Syncro transaxle shifts "slower" than 2WD transaxle

[Sodo]

Here's some info that I got from talking with SyncroShop (Tom Lengyel).
No doubt other people know it as well,
but I made up a SAMBA diagram hoping its easier to understand the reasons.

Syncro and 2WD have basically the SAME external shift rods, but this discussion relates to the transaxle INTERNAL differences.

Hope this helps to understand the Syncro. There are more gears than what's shown in the "Syncro trans side-view cutaway". They are red in the "isometric" of the low gear housing.

SyncroShop says "shift with two fingers".
Which will be "a little slower" than shifting a 2WD.
You need to allow a little more time for the undersized synchronizers to match revs with the added gear weight.

Shifting from 3rd to 4th for example, just imagine how fast the granny idler set is spinning! being a 6:1 it's spinning about than 6x the speed of top gear.
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[IdahoDoug]

I like the SyncroShop's shifting advice. Over the years, I've driven a lot of valuable manual transmission cars and a lot of old manual transmission cars. That two finger rule will ensure you are gentle on the hardware and its my own mantra for those situations as well.

On the opposite end of the spectrum, I find it distracting to the point of wanting to say something when I'm in a manual car where the driver jams gears into place so firmly you'd swear the shifter is flexing....
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[levi]

That doesn't mean I'm going to be shifting like this guy.
No.

https://youtu.be/CM76f7nChSU
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One of these days I'm gonna settle down,
but till I do I won't be hangin round.
Going down that long lonesome highway,
gonna see life my way

https://youtu.be/cSrL0BXsO40

[MarkWard]

When you say 1st gear on the syncro to be clear you are referring to the "granny" gear?
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[tjet]

I don't think he's referring to the "low" granny gear. I attempted to shift from the granny gear to 1st while moving = bad idea. I usually make a complete stop, then move it into 1st.

[Pcforno]

When my trans is cold, I double clutch and rev match until it’s warmed up

[Sodo]

[?Waldo?]

I have owned/operated both 4 and 5-speed 2WD transaxles and have not noticed the 5-speed to be any harder to shift.

[Sodo]

It could be subtle. And may not show up unless you are the type to "shift hard & fast". The single gear pair of the 5 speed may be within the capability of the 2WD synchros. Just a guess. I've never even seen a 5 speed 2WD.

And 4WD has a lot more gears than the 5 speed 2WD. There's the double-reduction to get to 6:1 for granny. And they are big & heavy too, and add bearings and shafts.
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[gears]

When we ran out of OE Syncro reverse gears, I had a lighter version made
.. I've also lightened G and "cluster" gears to see if that helps.

I've got one more trick up my sleeve to help eliminate baulky 2nd gear shifting ..
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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

[?Waldo?]

[outcaststudios]

[Sodo]

The "5 speed tranny" is similar to the Syncro, because they added another forward gear pair outside of the main transmission housing. But the 5-speed does not have the compound reduction (no granny). First gear in the 5 speed is a typical 4:1 first gear as limited by the shaft spacing.
Generally you just count the forward speeds.

[?Waldo?]

The 2WD 5-speed does not have a 'granny gear'. It has 5 forward speeds all of which are used in normal driving.

[MarkWard]

Like shifting into reverse, I would expect to be at a dead stop to select "low, 1st, or granny gear in a syncro. I recall the ratios are similar between reverse and low in a syncro gear box. While both are synchronized, I think its ambitious to think you could select either low or reverse with forward momentum winding down in the gear train.

My owners manual specifically states "Shift into reverse only when the vehicle is not moving. There is not a warning for shifting into Low gear. Once I get my syncro on the road, I will expect most of the time, I will be using the other 4 forward speeds and will be selecting low as I would reverse from a stop, unless I manage at some point to put myself into a hairy spot some day.

I do like the pictures of the lightened gears above. My racing transmission has lightened gears. Nothing wrong with lightening rotating mass if strength is not impacted.
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[Sodo]

[flomulgator]

Thank you Sodo for showing the issue and thank you Gears for trying to address it!
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She's built like a steakhouse, but she handles like a bistro!

[tjet]

[outcaststudios]

[Reventlos]

Random observations: I've owned four Syncros over the years. I had two rebuilt with different R&P and an aftermarket Weddle 1.14 3rd gear. Both of these boxes crunch(ed) shifting into 3rd. They are otherwise fine, but do seem stiff compared to a 2WD. My doka (around 135K km) has never been apart, and shifts like a dream. FWIW, I have Swepco 202 in the doka (stock motor), and Swepco 210 in the 1.8T equipped tintop. I change the fluid yearly, and so far it has been very clean, and the 1.8T box has held up great with 200+HP.

Any other anecdotal data on these aftermarket gears being noisier/balkier?