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BluDestiny

Modified STI swap or r180 w/ quaife with CV axles

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My 240z make some horrible decel sounds in gear coming from the diff in there now, making think the pinion bearing is going. So since I'm probably looking at upgrading. I'm debating on either going with an STI diff 3.9 and the beta motorsports (wolf creek) stubs, or using an existing 4.11 r180 diff I found at the junkyard  and doing a full rebuild with a quaife lsd. 

 

Along with that I'd like to go with a CV axles conversion from wolf creek. Will this work with the STI stub axles? 

 

Would the stub axles work with a STI diff that has a cusco unit in it? like this: http://forums.nasioc.com/forums/showthread.php?t=2732401

 

I know I can find stock STI diffs sub $450 all day long, but for the stub axles and diff at $900-1000, I'm considering going with a fresh quaife. I want to know if the performance of the quaife is justified. 

 

This car will never have more than 300hp. I want to stay with the L that it has now. I also have a RT diff mount going in along with some T3 rear control arms. 

 

Axles: http://www.wolfcreekracing.com/index.php?option=com_content&view=article&id=72&Itemid=61

Diff I'd use with the 4.11: http://whiteheadperformance.com/products/quaife-qdf5l-atb-helical-lsd-limited-slip-differential-nissan-r180-diff-115mm-datsun-240z-280z-280zx-510/

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The Quafe is fine but there's no performance advantage to it over a good clutch pack LSD.  ALso look into the OS Giken Super Lock.  Better performance then the two you're looking at now.  Part number is NS081HA for the R180 with a 115mm ID ring gear.

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John, and to anyone that has used the wolf creek CV conversion axles, do I need to specify which stubs are currently in the diff? or are most datsun/nissan r180's the same spline count? 

 

Also since I'm looking at having this diff serviced, is there anyone you'd recommend in the LA area? I know you pointed me to someone in Orange I think last time. 

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If you're interested I have an 07 STI diff (3.9 CLSD) with ultra-low miles that I would part with if you're interested. I'm in San Diego / Riverside Counties in SoCal. It's still in the box from the dealer.

 

As far as stubs and using WCR cv axles, you could use the stubs that WCR sells separately.

 

You could convert the diff to buttons and bolt-in axles and use nissan OEM stub shafts, not sure which model z they came in, but my 260z doesn't have that style.

 

Or you could go unconventional. The driveshaftshop sells a r180 stub with 930 bolt pattern, but I don't know its quality or if it'll work with the WCR cv axles. http://www.driveshaftshop.com/import-driveshafts/subaru/r180-stub-with-porsche-930-108mm-cv-mount

 

Front diff r180s from early 80s pick-ups have a stub shaft that might fit in the diff, some people have played with those. Try searching that. I think the cv bolt pattern is 2x3 with tripod style joints.

 

I've also read that people have used 80's maxima cv axles, swapped the center shafts with 280zxt cvs, and used modified companion flanges.

 

Ymmv

Edited by jthom5147

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I know the r180's out of the pickups come with bolt in stubs, with like a 6 bolt flange (3 pairs of 2) and a tripod CV, but it would need to be shortened and the other side made to work with the stock wheel flange.

 

I sent WCR an email asking if they make the CV axles to work with the STI stubs, or the stock stubs, or they can do both. I would think since the STI stubs have the stock flange, they will be fine (which is what you said).

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I don't believe the sti came with a flange.

 

IIRC, sti came with a diff-side extending cv joint that plugged directly into the diff and a wheel-side fixed cv joint that was splined and extended through the wheel hub like most (all?) modern IRS vehicles.

 

http://forums.hybridz.org/topic/73182-subaru-sti-r180-differential-and-axle-conversion-revised/

 

See that link for a thread using the sti axles, with modded wheel-side cv joint and shortened center bars.

 

Edit: the WCR axles are designed to bolt to the stock 4 bolt stub shaft pattern used on the Ujoint half shafts. It's the same pattern as on the stub axle companion flange and r200 stub shafts and earlier 240z r180 stub shafts.

 

R200 stub shafts don't work cause 29 splines not 27 splines.

