ZCar Forum banner
Status
Not open for further replies.
1 - 10 of 10 Posts

·
Registered
Joined
·
107,695 Posts
Discussion Starter · #1 ·
This article is for the tech article here I am asking you guys to add a bit more and correct any thing you can find . Greg I am wondering if you can put the picture of you LSD rear end because I have none . You can also add the nessary step to install it into a 240 .



I have just completed my install of an 8/88 turbo clutch pack 3.7 LSD(limited slip differential) into my 78 280Z . I will try to make this as informative as possible to clear up and grey areas surronding this subject . This modifiaction can easily done in a day and is a fairly simple here are the things you will need .
Shop Tools
Jack, Jack stands, Socket set, wrenches, air impact
Thing you will need to buy
75-90w synthetic gear oil, input and 2 side seals for diff
Things you might need to buy
Front differential insulator mount, moustache bar bushing polyurathane .
1) go to a junk yard find an 87-89 300 ZX turbo, (*****DO NOT get the rearend from an 88 SE all white even the wheels, and special guages. This vicous LSD is hard to make work, the halfshafts do not snap in place properly, it is tagged visous on the differential****) . Jack up the rear of the car, verify it is LSD by spinning one wheel if other wheel spins in the same direction then it is an LSD . The limited slip also has a finned aluminum cover on the back of the differential . These differentials are an R200 unit with 12mm bolts for the carrier instead of the older style 10mm like on the 280zx-z . This makes the gears non interchangable between you old and new rear ends .
2) Taking it out the halfshafts pop right out, take the driveshaft, front, rear diff mount bolts off . It comes right out. I can't remember some of these details I was Hung Over that sunday.
3) Taking the rear end from my 280 I do remeber, put the rear in the air with jackstands (always use jack stands), take the tires off and drain the diff.
a} Unbolt diff from mustache bar there are 2 nuts on the back, and moustache bar from frame 2 vertical bolts leave it sit there.
b} Unbolt halfshafts from axle housing (where drums are), I had to use wrench and they are very small nuts muscle
c} Pop the halfshafts out of diff with 2 pry bars, mark them drivers and passengers side .Now is a good time to inspect the u-joints, use a pinch bar and check for play
d} Unbolt front diff crossmember, undo front insulator mount from crossmember
e) Unbolts driveshaft from front input flange on driveshaft, I akwardly used a wrench again and a few cuss words it is tight in there.
f} pull the diff out back first then pull th nose out .watch its heavy
g} take the diff stap off

Now swap the rear covers, change the halfshaft seals. You need to swap
the front input flanges, take the nut off the front air impacts
helps alot . Change this seal as well , it is probably time to change
front insulator mount also mine was torn in half big clunk !!

4) Installation is not too bad if you do it in this order
a} Put the nose over the sway bar and lift the rear up into the rear crossmember, it should sit there loose.
b} Jack the rear of diff up high, install one halfshafts it pops right
in and put the nuts on axle side, then do the other .
c} Install driveshaft bolts
d} Install front insulator mount on front crossmember and attach front crossmember.
e) Lower jack until the rear diff bolts into the moustache bar.
f} Raise the jack and, attach moustache bar to the frame .
g} Add a good quality synthetic gear oil to diff most synthetics do not need friction modifier do limited slip read the bottle I used 75-90w Mobil 1

I have not tried to change the speedometer cog gear but if you swap it
from the same car it should give you the right ratio . My car has a
bit more snap due to lower gears and limited slip is amazing . I
floored on the gravel roads and if was bumpy the rear of car would
step out now if it does spin its perfectly straight , the car feels
much more controlled .
 

·
Registered
Joined
·
107,695 Posts
Discussion Starter · #2 ·
<b>RE: Check info for tech article (greg look)</b>

I have read your article and was pleased with the information. Process looks good except where you had a hang over.... It needs to be word smithed alittle bit... not bad... a quick example is near the end in section G. the word do should be to in the second line.

Small stuff.... but you asked.

Dennis
 

·
Registered
Joined
·
1,826 Posts
RE: pictures of LSD

The LSD on my car is installed with the finned cover using a custom rear mount. You can find a close side view of it installed here and a really good rear shot <a href="http://www.flash.net/~joeao/greg/zcarpics/4-15-99/rearend.jpeg.jpg>over here</a> . I currently have the rear out again so I can clean and paint the rear suspension and run the new fuel lines. I haven't put a new rear gasket on it yet, so I can take a few pics of the inside to show what a LSD looks like on the inside. I don't have any standard rears to take pics of for comparison, anybody close to me (Fort Worth) that does? Notice in the side view pic that you can see all the way through the center of the rear. You can actually push a rod through one side and have it come out the other. On a standard rear there is a shaft that blocks your view and would prevent running a rod through it. Let me know what other pics you may need and I'll send them to you or whoever. as far as installing the rear pics of any R200 in a 240/280z would work since not many people will go through the trouble to keep the finned cover.
greg
71 240z
 

·
Registered
Joined
·
1,826 Posts
RE: info on CV shafts

after emailing and calling anybody I could think of about these shafts here is what I have come up with. A companion flange as I describe it is the piece that the axles attach to at the wheels.

