R180, 4.11 Reaer End Instillation Instructions

O.K. Here it is I hope, I have tried a couple of times, so hopefully it works this time!

Zlish:rolleyes:

Datsun Tech - Modifying a 200SX 4.11 Diff for your 510 or Z

4 . 1 1 2 0 0 S X R 1 8 0 S w a p

Recently I found a R180 with 4.11 gears in a '85 200SX. I decided to swap this

into my '74 260Z to upgrade the 3.36 rear end that came stock with the car. Now

most rear end upgrades for the first generation Z entails swapping the R180 for

the hefty R200. This guarantees added bulletproofing of the drive train,

especially wanted if you are running a high horsepower/torque engine.

Additionally, Turbo 200SXs did come with 4.11 R200 rear ends. However, I am

still running the stock L26 that came with the car, and will probably run it

until the day it blows, since it's still standard throughout, even after a

rebuild years ago, and has been true to me since I've owned the car since 1985.

Therefore, I felt that the R180 4.11 upgrade will be sufficient for my needs.

Additionally, it will swap into my '71 510 easier if I want to play with it

there.

By staying with the R180 rear end, it minimizes the amount of work that is

entailed when adding a R200. Don't have to change moustache bar, half shafts,

drive shaft,. the front differential mount and insulator, or the rear transverse

link mount.

However, this upgrade is not without it's share of work. The main problem is

that the half shafts from the 200SX are CV type whose splined ends snap into the

differential rather than the bolt in stubs found in early Z cars and 510s. I

thought I could outsmart the engineers by pulling u-joint style half shafts from

a 280ZX that use snap in ends. However, those were all R200 cars and the

diameter of the splined ends are about 3mm larger. Therefore, no luck.

I consulted Dave Carroll or Experimental Engineering in Seattle on the

feasibility and process involved in this conversion. The following is a excerpt

from the conversation, step by step on what is involved in the conversion.

I think you can easily do this yourself, the only "special" tools you'll need

are a torque wrench, a big hammer, and a 3/16" pin punch. Here's how you do

it,step by step:

1) Drain the oil and pull the rear cover off the diff.

2) Match mark the bearing retainers (aluminum things with 5 bolts) on the sides

of the diff housing so you can put them back on the correct sides and so they

are indexed the same way. I make a small center punch mark on the retainer that

corresponds to a similar mark on the housing on one side and the same except

with two marks on the opposite side.

3) Pull the bolts that hold the retainers in.

4) Pull the retainers out *one at a time* being sure that any shims under them

stay with the appropriate retainer. Make sure there are no shims stuck to the

housing! I tie the shims onto the retainers with a zip-tie so there is NO WAY I

can mix them up. When you pull the retainers the carrier will be loose, don't

drop it! If the retainers don't want to come out by hand try this: Use a hammer

and drift against one of the "ears" on the bolt flange to rotate the retainer.

This usually breaks the seal and any paint loose so the retainer slides right

out.

5) Pull the carrier out of the housing being careful that neither of the

bearings falls off. The bearings should be a light press fit but sometimes they

will slide off. If one does slide off be sure that any shims under it stay with

it and zip-tie it to the corresponding retainer.

6) Clamp the carrier in a bench vise across the "flat" part of the opening with

the ring gear up.

7) Match mark the ring gear and carrier so it all goes back together the same.

Note that the gears are harder than your center punch so a carbide scribe works

best. You can use a paint marker or felt pen but you must be VERY careful not to

wipe off your match marks.

8) Flatten out the lock tabs for the ring gear bolts.

9) Pull the ring gear bolts and gently tap the ring gear down with a drift or

block of wood. Work your way around if it's stubborn so it doesn't ****

sideways.

10) Take the ring gear off of the carrier.

11) Match mark one spider gear and one side gear to the carrier.

12) Match mark one end of the spider pin (big pin going crossways through the

carrier) near it's edge so you can re-install it with the same orientation.

13) Locate the small roll pin that retains the spider pin and tap it out with a

pin punch. Don't lose it! it's the only "small" part in the diff.

14) Tap out the spider pin being careful that the bowl shaped thrust washers

each stay with their respective spider gears and that the side gears don't fall

out. I zip-tie the washers to the spider gears. Note: Some diffs don't have

these washers.

