Mazda MX-5 Miata banner
641 - 653 of 653 Posts

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #641 · (Edited)
diff time;)


the 4.778:1 cwp in a pigshead, buried unloved :unsure:


time to assemble the 5.38:1...


the bit that's going to spin a lot!


the pinion flange test-fitted, no collapsable-spacer or oilseal yet as this is to check the pinion's 'intrusion' into mesh with the crownwheel. I've used the pinion-shim that was previously fitted to this pigshead & 4.1:1 - hopefully close enough🤨


bits...


time to fit & torque the crownwheel to LSD bolts (Locktite used as locking compound)
60ft/Lbs in opposite / circular position motion, repeated twice.


3J's Plate LSD.


ratio marked be manufacturer, bought through Bofi but resold frpm Paco in USA (unsure of actual machineshop that cut these gears)


looking through one of the 'windows' into the LSD, can see one of the 'sunwheel teeth and unused crosspi 'ramp' cutout.


this is dangerous, if you've never encountered then best stay away if possible o_O:eek::confused:


the Antichrist of engineering, 'Engineers Blue' or marking blue ('Blue for short?) spreads fear into the hearts of mortal men🤭
basically a blue coloured grease BUT gets everywhere....


aplied as a whitness mark onto a few (5 here) of the driveside teeth then turning the pinion while adding a 'drag' or brake force with hand on the crownwheel to squeeze the blue onto the pinion...


after one revolution...


another revolution, looking promising...


the pinion from below the diff spool / LSD.


pinion teeth viewed from above.


close-up (ish) of the pinion teeth, the marking blue has transfered nicely showing an almost perfect mesh pattern 😎



you know it's a low ratio when the crownwheel is near the pigshead centreline 😎

hopefully tomorrow I'll get time to check the 'coast' side teeth and if good will set diff bearing preload and fit the pinion bearings 'collapsable-spacer' then drive-flange oilseal and reset the pinion bearing preload :D


enough for tonight...

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #642 ·
righteho...


smeared marking-blue on the 'coast' teeth to check the overrun mesh (it's my expensive diff so check everything!!!)


spun the pinion a few times (again adding a 'brake' effect to the diff spool)


another view.


the pinion markings (drive & overrun)


another view...


pinion from below, gives a different view...


crownwheel again, the origonal aplication of blue after rotation...


and finally, the last photo!

I've uploaded this photographic overkill as a record, in the future OI can re-blue & compare the wear marking (& wear? :unsure: to judge the lifespan as the pinion will get a lot of abuse due to the low ratio 😕

strip, fit pinion spacer & oilseal then rebuild to follow tomorrow hopefully....

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #643 ·
collection of 'bits'...


pinion parts order, new collapsable spacer to fit between bearings.


in their order.


and the pinion back in the pigshead...

I've collapsed the collapsable spacer to set the preload on the pinion bearings BUT not not finally fitted the oilseal & flange as I'm thinking of making a solidspacer as this would allow for 'idiot-proof' flange removal & replacement, will think about that tomorrow....

will this be the longest diff build?

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #644 ·
recieved a new (in box) but secondhand and somewhat discounted Stack ST3403 Lambda gauge kit with Lsu4.9 02 sensor, these are not cheap so when one appeared on ebay with a bin or best-offer I couldn't resist being cheeky 🤭
being cheeky paid off and it was bought for a significant discount 😎



8 pages of distractions 🤨

I'll probably just plug it into the ecu for tuning not pretty lights :unsure:

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #646 ·
back to the engine fitment,its raining todat so I'm staying indoors :unsure:


thinking sumps (well, drysump)


theres a minor steeringrack clearance issue, ok the cylinderblock is supported on wood to raise slightly but my plan on using redily available cast aluminium pand is under threat & I might have to resort to fabricating / modifying a 'standard' Vauxhall steel oil pan..


I have a 'Pace' drysump pan, this has the front and rear scavange pickup points as 'wells' in front and rear with a 'trough' to collect the oil.


I also have (on an engine) a 'Titan' drysump pan, this has the front scavange pickup point more central and might work with Mazda's enginebay layout.


otherwise its time to chop&weld...

more thinking to follow....

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #647 ·
so, whatsinthebox? 😮


Mx5parts pulled out the stops with this order, less than 24 hours from pressing the 'buy' button to delivery :cool:



2 x Front Upper Wishbone Arm Nut, MX5 Mk1/2/2.5
1 x Front Lower Suspension Arm, MX5 Mk2 & 2.5 (left)
1 x Front Lower Suspension Arm, MX5 Mk2 & 2.5 (right)
2 x Windscreen Wiper Arm Nut, MX5 Mk1/2/2.5
2 x Split Pin, MX5 Mk1/2/2.5
2 x Front Upper Wishbone Arm Bolt, MX5 Mk1/2/2.5
2 x Front Upper Arm & Track Rod End Castle Nut, MX5 Mk1/2/2.5
1 x Windscreen Wiper Linkage, Complete, RHD MX5 Mk1

so, front suspension nearly all new components / top & bottom genuine wishbones & new tubular front subframe 😎
why new wishbones? all my 'spares' are scruffy to say the least, new are clean (obviously?) and hopefully straight as used components can be 'weathered' from ~30 years use.

overkill maybe but wishbones are an expensive futureproofing and I've the possibility of using them to make jigs from:unsure:

the wiper linkage was a 'because it was available' and my 'old' linkages were scruffy & siezed / worn...
one less thing to worry about.

hopefully sort the diff tonight and maybe drop the complete drysumped XE in the silver car to assess fitment & 'see' problems 🤨

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #651 ·
back to the diff...


cleaned the pinion flange & removed the ballance-weight thing, refitted the oilseal protector / guard plate as theres a chance this diff may end up in dirty conditions 🤨


test-fitting the oilseal....


the oilseal has a 'lip' that protrudes into the protector so checking it fits togther...


flange fitted & tightened to the previously decided preload.


Lsd fitted & backlash set @ 0.004", the bearing preload needed setting when this was photographed hence the locktabs were not fitted.


subject of diff spool / Lsd bearing preload, enter the micrometer.

tomorows job, re apply 'blue' and inspect the teeth-mesh then put it ready to bolt onto the car.

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #652 ·
final mesh pattern checks done, goodenoughforme 😎


crownwheel drive.


crownwheel coast.


pinion drive.


pinion coast (top) and drive (bottom).


Locktabs fitted to the diff bearing adjusters and Done:cool:

just paint on the pinion / propshaft flange and forget about it untill rear suspension assembly time 😎

Rich.
 

·
layabout
Joined
·
2,795 Posts
Discussion Starter · #653 ·
5.3:1 Lsd / diff filed in a cupboard ready for use (& forgotten - with the 4.778:1), started tidying the workshop 😮

made a dent in it and can see some floor (no photo's sorry BUT IT HASHAPPENED!)

next job is (probably?) the welding table and altering & painting the tubular subframe 🤨

Rich.
 
641 - 653 of 653 Posts
Top