Dtsnlvrs Posted December 24, 2006 Share Posted December 24, 2006 Well I just wanted to start by saying thanks to those that helped me with guidance, info, and or parts prior to me doing this swap. Thanks to jmortensen for technical advise, johnc for advise and parts, 2ManyZs for a kind ear, 260pos for getting your hands dirty today, and to rc's240z for helping me to unload some parts and free up the cash to do this. This all started with the need to get my RPM up into the working range for my cam and carbs and still be able to use 5th gear. With my old 3.54 rear and the 81-83 N/A 5sp, I could not use 5th unless I was at 70mph or higher, anything slower and the motor would lug and ping. The first thought was to buy a r180 lsd (could not pass on the price) and find a suitable 3.9 or 4.11 gear set to match it with....well didn't nissan throw us a wrinkle on that one as in pre vs post 76 r180 diffs. So plan B, find a suitable buyer for now useless 110mm R180 LSD (Thanks Ron) and then buy a 4.11 or 4.38 Late R180 diff and get John to make the diff side stubs for it. Well I found a junk yard in Lincoln, NE that had multiple 4.11 R180 from 200sx and they would sell one for $100 shipped to Vegas. John made me a beautiful set of diff side flanges and it was time to go thru the diff. Now some people are gonna scoff at some of what I say, but here it goes. Opened the diff up, and verified that it was indeed a 4.11, pulled the side bearing retainers and removed the carrier for inspection. All is looking good. No unusual wear patterns or scuffing on the bearings or the ring gear. Shine a flashlight into the housing to get a good look at the pinion and it looks great, no scuffing or unusual wear. Replaced the bearing retainer O-rings and back in she goes. I also replaced the side oil seals, however with this and almost every other nissan diff I have done, unless I remove the pinion, I will not replace the pinion oil seal...never seen one leak so why bother to risk damaging the pinion to replace it (see told you some people will scoff). I cleaned the rear cover mating surfaces and installed a new OEM gasket with a light (skim) coat of RTV. All the bolts were tightened and torqued to spec and a new diff breather was installed. Then I slipped the new stub shafts in and with a slight tap of a hammer, they were registered. Now she is ready for install. I will not bore ya'll with a play by play of the install but I will point out some must do's and do not's. 1. DO re-lube U-joints when doing this, got em out already why not take advantage of it. 2. DO tighten the rear drums, already got the wheels off, see 1 above. 3. DO use anti seize on the halfshaft mating flanges, save yourself for next time. 4. DO NOT tighten diff to diff mount bolts until the end...I know it is a PITA to use a 12pt 17mm box end to tighten them little F$%KERS once it is installed, but there will be no pre-stress on the Moustache bar if you do it this way. 5. DO NOT assume that the Diff to Moustache bar mount nuts are tight enough...25% of diff clunking is from the diff shifting in the moustache bar...tighten them suckers German style if ya know what I mean. That about sums it up...If you want or need more info on how to swap a diff....buy a freakin service manual, crawl under the car and figure it out...esp if you plan on just dropping the diff w/o dropping the entire suspension and exhaust. Oh and tomorrow I will post the road test update Quote Link to comment Share on other sites More sharing options...
olie05 Posted December 24, 2006 Share Posted December 24, 2006 so was this a r200 to r180 conversion? Quote Link to comment Share on other sites More sharing options...
Dtsnlvrs Posted December 24, 2006 Author Share Posted December 24, 2006 so was this a r200 to r180 conversion? Um, nope..a early to late r-180 conversion....more af a ratio change thing...I am just happy that it is done Quote Link to comment Share on other sites More sharing options...
260pos Posted December 29, 2006 Share Posted December 29, 2006 So, how does it go? Did the 4:11’s get you into the powerband as hoped? I appreciated the comradely and of course the wisdom you so freely gave to me. I’m working on my kid’s little Honda XR80 right now. I’m trying to source a long travel swingarm for it. Going a bit nuts with it, another hybrid. Love the Japanese’ interchangeability! But when I get the Z parts together, we will tune those SU’s and we can bench race some more! Thanks Russell Jim Quote Link to comment Share on other sites More sharing options...
Dtsnlvrs Posted December 29, 2006 Author Share Posted December 29, 2006 Yes, the ratio change did get me into the powerband I wanted. It is perfect, just a little tweaking of the carbs and we should be spot on. On a side note, I now have a wicked vibration that is speed specific...could be halfshafts or tires...gotta sort that one out...I am inclined to believe it would be the halfshafts.....never felt out of balance tires cause this much vibration. Quote Link to comment Share on other sites More sharing options...
260pos Posted December 29, 2006 Share Posted December 29, 2006 Well switch the tires back to start, then check the bolts that my skinny a$$ tightened... Quote Link to comment Share on other sites More sharing options...
Dtsnlvrs Posted December 29, 2006 Author Share Posted December 29, 2006 Well switch the tires back to start, then check the bolts that my skinny a$$ tightened... Got it at Big O Tires right now doing a re-mount (left to right) and balance. We shall see if that does it. Quote Link to comment Share on other sites More sharing options...
tannji Posted April 26, 2007 Share Posted April 26, 2007 Got it at Big O Tires right now doing a re-mount (left to right) and balance. We shall see if that does it. Just a request for an update on the vibration... ran across this thread doing some research on the R-180 option. Quote Link to comment Share on other sites More sharing options...
