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[General] [VP - VZ] How To Put Together An IRS Diff DIY Style + How To Identify An LSD

WheeliPOP

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Hey Fellas.
Good write up, I used the carrier cover with a couple of bolts to undone the bearing retainers.
I removed my 3.45 LSD from its IRS Carrier, its going into a live axle.
Question ????
1. Can I just put my LSD on to the cars current 3.08 crown, and that will save me having to set up back lash ?
and playing with the pinions ?
Seems like the quick and easiest way,
to get the IRS fun, without hauling that IRS 150kg set up ? :D
thanks again.... Don't ask me why I'm driving a FORD hahaha It was an accident.
 

immortality

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It is possible to just bolt the 3.08 ring gear onto the LSD carrier and put it all back together but that won't guarantee the backlash will be identical unless the machining of both carriers were spot on. No harm in trying though and seeing how it turns out, just make sure you don't mix up the 2 pre-load shims that sit behind the outer bearing cups.
 

WheeliPOP

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Thanks Immortality. It's just the live axle has 250,000 km on it.
And the 3.45 crown and pinion has 80,000km on it, And I'm guessing putting the 3.45 crown onto the 3.08 pinion would be unwise, haha due to wear.
Just swapping Pinions seems a PITA, while working on a drive way.
Even just fitting the 3.08 gear to the LSD, then driving it to the Diff Specialist for reshimming / back lash adjustment sound cheapest and easiest?
Cheer for the quick reply, my first time working on diffs, a lot of dodgy information, but the consensus is the same, even if it wears the 3.08 gears I'll still have the 3.45 :D
when I actually have some money, to stuff in my crummy ford rear end, But LSD's are where the funs at :D
It cost me the donor car, slapping a tree. cheers.
 

immortality

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Can't mix crown wheel and pinions as they are machined as a set and also they are different ratio's so the teeth counts will be wrong anyway.

If it's set up right wear shouldn't be an issue.

These diffs were built to fairly good tolerances from the factory so it certainly can't hurt to chuck the LSD carrier in there and see how it looks, would be good if you had some sort of way of measuring backlash.
 

WheeliPOP

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Yeah, like Wazza stated, might be worth getting a spare diff housing and fitting it in.
Then the shop can set the tolerances, and then I can swap the whole lot over, on a weekend.
Got quoted $150 labour, with live axle off the car and taking both diffs in.
Reckon Fitting the 3.08 crown, will be the quickest ? fingers crossed haha for tolerances.
Then rebuild a spare housing, with the 3.45 and let the shop set it later,
I do everything 3 times, the hard way a PITA but by the time I've had enough, I usually know what I'm doing. haha Cheers
I'll post how I go with the 3.08 crown, on the LSD, give it a week. Thanks Immortality.
 

WazzaVN

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Yeah I wouldn't mix gear sets man. Guaranteed failure lol. Pinions aren't too bad if you have a rattle gun. The first time I did my crush washer up too tight and didn't make it out my driveway haha. I learn things the hard way too :D Just have to do it up till you get a bit of resistance when you turn it it's not too bad. Learn from my mistake. It is good to have a spare diff if it all goes to **** though.

If you want to try setting the lash yourself a dial gauge can be had pretty cheap off eBay.
 

WheeliPOP

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Hey Wazza - Immortality.
Read the 20 odd page doco.
Pulled down my 3.45 hp ss and my 3.45 lsd both IRS.
Now for my relunctantly dumb question ?
The bearing cups on the side mounted bearings, seems to be a varied amount of play being between the 270,000km and the 80,000km.
Would I be looking to remove and use the matching bearing cups ?
as the 3.08 live axles bearings have 250,000km on them. So I was looking to put 80k bearings into 250k cups ?
simple answer is new cups and bearings ? or is it possible to remove the IRS cups and use on the live axle set up ?
Trying to avoid the initial test drive and its an unholy horror.
Then It will be round 2. followed by round 3.... haha cheers.
 

WazzaVN

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I'm a bit confused. Are you talking about the bearings on the diff Centre? They would be hard to get off without wrecking them so I would advise just getting some new ones.

If you're talking about the ones that screw into the side of the irs housing with the axle seals you can just pick the newer ones and use them.
 

WheeliPOP

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yeah just got the pinions out,
saw a youtube were he removes the bearings on the diff centre with a grinder and a claw hammer, hahahaha
seems like a PITA, but I'd say I'm better off going with new bearings and cups. more $$
By the end of it, I'll probs just buy those 2 instruments, and set it up with my 3.45 pair.
As I said I' do everything the hard way 3 times :D time for a drink.
Next step is to crack the 3.08 out and get diff oil etc.
swap crowns, slap in the LSD, and see how it goes.
Cheers Wazza. Hopefully. I catch a break. and the tolerances are at least bearable. There only 3.08's :D
 

WazzaVN

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If you go to a diff shop you should be able to get bearings off them. I think for a full set of bearings for me it was about $80. So maybe 50 or so for the Centre bearings. While your there get some lapping paste and some pinion shims, That should be bugger all. I would recommend a dial gauge to test your lash with too.

Where you swapping from irs to live axle I can't remember?

If your pinion is going back in its original housing don't worry about new shims or a new crush washer the old ones will do fine. If changing housings though get some shims and a washer just incase your pattern is out. Also if your pinion bearing is in good nick just leave it. That is the mother of all bearings to change finish remember right lol was not fun to get off.

Good luck mate hope it all goes smoothly :D
 
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