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SyncroGhia Sat Mar 08, 2014 12:04 am

derekdrew wrote: Another option for rear inner boots is the "bates boot" new style.

=======================================

From a list email I sent out a month or two ago:

I think I tried a new style "bates boot" on one side and the 930 "small boots" on the outside.

You can also try to cross reference off these numbers:

-- VW: 443 498 201B

-- Meistersatz 103 2147, 02306260, 1158 Boot Kit 108mm Rear Inner And Outer

-- Lobro 300516, also says 6153157500007 and also says 4 019064 105114 Boot Kit 108mm Rear Inner And Outer

I don't think you should be limited to those OEM cross references though.

I cannot remember why I chose aftermarket boots instead of OEM boots and I don't see what I chose listed in my computer, which is criminal.

I might have chosen something like this for the outside: http://www.mooreparts.com/8779-AC501105KIT*/

If you choose a smaller boot for the rear outer, you can run a little more "droop" without having the boot hit inside the trailing arm, I think is the logic.

At the time, the Bates boots were well regarded.

I used this vendor, which was well recommended and knowledgeable: http://www.racereadyproducts.com/cv-boots/bates-boots/

Thanks Derek,

I'm going to have to move away from the standard design (below) as the driveshaft is actually hitting the inside edge of the pressed steel flange.



Also due to the design of the boot, there isn't enough length of the boot (corrugated area) when the suspension moves into full droop and the rubber is being pulled against the lip of the metal flange (that is there for the clip to hold the boot onto) and the lip is acting as a sharp edge to cut the boot.

My CV boots can last anywhere from a week to a month. No more.

Looking at your links to the Bates boots... I like the idea of the boot going over the complete CV joint.



While I believe that the prices are good and that product is probably reliable, I just can't afford to buy 18 kits plus spares for all of my vans and then have to bring spares in from the US each time I need one.

So... I'm going to start looking for a CV boot that will fit over the entire 108mm CV joint and use the original metal flange (which I happen to have lots of now!) as the ridge for the clip to hold the boot on.

If anyone has ideas as to which boots to look at please let me know :)

MG

insyncro Sat Mar 08, 2014 7:11 am

MG,
At the track we use double boots.
The outer boot is usually leather or a synthetic material.
This doesn't really fix the tearing of the inner rubber boot, but does keep the grease in place and allow longer service intervals.

I read through the last few pages, but missed where your boots are tearing.

Are you using a band clamp on the axle side of the boot?

What grease are you using?
I ask as I am seeing degradation of other boots and bellows on a regular basis.
Gear oil seams to be weakening some of them and they are splitting.

Could certain greases and fluids have an ingredient that attacks recycled rubber products or has the quality of the rubber itself fallen to the point that we are seeing these amazingly short lifespans?

What has lead me to ask is I recently had some very expensive fuel line turn to mush due to excessive levels of ethanol in the fuel (I had it tested).
What was also disturbing was that the test showed one "unknown" substance in the fuel and it was 3% of the total :shock:

