Test 7.5" limited slip / where do I weld??

[Surrey]

Hey, I was wondering if there was a way to test if my limited slip is any good still, without pulling it apart? (its currently not attached to anything... Stripping down an old truck, which has 4.10 gearing, my "new" one has 3.73)

If it is shot, I was thinking I would just weld it up, but Im not exactly sure what to weld to what... Can anyone provide some details on that, and perhaps a picture?
Also what do I need to replace when doing something like that? Obviously the gasket on the inspection plate... what else?

Thanks.
p.s. I know welding it up will cause the back end to hop around corners, but its not a daily driver or anything, it just has to get me to the trails and home again.

 

[AllanD]

You can't weld up a limited slip simply because there are too many pieces.

If you want to wld one up you want a conventional open diff

And before welding you want to remove all the shim washers from between
the "spider pinions" and "axle" gears and the carrier and carefully degrease
everything.

AD

 

[alwaysFlOoReD]

You can't weld up a limited slip simply because there are too many pieces.

If you want to wld one up you want a conventional open diff

And before welding you want to remove all the shim washers from between
the "spider pinions" and "axle" gears and the carrier and carefully degrease
everything.

AD

And then weld the side "axle" gears to the spider gears. I've seen pics but don't have any handy.

Richard

 

[Boggin]

tech library got pics

 

[Surrey]

You can't weld up a limited slip simply because there are too many pieces.

If you want to wld one up you want a conventional open diff

And before welding you want to remove all the shim washers from between
the "spider pinions" and "axle" gears and the carrier and carefully degrease
everything.

AD

Really? That sucks balls. What would I have to get my hands on to weld it?
I have another axle with 3.73 gears in it (whats under the new truck now) thats not a LS, but the one with the LS is 4.10 gears. My plan was to weld up the 4.10 geared axle and put it under the new truck, I wanted to hold onto the 3.73 in case my girlfriend gets a license and starts driving the truck before I can afford to upgrade to bigger axles with a real locker...

Are there any redneck mods I can make to the LS, like cram extra clutch plates in, to lock it up?

Thanks.

 

[gwaii]

You can't weld up a limited slip simply because there are too many pieces.

If you want to wld one up you want a conventional open diff

And before welding you want to remove all the shim washers from between
the "spider pinions" and "axle" gears and the carrier and carefully degrease
everything.

AD

i've welded plenty of limited slips....but i certainly prefer opens.

if you are going to weld it,remove the carrier and strip it down.throw away all the clutches and shims,all you'll be using is the carrier,side gears,and cross pin.

set the side gears in and put a bolt through the axle hole and a nut and washer on the inside...tighten to hold the side gear steady.now,weld all around where the side gear meets the carrier.let it cool some then put down more weld.keep building it up till it fills the space where the clutches used to go(see why i prefer opens?)take the bolt out.

do this for both sides.let it cool slowly(don't 'quench' it-you'll crack the carrier)then reinstall the bearings and ring gear.set the carrier back into the housing,install the axles and clips,put the pin back(no spider gears are needed)and cover/oil....she's done

 

[Surrey]

For putting it all back together, what parts do I need?
New gasket, obviously...
Crush sleeve? What else? Im new to differentials, more of a motor-and-suspension kinda guy...
I tried looking online for a kit of some sort, but couldn't find anything.

Thanks.

 

[heptofite]

just going to go ahead and point out that it's illegal to have a welded differential on public roads in most places.

 

[Surrey]

just going to go ahead and point out that it's illegal to have a welded differential on public roads in most places.

Everything is illegal these days... Although I havn't seen any literature that says they are illegal. Hell, some body rust is enough to fail a damn Vehicle inspection...

Besides, its not a daily driver or anything, the only time its on public roads is to get to/from the trails...

 

[gwaii]

For putting it all back together, what parts do I need?
New gasket, obviously...
Crush sleeve? What else? Im new to differentials, more of a motor-and-suspension kinda guy...
I tried looking online for a kit of some sort, but couldn't find anything.

Thanks.

you won't need a crush sleeve or seal,the pinion won't be removed.

it's a good idea to get new carrier bearings,most diff covers are sealed with rtv so a gasket isn't needed.

so,oil and rtv,and if you choose,bearings.axle seals if they look like they are needed.

 

[AllanD]

And then weld the side "axle" gears to the spider gears. I've seen pics but don't have any handy.

Richard

that only works well if there isn't a rediculous ammount of wear.

And with a HUGE "BTW" hat the Limited slip carrier is inherently weaker than the open carrier.

If you want to weld and not have it (unexpectedly and spectacularly)
"unweld" itself weld up an open.

On an open carrier if the drivers side axle pinion (the ring gear side) is
fully welded to the carrier before assembly and the rest of the diff
then put together and welded the passenger side axle pinion is welded
the spider pinions are essentially irrelevant, because the cross shaft pin
is no longer under load

And you cannot do it that way with a limited slip carrier, welding the pinions
and axle shafts to each other the spider gear cross shaft is still under load
and the carrier is weakest through the web around the spider gear cross
shaft bore.


AD

 

[Surrey]

that only works well if there isn't a rediculous ammount of wear.

And with a HUGE "BTW" hat the Limited slip carrier is inherently weaker than the open carrier.

If you want to weld and not have it (unexpectedly and spectacularly)
"unweld" itself weld up an open.

AD

So I should get an open carrier out of a wrecker to install then?
I could pull the open carrier out of my other axle, weld that, and install it in the one that currently has the LS?
And then install the LS carrier into the other axle in case I need it down the road...?

 

[7.5L_STX]

just going to go ahead and point out that it's illegal to have a welded differential on public roads in most places.

what a party pooper, like a police officer is going to crawl under your rig and pop the diff cover off to check, and if you have an axle with a 3rd member then its completely impossible for them to check. everythings fawkin illegal now, sorry to say but most people are pussies and complain too much.


jeez lighten up buddy.

 

[gwaii]

So I should get an open carrier out of a wrecker to install then?
I could pull the open carrier out of my other axle, weld that, and install it in the one that currently has the LS?
And then install the LS carrier into the other axle in case I need it down the road...?

with what you are intending to do,as long as you are willing to expend the time and welding materials to do it,i'd just weld the l/s carrier you have.just follow my instructions.

fwiw,the diff in my ranger started out as a l/s.while it's a 10.25,and not a 7.5-it's still turning 44'' tires with big-block power and has never been treated nice.

it's never let me down,and in the refit is one of the few things that will not be getting any attention.

 

[heptofite]

what a party pooper, like a police officer is going to crawl under your rig and pop the diff cover off to check, and if you have an axle with a 3rd member then its completely impossible for them to check. everythings fawkin illegal now, sorry to say but most people are pussies and complain too much.


jeez lighten up buddy.

they wouldn't need to pop the diff cover to know, the fact that your tires chirp each and every single time you go around a corner would be all the proof they need.

besides, welded diffs on street vehicles is dangerous to both yourself and others on the road, i don't want to get plowed because somebody is suffering from spool induced understeer.