Syncro transaxle with pressure oiling/cooling

[big swifty]

I have been urged to start a new topic to present this info which was previously on pg 16 of this seminal thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0.

Standing on the shoulders of giants…here is my system. A bit of background first:

While stopped at a red light, minding my own business, I was rear-ended by a texting fool. Since my van sits on 16" rims with Syncro.org springs and OME shocks and his car was low, my relatively low-mileage TDI engine was obliterated and the transmission low gear carrier mounting attachments were broken. At first, the ins co wanted to put a “junkyard” engine and syncro box in my van. I had documentation of the rebuilds for both, along with the taller gearing in the "rebuilt" trans. (The rebuilder of my original box did an ok job according to syncroshop. He is an expert Porsche dude who has rebuilt many 911/912 transmissions but not many syncro transaxles.) They also appreciated the rarity of the syncro transmission while searching for a "replacement". I managed to source one of the last (new from VW) factory ALH replacement engines and negotiated a transmission rebuild from the offender’s insurance carrier. I had previously squirreled away an aluminum case and gear carrier from when they were last available from Weddle. As we know, Gears has made available some amazing parts. I went for the GT billet carrier, new GT R&P, new GT mainshaft, new GT 3rd and straight-cut 4th. New low gear carrier and alu bellhousing. All new bearings and syncronizers. So, I basically have a brand new syncro transmission with oiling at the pinion bearing, gun drilled mainshaft and 4th gear.

My wife has instructions that I be buried in my Syncro coffin.

My filtering is a la Soto with 2 Canton housings; one with their stock element and one with Tom’s magnetic filter all fed by a Weddle pump, cooled via a Setrab and temperature controlled with an Inkbird with a manual override. Porn follows:

ALU bellhousing

Billet carrier with a milled 0.001" clearance for 4th gear thrust bearing

Apparently, the measurement has to be done on the inside through the main bearing hole with the gear case installed. Then pulled apart, take out the race and mill out another one or two thou being sure to setup the mill and housing each time. Lather, rinse, repeat.

Low gear carrier

Comparison of what Vermont winters does to a bellhosing vs. new.

1st 2nd and 3/4 slider hub

4th

Drilling for pinion bearing

Assembly begins

Checking clearance for chrome molly retaining ring

Mainshaft and 4th oiler

Good things come to those who wait

Filter housing and plumbing fittings

Magnetic element (not my picture)

Weddle pump and element filter. The pump is mounted on a provided plate with a cover

Suction

Vertical magnetic filter mounting. The cooler and it's ports is visible above.

Cooler behind PS tail light

Distribution manifold before and after mounting. I sheathed the hoses to prevent chafing as it crosses the skidplate

I also sheathed the line going up to the cooler

Oiler input (pardon the blur)

With this configuration, the crossmember has to be clearenced with a BFH

Inkbird

Finis.
I will be watching the filter effluent closely as mileage mounts and will report back. It will be interesting to see what appears on the magnets of an essentially brand new $yncro transmission behind a chipped TDI engine with an 11mm pump, larger turbo, larger injectors. At the time of this rebuild, with about 60k on the previous "rebuild", the used components looked "not bad" according to syncroshop.

I drive thoughtfully. With great power comes great responsibility

Hoping that this will continue to inspire people and push the care and feeding of the Syncro MT as far as we can.
_________________
Evan
1987 Vanagon Syncro // Westfalia pop-top graft // Factory new ALH. 11mm IP. AFN 110 RC 2,3,4 // S7 turbo// Titan P502's
2013 Golf 4d TDI. Deleted. Tunezilla Stage2.
1991 Jetta coupe TD. Giles Superpump. SOLD

[erste]

Very, very nice.

I like the location and cover for the pump. How is it mounted to the chassis rails? Looks like it would be bolted but I don't see any hardware in the right of this photo:

[I am square]

Nice work
_________________
Dustin

'73 Thing
'86 Syncro Doka
'85 Vanagon
'08 R32
'14 Tiguan

[big swifty]

[Sodo]

Cool.
How many miles so far?
Did you filter from mile zero?

