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80 series front diff rebuild
Posted: Mon Aug 04, 2008 6:12 pm
by brad 93hilux
Hey i have a 80 high pinion front centre and have bought all new gears, bearings, airlokker and solid pinion spacer....
Question is how much am i looking at to get all this set up... and where?
Not sure where to go as i have previously had trouble with diff and gear places...
Or is anyone off here interested in doing this for cash?
Cheers
Brad
Posted: Tue Aug 05, 2008 5:54 am
by lshobie
I am in canada but tings are about par between here and there. I just rebuilt the same type of diff and had an ARB installed as well - cost me about 250. The guy is an old timer mechanic - no shop - just does things in his small shop. These diffs are easy to set up I am told and they are like old school ford diffs - pretty easy.
The tranny and diff shops around here are thieves and I won't even go near them anymore - find a well rounded mechanic who has set up diffs before and you are off to the races - er mud.
Good Luck!
Posted: Tue Aug 05, 2008 9:41 am
by djroberts
where do you live mate. im in vic, might be able to help you out if you are local?
Posted: Tue Aug 05, 2008 9:53 am
by DIRTY ROCK STAR
good work on the pinion spacer. let us know how it goes.
i have one from trail gear (thru locktup)in the front of my 80 diff. but the locker isnt working too well currently. im hoping it keeps it working fine and prevents the death of the front diff.
Posted: Tue Aug 05, 2008 1:43 pm
by duck
bit off topic but how dose the pinon spacer work and were dose it go, im guessing it pushes the deeper so there is more contact on the crown wheel?????
Posted: Tue Aug 05, 2008 2:58 pm
by ferrit
it replaces the crush spacer which can often, not suprisingly, crush down and causes your pinion to come out of full contact with the crownwheel- you get all the load on the tips of the teeth rather than the faces, and thats when something usually shatters.
The solid spacer cant crush down and helps prevent this from happening- You'll still bust a crownwheel or pinion by being an idiot, but its a lot harder than normal
Posted: Tue Aug 05, 2008 3:59 pm
by dow50r
Bring it over with a case of carlton fusion for us and i will help you put it together Brad.
Andrew
Posted: Tue Aug 05, 2008 5:44 pm
by brad 93hilux
yeh im basically in wollongong NSW
Yeh the pinion spacer and all the stuff (minus the lokker) has come from locktup4x4...
Hey dow50r, that sounds awsome... Would be much appreciated...
I have sent you a PM...
Brad
Posted: Wed Aug 06, 2008 11:32 pm
by duck
dow50r wrote:carlton fusion Andrew
i think this dude just drank some carlton fusion

Posted: Sat Aug 09, 2008 8:21 am
by dumbdunce
I like building diffs.
Posted: Fri Mar 20, 2009 8:58 pm
by dogbreath_48
ferrit wrote:it replaces the crush spacer which can often, not suprisingly, crush down and causes your pinion to come out of full contact with the crownwheel- you get all the load on the tips of the teeth rather than the faces, and thats when something usually shatters.
The solid spacer cant crush down and helps prevent this from happening- You'll still bust a crownwheel or pinion by being an idiot, but its a lot harder than normal
How exactly does the spacer get crushed?
Posted: Sat Mar 21, 2009 6:54 am
by dumbdunce
dogbreath_48 wrote:ferrit wrote:it replaces the crush spacer which can often, not suprisingly, crush down and causes your pinion to come out of full contact with the crownwheel- you get all the load on the tips of the teeth rather than the faces, and thats when something usually shatters.
The solid spacer cant crush down and helps prevent this from happening- You'll still bust a crownwheel or pinion by being an idiot, but its a lot harder than normal
How exactly does the spacer get crushed?
on assembly, the pinion nut pulls the collapsible spacer in. under load, nobody has ever been able to adequately explain to me how the load on the pinion might further collapse the spacer. I've pulled apart plenty of diffs with collapsible spacers that are perfectly fine, but with dead bearings or gears.
it's possible that a solid spacer contributes to the bend strength of the pinion shaft - under high loads the pinion head is pushed away from the crownwheel and some bending is introduced into the pinion shaft, which will cause accelerated wear to the bearings and cause the gears to crumble. it's a theory. Even diff and gear specialists I have asked over the years have never been able to give any explanation beyond "it's just stronger, mate, I mean, look at it, of course it's stronger"
Posted: Sat Mar 21, 2009 11:29 am
by brad 93hilux
dow50r wrote:Bring it over with a case of carlton fusion for us and i will help you put it together Brad.
Andrew
This post was a while ago... i have been driving on the newly assembled diff (thanks to Andrew) for 7 months now...
Don't know why some one would complain about another person especially if they are trying to help you....
thanks dow50r for all the help with the front diff.. much appreciated.
Brad
Posted: Sat Mar 21, 2009 12:49 pm
by dow50r
Gday Brad, i was wondering how you and the diff were going ....gota laugh at the photo too, didnt see that till now...he obviously has had one too many fusions lol
Andrew
Posted: Sat Mar 21, 2009 2:57 pm
by dogbreath_48
dumbdunce wrote:dogbreath_48 wrote:ferrit wrote:it replaces the crush spacer which can often, not suprisingly, crush down and causes your pinion to come out of full contact with the crownwheel- you get all the load on the tips of the teeth rather than the faces, and thats when something usually shatters.
The solid spacer cant crush down and helps prevent this from happening- You'll still bust a crownwheel or pinion by being an idiot, but its a lot harder than normal
How exactly does the spacer get crushed?
on assembly, the pinion nut pulls the collapsible spacer in. under load, nobody has ever been able to adequately explain to me how the load on the pinion might further collapse the spacer. I've pulled apart plenty of diffs with collapsible spacers that are perfectly fine, but with dead bearings or gears.
it's possible that a solid spacer contributes to the bend strength of the pinion shaft - under high loads the pinion head is pushed away from the crownwheel and some bending is introduced into the pinion shaft, which will cause accelerated wear to the bearings and cause the gears to crumble. it's a theory. Even diff and gear specialists I have asked over the years have never been able to give any explanation beyond "it's just stronger, mate, I mean, look at it, of course it's stronger"
This was all i could (and others, with extensive experience building diffs) think of also - comes down to elastic deformation of the spacer.
Have you often come across a diff that has lost its pinion preload because of spacer deformation?
Posted: Sat Mar 21, 2009 3:15 pm
by dumbdunce
dogbreath_48 wrote:
This was all i could (and others, with extensive experience building diffs) think of also - comes down to elastic deformation of the spacer.
Have you often come across a diff that has lost its pinion preload because of spacer deformation?
the pinion bearings can't lose preload simply by the spacer being extra collapsed. the bearing cones (inners) can't move any closer together whether the spacer is there or not - the spacer just gives the nut something to do up against. if the spacer is collapsed then the nut has no torque behind it and therefore not much friction, so it doesn't take long for the staking to come undone and the nut to work its way off. by the time it's turned 1/8 of a turn out, the bearings are unloaded and they will fail or the pinion will walk over the crownwheel.
my other 'theory' on the value of solid spacers is that they prevent the pinion shaft shortening due to windup/twist in the pinion shaft itself - there is some serious torque available at the pinion shaft especially in low range which could twist the pinion shaft a few degrees and shorten it a fraction of a mm. if this shortening acted to pull the collapsible spacer in, and also bottom out the bearing rollers on the cones, damage would result.
but I still "believe" in collapsible spacers as the best way to set up a diff, they allow a high degree of precision when setting up the pinion bearing preload and are cheap and easy.
so in answer to the original question, probably not. it's a hard thing to measure.