15) Remove the side gears being careful that the thrust washers stay with their

respective gears, use zip-ties so you can't mix them up. Note: Some diffs don't

have these washers either.

16) On the donor side gears that had bolt-in stub axles, tap out the threaded

inserts. You can do this by sitting the gear over the opening of a bench vise

and tapping down with a drift. (If you bought new threaded inserts disregard

this step.)

17) Line the spline dents on the threaded inserts up with the splines in the

side gears you'll be using and tap them in until they feel "solid". (On new

retainers there will be no spline dents.)

18) Put the side gears back into their respective sides of the carrier being

careful that the thrust washers stay in place (if applicable).

19) Slide the spider gears back into their respective positions in the carrier

being careful that the thrust washers stay in place (if applicable).

20) Put the spider pin back through the carrier lining up the match marks and

line up the pin hole by eye.

21) Re-install the roll pin with a pin punch.

22) Line up the match marks and tap the ring gear back onto the carrier.

23) Install the ring gear bolts with lock tabs and torque them in a criss-cross

pattern using three steps to come up to final torque.

24) Carefully bend the lock tabs back into position so the bolts can't back out.

25) If either (or both) carrier bearing(s) were loose on the carrier clean them

and the carrier studs with acetone and re-install with their shims (if

applicable) on the carrier with Green Locktite (stud and bearing mount).

26) Slide the carrier assembly back into the housing.

27) Carefully install one bearing retainer loosely making sure the match marks

line up and the shims stay put. Don't force it!

28) Carefully install the other bearing retainer loosely making sure the match

marks line up and the shims stay put. You may need to wiggle the carrier and

rotate the pinion gear a little to get this retainer to seat.

Don't force it!

29) Install the retainer bolts finger tight and check to be sure the carrier

turns freely with the bearing retainers and shims fully seated.

30) Tighten the retainer bolts and check to be sure the carrier turns freely.

31) Put a dab of grease on the O-ring on each stub axle retainer bolt.

32) Install the stub axles and tighten their retainer bolts. Be sure the O-rings

go smoothly into the chamfer in the stub axle face.

33) Clean the rear cover gasket surfaces and install the rear cover with a new

(dry) gasket or Nissan silicone. If you don't want it to EVER leak (even with

synthetic oil) use Nissan silicone and no gasket.

34) If applicable, wait an hour so the Nissan silicone has set up.

35) Add the diff lube of your choice. It's much easier to do on the bench than

in the car!

You're done!

If you use this method EVERY part will go back together EXACTLY the way it was

before so the diffs longevity will not be in any way effected by disassembly and

reassembly.

Notes:

1) This procedure works for R160s, R180s, R190s, and R200s.

2) R160 and R180 side gear threaded inserts are interchangeable.

3) R160 and R180 stub axles will interchange if you cut the dust covers off.

4) Nothing from an R200 will interchange with an R160 or R180.

5) Nissan silicone is about $20 a tube but is one of the best investments you

will ever make. This stuff is so good that Nissan no longer uses oil pan gaskets

on any of it's engines. Also, it will not harden in the tube like the crap they

sell at virtually all auto parts stores.

The job pretty much went as described. I didn't go with the Nissan silicon

though, at $30 a tube locally, I figured I'd take my chances with a new Felpro

gasket. Now the oilpan will be a different story, when the time comes.

Getting the diff out of a Z is a big task. Unlike a 510 that slides out nice and

easy, the Z.

1. Support the diff with a small floor jack (I had an extra) 2. Unbolt the

swaybar and drop it out of the way.

3. Unbolt the driveshaft.

4. Unbolt the halfshafts.

5. Unbolt the mustache bar from the body and the diff.

6. Lower the diff so that it will clear the rear support brace to the xmember

assembly.

7. Reinstall in reverse order.

Remember to install the proper pinion gear from the donor car, or your speedo

will be out of whack.

A NOTE ON PINIONS: The more teeth on a pinion gear, the bigger in diameter it

will be. Some pinion bodies will run the gear/shaft offset. Pay attention to

this as you install the new pinion. If it feels like it won't go into the

tranny, don't force it. Simply knock out the 1/16" pin that holds the gear to

the body and swap it into the body of your old one (assuming that one is offset

and the other is centered). This will put the gear at the right height when

installed. Small gears go on offset bodies and big gears go on centered bodies.