Having a positive flow of filtered-only oil fed to the center of the pinion bearing seems reasonable the bearing will last much longer.

Plus capturing and removing other trash.

---------

I posted a couple oil-pipe kits in the classifieds for the Guard transaxle gun-drilled Syncro mainshaft.
https://www.thesamba.com/vw/classifieds/detail.php?id=2311854
_________________


'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop, EJ25, cooled filtered (original) gearbox
....KTMs, GasGas, SPOT mtb

All Vanagons should do this:
Add direct starter-to-chassis cable THEN delete ground strap at front transaxle mount.
The best time to do this mod was in 2010. The second best time is TODAY.
If your starter is slow, this is MORE important.

[Jake de Villiers]

That's really beautiful.
_________________
'84 Vanagon GL 1.9 WBX
'86 Westy Weekender Poptop/2.5 Subaru/5 Speed Posi/Audi Front Brakes/16 x 7.5 Mercedes Wheels - answers to 'Dixie'
@jakedevilliersmusic1
http://sites.google.com/site/subyjake/mydixiedarlin%27
www.crescentbeachguitar.com
www.thebassspa.com

[big swifty]

[tjet]

Does the straight cut gear solve any known issues, or is it just stronger? I know there's a 4th gear temp issue at high speeds.

Nice trans, btw. I really like that magnetic filter. I now need to get one just for the cool factor.

[big swifty]

[gears]

Thanks so much for showing the GT parts in action, big swifty .. The build looks extremely professional.

We've been steering TDi guys toward straight-cut gears whenever possible. I believe straight-cut gears will stand up to the powerful pulses of the TDi engine better than helical gears (at least we've had good success with them in Porsche world).
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[4Gears4Tires]

Aren't straight cut gears extremely noisy?
_________________
'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[gears]

The F1 tooth profile ones we made were unfortunately too noisy (sounding like Hewland gears). But the F1 tooth profile is overkill for VW 3rd & 4th gears.

The smaller "street" tooth profile which we now use for VW straight-cut gears are MUCH quieter, with positive feedback from every user so far.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[big swifty]

[big swifty]

Pictures of first transaxle oil change at ~600 miles.

plug

filter

plates

plates

magnets

_________________
Evan
1987 Vanagon Syncro // Westfalia pop-top graft // Factory new ALH. 11mm IP. AFN 110 RC 2,3,4 // S7 turbo// Titan P502's
2013 Golf 4d TDI. Deleted. Tunezilla Stage2.
1991 Jetta coupe TD. Giles Superpump. SOLD

[4Gears4Tires]

You spent all that effort to drive 600 miles in 2 years?

Looks like the oil filtration system is working well.
_________________
'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[big swifty]

[Syncro Jael]

That looks really great. The GT Parts should really perform well even with the TDI pounding.

I was always overkill on replacing the gear oil. Every 10k miles or at least yearly. Oil is cheap insurance compared to transaxle rebuilds. Your magnetic filter is also very nice.

I also set my cooling system up so that in cold months the cooling radiator could be closed off to the ram air so that the oil would heat up quicker. Then I could turn on the circulating pump at 80°f.

I also always ran down the highway with the front diff coupled, if you still have a VC, to take some of the load off the transaxle. Watching the transaxle temps drop when doing this will make a believer out of you.

That is really nice documentation for everyone also! Great Job!

Cheers,
Ron
_________________
1987 Syncro Westfalia Hightop - NAHT
Subaru EJ25 Forged Frankenmotor, Triple Knob.
Jael = (Mountain Goat)

[dobryan]

[valvecovergasket]

wow! super clean install!

one thing maybe to throw out there - depending on the temps youre seeing those push on hose ends may benefit from clamps as well
https://www.anplumbing.com/push-on-ensure-clamps.html

pressure is probably negligible, so its probably not as relevant as it would be on an oil cooler sort of application, but figured it was worth mentioning

[Syncro Jael]