TheSamba.com :: View topic - VW 297 Swing Diff Tool

Mon Aug 14, 2017 12:38 pm

The 287 tool is nice, but far from essential. It merely cuts the "averaging" step out of measuring with a good digital caliper or micrometer. I used the 289d and those two 297 brackets with far greater frequency than the 287.

This photo shows what the "ideal" measurement should be after zeroing with the 287a block:

It should be accepted that NONE of these tools are more important than knowing 1) What proper diff bearing preload feels like, 2) What a proper bluing/burnishing pattern looks like.

All of these tools merely get you as close as possible in the shortest amount of time .. doing a job from scratch without them can take forever (although those tables of most commonly used shims will certainly help).

Mon Aug 14, 2017 1:58 pm

I kinda like this vw gear sets, nice patterns. me being from the v8 world and many diferent rearends.and diferent gear manufactures,Ive had some gears that if you set them up perfect, they were shit, howel,wine, shit pattern even loaded very hard.I dont know if the engraving guy was stoner or what. thats when knowing what a pattern looks like and reading it and adjusting it the correct way and getting a good pattern then 1 more adjustment and...perfect.I learned long ago, you need to load the gears hard when checking patterns on that stuff. my vw didnt realy change much, I gess the way the gears are cut or just being paralelleoid or whatever thay are. I messured the 2 cases I had and did some math( yes math not meth) from all the shims on the gears I was swaping and.....dam effing nice pattern...and there quiet....well hear is a question for the exsperts...if the ring&pinion depth& lash arnt right ....do they make any noise like all the others(v8)??? this one that had a dead pinion bearing letting the opinion go forward atleast .060" was still....quiet with no wine just exsessive backlash and some clicking. and off corse the main shaft bearing was noisey too. (klickenberg 3:88 gear)so do these gears wine/howell when pinion depth is off???

Mon Aug 14, 2017 1:58 pm

I thought the VW297 served two functions:

First with either the pinion or ring gear out the dial indicator can be set to record movement side to side (diff shim total). Push or pull diff to one side and then zero out the indicator, then go the opposite direction and record total movement.

Second is with pinion and ring in place and pulled against the ring gear side cover, then the indicator is zeroed. Back lash can be measured and the diff moved until the desired back lash is set. (Ring Gear Shim)

Then some math:
Total Diff Shim - Ring Gear Shim = Non Ring Gear Shim Thickness

Of course the book I think had adding .003" or so to both of these numbers for the initial shims to test out. I think more commonly now though people will run the new preload on used bearings and a little more on new bearings.

I took the stand and measuring inside to inside of side covers a different way to get the total diff shim thickness.

Mon Aug 14, 2017 2:09 pm

mark tucker wrote: I kinda like this vw gear sets, nice patterns. me being from the v8 world and many diferent rearends.and diferent gear manufactures,Ive had some gears that if you set them up perfect, they were shit, howel,wine, shit pattern even loaded very hard.I dont know if the engraving guy was stoner or what. thats when knowing what a pattern looks like and reading it and adjusting it the correct way and getting a good pattern then 1 more adjustment and...perfect.I learned long ago, you need to load the gears hard when checking patterns on that stuff. my vw didnt realy change much, I gess the way the gears are cut or just being paralelleoid or whatever thay are. I messured the 2 cases I had and did some math( yes math not meth) from all the shims on the gears I was swaping and.....dam effing nice pattern...and there quiet....well hear is a question for the exsperts...if the ring&pinion depth& lash arnt right ....do they make any noise like all the others(v8)??? this one that had a dead pinion bearing letting the opinion go forward atleast .060" was still....quiet with no wine just exsessive backlash and some clicking. and off corse the main shaft bearing was noisey too. (klickenberg 3:88 gear)so do these gears wine/howell when pinion depth is off???

I've started doing some transaxles on the side and never heard anyone complain about them being loud. I saw one where the pinion shaft was about an 1/8" forward and no complains except when he took out the key on the 3-4 hub.

The only people I ever hear talking about the ring and pinion whining is drag racers with experience of blowing them up, they hear a whine as the teeth are laying over and there backlash is going away and know they only have a couple more passes before it goes.

