Im a fitter and turner so yeah I do have quite a good mechanical knowledge. I have never built a diff which is why I'm asking. And yes I do have a magnetic base dial indicator, and yes I do have bearing blue to check meshing of gears. And I have rebuilt many worm drive gearboxes so I know the mesh patterns.

To me the idea of these diffs is stupid, compared to the nut type, where you just tighten the nuts to get the backlash and preload on bearings.

I didnt think of looking through the GTR manual, but I do have one somewhere, I'll check it out. So I suppose maybe nissan could help me out with these shims. At the end of the day if I spend $20 on 20 shims that should see me through to get it right, Id be much better off having the satisfaction of doing it myself and not spending $300 odd at a diff place that really dont give a f*ck if they get the diff spot on or not.

Thanks for the advice for those of you that have helped out. I'll see how I go with this and I might do up a tutorial

[skylinegtts]

can you let us know on the shim part numbers and prices?

it'll be good to know when i get around to it.

[R.3.2.G.T.R]

http://www.skylinesaustralia.com/forums/Di...tml&hl=shim

[skylinegtts]

i believe theyre different shims, theyre shims for the viscous centre. Not the shims for the centre and pinion alignment, i could be wrong though.

[turboedsloth]

Did you mix the shims up? i've put a few mechanical centres into the R200's and have never had to change the shims. There are quite a few manufacturers still using this style diff, Holden used them til the VS beam axle, as did ford in the falcons. And Mazda/Ford use them in the 4wds. They are a pain in the ass to setup but they work well

[hardsteppa]

so, replacing the bearings in the diff and of course there's many variants of the r200 diff so not finding conclusive answers on this, and the workshop manual i have is from the old longnose z31 diffs so not applicable for several areas.

Mine is non abs short nose R33 r200 diff with cusco centre. 

For setting the preload on the pinion bearing, seems later variants (350z) have a crush-tube that tightening the big nut at the tailshaft end of the pinion will crush as it tightens, increasing bearing preload, so the specified torque range for the nut is VERY broad. But from the r33 diff i dismantled on the weekend (planning on doing mine shortly, test run) there's no crush tube, it's a solid cast piece and there's a shim either side of it, 1 for setting pinion height and the other for setting bearing preload i'm assuming. All well and good and the pinion is going back into the same housing just with new bearings, but givn there doesn't seem to be any "crush" there should be a fairly specific torque setting for the big tailshaft end not, which i've not been able to find..although from the nut i removed, imagine it will be 150lbs plus....anyone know the torque specs or have an r33-specific r200 diagram? 

[hardsteppa]

ok so after not finding too much info online for the above i feel obligated to share what i found, and hopefully will help anyone else later on. This isn't a walk-through or how-to, just some points and suggestions, and i'd suggest you be at least reasonably mechanically competent before opening the diff, also have plently of time on your hands, and a full workshop at your disposal as you'll need in additions to jackstands, range of sockets, spanners etc - at LEAST - 10+ ton press, and press fittings, bearing puller, pulley puller, torque wrench, gear dye. 

Firs thing, remove diff...obviously...like i said, not going to cover all that.

 

make suitable tool for holding diff in place while you work on it

[hardsteppa]

remove diff centre, keeping check of where everything was to begin with. Remove pinion nut - first mark with paint-pen, the location of tailshaft flange and pinion nut, and measure depth of pinion nut on pinion shaft (for reference on reassembly). Mine was 6.28mm deep on shaft on one side.

Press out pinion assembly, making sure it's supported/caught when it comes out. Press out both pinion bearing races from housing (they come out easy)

Clean the schiess out of everything once disassembled. 

[hardsteppa]

when pinion parts are disassembled, the topmost spacer closest to the pinion gear has a bevel on one inner side - this goes on the gear side. Press new bearing onto pinion with fair amount of force so it's well and truly seated. Remember you're pressing the inner part (solid metal ) rather than on the moveable race.

Press the new bearing housings into the housing once everything's cleaned spotless.

 

 

NOW - bit of moly or multipurpose grease onto the  bearing races prior to fitting. Pinion goes into housing - support it from underneath, and press tailshaft (smaller) bearing onto pinion. Don't press it all the way, just enough so it's on the shaft and secure in place - this is part of setting the bearing preload. 

[GTSBoy]

Andy,

I forgot to come back to your previous post a couple of weeks ago.  Just FYI, my diff, and all the collection of diffs I had apart to build my frankediff, have crush tubes in the pinion.

[hardsteppa]

jeez that's annoying...the last post has disappeared completely. Must have been all those racial and homophobic slurs and references to jews that i put in, in addition to diff-related information...will type up again and repost shortly.

anyway gtsboy that's the nature of the r200 hey, many diff-erent variants. Both the diffs i have here are the same, with a pinion spacer tube (solid cast metal item) rather than a crush tube. This page from the s14 manual matches the diffs i have, which are both 5-bolt shaft R33 items, although one with longnose/abs sensor, other one shortnose/non-abs.