R180 stub shafts don't work cause bolt-in not circlip.

The stub shafts sold by WCR are very high quality, have the 27 splines to fit in the r180, and are clip in so no diff conversion is necessary.

 

For your power goals, oem r180 would be fine but if you're not doing the diff work yourself it won't be that much more expensive in the long run to save your $ on diff work to convert to bolt-in stubs and just buy the better product WCR stubs

Edited by jthom5147

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Yes you're correct, I just checked under my daily haha. Anyway Todd at WCR got back to me and did say the STI stub conversion axles do work with their CV conversion kit (because 4 bolt pattern), and that the STI stub conversion axles are pretty beefy. 

 

So I'm now probably going with an STI rear dif,  Wolf creek stubs and the Wolf creek CV kit. 

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Resurrecting this thread because I'm desperate for answers.  

 

I have a 1972 240z with a Rebello 3.0L & Borg-Warner 5-speed from a 280zx turbo and the 04-05 sti CLSD. For the past few months I've been trying to diagnose an issue thats driving me insane. When I abruptly crack the throttle (in any gear, but much more noticeable at highway speeds or in corners) rear suspension becomes upset and the rear end of the car essentially jumps/hops out to the right an inch or two. When I say jumps, I don't mean like wheel hop but more like the rear of the car just abruptly wiggles out to the right slightly so it's not a smooth transition from off to on-throttle. It's really noticeable if I'm coming into a corner, I downshift then get onto the power again. If I'm already under slight throttle and I roll on additional throttle it's a non-issue, so it only happens during that initial transition onto throttle, especially when it's abrupt. 

 

I thought the issue was suspension related so I've been chasing it that way, doing all T3 components in the rear, but no change. Finally it dawned on me yesterday that it might be the diff. It almost feels like one of the rear wheels is engaging half a second after the other and it's causing the rear of the car to hop/wiggle out to the side when the throttle is applied. Does that symptom  make sense for a CLSD? If so, what would cause this? 

 

I'm looking at the OS Giken Super Lock NS081HA above that John recommended. This is probably a stupid question, but if I want to maintain the 3.5 ratio in the STI r180 (that works better with the T5) can I install the Giken unit into my subaru CLSD or does it need to be installed into my original 1972 stock open diff r180? I'm not terribly familiar with how these work, so does the Giken unit have it's own gear ratio and just completely replace the internals of whatever r180 I install it into, regardless of wether I use my 1972 open diff or my 04 STI diff or does the ratio stay the same as it was from the factory after the Giken install?

 

Many thanks,

 

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I think this would be best in its own thread.

 

Have you checked the axles? I had a VLSD and suspected the delay to be a combo of the coupling taking a moment to lock and the axle having play in the tripod.

 

Could also be a case of the Subaru diff being old and needing the discs serviced or re-stacked. John had also mentioned overheating the R180 with track work and needing frequent fluid changes and or a dedicated diff cooler.

 

The os-giken is just the center and would bolt to the gear already present in the differential. I'm seeing two different part numbers for the 240z and the STI, so there may be some differences. I imagine that difference would be on the input axles. If you like the Subaru diff and are set on the OS giken, I would just purchase the unit for the STI rather than for the Datsun. Granted I think if you are putting out a bit of power with the Rebello, the extra size and capacity of an R200 would not go amiss.

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Posted (edited)

Any chance your rear tires are of different diameter?  I had that happen once on a Pathfinder with a VLSD.  Took a while to figure out.  

 

On clutch LSD's there's a clutch pack for each axle.  Maybe you just need new clutch discs,as Seattlejester says.  Don't know where to get them.

 

https://www.rallispec.com/dif_ohk_sti_t.html

Edited by NewZed

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Thanks for the replies. The tires are definitely the same size. The half shafts have new U-joints so there shouldn't be any play there, but I'm considering CV's at some point anyways just to tighten things up further. The car is street driven (street-thrashed, really) but not raced, autocrossed, etc so I was hoping I could get away with running the R180 but maybe not. I'm happy with the ratio on the STI diff, so if I stick with the r180 I'll snag the sti unit instead of the datsun one. Looks like finding a 3.9 in an r200 could be tough. I assumed that since STI's put down close to rebello power I could get away with it. 