1-use stock 81-83 turbo shaftsand companion flanges. They are all the same length. The fit will be very tight in an earlier 240 or 280. You will actually bottom them out installing them in your car. You have to disconnect the top or bottom of the rear suspension and swing it out to install the shafts. Then get a helper and force the suspension back in place and hook it back up. A little clearance can be had by shortening the companion flange as much as can be allowed and it still seal (about 3/8 inch). Doing it this way will in all probability limit your suspension travel. I would not recommend it at all for safety reasons, but many have done it with no problems so far.
2-machine custom companion flanges and use the aforementioned shafts. Making your own flanges will allow you to make them shorter and provide the necessary suspension travel. expensive, mainly due to having to have the adapters splined. One guy I know who did this said it would cost about $300 to build the companion flanges again on a small scale. He worked in a machine shop and was able to do it much cheaper for himself , of course.
3- make adapters to mount to the stock 240 companion flange. The stock flange is much shorter than the one used with turbo CV shafts. making a plate to adapt would require good machine shop work and very good welding. Probably the easiest and cheapest way to do this. Personallay I wouldn't feel safe with welded adapters. I plan on drag racing this car very hard with slicks and high rpm launches, possibly pulling one or two wheels off the ground when I leave if all goes well. Therefore I wouldn't feel confortable with welded adapters, but it should work okay for lesser HP cars. But lesser HP cars wouldn't need the CV shafts, right?
3-Find shorter CV axles. So far the shortest ones I know of are the 81-83 ZX shafts. The 300z shafts are a few inches longer, and the ones from the mid eighties maxima(I think it's a maxima) are even longer. The trick is finding a shaft to fit the R200 rear. The 280 and 300z shafts are one piece. the maxima shaft has a seperate output flange from the rest of the shaft. I could use the output flange from the maxima if I could find the right shaft in another car, even a different make.There are only about three basic sizes of the "tripode" style CV shaft the Z's use.
4- Have a custom shaft made. this is what I'm currently looking into. I sent a shaft over to England to the original manufacturers of the Nissan shafts. hopefully they will have a stock size shaft just an inch or two shorter than the 280zx unit I can use. I can always have a set made, but then that raises the cost considerably. I should hear something back by Monday. I was going to have the stock shafts shortened and resplined (the shaft inside the boot you can't see), but the diameter of the shaft is less than the spline diameter, so that's out.

Like I told Z-iggy, I want to do this car RIGHT the first time. I know Scottie said he enjoyed breaking his ujoint axles, but I don't think I'd like it as much. Now if I start breaking CV axles, that's some serious power. Any other ideas out there? I'd be more than willing to try them out.
greg
71 240z
 

·
Registered
Joined
·
1,323 Posts
Greg

I know this conversion has been done successfully with no major mods. I hate to send you in this direction, but Uthor and ZDAD have made this conversion and run it on there 70-78 Zcar that runs 11.4. It can be done, you just need to know the right combination of parts. Do a search on Autoforums for ZDAD or Uthor and you can get their e-mail to ask how they made it work.
 

·
Registered
Joined
·
1,826 Posts
RE:pictures of LSD (good)

Couldn't tell if my last post worked. I was jsut getting blank screen when tried to read it. Here's the links to two pictures I have on the LSD rear mounted in a 240z. I kept the finned cover and had a custom brace made to clear it. I think it looks pretty nice. If somebody local to me (Fort Worth) wants I can take some pics of their car with a normal R200 installed for comparison and send those. Just email me. I also have my LSD back out, so if you want internal pictures I can do that as well. Also notice in the side shot of the LSD that you can see clear through to the other side (it would help if I had a light on the other side). On a standard rear the bar that hold the spider gears in place blocks your view through that hole. Anybody interested in a pictoral of the difference between a LSD and standard rear ends?
greg
71 240z

Oh Yeah, the pictures- let me know if you want more/different ones
side shot
rear shot
 

·
Registered
Joined
·
1,826 Posts
RE: Greg

Yeah, that's one of the car's I've seen with it. Doesn't Boost have them on his car as well? Brent's the one who told me to shorten the companion flange 3/8 an inch to help clearance. He said it was still tight as ****, though. Had to put some muscle into it to get the strut to squeeze back into place. I know it will physically fit, I'm just trying to get a little play room. I think the Maxima flange is a little shorter than the Z's. That might add a little more room. After I see what the England guys have to offer I might have to go back to mixing and matching. I'm determined to make this work and work right, not just "fit".Have you tried them on your car yet? I would liken it to trying to put together a motor with only 1 thousandth of piston clearance. Sure it fits on the bench looking at it, but what happens in actual use? See what I mean? I'm sure I'll change my mind when I find out the cost of new shafts.
greg
71 240z
240z turbo wrote:
-------------------------------
I know this conversion has been done successfully with no major mods. I hate to send you in this direction, but Uthor and ZDAD have made this conversion and run it on there 70-78 Zcar that runs 11.4. It can be done, you just need to know the right combination of parts. Do a search on Autoforums for ZDAD or Uthor and you can get their e-mail to ask how they made it work.
 

·
Registered
Joined
·
1,323 Posts
Go to Zhome.com

Go under the modifications for more HP, then go under the Ford 5.0 section, scroll to the bottom of the screen and choose half shaft modifications. The guy talks about what he did to get the CVs to work in his car. Let me know.
 

·
Registered
Joined
·
107,695 Posts
Discussion Starter · #10 ·
<b>Greg </b>

I will add the info you gave me along with the pictures . I assume you read the article at zhome.com and still had no luck getting CV's to work . I will post a link to your site in the article . I would like the pictures of the inside of diff, I will then explain a bit more on the theory of limited slip and the parts of the rear . I am going to hold out a bit longer on publishing it to make it more comprehensive . If anyone has any question post them here (my motto DUMB QUESTION KEEP ME FROM DOING DUMB THINGS!!)
 
1 - 10 of 10 Posts
Status
Not open for further replies.
Top