Complete Rear End Rebuild & Refresh w\ Z31 R200 LSD + Greddy Cover - Pictorial

[slownrusty]

So I started this project back in late August and will finally finish it this weekend (tomorrow).

 

I went from this:

 

to this:

 

Even though I know my car well (after almost 13 years of ownership), I have never touched the rear end or subframe until August of this year. I enjoyed this project, although the lifting was very heavy for one person and tricky with one pair of hands - but "do-able".

 

This thread is intended as a step by step for anyone attempting to rebuild their 280ZX rear end or installing a Z31 LSD, so happy reading!

 

Step 1: After you secure your car on jack stands and remove the wheels.  There are several ways to proceed, remove the axles and diff by itself or the entire rear subframe with everything attached as one large heavy piece including the diff and axles.  At first I was going to just install the Z31 LSD diff and new A-Arm \ sub-frame bushings and be done in one weekend and then the slope got slippery very quickly and turned to 2+ months of work.  In the picture below I removed the axles by using double open ended wrenches to separate the axles from the hubs (12mm bolts, 6 per side).

 

To remove the axles from the diff requires a good tug due to the C-clip on the diff end or gentle persuasion from a pry bar and the axles come right out, also have removed the lower shock bolt:

 

 

Axles out and to the left of the picture below you can see the hand made 3.5" mandrel exhaust, which I had made to route under the left axle.

 

Step 2:  Disconnect the 4 drive shaft bolts to the diff Companion or Pinion Flange, these have factory blue Loctite on them

 

Step 3: Disconnect all the rear brake lines including the e-brake, paying extremely close how the ebrake is routed and hooked up as it pivots on some interesting and neat bracketry

 

 

If you like you can remove the R200 rear end by iteself by loosening the 4x17mm long bolts and nuts that connect it to the subframe (in red), this will also remove one exhaust supporting bracket

 

If you are dropping the subframe to replace the bushings the main bushing bolt is located behind the front seats:

 

You will have to also remove the subframe locator brackets which is a three hole bracket and takes very little time, after that the entire subframe will slip down, have your floor jack centrally placed to lower slowly.

 

Voila!

 

Everything out:

 

A quick snap of my rear coilover and Walbro 255lph fuel pump

 

Starting dis-assembly on my work table:

 

Step 4: Subframe / cross member Bushing Removal

Puller, Map Gas and Impact gun does the trick the best:

 

 

Step 5: Completely dis-assembled

 

I wrote a procedure on how to remove the steel sleeves from the control arms here (pain in the butt that was):

http://forums.hybridz.org/topic/114778-completely-humbled-wow-280zx-rear-control-arm-bushing-removal-pics/?hl=%2Bbushing+%2Brear+%2Bcontrol

 

Everything removed that I wanted powder coated, 30 years old and 147,000 miles, parts are beginning to show their age:

 

I chose a metallic silver as my color of choice for Powder Coating, and two weeks later, looking good:

 

Edited November 2, 2013 by slownrusty

[slownrusty]

In the mean time I came across a rare gem Greddy R200 cover that I had to have and make work with my Z31 rear end.  It would require modifying the stock rear end R200 bracket by extending it (from the red lines) and adding "ears" to it, this was done with a TIG welder to control the heat and localize the welding to not affect the rubber in the new bracket / insulator and done by the talented guys at PowerFab here in Houston (the Greddy cover was also purchased from them).  This was definitely the bling in the project.

 

 

 

 

 

 

The Greddy cover required two spacers or washers to bring the mounting point back to the stock geometry, here I am checking it against the stock cover with a level:

Edited November 2, 2013 by slownrusty

[slownrusty]

I also was able to obtain some sweet and beautifully (precision) custom made stainless subframe cross member bushings from my good friend FricFrac (which came with rubber insulators).  To install them required buying a pair of special pair of 14mm bolts (150mm length x 1.5mm pitch), the factory bolt is a weird taped bolt that is fat in the middle and transitions from 14mm to 12mm in overall diameter.  Also to install the custom stainless bushing  will require drilling out the subframe bracket stay from 12mm to 14mm (see picture below).  Also thanks to JeffP as his website was extremely helpful (hope all is well Jeff!).