 

All of that said, in your opinion do the symptoms I described earlier point to an issue with the diff? Can there still be a lag in engagement between sides on the diff even if the tires are not breaking loose and you're jus going from off to on throttle?

 

Do you think upgrading to the super lock (either with the r180 or r200) and making sure the backlash is correct would solve the issue? 

 

 

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Posted (edited)

There's a clutch for each side.  They wear.  Draining the oil would be the quick easy way to learn more.  Take the cover off and see what's going on in there.  Check the oil for flakes or fragments.  Might be able to pull the clutch packs without pulling the diff.  It's possible on Fords, for example.

 

There's other things that can happen like the pinion shaft working its way free.  Not sure how Subaru holds theirs in place. Surprising how little there is on the interweb about these diffs.  All kinds of Datsun/Nisan stuff.  Probably the same as Nissan, but I've not taken one apart.  Ford has a bolt that works its way loose at times.  Probably want to find that out before it makes its way free.

 

p.s. I've seen threads about other cars where people wondered for many miles about a diff noise then finally opened it up to find carnage.  If it's not acting right best to open it up and look before it gets really bad.  I shot a pinion shaft through a diff cover when I was a high school kid.  Couldn't take the time to figure out why the car took tight corners weirdly.  It went straight just fine, and it was a weekend night.

Edited by NewZed

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As the others suggested, open it up and confirm what you've got and it's condition.  This thread from NASIOC may help:

https://forums.nasioc.com/forums/showthread.php?t=2597453

 

We've also had some threads here on this topic.  Here's one that may help as well:

 

Just curious if you really need to spend a bunch of time and money on a new LSD if you don't plan to race the car.  Would an open diff suit your needs?  The Giken's a nice unit, but far from cheap.

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Hey All, So I drained the oil this am and got the rear cover opened up. The oil was VERY dark, but no shavings or particulate and nothing on the magnetic plug.

 

I have a dial indicator coming tomorrow, but just did a quick test in the meantime. With the car up on jacks, when I rotate one wheel it will turn roughly 3-4mm before the other wheel starts to move in the opposite direction, so there is certainly some play but everything turns smoothly. When I rotate the driveshaft there is slightly less play (maybe 2-3mm) but still noticeable. Is the play primarily a result of backlash or could a bad clutch pack cause the slack? Should you even be able to feel ANY play when you rotate the wheels or driveshaft or should it feel 100% direct? I also looked at the half shafts but there is zero play there, so the slack is all coming from the diff. I put the car in gear up on jacks and asked my wife to let the clutch out abruptly, there's a distinct clunk which is the sound of the play before the slack gets taken up. Once it's spinning everything runs smoothly, but there's obvious initial play and the more abruptly she let out the clutch the more noticeable it is. Can't tell if this is clutch pack related, improper backlash or a little bit of both. 

 

JHM, I totally hear you about the OSG unit $$$. That said, I drive the car pretty hard and after the rebello at this point the OSG is a drop in the bucket. I never plan on selling this car so I'd rather have it dialed in 100% and just be a joy to drive so whatever it takes, as they say. I'm by no means made out of money, but this car is my only vice and my biggest hobby so I want to make sure the old girl has whatever she needs. I've been chasing this driveline slack forever, so I just want to get it squared away. If that means an open diff that's fine, but I believe my original 240z r180 was an open diff and it still had slack, so I feel like I've been there before.  

Edited by zev

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IME, it's not unusual to have play in the differential (regardless whether an R180 or R200, with various center sections).  If your's is a CLSD, would a friction modifier additive help this issue you're having now while driving?

 

If you're set on replacing it altogether, consider all the alternatives besides just OS Giken (Quaife, Cusco, etc).

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On 8/31/2020 at 8:40 AM, zev said:

When I abruptly crack the throttle (in any gear, but much more noticeable at highway speeds or in corners) rear suspension becomes upset and the rear end of the car essentially jumps/hops out to the right an inch or two. When I say jumps, I don't mean like wheel hop but more like the rear of the car just abruptly wiggles out to the right slightly so it's not a smooth transition from off to on-throttle. 