derekdrew Sat Mar 08, 2014 7:35 am

In testing, at an extended amount of "droop" or "drop" (not radical) and with precision measurements I found that the tolerance for an axle to be either so long that it could bang both the inner and outer flanges at the same time (with really bad results) OR that it would be so short that it would yank the CV joints seriously out of whack was 1/2". Since the axles come in 1" increments, this means that there is a 50% chance that the average person's axle is a time bomb and they will be wondering why their CVs failed or their flanges were getting pounded or the circlip seemed to be in a sub-optimal position. I started an XLS step by step calculator for everybody to use that would explain all of this and help eliminate doubt as to the words that you are reading now, but I failed to finish it. The variables are much higher than they might otherwise seem to be because the position of the circlip being so critical and that there are so many flange designs and dimensions going around, and the CVs behave oddly at various angles (sometimes binding) and you should be aware of how far the star will move in an out at a given angle without binding and it even matters whether you are using an OEM blue oil cap in the middle of the flange on the transmission or something else like the Ultra Grey referred to earlier in this thread. I would say that after I was finished I was fairly furious feeling that the probability that the people reading this thread would do it right was low unless they had a LOT of patience and time on their hands. I don't believe in buying off-the shelf solutions without doing the measurements in the xls, which I have FAILED to publish, so if somebody wants to shove a banana in my mouth and tape my eyes shut after reading this it would be deserved until I publish the xls. I will be forced to publish the xls in a few months. You definitely should NOT assume that both axles should be the same length unless you can move your engine-transmission assembly latterly to achieve that, or unless you measure (think old TV antennas) and find out that the distances really are identical on either side for your van. Also, you may wish to use a spacer on one side of the van or the other or both. Spacers are a great way to bail you out of fit problems described in this post. An example of a spacer with greasing points is here: http://www.imcoproductsinc.com/page/cvgreasetools You don't need to do all of this precision measuring in the front because the front's geometry changes depending on articulation of the wheel. I am very skeptical that you should go to a website and click on 930 cvs for syncro and order them without doing the measurements and I am skeptical that you should take the advice of somebody over the phone as to the right lengths. Get under your van with those antennas and think about how the spacer (if you are using one) and the location of the circlip groove affect things and measure both sides differently. I have been meaning to write this here for a year or two. Maybe I already did. I did not have time go to back through this email to tone down or eliminate all the points that are too strongly worded or sound dogmatic. I am sure that we can get 10 people to respond here that they bought an off-the shelf 930 setup and it "works fine" to take that into advisement when reading these words. Another caveat is that if you are not running any extra drop, meaning that you are using stock rear shocks and a stock rear 16" trailing arm mounts, then the issue is much less critical. But it is possible that even a 14" rear trailing arm mount allow more drop or droop in the back than the factory intended because these mounting points are different 16" vs. 14".

derekdrew Sat Mar 08, 2014 9:41 am

Here is alternate instructions from Sway Away, but I am not sure that these take into account how the circlip works properly, so its use is more limited than it would otherwise be. It can help start you thinking about it. But what is complicated is that the key thing to think about is either circlip to circlip length, or circlip to flange, under various conditions of plunge and angle, I think, going from memory of the xls.

Make a Set Up Axle
=============

The best way to measure your car for axle length is to use a set up axle. There are several ways to do this.

You can cut and sleeve a stock axle or any old axle that has the proper splines on it. A friction saw works well to cut the axle in half. You can use a piece of angle iron to sleeve the axle. Cut it so that it is about 6”
shorter than the straight across flange-to-flange dimension. Use some hose clamps to hold the cut ends of the axle in the angle iron. You can now adjust the length of the axle.

Measurement
=========

There are two positions that should be checked for proper axle length. One, the most important, is at full droop. The other is at the straight across position.

Set Up
=====

Install the CV joints on the set up axle. It is easier if you leave the boots off. It is even better if the CV joints do not have any grease in them. You need to be able to see where the CV center is in its lateral travel.

Full Droop Measurement
================

With the CV center, centered in its lateral travel, adjust the length of the axle so that the CV joints will just bolt up to the flanges. You do not want the CV joint to extend to the point where the CV joints run out of their lateral travel. This will break the CV cages.

Straight Across Measurement
===================

Check to see that the axle is not so log that the ends of the axle contact the insides of the CV flanges when the axle is pushed to the end of its lateral travel in both directions. If the axle length is set accurately during the full droop measurement, the axle length will most likely OK here.

Check The Other Side
===============

It is important to check the axle length on the other side. Many times, the lengths are different from side to side.

Ordering
======

The most accurate way to call out the axle length is from clip to clip. Remove the axle from the car. Measure from clip to clip or from outside of star to outside of star. Add ¼” to this measurement. This is your clip-to-clip length on the new axles. Axle lengths in our catalog are over all lengths. Add the following amounts to get over all lengths. Some out board hub assemblies require half dome or full dome ends.

To get over all length for axles with flat ends
==============================
Add 5/16” for VW 33 tooth axles.
Add 5/16” for Porsche 930 axles.
Add 5/16” for Porsche 934 axles.
Axles with ½ dome ends, add 5/16” for each

SyncroGhia Sat Mar 15, 2014 1:39 am

insyncro wrote: MG,
At the track we use double boots.
The outer boot is usually leather or a synthetic material.
This doesn't really fix the tearing of the inner rubber boot, but does keep the grease in place and allow longer service intervals.

I read through the last few pages, but missed where your boots are tearing.

Are you using a band clamp on the axle side of the boot?

What grease are you using?
I ask as I am seeing degradation of other boots and bellows on a regular basis.
Gear oil seams to be weakening some of them and they are splitting.

