L Series Fr diff stubs Auto/man same?
- steptoe
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L Series Fr diff stubs Auto/man same?
Anyone know if the front diff stubs of L series 3 speed auto 4WD are same as those found in manual 5 speed 4WD d/r boxes ? Lets just keep it to 23 splines
- steptoe
- Master Member
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- Joined: Thu Oct 06, 2005 10:00 am
- Location: 14 miles outside Gotham City
I had a funny nasty thought.
Did I word this question correctly as my head was thinking? And did I get the correct answer I was looking for?
I should have asked...
Are 23 spline front diff axle stubs on 4WD L Series 3 speed Automatics the same as or interchangeable with same of a 5 speed manual? Explaining my thinking is that auto V manual that use tran fluid V 80W90 for diff lubrication may use different bearings bushes needing different bearing or bush surfaces.
GOD - you meant same thing ?
Specs say front diff of both auto and manual uses 80W90 which I used to top up but I drained pink fluid ?? Auto leaked into front diff
Did I word this question correctly as my head was thinking? And did I get the correct answer I was looking for?
I should have asked...
Are 23 spline front diff axle stubs on 4WD L Series 3 speed Automatics the same as or interchangeable with same of a 5 speed manual? Explaining my thinking is that auto V manual that use tran fluid V 80W90 for diff lubrication may use different bearings bushes needing different bearing or bush surfaces.
GOD - you meant same thing ?
Specs say front diff of both auto and manual uses 80W90 which I used to top up but I drained pink fluid ?? Auto leaked into front diff

I'm confused. Autos (should) keep the ATF and front diff oil separate, yes? And at the end of that post you say auto diffs use the same oil as manuals. That suggests (to my mind) that the bearings etc in auto and manual diffs have very similar properties.steptoe wrote:Explaining my thinking is that auto V manual that use tran fluid V 80W90 for diff lubrication may use different bearings bushes needing different bearing or bush surfaces.
GOD - you meant same thing ?
Specs say front diff of both auto and manual uses 80W90 which I used to top up but I drained pink fluid ?? Auto leaked into front diff
My initial response on tuesday was just based on looking at the auto L series I wrecked a while back - the stub axles and driveshafts were externally identical to those on my manual transmission. As for your question about stubs being interchangeable: dunno, but I'd guess so. No doubt someone can correct me.
This is the third or fourth time I've thought I should have hung onto that auto rather than sending it to the crusher. Would have been interesting to crack it open.
Dane.
- steptoe
- Master Member
- Posts: 11582
- Joined: Thu Oct 06, 2005 10:00 am
- Location: 14 miles outside Gotham City
I tossed a FWD auto a few years back after giving up trying to get beyond the diff. GOD worry no longer it woulda been a big PITA and not gain much from it.
Both the auto and manual are supposed to have 80W90 type gearbox diff oil. I think my 3 sp 4WD auto from the 3/87 GLTA must have been leaking internally from auto to diff. Pink was leaking from front axle seals and posibly the only finger tight controls on RHS and I had to keep topping up auto side of the fluids !
ANSWER IS
BOTH the auto and manual use 23 splines on the outer end [excepting mpfi and turbo]
The AUTO has 23 splines inside as well on ~ 27mm shaft
The MANUAL has 25 splines inside on ~30mm shaft
you can see where FUJI went with this can't you ? 25 in, 25 out on mpfi and turbo!
So, the shafts are not interchangeable for the spline count inside and the shaft diameter where it sits in the bearing. SORTED
Both the auto and manual are supposed to have 80W90 type gearbox diff oil. I think my 3 sp 4WD auto from the 3/87 GLTA must have been leaking internally from auto to diff. Pink was leaking from front axle seals and posibly the only finger tight controls on RHS and I had to keep topping up auto side of the fluids !
ANSWER IS
BOTH the auto and manual use 23 splines on the outer end [excepting mpfi and turbo]
The AUTO has 23 splines inside as well on ~ 27mm shaft
The MANUAL has 25 splines inside on ~30mm shaft
you can see where FUJI went with this can't you ? 25 in, 25 out on mpfi and turbo!
So, the shafts are not interchangeable for the spline count inside and the shaft diameter where it sits in the bearing. SORTED
EA82 and EJ diffs are the same, interchangeable.. (you can have a front LSD for a WRX in your L box if you want). So the stubs are too.El_Freddo wrote:Can anyone tell me if this is the same for swapping EJ diff stubs to EA units? I'm wanting to do this with a gearbox I'll be playing with for a mate.
Cheers
Bennie
Owned - 89 Brumby, 83 Wagon, 83 Leone 4WD Sedan, 83 Touring Wagon, 99 Outback
Own - 87 Brumby, 93 Liberty, 09 Forester
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Own - 87 Brumby, 93 Liberty, 09 Forester
Offroading Subarus Facebook Page