TheSamba.com :: View topic

Thu Aug 30, 2007 11:20 pm

some transaxles have the shims , and others dont , they only have the spacer , if the tolerances were within 0.1mm there was no shims , the shims were made in various thicknesses and if the one bearing cover was machined a bit lower , it cause the crown wheel to mesh deeper or shallower than it's previous position . I dont think that it would be to critical as I have disassembled several transaxles and many of them have the same amount of shims on both side , and they were the same thickness , If you take yours apart , check and see how many is on each side , if there is around the same count it would probably be ok . the other alternitive is for what you might spend having it set up in a shop you might pick up a different transaxle out of a Beetle and the gears would already be set up .
Either way best of luck .

Fri Aug 31, 2007 5:31 am

Quote: Bus Boys has a decent tutorial on how to do a ring gear flip straight axle conversion.

http://www.bus-boys.com/instruct-swing-pg1.htm

thanks for the link!!!

dms-

I’ll look for shims and make sure there is the same # on each side. Also like you said, i would think I could pick up a trans for about the same price as having a shop around here get involved. Thanks for the input.

Fri Aug 31, 2007 6:28 am

dms wrote: some transaxles have the shims , and others dont , they only have the spacer ,

Sorry, the spacer is what I meant as the "shim". At our shop we have them in thicknesses ranging from .100" to .150". These are what you use to set the correct backlash. Then use a papergasket if needed to get it dead nuts on.

The spacers are not a generic standard thickness. They are avaliable in different thicknesses to set the backlash correctly.

If you've flipped them before with no issues on your own tranny's, that's cool, but IMHO, when you're telling someone else to do it to thier own vehicle I take the safe route and tell them to do it the right way. Because "what if" they just flip it like you say, and it toasts thier ring and pinion. What do you do then? Tell them your sorry? Buy them a new R&P? This is the standpoint I come from.

Fri Aug 31, 2007 7:02 am

Eaallred wrote: If you've flipped them before with no issues on your own tranny's, that's cool, but IMHO, when you're telling someone else to do it to thier own vehicle I take the safe route and tell them to do it the right way. Because "what if" they just flip it like you say, and it toasts thier ring and pinion. What do you do then? Tell them your sorry? Buy them a new R&P? This is the standpoint I come from.

Point well taken. However, I'm not telling anyone to do one thing or another but simply what I've done and my experience with it. Similarly as with the engines I build, I rather do it myself and know exactly what went into it than trust anyone else but so long as I am confident enough with the job at hand. If it fails for whatever reason I can then tear right into it, figure out what went wrong and go about fixing it right away. When you buy and engine or a tranny and it fails, you cannot touch it unless you want the warranty to turn to dust! You'd have to remove it, ship it or take it back, wait for the builder to examine it, possibly giving you the bullshit story of "you installed it incorrectly blah blah blah..." and lose your warranty anyway. Not to mention the down time. :roll:

People should do what they think they are capable of and if what they are capable of is to pay for someone else to do it then by all means that's what they should do! I am no expert in any sense of the word, simply have been doing my work since I could drive and of course that includes quite a few failures. Learning from my mistakes along the way I've also learned to save my money wherever I can. I still do have my "sources" of help if I think I can't do the job by myself or altogether. :wink:

As an example of some jobs I personally "farm out" is the windsheild replacement on the Plump Truck (derv). I've done glass before with some help but was more than happy shelling out $200 for the glass shop to spend 2 hours installing it for me. I don't know if they use one or many windsheilds while they were at it. I do know that I didn't sweat a drop on it! 8)

But hey, whatever floats your boat! :P

Fri Aug 31, 2007 9:08 am

ekimikem wrote: Bus Boys has a decent tutorial on how to do a ring gear flip straight axle conversion.

http://www.bus-boys.com/instruct-swing-pg1.htm

Alright, I've read through this tutorial and they only reference the need to flip the ring if using a bus tranny-to-straight-axle conversion. Now, I've always considered the Bus Boys to be quite the experts on transmissions and seeing no reference to shims and backlash "must do's" leads me to believe it isn't as critical as some here are portraying it to be. :?

I can see it being such when applied to racing and like that where every bit of advantage is to be used but obviously for simple everyday drivers must not be so vital. Otherwise the Bus Boys surely would have at the very least mentioned it. 8)

Fri Aug 31, 2007 4:42 pm

They do mention the shim on page 3 paragraph 2 but only to keep it on the same side of the carrier if the bearing comes off in the side plate. From experience the bearing typically stays on the carrier in which case the shims wouldn't be an issue.

Fri Aug 31, 2007 11:48 pm

Eaallred wrote: dms wrote: some transaxles have the shims , and others dont , they only have the spacer ,

Sorry, the spacer is what I meant as the "shim". At our shop we have them in thicknesses ranging from .100" to .150". These are what you use to set the correct backlash. Then use a papergasket if needed to get it dead nuts on.

The spacers are not a generic standard thickness. They are avaliable in different thicknesses to set the backlash correctly.

