Transmission issues - stock '89

[korfmach]

Greetings--I'm having some difficulty diagnosing some transmission noise. Van is a stock '89 with 2.1 and 091 transmission, with 175k miles on both. Here are the symptoms:

Under load, all four gears: fairly loud whirr/buzz, significantly louder than engine sounds. The pitch/intensity of the sound is parallel to engine speed, not vehicle speed.

Noise is not present when coasting, shifting, or when the drivetrain is otherwise not loaded. Transmision shifts just fine with no binding/grinding. Clutch pedal engagement is pretty high.

Noise is not present with transmission in neutral, clutch in or out, engine at idle or above idle.

There's a little bit of rattle in neutral with clutch engaged, which I think is just the old TO bearing.

The van is new to me; when checked, I had to add about 1.25 quarts to the transmission. I haven't yet checked the drain plug for metal shavings.

My suspicion is that the main shaft bearings are shot. One shop theorized that it's the R&P, but I'd think that the noise would be indexed to vehicle speed instead if that were the case. Thanks for reading, and in advance for your wisdom.
_________________
1989 Westy
2016 Golf TSI

Gone, but not forgotten:
1974 Dorper Baywindow, "The Bleeding Trout"
1998 Jetta TDI, "Trixie"
1987 GTI, "Heike"
1974 Thing, "The Luftwaffel"
1974 Ghia
1966 Ghia

[?Waldo?]

Stock '89 transmission offered in North America was the 091/1 (4-speed) although a lot of places incorrectly call it an 094 as it shares most parts with the 094. Is yours a stock 094 (5-speed)?

[MarkWard]

You can’t access the mainshaft without first removing the differential. Short of pulling the transmission, draining and checking the magnet will give you a better idea what’s going on.

The last 2 transaxles I worked on had damage on the internal shift shaft where the large mainshaft bearing was letting 3rd gear idler grind into the shift shaft. It’s possible to remove the shift shaft with the transaxle installed to inspect.

[korfmach]

[?Waldo?]

The WBX trans was the 091/1 not the 091 (earlier air-cooled) nor the 094 (5-speed).

[Zeitgeist 13]

VW really should've had a more distinct nomenclature for the various iterations of these trannies. The 091 is quite a bit different from the 091/1, so you'd think they would've labeled the latter an 092.
_________________
Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[korfmach]

[MarkWard]

The wear item is the gear carrier that supports the mainshaft. They are repairable or better replaced with the one that has the bosses for the aftermarket mainbearing retainer plate.

You’re going to be paying freight if you send yours for rebuild or as a core return if you buy one off the shelf. Buy one out right and then decide about the core. Someone might offer to buy your used trans and pay shipping.