Installing a Hilux spool into an A70 supra diff

[Disturbed1]

After reading so many threads about how easy it is to bolt an a70 lsd into a hilux housing, and that its impossible to go the otherway round (ie, fit a hilux spool into an a70 housing), i decided to bite the bullet and give it a crack myself...

here is the findings to date. Note i only got the spool yesterday so its not installed and operating just yet..

pics are as it stands. note that both centres weigh exactly the same as pictured... therefore, if you bother goign this path to save weight (like myself), then you are saving the weight of the ring gear, the bolts attaching the ring gear and however much weld you pump into the open diff to lock it. all up approx 3.3kilos.

so whats required to make them fit... there is 3 areas that need addressing.

#1
The ID of the hilux spool measures 34mm and the supra stub axles measure 34.93.. therfore you choose which item ud like to machine to suit. (I'll be boring out the spool)

#2
next issue is the location and depth of the splines. the hilux centre has alot deeper spline section then the supra, therefore about 10mm will need to be removed from both sides of the spool.

#3
The hilux centre runs a 45mm ID bearing, where as the supra runs a 50MM ID. therefore both spool journals will need to be sleeved. one sleeve as per pic 6 (this extends the bearign shoulder closer to the wheels) while on the otherside, 2mm ish will need to be machined from the shoulder to move it closer to the diff centre and a simple 45-50mm shim installed (could prob do a better job explaining that if need me)


those who have done previous research into this topic, there is no need to machine off 3mm of the crownwheel flange...


pic 1


pic 2


pic 3


pic 4


pic 5


pic 6


Uploaded with ImageShack.us

[Shane001]

Hi mate, have a closer look at pic 3, I'll put money on that being 6mm lol!

ie 3mm either side (measure pic 4 to confirm), there's your 3mm offset on the crown wheel flange.

[madmont]

Sure looks like the overall length is about 6mm different which when taken into account gives about 3mm offset difference. Do not overlook putting in grooves for the clips and spacers on the ends of the spool to bring it to the same length as the original centre.

[madmont]

Here are a few more pictures for you
The centre with the axle in it is from an A70 the one with the 4.3 ring gear fitted is from a 99 Hilux and has 50mm journals for bearings . As you can see the difference in lengths is about 8mm and the difference in height of the flange from the end on the table is about 1mm . If a 3mm spacer is fitted when you are using a A70 centre in a Hilux the centre can be adjusted for backlash with the adjusters. If the backlash is wrong with the supra centre you have to adjust the sizes of the spacers to attain the correct backlash. Offset as far as I can tell is 3mm difference



[

[Disturbed1]

and installed.........

fit the centre back in myself usign the shims that where already in it and it was pretty tight... really should have ordered some smaller ones but ohwell. will see how she behavious..



Uploaded with ImageShack.us

[JustenGT8]

Nice work. I went with a 3.54:1 ratio in my conversion as well, which meant a shitload more work as the bigger pinion meant more offset required. Diff shop raped me big time

[Shane001]

and installed.........

fit the centre back in myself usign the shims that where already in it and it was pretty tight... really should have ordered some smaller ones but ohwell. will see how she behavious..

Hi mate, great job, though I hope you've remembered to set your preloads and backlash right, could be in for a world of pain otherwise

What was the final outcome on dimensions?
Also did you end up machining a groove for the snap rings or are you going to run it without?

Very interested to hear how this goes.

Cheers.

[Disturbed1]

havent set the preload or backlash - may pay someone to do it before i bolt it in my car. backlash feels good but the centre needed to be tapped in with a rubber mallet to get it into place so would assume preload on the bearings is high.. certainly come out alot easier then it went in but not sure if thats cause it come out coated in oil

didnt put the snap-ring grooves in although it wouldnt have been much extra effort (dad didnt have the tool to do it at the time). mate has an r31 with s13 centre and his axles dont use a circlip and he hasnt had any dramas

[Shane001]

U definitely want to set it up right before you put it in the car. Otherwise you could fuck u're bearings or gear set, or worse the entire unit. U'll find full instructions in the TSRM. Not difficult to do it yourself and probably get a better outcome TBH lol! Most diff shops won't take the time and/or don't know how!

Still not convinced re the snap ring. Once you install it in the car you might want to check the effects of full suspension travel on these stub axles. U don't want them to be sliding in and out.

[takai]

You also dont have to sleeve the bearings up to 50mm. There are off the shelf bearings with a 45mm ID rather than 50mm ID. Toyota used them on other diffs.

[madmont]

As far as I know Toyota use an odd size bearing with 50mm ID

[Disturbed1]

You also dont have to sleeve the bearings up to 50mm. There are off the shelf bearings with a 45mm ID rather than 50mm ID. Toyota used them on other diffs.

with 83mm OD?