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Limited slip front?


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I was able to find a five speed with low range for my '92 Loyale, I was also excited to see that Torq sells a auto locker for the rear. It got me thinking about the front. I don't need a locker up front, but I wouldn't be opposed to it either.

I've seen notes that the EJ and EA transmissions are similar and that a front LSD for EJ transmissions may fit the EA. As with any of this, the info seems to be somewhere between a rumor and old forum posts linking to other forum threads that don't exist any longer.

Has anyone thrown any kind of a LSD in a 5 speed (with the low range) trans? The transmission is out of the car and I have some time to dig into it if there is such an animal. Looks like I can split the case and get to the diff fairly quickly while the trans is out.

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I’ve done it in a complete bitza box! 

I used an OBX helical diff - and found out after installing it that some bloke does a kit to build it up to be better than it is when it comes from the factory. The cheap build apparently has washers of different thicknesses and springs that don’t have the same rates or something. Mine worked well in the AWD box I put it in. 

To clear the low range gears you’ll need to chamfer the bolt heads on the diff. They’re Allen key heads so should be able to do it and retain enough meat to use the Allen key if ever needed to remove the bolts. 

Here’s a pic of box one time I had it open after it’s initial build. 

3T8w64.jpg

The phase 1 EJ cases (“4 bolt” bell housing mount) are the same internally as the EA82 cases for the two front units that you split. The rear housing needs to match whatever internals you’re using, and the front cases need to match in terms of single range/dual range internals. Can’t use dual range cases with single range internals and vice versa.

EG: L series PT4wd dual range 5spd will work incased in a set of phase 1 EJ casings - must be a dual range case set though. Then the rest of the L series gear bolts on the back end. Up front it’ll bolt to an EJ and use all EJ factory flywheel, clutch pressure plate and disc ;) 

Phase 2 gearboxes (“eight bolt” bell housing mounts) are only good for building AWD boxes from.

Cheers 

Bennie

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The major dimensions of the diff (i.e. ring gear size, side bearing size, and the relative location of them) is the same as the EJ 5speed diffs. So anything listed for, say, a WRX will fit in the box.

 

BUT. most are designed for 25 spline axle stubs. This part is relatively easy, "just" have to purchase EA82t axles.

The bigger challenge comes with clearance with the low range gears. The low range gears protrude down into the front diff area, so a diff engineered to fit in a WRX case would not have to worry about this.

You can kind of see in this picture, on the left, an OEM 5MT front diff, on the right a Carbonetic LSD. Arrow pointing at the shoulder that sticks out just a bit further than the stock casting.

diffdiffs.jpg+

 

@el_freddo was able to remove some material in that area to get the OBX unit to work. I took some measurements, and believe that in order to clear the 1.59 low range gearset, I would have had to remove too much material from this diff, and would have compromised it. I think it might have been doable with the 1.19 gearset, but never tried it.

 

If you start looking at various different brands and styles of front LSD, you'll see some have more of a curve there, and some are more squared off. So I suspect some would be possible, but I wasn't willing to start buying them just to see....

 

In the end, this stumble put enough of a delay on my 4.444/1.59/front LSD transmission build that I finished my 4Runner, and realized what real gearing was. And so, the Subaru project sits. Likely never to be finished. 

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1 hour ago, Numbchux said:

In the end, this stumble put enough of a delay on my 4.444/1.59/front LSD transmission build that I finished my 4Runner, and realized what real gearing was. And so, the Subaru project sits. Likely never to be finished. 

I have a Jeep Cherokee which is my main "wheeler", and the Subaru project is more because it seems weird. I want to see how much I can do with the platform (keeping with Subaru parts and not throwing live axles under it).

This is good info, and gives me hope. I probably won't even break into the transmission until next spring, but I'll make sure I document things appropriately.

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Thanks @Numbchux - I was meant to mention the 25 diff spline stub axles but forgot! 

If you have a PT box, forget doing a ratio change, very difficult to pull off and I’m yet to hear of anyone that’s done it yet. A 4.44:1 diff in the PT box would be awesome, more so if a matching 5th ratio can be added in for good revs at cruising speed. 

Cheers 

Bennie

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11 hours ago, el_freddo said:

Thanks @Numbchux - I was meant to mention the 25 diff spline stub axles but forgot! 

If you have a PT box, forget doing a ratio change, very difficult to pull off and I’m yet to hear of anyone that’s done it yet. A 4.44:1 diff in the PT box would be awesome, more so if a matching 5th ratio can be added in for good revs at cruising speed. 

Cheers 

Bennie

Yes, have to be AWD to use 4.111 or 4.444 gears.

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on the loyals the e break is on the front ive used it to get out of alot of spots when the front end just wont bite  works kinda like a limited slip and dosent take any mods to make it work

i was nose down in to some ones rig about a foot away from it on a huge sand hill and even with the rear locked it wouldent back up the hill i used the ebreak trick and it backed right up no problem

ive used that trick many times

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2 minutes ago, ferp420 said:

on the loyals the e break is on the front ive used it to get out of alot of spots when the front end just wont bite  works kinda like a limited slip and dosent take any mods to make it work

i was nose down in to some ones rig about a foot away from it on a huge sand hill and even with the rear locked it wouldent back up the hill i used the ebreak trick and it backed right up no problem

ive used that trick many times

I feel completely stupid for not thinking of this. I used to use this trick on my Jeep before I locked the rear.

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50 minutes ago, ferp420 said:

on the loyals the e break is on the front ive used it to get out of alot of spots when the front end just wont bite  works kinda like a limited slip and dosent take any mods to make it work

i was nose down in to some ones rig about a foot away from it on a huge sand hill and even with the rear locked it wouldent back up the hill i used the ebreak trick and it backed right up no problem

ive used that trick many times

Ive seen off road guys split the e-brake to two handles. Let's you lock up a rear tire if it's off the ground, or to turn tighter on a trail.

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23 hours ago, Ionstorm66 said:

Ive seen off road guys split the e-brake to two handles. Let's you lock up a rear tire if it's off the ground, or to turn tighter on a trail.

that works on the l series if you have a open diff and rear disk breaks and honda calapers

once the rear is locked that wont work on the rear and the front dig works better than cutting breaks

you could seperate the front but why that just complicates the situation a single lever is extremely eazy and dosent require any thought

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