VW 297 Swing Diff Tool - How well does it work?

[Casting Timmy]

I've rebuild T1 IRS and Bus IRS boxes of the seventies, but have never done a swing axle box before. I have a copy of an old transaxle rebuild booklet that shows how to make a VW 297 tool. I was thinking about building this tool for myself and wanted to know how well the original tool worked and any likes and dislikes with it.

Push/ Pull Assembly
The book suggests using a tube retainer and welding a flat plate over it to make this part of the assembly, I will follow this I believe.

Diff Housing Inserts
I do have a swing axle side gear and a diff shim, I figure I can use the dimensions from these two pieces to make the inserts and then use all thread to make the clamping portion.

Backlash and shim measurement
I think this can be done with some simple pieces welded to the end of the diff housing inserts. Maybe something that mounts to the side cover to mount a dial indicator.

Anyone have feedback on how the facotry tool works (good or bad) and anyone do their own DIY version?

[gears]

There's a couple pieces in the kit that make a PITA job quicker. Might be easier to find a used kit for sale than making one from scratch. PM sent ..
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Casting Timmy]

On swing axles is it just luck of the draw were the bearing sticks? Reading the Bentley it reads like you have to press the bearings out of the side covers, but I see diffs here and there at swap meets and online with the bearings on the diff.

So I assume that they don't always come out that way, or is that most likely as they didn't remove the axle first and figured it out later?

I also need to research those early 1st and 2nd idlers to see if they are still available or not.

I just got my TIG and am enjoying learning to weld with it, really nice to have control over the amperage like that.

[gears]

"In theory" the bearing is supposed to remain in the side cover. In reality, an alloy cover gets sloppy over time, so upon disassembly the bearing usually remains with the diff.

Building with high quality properly dimensioned parts makes the swingaxle shim selection job a lot easier. On my own transaxles, I've chucked the diff body in a lathe, and lightly sanded the bearing surfaces to reduce the interference fit.

With the later Bus transaxle, VW used their noggin by designing in side adjusters, making the job 20x faster. Porsche of course remained pig-headed, requiring shims for diff adjustment. We finally built a Porsche side cover copying VW's side adjuster design which at least speeds the job up when pressed for time (trackside rebuild).
https://www.thesamba.com/vw/gallery/pix/1039471.jpg
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[esde]

Is the old transaxle rebuild book this one?

I have used that, the Long CD, and the bently. Between all three I've managed to get a few transmissions together without extra mystery parts, and they all work well so far..

As for the diff tool.. I found that if you take a spare swing axle differential, you can modify it to help measure a few things. I mounted a dial indicator in the center, and use it to show the unshimmed distance to the pinion face. Helpful for setting up a ring/ pinion in a new case.

I also turned the differential down where it fits the bearings, so the bearings stay in the side covers, and the diff is more easily moved side to side. There is a stud centered in the differential behind the indicator so I can mount my indicator stalk sticking out through the side cover. Position the indicator on the side cover, when you slide the diff side to side it shows the total shim thickness. Of course it doesn't show you what the side to side split of shims is for a good pattern, or how much to add for preload. But it was free to make good enough for me and the one trans I build a year.
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modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[Casting Timmy]

I lost my orginal notes.....but the typical shim thickness comes from a guy with a yellow beetle doing a wheelie as his avatar.

Stock Diff Typcially ~.135" on Both Sides
Super Diff w/HD Sidecover ~.120" Left/ ~.150" Right

113-517-167-K Side Gear Spacer Kit
113-311-39K 4 Bolt Pinion Bearing Kit

113-517-199 2.8mm .110"
113-517-201 2.9mm .114"
113-517-203 3.00mm .118"
113-517-205 3.10mm .122"
113-517-207 3.20mm .126"
113-517-209 3.30mm .130"
113-517-211 3.40mm .134"
113-517-213 3.50mm .138"
113-517-215 3.60mm .142"
113-517-217 3.70mm .147"
113-517-219 3.80mm .150"
113-517-221 3.90mm .154"

113-517-245 .25mm .010"

[Casting Timmy]

That's the book I have a couple pages from as well with a design for a DIY tool on the 297. I am going to look for a broken swing axle or maybe borrow one so I can take it apart and see what the diff section looks like in it.

Thanks for the tips on the side covers Gears, does it matter that they get loose or is that why people besides a little extra power with their motor put more side load on the bearings with those magnesium covers?

Does anyone know the world history of swing axle side covers? I've read that VW went to oring seals on the swing axle side covers as well, but when was that and did they ever make those out of aluminum as well? I think there are a couple designs on how the tubes seal to the side covers as well??? I think the Mexican beetles did something with orings?

As I research all of this more I'll keep adding my notes here to help others as well.

[Casting Timmy]

esde....here is a thread you might find useful at times.

http://www.shoptalkforums.com/viewtopic.php?f=50&t=105240&p=747534#p747534

It's mainly logging the pinion shims for the "big nut" trans, but someone has a quick subtraction for the 4 bolt stuff.

