bjhines Posted January 11, 2006 Share Posted January 11, 2006 There are TONS of R180s out there from other makes and models (even LSD units)... but there has never been a "BOLT IN" solution to using them in early model 240Zs... or even 280Zs for that matter... This is a way to make late model R180 differentials from other makes work in early model 240Zs... with the original 240Z driveshafts/halfshafts. The problem.... most late model cars with R180s use snap in 25 spline CV axles... There is/was no combination of stock parts that will allow you to use these rear ends without extensive work modifying the outer wheel stub axles to accept CV joint type half shafts.... in case you havn't looked... this is not easy or cheap... apparently... I am the first person to attempt to modify one of these late model R180s to use STOCK bolt in halfshaft stubs... with no cutting or grinding, no adaptors, no pressing, and no problems with leaking gear oil. The answer.... There was much discussion about manufacturing a button adaptor to allow the early bolt in 240Z halfshaft stubs to snap into the new R180s.... well... it turns out that Nissan/Fuji Heavy Industries already made the adaptor... and they are installed in every early style R180 used in 240/260Zs. The buttons are pressed into the inboard side of the side gears in the differential carrier...and they are quite easy to remove and reinstall by tapping them lightly with a hammer... The process..... You really need the FSM for the R180s used in the early 240Z cars... I am confident that the torque specs listed there are correct for the later style R180s as well... You must dissasemble the carriers for the early R180 and the newer R180... When you remove the side gears... pop out the threaded "button" that the stub axle bolt engages when you bolt on the side flanges/stubs... then pop it into the new side gears that go in the newer R180... Here is a picture with the button installed in the new gear on the left.. the old gear is on the right.... http://album.hybridz.org/showphoto.php?photo=5384&size=big&cat=500&page=1 reassemble the new carrier with the buttons in the side gears... leave out the center pin cover and get rid of the snap rings... Here is a picture of the completed assembly with the unused parts on the carrier flange. toss the snap rings and the center pin cover in the trash. http://album.hybridz.org/showphoto.php?photo=5393&size=big&cat=500&page=1 Here is a picture of the late model snap style carrier as it came from the factory. http://album.hybridz.org/showphoto.php?photo=5392&size=big&cat=500&page=1 Here is the differential with the bolt in side stub axles installed and ready to mount in the car... http://album.hybridz.org/showphoto.php?photo=5391&size=big&cat=500&page=1 It is a done deal.. and it does not take any heavy equipment.. just patience, hand tools, and a FSM for reference... The center pin cover serves as a side flange seal protector... It limits the insertion of the snap in side stubs so that they do crash into the seal when poeple hammer them past the snap rings... there is no room for it in the carrier with the bolt in buttons installed... obviously the snap rings serve no purpose and can be left out. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted January 12, 2006 Share Posted January 12, 2006 I appreciate you taking the time and effort to post your detailed instructions. However, at the risk of sounding argumentative, I would like to make a few points: There are TONS of R180s out there from other makes and models (even LSD units)... Other makes using the R180? Who are they? If you are alluding to Subaru you should realize that they used the smaller R160 diff. There is/was no combination of stock parts that will allow you to use these rear ends without extensive work modifying the outer wheel stub axles to accept CV joint type half shafts.... in case you havn't looked... this is not easy or cheap... Well, here’s what I did to use the R180 CV axles in a 240Z: Unbolt the stub axle companion flange and swap with the CV companion flange. Tighten bolt. What part of that is not easy or cheap? I wonder if you are confusing the R180 CV axle with the R200 CV axles? ...You really need the FSM for the R180s used in the early 240Z cars... I am confident that the torque specs listed there are correct for the later style R180s as well.... You may be confident, but you’re incorrect. The torque for the ring gear bolts is different. It’s 50.6 to 57.8 ft-lbs for the early (240Z) R180 diff and it’s 65 to 72 ft-lbs for the later (like the Maxima K type) R180 diff. I would recommend getting one of the 1981-84 Maxima FSM’s as well. Quote Link to comment Share on other sites More sharing options...
