Fresh 091 rebuild with 2nd gear issues

[joshluther]

I recently bought a freshly rebuilt 091 with upgraded parts and taller 3rd and 4th to install with my tdi swap.
Everything was fine for the first 2500 miles but then without warning I wasn't able to downshift at all into second gear unless I was almost stopped, there was no grinding it just physically wouldn't go into second. A few hundred miles later (mostly highway) I was able to double clutch and downshift smoothly, but now 500 miles or so after the initial problems started it feels like it's not engaging 2nd fully and pops out under acceleration.
I drive commercial trucks for a living, I know how to shift properly with and without a clutch so technique isn't the problem.
I'm 1500 miles into a cross country road trip and I'm wondering what my next step should be.
Would a loose 1/2 shift fork do this?

Currently in Silver Point TN

[4Gears4Tires]

Might want to post what city are you close to. Just in case.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[joshluther]

[MarkWard]

091 4 speed, not an 091/1 4 speed? If it’s an 091, those shift forks have a pinch bolt to set the forks. It’s possible something has fallen out of adjustment. But you need to exhaust all external possibilities first. The external linkage may be out of adjustment or has worn bushings. Check all the mounts as well, TDI has a lot of torque and the drivetrain could be shifting enough to pull it out of gear. I would normally expect a problem with 1st if the internal shift fork shift shifted. 1 and 2 share the same fork and hub. Bummer.

[Howesight]

The angles of the engagement teeth on the slider and the gear itself are what keep the gears engaged and prevent the gearbox from popping out of gear. Barring a shifter adjustment problem, this symptom of popping out of gear means a rebuild (to replace 2nd gear and the 1-2 slider) is in order.

The shifter adjustment is, however, related. If the shifter linkage is not properly installed, then second gear may not fully engage, or may engage, but be subject to some force pulling toward the neutral position. This partial engagement can damage the engagement teeth on the slider and the gear itself. I have mistakenly installed my shifter mechanism on my syncro causing the same problem, but that mechanism is somewhat different from the 2WD linkage.

Hope this helps!
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'86 Syncro Westy SVX

[mikemtnbike]

You're 100 miles from Asheville, we have two shops here that can get you right if you need pro help. Asheville Vee Dub and Westy Motorwerks good luck!
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1991 Vanagon GL 2.1 AT Westfauxlia. "Frankie" Totaled https://www.thesamba.com/vw/forum/viewtopic.php?t=764510&highlight=carnage
1995 Eurovan Camper "Marzivan"
2020 GTI SE manual

[ZsZ]

What was the temperature? What oil you have in the box?
I have troubles putting into 2nd on my 5 speed filled with 75W-140 GL-5 when cold.

A shifter alignment is a relatively easy thing to do. I usually override the Bentley/factory method and put both the lever and the gearbox in second, then thighten at the middle splined part. Then I put into 5 and if the lever is on tension then loosen and re tighten in the middle.
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Zoltan
1.9 MTdi 2wd Multivan (ex Caravelle)
Van since 2006, engine since 2008

[joshluther]

Thank you everyone! It was just the shifter rod out of adjustment. Headed west on 40 now