Rebuilding an 091 transaxle

[Kiwi1966]

Thanks for your advise - I have the bently and have the jig and tools I have made to do big pinion and small pinion nut , so I will crack on, unfortunally good transmission builders are not as plentiful here in New Zealand as the States. Just wanted to clarify the measuring method as was not tookeen to do the torque method to set preload on the diff bearings.Just hoping pinion depth does not change with the new pinion bearing.What would O do with my time without these old dubs to work on😁
Regards Ross

[SGKent]

just remember that you are setting preload on one side only. If you set it on both then the preload would be double what you want.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Amskeptic]

[sodbuster]

Both are kind of correct. lets take this from the top. the S-2 S-3 refrence is just a way of keeping track of your pinion and diff bearings shims when setting up a ring and pinion.

But 002 and 091 do not use shims in the s-1 s-2 locations because of the threaded collars. but on the old swing axle and IRS bug transaxles it was like this.

S-1 pinion shim. Sets pinion depth.

S-2 Differental shim ring gear side of differental. Sets differental bearing preload and ring gear backlash

S-3 Differental shim NON ring gear side of differental. Also sets differental bearing preload and ring gear backlash.


So the use of S-2 and S-3 in the case of 002 and 091 gear boxes is still a refrence for diff bearing preload and ring gear backlash. It just no longer requires shims to acheave the same result.

002 and 091 diff bearing preload is established prior to installation of the pinion shaft and gear sets. then removed before finnal assembly.
when doing finnal assembly and setting backlash both threaded collars are most times required to be moved to set the ring gear backlash and maintain the aspect ratio of the diff bearing preload.

Sometimes though, you get lucky and only need to mess with one threaded collar to get the desired results,

https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[SGKent]

Colin - what Sodbuster said. What I meant was if you set the preload 1/x " on one side, that is the total preload. It is not 1/x" of side one, and then again 1/x" on side two. Also, don't try to set the preload using the torque method. It doesn't work. I think the VW manual is kind of a misprint - I believe the published drag they give is for the whole gear train and pinion not just the differential drag. Rick Long said to me only to use the 1/x" thing given in his CD and not the torque thing. But with cotton in my ears I used the torque thing to set preload, and could never come close to that preload without over stressing the case.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Amskeptic]

[Amskeptic]

[sodbuster]

[SGKent]

I could not get mine to 30 inch pounds period. Is this reading the pinion resistance too?
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Amskeptic]

[sodbuster]

[Amskeptic]

That 3/4 shift fork photographed above for Chloe's 002 apparently is not available.

I had it welded up and milled to "close-to-correct", then sanded it down to a final clearance of .016" at each pad. I undercut around the pads by a couple thousandths with a dremel to allow oil to get in between. I figured Volkswagen determined the surface area of contact to hit the sweet spot between friction/heat and adequate lubrication for the expected work load.

As SGKent has alluded to, the stress/anxiety of pressing all these precise parts into a magnesium box never to see again until you drive it, not as fun as I thought.
Colin

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www.itinerant-air-cooled.com

[SGKent]

[Amskeptic]

[SGKent]

Colin - kudos to you for trying. We all read that Bentley chapter for years and said let's give it a try. Kudos to guys like Paul (Gears) and Sodbuster, Mike (BigBore) who actually do this in their sleep.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Clatter]

I managed to get ahold of that fancy red wierd cm/kp whatever-it-is mysto turning torque wrench they show in the Bentley, plus a small standard torque wrench, and also that same calc with hanging weights.

In the end, none of these would produce good results.
They will give you a feel for what the numbers are supposed to be like,
But in the end your experience and intuition will have to come into play and some common sense applied.
There’s just too much variation in bearings and all now to use measurements.

Had one i took to Scott at Metalcraft Motorsports in Sanger, clean and assembled for him to feel the turning (he has done hundreds).
It was what i felt was right on the borderline of too tight..
I hemmed and hawed and tried different settings until getting it there.
When i brought it to Scott he did ruminated for quite a while before deciding i was OK, but right at the edge.
Felt really really good to learn my sense of feel was ballpark or better.

So do your measurements but don’t take them as gospel. They aren’t.
Even a beginner will have to do it by feel.

Bentley is wrong.
There. I said it. Hope I don’t get eternally damned for my heresy.
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Bus Motor Build

What’s That Noise?!?

[Amskeptic]

[Amskeptic]

[SGKent]

torque the pinion nut before you spin things or they will rub.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Amskeptic]