I also think the older a gear set is I don't grease it out until the backlash is a little looser, they pattern a lot better if you can get them to where they were wearing at. (I should mention I set up by the numbers first and then pattern with grease in the end to finalize)

Mon Aug 14, 2017 3:16 pm

A few photos relevant to Mark and Tim's comments:

Low quality R&P supposedly set to "as good as possible" after a mere 500 miles of easy driving:

When an R&P set wears, the ideal pattern slowly spreads out. I don't have any photos of high mileage VW R&Ps, but here's a high mileage Porsche 915 pinion that illustrates what I mean:

You're absolutely correct on setting older R&Ps to the high side of allowable backlash, Tim. To add to that, because it's hard to transfer R&Ps to precisely the same position, a tiny chamfer should be ground on the sharp edges of both ring gear and pinion teeth.

Tue Aug 15, 2017 3:52 am

I do not deviate from factory specs. If you want to experiment beyond those specs, it is on your own time.

There is a whole lot of information on Ring and Pinion relationships...pinion depth, proper wear patterns -where it is toe vs. heel.

As I said before, if I am moving a ring/pinion from a box, I will measure the specs before I take the parts out. I will faithfully reproduce those specs -specially the pinion height or depth - in the new box.

Ring gear endplay is easy w/ the VW297. You will figure it out. :D

You can also tighten up the preloads on the pinion bearings to your heart's content. But be conservative or you will cook the roller bearings and races when squeezed too much.

peace.

Thu Aug 17, 2017 6:42 am

I searched around a bit and found out that a T1 flange fits the tube retainer flange good enough that I can weld that one and not have to machine an end cap. I like this a bit better as it should be a lot easier for me to just machine the adaptors to connect a threaded rod to a handle.

The pushers I will make out of 1/4" steel as I have that at home. I used an old diff shim to mark the outside profile and will work on roughing it in before going to the lathe.

I also looked over the Bentley again briefly, it is interesting on the swing axle side you measure the diff and then the distance between the bearings and then only use the 297 to figure out the S1 shim. If you look at the IRS version, which I don't know anyone that has that tool, it talks about leaving the ring gear off or the pinion out to get the total shim stack amount (pre-preload) using the tool.

My assumption is that the 297 tool can do this same feature and the Bentley like always didn't update the procedure. I do have a love/ hate relationship with the Bentley manual, I really feel like you need teh blue and orange at minimum to do a T1 box, but having the green? (70's bus) manual is preferable as well. Even with the 3 manuals you will be searching out some missing details clearly listed in the factory manual. Bentley had to have access to the factory manual based on how the book is laid out, they just didn't transfer all of the information and update it as time went on.

A small/ interesting fact is even the factory knew the turning torque on used pinion bearings didn't meet the earlier call outs in the manual. I have a factory sheet for the 091 where the inspection is change to 7 in-lbs or less and the new inspection was no side to side movement at the top of the pinion shaft after adding just the pinion shaft to the case.

Thu Aug 17, 2017 9:54 am

Timmy - what are you making? You are making me cry man. :lol:

I am trying to understand what else you need. You already got the full VW297 - That is about it.

The only other thing you will need is a large puller for taking off the large ballbearings off the differential when you remove the spacers/shims.

Thu Aug 17, 2017 11:51 am

I don't have the 297 tool set, I am making my own version of it based on plans from the book earlier in this thread and a few modifications to make it easier for me to make.

The pieces in the vise will be built into the 297 tool that bolts to the side cover with the handles for moving the diff side to side.

The flat piece of steel with the silver circle on it will make one of the pieces for bolting on either side of the diff. One will definitely have to be drilled and tapped, the other one will need an arm that comes out for measuring side to side movement and backlash.

Thu Aug 17, 2017 3:49 pm

No VW 297? Oh man- you are a glutton for punishment, ain't ya?

My first Swing build was frustrating when i didnt have the VW297 set. Had everything else. I made some tools too - but came to the conclusion i gotta have the tools. Whenever i see them, i buy them. Now i have 4 or ao sets of these bastards. I sold at least a dozen of these.

Proceed if u want to satisfy your curiosity. But please dont set the garage on fire when you reach the point. Or go on a rampage. :lol:

I do admire your tenacity. I just cant do it anymore the way you are going. More power to you though.