bjhines Posted January 12, 2006 Author Share Posted January 12, 2006 Ahhhh.... I did not realize that they were different torque specs... VERY SCARY!!!! I will retorque them before it goes under the car... VERY GOOD TO KNOW!!! thank you... " Other makes using the R180? Who are they? If you are alluding to Subaru you should realize that they used the smaller R160 diff. " I have to do some research on this... It is my understanding that the Subaru R160s may be the only ones that use 25 spline axles..There is some question as to which stubs the Subaru R180 had. "" Well, here’s what I did to use the R180 CV axles in a 240Z: Unbolt the stub axle companion flange and swap with the CV companion flange. Tighten bolt. What part of that is not easy or cheap? I wonder if you are confusing the R180 CV axle with the R200 CV axles? "" Ahh haa.... this is truly a neat solution to put CV axles in a stock 240Z...but do you mean to say that you found inboard differential stubs with 25 splines on a CV halfshaft that literally BOLTS into the 240Z R180 differential.. and bolts directly to the stock WHEEL flanges...THAT IS GREAT TO KNOW....!!! If you mean that you have to remove the wheel stub axle flange then it is a little tougher to remove the staked nut than you allude...but it may be the preferred way to go when you are using a STOCK 240Z R180 and you wish only to upgrade to CV AXLES.... BUT... my problem was the fact that MY NEW differential had snap in style 25 spline axle retainers... I had to find SNAP IN 25 spline SHAFTS to fit the 240Z chassis and wheel flanges... but instead I reworked the carrier to accept the original 240Z bolt in stub shafts using the original halfshafts... In other words this turns ANY NEWER 25 spline RXXX differential into a BOLT IN STYLE HALFSHAFT old school 240Z compatable replacement... It may very well work with the R160/180 LSD units too. AND NO... there is absolutely no confusion on my part about the difference between 25 spline halfshaft stubs... and side specific, 29 spline, R200 stubs... I have examples of both...bolt in 25 spline and snap in 29 spline... I have an R200 NISMO LSD... installed in a 1972 chassis...piece O cake..well documented...expensive... I have this BRAND NEW never installed R180 going into another 1972 chassis...I was not able to come up with driveshafts that would satisfy the late style snap in stub sockets...with a 25 spline count, and of equal length, that would bolt to the 240Z wheel side flanges. Quote Link to comment Share on other sites More sharing options...
240Z_Master Posted January 18, 2006 Share Posted January 18, 2006 Hi there all... I used CV Companion Flange from a 1st gen Maxima and a R180 carrier from a 4.11 200SX. My problem is that the 1st gen maxima axles I got are frankly too long. I have a series 1 240Z. Are there different axles I should be using? or am I just not installing them correctly. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted January 20, 2006 Share Posted January 20, 2006 ...I used CV Companion Flange from a 1st gen Maxima and a R180 carrier from a 4.11 200SX. My problem is that the 1st gen maxima axles I got are frankly too long. I have a series 1 240Z. Are there different axles I should be using? or am I just not installing them correctly. You can disassemble the R180 CV axle and replace the center shaft with a shorter one from an R200 CV axle. The difference in lengths are: 280ZX Turbo (L side) _______________ 14 3/16 inches 280ZX Turbo (R side) _______________ 14 11/16 inches Z31 non-turbo (L side) ______________ 15 5/16 inches 280ZX/Maxima (R180 either side) ______ 15 7/16 inches All the above center shafts are interchangeable. Quote Link to comment Share on other sites More sharing options...