I made a pinion depth tool using a piece of pipe for the IRS bearings and a bolt that comes out to touch the pinion head. I then remove itand measure / do the math to get depth if setting a new gear set. The older sets I start with my notes and then set the backlash using the numbers and check it with grease to see if their tight spots around.

Your pinion depth tool will even work with IRS if you are doing the dual side cover cases, you just need two swing side covers.

[esde]

Those charts are helpful to have, thanks. Would be nice to compile all that stuff into a pdf, so that people could grab it as they need it..

I have all 38 pages of that manual saved, do you have the whole thing? If not I could send it to you. Or maybe someone smarter than I (or with more spare time) could upload it to the Samba literature archives, though I doubt anyone would ever look for it there. There's a scrap swing axle diff sitting in my pile, yours for shipping cost from 19123, though you should be able to find on closer. And, I haven't rebuild anything newer than 1965, and none of them had the o-ring style side covers, just paper gaskets. Just pulled a 66 type 2 box down for the 3-4 gear set, no o-rings there either.
_________________
modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[Casting Timmy]

I have the manual, it's neat to read in areas and really confusing in other areas. I'll keep you in mind for the diff, but I think I can find one locally. I know a guy about two blocks from me, just need to hit him up as if he doesn't have one he will know who does. He seems to be the local contact and we trade parts and work at times since we're so close to each other.

Maybe Bruce will chime in, he knows the history of transaxles world wide really well.

I know some take the old covers and cut the oring grove in them for the case side.

[gears]

Now THAT would be a waste of time. I can't imagine an early side cover being in good enough shape to justify the machining time. Plus the main case is machined differently to accept the O-ring.

I would have thought a '66 would be O-ringed (but then it's been almost 25 years since I've done swingaxles).
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[gears]

.
There are two indicator brackets in the 297 kit (which I've labeled in the photo) that make R&P set-up a lot easier.

One bracket works in conjunction with the 289d mandrel to measure total shim starting point (like esde describes), and the 2nd bracket works together with the 1st bracket to measure backlash.

I'm curious, esde .. What method do you use to zero your homemade tool for pinion depth measurement? The 289d comes with a machined block, making zero'ing quite straightforward.

_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Casting Timmy]

The book I believe has you correlate the indicator tip to the bearing diameters on the diff housing.

Ideal centerline to pinion face - half the bearing ID = zero distance for the indicator.

My tool is a bolt out the side of a piece of pipe, I measure bolt face to the back side of the pipe and then subtract half the pipe diameter to get centerline to pinion face.

[esde]

[gears]

There's definitely a certain satisfaction to making your own tools .. especially with todays scarcity/expense of the factory ones. One of my best upgrades was the digital indicator with reversible read and push-button zeroing, which eliminates any chance of misread.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Bruce]

[Casting Timmy]

Bruce have you noticed on the early throw out bearings that Empi didn't drill the clip holes very deep? The Sachs are more expensive, but have significantly more of the clip in the throw out bearing. Those Empi ones I will never do again as it just seems like the clip will shot out why you sit there and look at it.

[Bruce]

Never in my life have I ever purchased a throw out bearing.
About half the cores have one on them. My rebuilds go to the customer without a TO bearing, then they get to buy one.
I have plenty of perfectly good used German TO bearings that I will never use.

Stop supplying the TO bearing and all your troubles will be gone.
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[Casting Timmy]

I went out and got some measurements to help and understand the plans in the book better.

The push pull piece calls for 3.5" diameter in the plans and this is correct, but a ~3.22" turn down will have it center inside of it. Then it calls for a 5" piece of all thread with nuts welded on each side of the cover. The plans call for a nut on the outside to turn it with, but I think making the handle will be better.

The pieces for the end of the diff, I started by measuring a side gear. The side gear is ~2.555" in diameter and the ID of a used diff shim I bought is 2.97" in diameter.

So far the plans seem very good, I wonder if this guy just copied a factory tool?

[nsracing]

Timmy - are you moving rings and pinions to different cases?

I would advice you to NOT get ahead of yourself. Get proficient w/ stock builds to start. Just do overhauls on stocks and play w/ it all you want. I started myself like that. My learning curve is very long. I am still learning myself.

The VW-297 toolset is strictly for the setting the ring gear. You will also need the other tool-stand to set the whole ring gear assembly to set your initial bearing/shim height, before you can use the VW297. The inside of the bearings have a very large spacer each and may/may not have thin shims along w/ them. This WIDTH is the minimum required before you can start setting the RING GEAR ENDPLAY.

The WIDTH of the bearings/ spacer pack has to be set w/ the tool/stand according to specs before you stick it in the case for measurement of endplay.

Back in the day, I have had a lot of correspondences w/ Mr. Long (Long Enterprises) and I have bought a lot of the spacers and shims to get me started w/ Swing Axles. I did almost all Swings for drags and HOT Street and quickly found out I needed an assortment of these spacers to set the ring gears. It helped too that I had my surface grinder to grind down large spacers to final specs so I do not have to use those tiny shims.

Here:

There is a standard tool that comes w/ it but if not can be made. Just get the specs from Bentley.