Thu Aug 17, 2017 6:07 pm

Honestly on T1 IRS I just set those up using trial and error, no tool to make it easier at all. It really isn't that bad, I'm really hoping this tool can help me out with my lack of shims on hand and it's fun to do.

I'm taking a break from side jobs this month and just playing around in the garage and learning my new welder and making a tool to help me take on swing axles easier.

On non IRS you can start with .060", tighten it slowly and evenly and feel how the diff slides side to side when you tighten it up. If you're getting close and the gap is too large put a couple shims top and bottom (.010 and .011"). If it starts to tighten up there you know .050" is a good place to start.

Take out .005"and spin it, add .005" and spin it, you keep doing that and you'll get a feel for it quick.

I really wish the blue Bentley had the typical range like they state with IRS, but I figure I will keep notes and eventually the tool won't matter a lot.

Thu Aug 17, 2017 10:03 pm

For IRS, there are a couple of tools you need to do the endplay. These have threaded studs and they will lock on the stubs. They also have a stud for use w/ a dial indicator tip.

A piece also needs to be machined so you can push on the race to take up the slack. There is also threaded large tool for the IRS to push the entire differential. It is not a must but nice to have.

For Swing - there is just not many things you will do w/ lack of the proper tools.

Sometimes, a VW297 parts show up. Look out for those. A piece here and there and you can complete the entire kit.

Fri Aug 18, 2017 6:58 pm

I found some pieces to make assembly a lot easier for me, everyone can find there own way to make it easier for them.

The next part I am using a small piece of 1"round drilled and tapped for 1/2NC, but it could be whatever you want or have handy. A breather stand nut makes a great piece for me to weld to go against the T1 flange on the inside. Up top I am trying to be crafty and am using two reverse shift rails and a couple gland nuts to make the handle.

I'll tap the hole deeper and will also cut down and finish off the top of the 1" shaft before welding this all up. Then it will be ready for final cleaning and paint.

That breather stand nut works out nice!!

Here is a view without the flange adaptor in place.

Fri Aug 18, 2017 7:26 pm

I loved the show McGyver. This reminds me of that. :D

Sat Aug 19, 2017 8:47 am

I'm no trans expert but I sure LOVE my factory tools! I think it's cool to make your own as well. I agree there's no substitute for experience and that you should use multiple Bentleys to get the big picture of the procedures. If you're a noob, it's worth it to find the original tools because you will learn faster by following along with the books and pics. If you're a guy like Timmy who already has the concepts understood, reverse engineering and making the tools can be much faster to getting boxes rebuilt. :)

Sat Aug 19, 2017 9:53 am

Here are pictures before and after welding, just need to get some all thread to finish out this part of the tool. A word of warning, bang off that flat piece of tin under the CV flange (I didn't and foundout that's a big hiding place for some oil)

Pre paint

Painted black so you can't tell how dirty it gets...hahaha

Sat Aug 19, 2017 3:47 pm

Good lord almighty- how are you going to check the endplay with it all enclosed??

You need to he able to move the entire differential left to right and vice-versa

Sat Aug 19, 2017 4:47 pm

Just like the factory tool, one side to move and one side to measure. I should start the diff tooling next and will finish out the measurement stuff last.

Thu Aug 24, 2017 11:47 am

Still need to get some all thread to finish the first piece, but I have started on the second piece anyways. I'll need to make two of these, one will be threaded in the middle so I can push the diff back and forth and the other will have pieces on it for measuring backlash and movement.

I did put a couple silver spots to show where the bolts that go through the diff will eventually be, need to get some all thread for that too!

Still have to take the OD down a bit, but it's getting there nicely.

This is all being done on an old Logan Lathe branded as Montgomery Wards.....best guess is mid to late 40's from what I was looking up on it at one point in time.

Thu Aug 24, 2017 4:31 pm

I started out w/ a small Craftsman lathe. I learned from that tiny lathe. Then I jumped to a fullsize Colchester 13". I never looked back. :D

I use Monarch lathes now. And to this day, I am always impressed w/ how good they machine. They will still be making parts long after I am gone.