 

I thought the issue was suspension related so I've been chasing it that way, doing all T3 components in the rear, but no change. Finally it dawned on me yesterday that it might be the diff. It almost feels like one of the rear wheels is engaging half a second after the other and it's causing the rear of the car to hop/wiggle out to the side when the throttle is applied. Does that symptom  make sense for a CLSD? If so, what would cause this? 

 

 

Are you doing your own alignments or has it been done professionally?  Might be that your car is "dog-tracking", as they say, and the twitch is due to that.  Or you do have a loose component but just haven't found it yet.

 

https://www.popularmechanics.com/cars/how-to/a111/1272576/#:~:text=This condition is commonly referred,perpendicular to the rear axle.

 

 

 

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Funny enough, I had the same logic when asking John "I'm going to autocross will so will an R180 sti diff be ok."

 

His response:

"I never ran a STi diff in my car.  I had a number of Datsun R180s over the years that had welded spider gears, Quaife, Nissan Motorsports, and OSG Super Locks.  All got very hot and none ever failed.  That's with 120 to 275 ft. lbs. going through them.  I had to replace the diff fluid frequently (Redline 80W/140), as often as every race weekend at the higher torque levels (even with a cooler).

 

I would not run a R180 on any race track behind an engine making over 300 ft. lbs.  Autocross is even harder on a LSD because of the tight turns and acceleration from low speeds.  Street is different because you are rarely at full power for more then a few seconds at a time."

 

Gosh. Miss him.

 

An alignment as Newzed mentions would be pretty informational especially if you installed T3 adjustable items. With stock arms it would tell if the chassis is twisted, but at least with the adjustable they should be able to get everything in spec. There are some binding issues that show up with trying to adjust toe using an H-arm design, so if it is really far out I would be skeptical of forcing it all the way into spec.

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Update. I pulled the diff out and there actually isn't much backlash at all (dial indicator coming tomorrow so I can get an exact reading) but there is definitely a good amount of play when I rotate the stub shafts in opposing directions. It's maybe a 1mm but it translates to what feels like way more play when I rotate the wheels in opposing directions. I can't find a spec on wether there should be any free play in the actual LSD unit, but I went ahead and ordered the OSG and I'll see if that has any play. If it's identical I'll probably send it back but if there is no play in the OSG unit I'll install. I'll report back either way. 

 

Also, I have had a professional alignment recently and there was no change in the rear end hop before/after, so I don't think dog tracking is to blame but I like where your head's at and definitely appreciate the input.  

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8 minutes ago, zev said:

Update. I pulled the diff out and there actually isn't much backlash at all (dial indicator coming tomorrow so I can get an exact reading) but there is definitely a good amount of play when I rotate the stub shafts in opposing directions. It's maybe a 1mm but it translates to what feels like way more play when I rotate the wheels in opposing directions.

 

So is it a clutch or a helical?  How about a picture?

 

I noticed above that you said you turned one axle and the other side turned the opposite way.  They should both turn the same way, in a properly working LSD.   I think if they don't that means there's no preload on the clutches or the friction surface for a helical.  So, if it's a helical I think that it needs new preload devices, whatever they are in the Subaru helical or new clutch discs if it's a clutch LSD.  The typical helical uses Belleville washers for preload and they wear out sometimes.  I'm not a diff expert so I might be mixing somethings up.  But if you post a few pictures others can tell you what you have and what might be wrong with it.

 

There are many different mechanisms involved in LSD designs, from the way the force is transmitted to the axles, to the way preload is applied, and how much.

 

Anyway, it's an interesting problem.  It will be a real bummer if just leave people hanging and install an OSGiken without figuring out what you have and how it works.  We're all here for entertainment too, you know.

 

 

p.s.  I tried to find a description of the Subaru Suretrac and all I can find is Eaton's page.  Eaton shows a clutch LSD in their video.  Can't believe how hard it is to find info on these things even though the cars are everywhere.  Just weird.

 

http://videos.eaton.com/detail/videos/differentials/video/4750907910001/suretrac-differential-operation?autoStart=true

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