The R31 Skyline/Pintara has a solid
rear axle but the rear discs are still
very suitable to be used on any Datto IRS rear end.
The bits you need from the R31 are:
disks rotors,
callipers and mounting brackets;
calliper to bracket
mounting bolts (2 each side);
flexible hydraulic
lines;
both rear handbrake cables.
(Note. Check that the rotors aren't
under size which is 9.4mm or wont be if
they need machining.)
Here is an abridged step
by step guide to fitting R31 rear disks to a Datto IRS.
Remove the half shafts,
short axles (you will need a breaker bar and a slide
hammer to do this), drum
brake components and backing plates. Disconnect the
handbrake cables but
leave the hydraulic lines in place;
(Note. Mark the axles
& bearing spacers so you know which side they came
from and return them to
the same side.)
Ream out the centre
holes of the mounting brackets a couple of mm to easily
fit over the lip on the
IRS hub;
Grind the lower and side
lips of the mounting brackets until they fit
absolutely flush on the
IRS hub and clear the control arm;
Drill out the lower
rearward mounting bolt hole to 11 mm on both of the
mounting
brackets;
Make a template for the
IRS flange bolts from a drum backing plate or from
the flange
itself;
Weld up the other 3
holes on the mounting bracket and re-drill them (10mm)
to suit the IRS bolt
pattern. Use the original IRS drum backing plate
mounting bolts to attach
the brackets. Re-install the small axles, I
recommend you fit new
lock nuts (PN 43262-21000 x 2) torqued to 240 ft/lbs;
Connect the hydraulic
lines and bend them carefully so they don't contact
with the outer uni
joints;
Bleed the system and
check that the rotors aren't binding. If there is any
sign of binding there's
a good chance the mounting bracket isn't absolutely
flush with the hub and
to fix this you have to pull it all apart again, so
take care the first time
round with the bracket;
Re-install the half
shafts;
Test drive it and enjoy
the stopping power.
Hook up the handbrake
cables which is a bit tricky. The R31 cables have to
be shortened a bit to
suite a 510, other models you just may be lucky.
As you can see it's a
fairly straight forward conversion as far as rear
discs go.
regards,
Terry
