Rear diff question..

1JUM2NV · Jan 1, 2014

Hey guys,

I've got a evo 3 lsd rear diff, I want to swap out my open centre on my lib diff on my jumbuck.

Question is when I swap the units over, do I need to get it all aligned? To stop premature wear?

Cheers in advance

Ben

BMGTZ · Jan 1, 2014

It would be sensible to replace all the bearings....and as i recall you need to change the crown and pinion any way?? if that is the case then yes you need to set up pinion preload. If Im thinking of something different and you can just bolt the limited slip pack to your crown wheel, then it is a bit less work as you just need to set up the tooth engagement between crown and pinion. so to answer your question....yes it needs to be "aligned"

1JUM2NV · Jan 1, 2014

When I swapped the diffs in the lib diff I went from .545 to .909. I have the crown and pinion aligned before.

I've been told they just swap over, so I'll be running the evo's lsd crown

But if I do, I'll speak to the place I had it aligned before to get a price

BMGTZ · Jan 1, 2014

will the crown that is there take the lsd pack you want to use? If so it should be be pretty quick for them to do it. If not then you need to change the pinion at the same time as there are matched together as a pair.....at least that was how it was on old school RWD diffs

1JUM2NV · Jan 2, 2014

ok I just want to make sure we are on the same page here.. so ill start again.

I was to swap out the open centre unit with the factory evo 3 lsd unit. I wont be changing/unbolting the crown wheel. since they are both running a .909 ratio

will I need to get an "alignment" done?

BMGTZ · Jan 2, 2014

now Im confused ben....how are you going to get the spider gear set off if you dont take the crown wheel off. The lsd and the spider gear set both attach to the crown wheel and the bearings are on the end of the lsd or the spider gear set. You will have to remove the crown wheel

EVOCPE · Jan 2, 2014

So I have 3.909 open diff atm? All u need to do is unbolt the open diff centre from the crownwheel and bolt the lsd diff centre to it

4piknup · Jan 2, 2014

Agreed↑
But you still need to set your crown wheel preload and tooth engagement. the only thing you dont need to do is the pinion preload

1JUM2NV · Jan 2, 2014

yeah I have a 3.909 open centre and I want to put in the 3.909 lsd, why cant I just swap over the complete units, they both have the same crown being 3.909 ratio.

for example in the in the 2 pix (yes one is a viscous type) we have the evo 2 diff and an evo 3 diff you cant just swap the out without changing the crowns.

I just want to make sure, not tying to be difficult haha

blackvr · Jan 2, 2014

The gear sets usually come as a matched set. So, by mixing sets of crown wheel and pinions, there "may" be issues. It is good practice to keep sets of gears together if you can. Sure, it will work putting the Evo 3 LSD centre and crown wheel in your current diff.... But, not good practice ! Hence, the need to unbolt the old crown wheel gear to then swap it to the new LSD centre. Its not a big deal to do this. Then it is a pretty simple matter ( as jack mentioned) to reset the preloads and backlash.

EVO-00X · Jan 2, 2014

If they're both 3.909 ratio then just take the existing crownwheel off the open rear diff centre and bolt it onto the LSD centre.
Take it to a diff shop and get them to replace the bearings and check tooth alignment and backlash (unless you have a press and dial indicator at home to check).
If its got excessive backlash and has too much play, then try the other crownwheel on. If its still ****, then grab another crown and pinion set.

4piknup · Jan 2, 2014

Tell you what, I will do your diff gears and you do my skirts and pods....
Are you putting on new crown wheel bearings? If not, you will need the races that go with the lsd centre as they are also a set

1JUM2NV · Jan 3, 2014

ok cheers for the answers, I just wanted to make sure that is all..

jack ill chat to the diff guys first and see what they would do and a price, I think I had new bearing put in when I did the ratio swap

khubner1 · Jan 3, 2014

hang on if your rvr has a 3.909 rear dif and the evo lsd is a 3.909 can't he not just swap the entire diff centers over? no removing of crowns and pinon etc

evo-gsr · Jan 3, 2014

Who has an rvr diff...?

BMGTZ · Jan 3, 2014

khubner1 said:
hang on if your rvr has a 3.909 rear dif and the evo lsd is a 3.909 can't he not just swap the entire diff centers over? no removing of crowns and pinon etc

what RVR .....? his is a bumbuck

evo-gsr · Jan 3, 2014

My question exactly...dunno where RVR came from either?

4piknup · Jan 3, 2014

Its a libero live axle, no irs

khubner1 · Jan 3, 2014

may bad i thought we were talking rears here and it a libero

EVOCPE · Jan 3, 2014

Has the lsd diff got new bearings? If so then juat swap the guts over. Measure the preload after its on

There's tonnes.on vids on youtube on how to check with a simple socket and some weights

Rear diff question..

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