 

 

 

Quick visual inspection of the Z31 LSD diff and a gasket replacement as well as new axle seals and the new poly urethane bushings installed in the control arms:

 

 

 

 

I also purchased an aluminum drive shaft which is about 3.5lbs lighter than stock:

 

Please note that you have to transfer the Companion or Pinion flange from the 280ZX R200 diff over the to Z31 Diff to re-use your 280ZX driveshaft.  Removal of this flange requires an impact gun and a 27mm socket and re installation you have to be very careful not to over torque the 27mm bolt as you will cook the bearings in the diff eventually.  I used very small bursts in the impact and kept turning the entire assembly by hand to make it was not getting too tight, if it does start to tighten up or get notchy back out the 27mm a smidge until the tightness goes away.  The final torque is around 100lbs.ft (less than the FSM) and I used red Loctite on the 27mm bolt.

Edited November 2, 2013 by slownrusty

[310z]

You do not have car parts on the kitchen counter do you? I would never do that. Ok, so my mother use to yell at me and my wife still does.

Nice write up.

[slownrusty]

But of course!  Being a single guy, I can get away with it.  Lets see I have diff Covers and a valve cover on the kitchen Counter, a new ball bearing turbo on the kitchen table and a rear spoiler on the dining room table.  Ahhh...good times

 

You do not have car parts on the kitchen counter do you? I would never do that. Ok, so my mother use to yell at me and my wife still does.

Nice write up.

Edited November 2, 2013 by slownrusty

[RB26powered74zcar]

Looking real good bro!

[slownrusty]

Thanks J, when are you coming for a visit?

 

Looking real good bro!

[RB26powered74zcar]

Thanks J, when are you coming for a visit?

 

One of these days...  

[tooquick260]

Real nice write up..

 

Great job!@

[jeffp]

Looks good to me. You will really notice the difference in the car handeling with the solid inserts.

One thing: You mentioned the torque on the pinion nut after you changed the flange.

1) NEVER USE LOCKTITE on the flange nut. The nut is already staked to fit the pinion gear threads tightly. NOTE: the use of locktite will give you irronious torque readings. The reason being is that as you use the socket/ impact driver. the locktite heats up with the friction of the nut to bolt threads and sets up.

2) never just utilize the torque settings listen in the manual, they are correct, but you MUST first determine the shimming of the flange to bearing inner race to get the CORRECT bearing preloading. This point is extremely important.

The correct way to do the job is to remove the diff carrier so that it is not in contact with the ring gear. Use the impact to get the bolt tight, AFTER YOU HAVE REMOVED ALL TRACES OF THE RED LOCKTITE FROM THE NUT AND THREADS ON THE PINION GEAR,torque the nut to specifications. about 125-146 foot pounds.

 

HERE IS THE CRITICAL POINT:

 

After you have torqued everything down, you will need an INCH POUND torque wrench to test the bearing preload. I believe the specifications are, and double check, 11-14 inch pounds. That is to say, it should take between those numbers on the torque wrench to just break the pinion loose to turn. So it should take between those numbers on the wrench as the gear starts to turn.

 

WHAT DO YOU GET IF YOU DONT HAVE CORRECT BEARING PRELOAD????? In a nutshell, a screwed diffy gearset. Incorrect adjustment will cause noise. To tight and it will overheat the bearings, and they fail, the diffy gears are toast. To loose of torque, and the bearings will be fine, but you eat up the ring and pinion gears, and the noise also, and then take out the bearings with metal shavings from the ring and pinion.

 

So you may get away with it, but if you are like me, it took all of about 5 good pulls on the freeway to destroy my diffy. I pulled the cover to find graphite in the oil and toast ring and pinion gears.

 

SO you have been warned and advised.

 

jeffP

[slownrusty]

Thanks for the great advice Jeff.  I appreciate it.

Yasin

[jc052685]

Looks good Yasin!

 

Good thing you know someone with a grab bag of R200s laying around, lol.

[slownrusty]

Thanks Jeff!