240Z_Master Posted January 20, 2006 Share Posted January 20, 2006 You can disassemble the R180 CV axle and replace the center shaft with a shorter one from an R200 CV axle. The difference in lengths are: 280ZX Turbo (L side) _______________ 14 3/16 inches 280ZX Turbo (R side) _______________ 14 11/16 inches Z31 non-turbo (L side) ______________ 15 5/16 inches 280ZX/Maxima (R180 either side) ______ 15 7/16 inches All the above center shafts are interchangeable. Wow, I like that whole 1.25 inches shorter bit from the ZX Turbo. I have a set of turbo axles thankfully, but it'll only help me with one axle. Quote Link to comment Share on other sites More sharing options...
mjfawke Posted January 24, 2006 Share Posted January 24, 2006 If you are alluding to Subaru you should realize that they used the smaller R160 diff. Not quite true. I have a VLSD R180 3.7:1 from a Subaru in my 240Z. And the STI WRX's have a mechanical LSD R180 in the rear. Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted January 24, 2006 Share Posted January 24, 2006 It apears we still have some gaps in the whole R-Diffs from Subi's. What models are you getting these LSD's out of. mjfawke, I notice you are in OZ, so you have many years of cool subi's we didn't get here in the states. I'd like to know and see a step by step done of the swap with a complete list of parts needed and their supply car. I plan on sticking with My R180 but would like to know what I can use as a close to bolt in swap if it ever dies. Quote Link to comment Share on other sites More sharing options...
mjfawke Posted January 25, 2006 Share Posted January 25, 2006 I never found out which model it came from - they were imported from Japan for swapping into later style Nissan R180's. The Subie shafts from the diff had the CV flanges removed and Datun flanges welded on, the front flange was swapped for a Nissan flange. My original diff was a 4.375:1 Nissan with the Subie VLSD, but that died and as a temporary measure I dropped the complete spare diff in (3.7:1) - two years later, it's still there as it suits the turbo well. STI mech R180's are very rare here, but I found a number of them available very cheaply in the US on Ebay. Quote Link to comment Share on other sites More sharing options...
bjhines Posted January 26, 2006 Author Share Posted January 26, 2006 you dont need to cut or weld anything for any R180 if you do what I outlined above... the only thing you have to check is the 25 spline shaft. Quote Link to comment Share on other sites More sharing options...
DAW Posted January 27, 2006 Share Posted January 27, 2006 I appreciate the post on the early/late R180 swap. I'd figured that the swap could be done by swapping side gears but I never realized that there was a removeable "button that makes it far easier. If I'm reading the post right, you are describing how easy it is to swap, say an R180 "K" 4.38 front differential from a 720 4WD pick-up (which uses CV's) into a 240Z while retaining the stock axle shafts (U-joint, bolt-in)...am I correct? Thanks for the info. DAW Quote Link to comment Share on other sites More sharing options...
bjhines Posted January 27, 2006 Author Share Posted January 27, 2006 absolutely... the bolts are threading into the original buttons that datsun pressed into the side gears on the original R180s that came in 240Zs. The "buttons" fit 25 spline side gears... also the same as used in Subaru R160s and R180s... the only problem I have found witht he Subaru diffs is that the R160 is much narrower than the R180... so the stubshafts will stick out of the sides of the R160 a few mm... but I do not see a problem with this in operation.. Quote Link to comment Share on other sites More sharing options...
mjfawke Posted January 29, 2006 Share Posted January 29, 2006 you dont need to cut or weld anything for any R180 if you do what I outlined above... the only thing you have to check is the 25 spline shaft. Yes - but I'm running a VLSD, which you cannot do with stock shafts. Quote Link to comment Share on other sites More sharing options...
bjhines Posted January 31, 2006 Author Share Posted January 31, 2006 ahhh yes... VLSD would be a problem.... CLSD appears to be possible.. but I have not had the time to poke around in the JY... There may be enough clearance to use the buttons.. but it has not been verified...yet... There seem to be more people opting to change to CV axles and later model, larger diffs... This would be a good thing for high horesepower cars...and it is my choice for my track built Z.... but I have other Z cars that could use lightweight, cheap, newer alterantives to the Quaife, Nismo, R2XX route... these subaru diffs seem promising... My personal situation was that I aquired a BRAND NEW in box..K-r180.. for a Maxima... I just wanted to install it with minimal cost and driveline changes.. to allow use of my existing spares for years to come. Quote Link to comment Share on other sites More sharing options...
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