If you've flipped them before with no issues on your own tranny's, that's cool, but IMHO, when you're telling someone else to do it to thier own vehicle I take the safe route and tell them to do it the right way. Because "what if" they just flip it like you say, and it toasts thier ring and pinion. What do you do then? Tell them your sorry? Buy them a new R&P? This is the standpoint I come from. I was just sharing the knowledge that I have experienced in dismanteling several transaxles and also from two vw mechanic that have 30 + years experience and there so far has not been any problems . when I submit a post that is the knowledge that I put into it . Yes there are several ways of doing this . to do a proper job there should be proper tools envoled to do the job . and perhaps the bearings should be changed as there could be a lot of wear there are all kinds of factors to add in .And then there is other methods for people that are on a budget ect that would flip the gears and be done with it and take their chances . I like to properly align the transaxle and have done the split case before and it works great .I have all the factory info if I need it . Somtimes things can be dealt with another way . for the future " My information may or maynot be correct use at your own risk" .

Sat Sep 01, 2007 6:37 am

dms wrote: Bettle

What is a Bettle??? and why is it mentioned in a forum about Beetles? :shock:

Sat Sep 01, 2007 11:33 pm

What is a Bettle?? , it is a spelling error of the word Beetle . Im glad you noticed ,it slipped passed me , thanks , I corrected it .

Sun Sep 02, 2007 9:26 am

This discussion seems to come up every few days ... and I see a bit of confusion in this thread.

IF you have side covers that have the O-ring, there are NO paper gaskets used for cover-to-main case sealing.... and even in the old style (without O-ring) there are NEVER multiple cover-to-main case gaskets used together on one side. The only gaskets used in multiples are those that shim the axle tube outward to attain the proper tube-to-plastic clearance... and in truth, attaining this precise clearance properly may be more a pain in the ass than checking R&P backlash.... especially as cheapo Brazilian gasket sets don't contain the ultra-thin German gaskets required to fine tune this adjustment. (This may be the most commonly mis-adjusted step of setting up swingaxles.)

If you have side covers that are so early that they don't have O-rings, I can almost guarantee they are worn beyond re-use, and should probably be replaced with the newer style. The telltale is when the diff cover comes off, and the bearing has stayed on the diff.... that cover is worn out. It's pretty common with most of the later O-ring style covers, too.

The differential shims are located beneath the bearing on each side of the differential. So long as these shims remain exactly where they are and are flipped with the differential housing, you are likely to fall within the range of correct backlash. You're not guaranteed of this, but your chances are at least 50%.

Flipping the ring gear does not cause the drive side wear pattern to change to the other side of the teeth. Visualize it ... the pinion continues to rotate in the same direction, and you're just moving the ring gear 180 degrees around that identically rotating pinion. The wear pattern on the backside of the teeth occurs only during deceleration, or reversed engine rotation applications (another subject in itself).

The likelihood of a close to original wear pattern is better in a ring gear flip than say, changing OE diff housings (while leaving the ring gear on the same side). But an absolutely identical pattern is extremely rare. A tiny bit of increased whine may occur, especially with high mile R&P sets .... but quite often you will be pleasantly surprised.

The real reason that you probably won't notice an increased whine is this: These transmission are old. The bearing are worn. The R&Ps are worn. When transmissions heat up, preload on the diff bearings normally disappears ... even if the parts are new. So, in these old bus transmissions, the thought of an R&P running perfectly true under all conditions is a falicy. That pinion is moving in & out of the ring gear, with R&P clearance acutally changing continually with every acceration and deceleration. In other words, the two parts are continually burnishing themselves against one another. This is occuring on a very small scale, but it is occurring nonetheless. So the thought that being .001" or even .002" off from the original pattern on a ring gear flip will cause some catastrophic issue is a false worry.

To the big mouth that insinuated that I was putting forth wild opinions the last time I contributed to this group: I've been involved with VW transmission upgrades for decades, and may be the only guy invited by Hot VWs to write an article specifically on R&P set-up, well over 20 years ago.

Sun Sep 02, 2007 1:46 pm

Gears , thanks for posting that , it was enjoyed here at this end . :)

Sun Sep 02, 2007 4:17 pm

So if I'm reading all this correctly, VW machined their cases so precisely that the pinion is in the exact center of the two side seating faces plus or minus the thickness of a gnat's ass. That is some righteous accuracy.

Sun Sep 02, 2007 5:10 pm

VW case machining is amazingly standardized, even between the transmission types. OE diff housings are nearly as standardized, which is why a novice can often get away with changing out stock OE housings without shim correction. Any time you add a "super diff" (yuck) or the like, you need to re-shim.

Sun Sep 02, 2007 5:30 pm

That is a very enlightening post. This is the stuff I like to read on the samba. Informative, concise, to the point, and from someone who knows (seemingly) exactly what they are talking about. Thanks.

Mon Sep 03, 2007 7:49 am

The subject of ring flips has come along very often and to date this has been the most thorough commonsensical detailed explanation posted so far, IMHO! :P

Thanks for the bit, gears! 8)

Tue Sep 04, 2007 5:37 am

Well yesterday I flipped the r&p and it’s seemed straight forward. I did not see any shims or spacer and it went together just about as easily as it came apart. The real test will be when it gets put back in the bus, but so far I am satisfied with how things have worked out…

Tue Sep 04, 2007 7:52 am

I can assure you that every VW trans on the planet has S2 and S3 shims (look in any manual). So obviously, if you didn't see them, the bearings were stuck on your diff rather than remaining with your side covers upon disassembly.

Edit that to say: "... every OE VW swingaxle trans on the planet... blah, blah

Wed Oct 20, 2010 8:31 am

mastajusty wrote: The real test will be when it gets put back in the bus, but so far I am satisfied with how things have worked out…

Its been a few years, how is it working out?