Syncaru 16 AWD build

[human compass]

I'm going to be going down the syncro conversion hole using a subi gears 5 spd with a pelequin. what are the groups thoughts on a subi front diff with pelequin vs a syncro front diff with pelequin?

any advantage to the suby front? I have easy access to a syncro non locking front diff and the suby front diff will be a bit of a pain to fit, but I'm willing to consider it if there is a significant benefit.

This rig will not be a hard core 4wd but rather an overlander designed for snow and overall drivability in mild/moderately rough conditions. setting it up for a south america tour.

thanks in advance

(PS please lets not get into lockers and low gear debate, I know the trade off im making)
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84 Westy Syncro- 3.3L SVX stage 2 tune,subaru gears 6speed with tbd, front locker, porche brakes x4, aux tank, radflo susp

[raoul mitgong]

I think that the only subi tranny option is currently 2wd. Could be wrong.
-d
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84 Westy with a 2.1 (Groover)
86 Tintop Syncro (Crow)
86 Tintop Syncro to Westy project (Tom Servo)
91 Westy (Only the top 12 inches of this van (a burn victim))

[snwbrdr435]

[alaskadan]

Thats awesome! The last time i read up on this they didnt have the front trans plate that now moves the out put shaft downward so it clears everything. The real question is does it work on a suby trans with high and low range?

[raoul mitgong]

[Pcforno]

I would figure out which engine you're planning on using, along with what size tires, then look at the subarugears ratios and RPMs, then decide which R an P ratio you need. Why limit yourself to 4.86 if that's not the gearing that's ideal for you? In addition, don't most subaru rear diffs employ a LSD? You'd be killing two birds with one stone that way...

[gears]

Why would you put a TBD in the front diff? Assuming a VC is used, a TBD will do nothing in the front, only in the rear.
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aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Pcforno]

Yes gears - I'm confused by the post as well - subaru typically uses a center diff with a VC to allow continual front/rear power that locks via VC with large slip. There were lots of other subaru transmissions that handled front/rear slip in ways other than a VC, such as a center Torsen and hydraulic clutch packs, but these usually came on VDC packages that required computer control.

Subaru utilizes a clutch pack on the rear diff (now the front diff where the OP wants to use) so there's no need for a peloquin. Some rear diffs didn't have a clutch pack and you could order aftermarket ones, but it would be simpler to source an OEM subaru with a clutch pack then to install an aftermarket one.

So I'm confused buy the question as well.
Perhaps the OP could clarify for us?

[11BC2]

[Pcforno]

Just did some reading on this - all the higher end models had LSD, including Impreza, forester, legacy, and legacy outbacks, not just wrx stis...

[D Clymer]

I would go with the stock Syncro front differential with a solid shaft in place of the viscous coupling. There are three advantages to using the stock VW front diff.

1. You can use 4.86:1 gears. With a Subaru front, the lowest you can go is 4.44:1. Considering a Subaru trans has a taller first gear than the VW trans, that's just not low enough.

2. The VW diff has a speedometer drive gear. With the Subaru you'd have to go with a GPS speedometer, or an electronic speedometer driven off of the Subaru transmission VSS.

3. The VW diff works perfectly with the stock front drive axles. No worries about custom axles and whether or not they are truly the right length.

There's only one advantage to using the Subaru rear diff up front and that's price. If you have a Syncro roller with no drivetrain, it's tempting to get a $200 Subaru R160 off of eBay rather than pay $700 to $1000 for one of the rare VW Syncro front diffs. But if you already have a working Syncro, I'd say it's a no brainer to use the original front diff.

Dave

[11BC2]

[Pcforno]

Good to know for the OP then! If going the subaru route get a STi rear diff? Or are the aftermarket kits even better?

[gears]

I think it's important to note that in VW Speak, a "Rear Diff" is what's in the transaxle.

In the original Subaru layout, a "Rear Diff" is what's in the separate differential unit, NOT what's in the transaxle.

So, some readers may be confused unless we take pains to "Differentiate" ;^)
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[human compass]

awesome discussion! thank you all!

so I already have a NA 2.5 suby installed. I'll be putting in a 5 spd suby tranny with a TBD.

what I'm hearing is that if I put in a suby diff, I need to make sure it has a LSD installed, its cheaper, I'll need custom drive shafts, I wont be able to gear the tranny as low.

Any advantage to using the suby diff? I cant see one (aside from cost).

thanks!
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84 Westy Syncro- 3.3L SVX stage 2 tune,subaru gears 6speed with tbd, front locker, porche brakes x4, aux tank, radflo susp

[human compass]

also, anyone know or have thoughts on how drivability would be with a 5 speed suby with a TBD linked to a syncro front diff with a TBD (non locking)?
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84 Westy Syncro- 3.3L SVX stage 2 tune,subaru gears 6speed with tbd, front locker, porche brakes x4, aux tank, radflo susp

[11BC2]

[human compass]

[D Clymer]

[human compass]

thanks Dave,

Do the suby transmissions all have a center diff? sorry if this is a dumb question
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84 Westy Syncro- 3.3L SVX stage 2 tune,subaru gears 6speed with tbd, front locker, porche brakes x4, aux tank, radflo susp