Dtsnlvrs Posted April 26, 2007 Author Share Posted April 26, 2007 Well, I had the driveshaft balanced, installed new tires, replaced the u-joints on the left side and I still have a vibe past 70mph. That leaves the right side u-joints, and the need to move the diff to the post 71 position. I will get this sorted out...I did have a thought...I used to get a vibe at 80-85 mph prior to the diff change...could the movement of the diff rearward have more to do with driveshaft pinion angle than halfshaft?...we shall see. Quote Link to comment Share on other sites More sharing options...
datman Posted April 26, 2007 Share Posted April 26, 2007 I use to get really bad vibration above 70, tuned out to be the bolts that hold the diff to the moustache bar...tightened them up and its been good since Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted April 27, 2007 Share Posted April 27, 2007 I run an early Nismo R180 LSD w/4.11:1 r&p. It's mated to a lightly modded 2.4 and type-A 5-speed. It makes for brisk driving and rapid gear changes. Not much for off-the-line racing but very zippy for curves, corners, and road racing. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted April 27, 2007 Share Posted April 27, 2007 When I went to the 4:11 gear set, I had what appears to be the same vibration you've described. The only way I eliminated it was correcting the driveshaft angle (moved the entire differential 1" toward the driver, but that is probably not an option for you). My guess was that the increased spin rate of the driveshaft due to the lower gear ratio brought an existing vibration to a speed that I normally drive at. Previous to that change I would guess that this vibration still existed at a higher speed, one not normally maintained (80 MPH), and consequently I perceived this vibration as "new". Just my take on my experience. Quote Link to comment Share on other sites More sharing options...
nullbound Posted April 27, 2007 Share Posted April 27, 2007 I've got a 4.11 r180 in my '78 280, also, which replaced the 3.54 r200 that was in the car when I got it. It's definitely fun around town, through curves, etc. I don't, however, have the vibration issues. Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted April 28, 2007 Share Posted April 28, 2007 I didn't read all of your first post but from what I understand you had a vibration past 85 mph with your 3.54 and now you have a vibration past 70 with your 4.11. In my mind this comes very close to ruling out the rearend as your problem. I don't know about the rest of your setup but I would suspect the transmission, maybe input shaft play or something of that nature. My truck does the same thing and the input and output shaft of the transmission have a lot of play. I went from 2.73 to 3.73 and started vibrating past 60 occasionally. In both cases since the engine doesn't vibrate at the same rpm in lower gears then it is most likely not the engine or anything attached to it (like the harmonic balancer or maybe loose mounts). It almost HAS to be the transmission. That's just the conclusion I've come to with my own personal vibration. Yours sounds similar and they're both 20+ year old transmissions unless you've redone yours or are running a different one. Quote Link to comment Share on other sites More sharing options...
Dtsnlvrs Posted April 28, 2007 Author Share Posted April 28, 2007 While yours is a good possible theory, I will discount it based on the fact that my original 85mph was constant thru 2 continents, 4 different transmissions, 4 sets of U-joints, and 3 engines...the only thing constant was the diff placement and the original driveshaft. Quote Link to comment Share on other sites More sharing options...
Dtsnlvrs Posted February 12, 2010 Author Share Posted February 12, 2010 Well it has been awhile since we visited the vibration topic discussed here. I had thought of moving my diff into the '72 position, but was shown another option to eliminate the vibration. A truly bolt on CV conversion. http://www.wolfcreekracing.com/wcrcvhalfshaftaxlekit.pdf Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted February 12, 2010 Share Posted February 12, 2010 I run a 930 CV setup in my 240Z but it was designed by me and machined locally. My cost was about $1000 complete. The difference is I use Porsche boots/retainers instead of the pieces Wolf uses. The design is basically the same otherwise. It is a great conversion! I'd never consider going back to an u-joint halfshaft. I'm waiting on some custom stub axle flanges (for my 5-bolt stub axles) to be finished so I can eliminate the outer CV adapter now. That will lengthen the halfshaft about 3/4". Quote Link to comment Share on other sites More sharing options...
DavyZ Posted February 12, 2010 Share Posted February 12, 2010 Very good follow up, even after a few years Davy Quote Link to comment Share on other sites More sharing options...
rucus01 Posted February 12, 2010 Share Posted February 12, 2010 Well it has been awhile since we visited the vibration topic discussed here. I had thought of moving my diff into the '72 position, but was shown another option to eliminate the vibration. A truly bolt on CV conversion. http://www.wolfcreekracing.com/wcrcvhalfshaftaxlekit.pdf I noticed the kit bolts to the stub shafts instead of having splines on the diff side. I have heard that one of the weak points of the half shaft is where splines meet to the stubshaft. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 12, 2010 Share Posted February 12, 2010 I noticed the kit bolts to the stub shafts instead of having splines on the diff side. I have heard that one of the weak points of the half shaft is where splines meet to the stubshaft. I think that the most common breakage is the stub axle that holds the wheel. Can't remember hearing of people breaking the stub at the diff... Quote Link to comment Share on other sites More sharing options...
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