Transmission Rebuild Questions (ABN, 5-Speed), from Chile.

[ben_in_bus]

Hello All.

We are far from home, vanagon virgins and singing the new-to-me vanagon blues. After a successful rebuild of our 1985 1.9L carb DG engine that died from snapped/corroded studs, it seemed best to deal with the whine-when-under-load sound coming from the transmission before driving from southern Chile back to Idaho. That story is being told incrementally, posthumously HERE.

Working with GoWesty, I was able to order many the appropriate parts that would be needed for a transmission rebuild...but because of circumstances, this was done before opening the gerabox. Working with a very competent vanagon mechanic here in Santiago, Alberto Muñoz, we removed the transmission and began disassembly. Yes, like the engine rebuild, we work exclusively from the on top of an old oil drum. In this post I will give an assessment of what we saw and pose some questions at then end.

The Observations

-CV joints, when connected feel tight. After removal there is a little back-and-forth play but Alberto says this is fine. They were pretty dry and will need a re-grease.





-There was engine oil in the clutch housing. Not much, but enough to worry after an engine rebuild. Will deal with this once the transmission is done.

-The fluid was dark, green-gray, but free of metal...probably an additive from the PO. Very little metal flake on the magnet. Things looking good from the outside...









-On the pinion shaft, the forward half of the plastic that holds the needle bearings under 1st gear was shredded/melted away. I have no replacement for this. Trouble.

















-On the main shaft, Inside the 5th gear, on the inner surface (the part that rides on the bearing), there are many fine, axial lines worn into the surface. You can see them and feel them with a fingernail. We have no replacement 5th gear. The main shaft has less markings, but they are there. Clearly the needle bearing also needs replacing. Strange thing is that the Bentley (p35.80) shows a needle bearing with two needles side-by-side. Ours is the regular single-needle bearing. Which is right? This appears to be the first time the gear box was opened.

















-We found, not surprisingly that 4th/5th synchronizer hub has the older square corners and luckily there are no stress fractures (yet). We got the more recent 'round corners' replacement from GoWesty and will do the replacement anyway.

-The inner race of the tapered roller bearing (pinion bearing) is pitted. Good thing we have a replacement from GoWesty

-Some of the brass synchronizer rings feel a little sticky against the gears...We have not cleaned them yet, but is this cause for concern? The teeth look good on all brass rings. The moly coatings looks good too.

-During dissassembly, the wavy lockring/circlip that holds the main shaft inside the gear carrier was broken.





-Everything else looks ok and is ready for reassembly.

The Questions

1. The needle bearing under 1st gear needs to be replaced. We are looking for one in the Muñoz junk yard, but not having luck yet. Is is possible to find one that is the same size in another vehicle or is this completely vanagon specific? They are not available from the VW parts stores here. Is there a 'reason' that this occurred that we need to resolve to prevent it for happening again?
2. Are the scratches inside pinion shaft 5th gear terminal? Is there anything we can do to rectify them or do we just need a replacement gear? This will not be easy to find. Seems like we might need a main shaft as well...scary. Is is true that the Bentley is wrong to show the double-needle bearing under this gear?
3. Are sticky brass synchronizer rings a cause for concern? How does one find replacements?
4. Is there a 'best' replacement for the broken wavy lockring at the front of the mainshaft?

A preemptive 'thanks' to the community for your help.

Ben

[gears]

The black oil is due to the plastic bearing failure. It appears that you were fortunate to disassemble when you did.

1) Brg # 094-311-431 This bearing is unique to 094 5-spd (& Syncro) transaxle.

2) The marks do not mean imminent failure, but they are not "normal" wear. This idler should certainly be replaced if you can get it. (BTW, this is 5th gear, not 4th gear.) This idler is a standard replacement item on any rebuild, due to the extreme heat experienced by top gear.

The needle bearing may look OK to you, but it also needs to be replaced. Yes, the Bentley is showing incorrect early style bearings, not 094 style bearings. This is the least significant of the many Bentley errors.

3) Moly coated synchro rings should always be replaced. "Sticky" does not indicate a problem, but when the moly coating wears off, the ring no longer synchronizes properly. These are a common replacement item that MUST be replaced with the coated type synchro rings, NOT the plain type as found on 5th gear. 5th gear synchro ring can usually be retained. 1st gear synchro is also often OK.

4) Page 35.70 of Bentley shows the proper replacement circlip. These are NEVER reused.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[gears]

1) In the Syncro 094, steel caged bearings (094 311 370) are used in pair to replace the 094 311 431 on G gear. On G gear, the bearings don't have to go over any splines on the shaft. This may be true on your 094 5-spd, as well. If you don't need the plastic split bearing in 1st gear position, use 2 of the 094 311 370 steel caged bearings. To be certain 094 and 094/4WD bearing size is the same, the 094 311 431 is a 25 x 31 x 27.8 bearing.

3) Moly coated synchronizer ring part #091 311 295A
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[ben_in_bus]

Gears (aka Pablo)

Thanks so much for your expertise. Clearly you have a lot to offer. I have taken a closer look at the housings and found that the exterior markings on the housings are:

• ABN 25 10 4 (manufactured Oct 25, 1984)
• 091 301 107C (clutch/bell housing)
• 091 301 103 D 2 (transmission housing)
• 091 301 173 C1 (gear carrier)
• 091 301 107 C (gear carrier cover)
• 470 (number etched on pinion shaft)

Does this indicate that this is not a 094 transmission but rather a 091?
Is this an issue? Does this change your suggestions?

I will need to make a purchase ASAP to be shipped to Chile. Do you which shop carries the best collection of parts, esp for a 5 speed, ABN 091?

Thanks,
Ben

[gears]

Ben

All of those individual parts that you list were used on 091/1 first, so they carry 091 casting numbers (those are not part numbers). The "470" on the pinion is the pairing number found on ring gear.

The VW dealer is where all the 094 rebuild parts are carried. You just need the individual part numbers to order with, so the dealer doesn't send the wrong parts.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[ben_in_bus]

Thanks for all the help. I have added some photos to the original post to clarify things. I am developing a shopping list and want to confirm that I have this right...I will need:

-new 5th gear for the main shaft
-new needle bearing for 5th gear on the main shaft
-new main shaft
-new first gear needle bearing
-wavy lockring for the mainshaft
-new retaining ring for pinion shaft.

Anything else to recommend while shipping south?

Many thanks,
Ben

[gears]

Pinion bearing 091 311 219
Mainshaft ball bearing 091 311 123C
002 311 125 A mainshaft needle bearing
113 311 113A seal
5th gear bearing 02A 311 265D
091 311 247B Synchro ring
091 311 295A Synchro ring (2)
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[ben_in_bus]

Thanks again Pablo for being consistently helpful.
Ben