Disc Over Drum

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"Disc Over Drum" -- easy conversion for H165 or H190 diffs! Fits over 14" wheels. Rotor approximately 280mm.

Overview

Find an Australia-built Bluebird with rear discs and swap the brakes over to the H165.

This design is a 'drum in disc' setup where the disc also has a small drum brake in it & this is the mechanical parking/emergency brake.

Remove the wheel bearing with a press so that you can change the backing plate, then install a new wheel bearing.

1200 ute diff with bluebird discs fitted

Sources

These come from Australia-built Bluebirds with live axle (non-IRS).

Version 1 of these rear disk brakes were used on all Nissan 910 Bluebird Series 1 TRX sedan & LX sedan except for the first few weeks of LX production.

Version 2 of these brakes were used on all 910 Bluebird Series 2 & Bluebird Series 3 TRX sedans & LX models [sedans & wagons].

Wreckers

Going price was about $100 in 2010. Buy the whole axle, diff and all. It will probably cost less than buying the bits.

Take a veneer caliper to the wreckers and check that you have at least 10mm of meat on the disc. 9.5mm is still legal but new discs are expensive ($160 AU each side)

[the DBA website specifies that the minimum thickness of the DBA614 rotor is 8mm, new rotors are available from $60- a pair plus shipping if you shop around.]

Prep

Remove calipers, put them aside for a cleanup or a recondition as you see fit

Remove discs, give them a quick cleanup

Remove the dust shields (splash plates) – large thin plates that protect the discs from mud, etc.

Take photos to document which way the shoes and the retaining springs go (they will only go one way but at least you know for sure).

Dismantle the brake shoes, inspect and replace shoes if required

Remove the handbrake cable by taking out the pins at the ends

Axle Removal

The two axles right and left, don’t mix up the backing plates – they only go one way

Remove the individual axles using the same process as with other Datsun diffs. See Rear Axle Removal.

Remove Backing Plates

Remove the axle bearings from the Bluebird axles, so the the backing plate/caliper adapters will come off the axles.

Use the normal process, chisel off the bearing retainer and bearing (or using a long bearing puller). Don’t worry about damaging the Bluebird axle as you won’t use it on the 1200. Neither of these items (collar or bearing) can be reused so just use brute force to break them apart

CAUTION: Don’t use the backing plate (caliper adapter) for any leverage – it is cast and can break

After the collar and bearing are removed there will also be a thin washer to remove, it should just slide off and then the backing plate is right to come off

Make sure you mark right from left and keep the small bits from the bluebird diff

Parts Check

Backing plates

Brake assemblies, both handbrake assemblies and disc brake assemblies.

Flexible brake lines for the disc calipers

All bolts, nuts, washers, clips – mostly so you have spares

IMPORTANT – keep the fittings that hook up the fixed brake lines to the flexible lines. The 1200 does not have these on the diff and you will need to weld them onto the 1200 diff

Also keep or sell the Bluebird diff centre- it will be a H165 and can be used in a 1200 ute diff.

Give everything a nice cleanup

Ute Fitment

Disassembly

You can leave the 1200 ute diff in the vehicle or remove it.

1. Remove the individual axles from the main body/housing. See Axle Shaft Removal.
2. Remove Axle bearings
3. Slide the brake backing plate off the old axle
4. Recommended: Pry the old axle seal out of the end of the housing. Always use a new seal.

Prep

We need to weld on the 'tabs' that will hold the flexible brake lines to the main body.

click

1. Find the tabs from the Bluebird main body – they were bolted on to the axle but we do not have anywhere to bolt it on to the 1200 so you may weld them
2. Weld on to the main body approx 6 inches from the edge – you need to clear the bump stop and just get inside the little tabs that hold the metal brake lines
3. You may also want to shorten the metal brake lines as they no longer need to go all the way to the backing plates

Assembly

Obtain two bearing kits (one for each side) – including new bearing, collar and seal.

So here is where we put the stuff we need off the Bluebird on to the 1200 Ute diff housing.

1. Reinstall the axles. See Axle Installation
2. Lift the axle assembly into the vehicle onto the leafs.
3. Attach spring plate and bump stops with the U-bolts
4. Connect the handbrake cables
5. Fit the discs and calipers (do this step after the diff is back into the car as there may not be room to fit the discs between the spring and the underneath of the car).
6. Connect up the hydraulic brake lines
7. Adjust the handbrake shoes

Handbrake Adjustment

Reportedly the handbrake is not very effective, so correct adjustment is criticial.

Adjust like typical auto-adjusting drum brake handbrake (e.g. B310)

1. Chock the wheels, then release handbrake lever
2. Jack up one side of the vehicle. Keep wheels on
3. Slacken the cable from underneath vehicle
4. Stick brake adjuster tool (or a large flat blade screw driver) in the slot in rear of the hub. Spin the adjuster (star wheel)
5. Tighten until shoes touch the drum, then slack off. Fit a pick (or 2nd screwdriver) to release the ratchet, then back off the adjuster
6. Repeat for other side
7. finally, tighten cable underneath car until brakes start to drag. Slack off.
8. test by rotating the tyre. If it seems good, lower car and final test.