Could certain greases and fluids have an ingredient that attacks recycled rubber products or has the quality of the rubber itself fallen to the point that we are seeing these amazingly short lifespans?

What has lead me to ask is I recently had some very expensive fuel line turn to mush due to excessive levels of ethanol in the fuel (I had it tested).
What was also disturbing was that the test showed one "unknown" substance in the fuel and it was 3% of the total :shock:

I'm using GKN CV grease and all of the boots are failing in the same place.

Here's one I removed from the Tristar just yesterday. To be fair, this has failed due to age rather than extreme angles but it's gone in the same place as they go on Limey so it's easy to use as an example.



The metal pressing has a small up turned lip where the boot fits over so that once the clip is in place, the boot can't just pull off.

With the drive-shaft at more extreme angles, the boot is pulled fairly tight over this turned lip which just acts as a knife and cuts through the boot.

I've tried GKN and other makes and they all have the same issue.

I've tried fixing the inner end of the boot closer to the CV joint to help stop it pulling the boot but I'm just running the angles at more than this design of boot/pressed flange can cope with.

Re drive-shaft length. Derek makes a very good point and again huge amounts of detail.

I'm using original VW parts so I'm not expecting to have issues with them.

I will however have to check this very carefully on the SWB Lightweight Syncro so it's great info to have.

MG

Jon_slider Sat Mar 15, 2014 10:54 am

SyncroGhia wrote:
With the drive-shaft at more extreme angles, the boot is pulled fairly tight over this turned lip which just acts as a knife and cuts through the boot.

Can you please quantify your axles' "extreme angles" either with an angle finder, or in terms of fender to wheel center dimensions.

Are you at 21" ride height at rest?
Does full droop exceed 23"?
Is your transmission mounted higher than stock? (more than 19" from fender lip to bottom of inner rear CV, obtained by measuring fender lip to ground, minus bottom of rear inner CV joint to ground)

Do you run longer than stock shocks, and or higher than stock transaxle position?
Do only your rear boots fail, or also your fronts?

sorry to hear of your boot failures

I dont have any failed boots with 21" ride height, 23" full droop, 19" from fender lip to bottom of inner CV, and Fox Shocks. My full droop axle angle does not exceed 19 degrees. (but I dont run 930 joints, I use 944's)

SyncroGhia Sat Mar 15, 2014 11:14 am

I can't give much for your data sheet other than I run stock Syncro 16 parts but I've moved the rear shock mounting up 85mm.

I worked out that the 108mm CV joints would cope with the arm dropping completely down so that the drive-shaft came into contact with tthe arm and still turn freely without a problem so I moved the arm up a bit to give 5mm clearance there and that's my lowest point.

I've no idea what angle they're running at but it will be a lot more than a 944 cv joint can handle.

Arch measurements don't really work as it's got 16" arches.

MG

Jon_slider Sat Mar 15, 2014 11:21 am

SyncroGhia wrote: Arch measurements don't really work as it's got 16" arches.

can you please give the measurements anyway. I can account for your arches, if you include a measurement from fender seam to ground:
The stock dimension from seam to fender lip is 2 1/8"


these measurements would help others know if their setup is different than yours

rear arch to wheel center at rest
rear arch to wheel center at full droop
rear arch to ground
bottom of inner rear CV to ground

SyncroGhia Sat Mar 15, 2014 11:27 am

Not at the moment no.

Limey is parked up 40 miles away in storage.

I have measured it previously and put it in the Limey thread somewhere.

MG

insyncro Sat Mar 15, 2014 11:52 am

MG,
I completely understand what is happening and will consult my connections at Porsche.
They will be in my neck of the woods next month once the snow is gone and the track has opened again.

Off the top of my head, there are ridges on the shaft side where the boot rests and is banded.
Have you tried removing the band on the shaft side and pushing the boot towards the CV and than using just a zip tie to keep it snugged, but still able move a tiny bit if pressured.
I do this with all CV boots and haven't had any tearing issues that I can remember.

SyncroGhia Sat Mar 15, 2014 1:54 pm

insyncro wrote: MG,
I completely understand what is happening and will consult my connections at Porsche.
They will be in my neck of the woods next month once the snow is gone and the track has opened again.

Off the top of my head, there are ridges on the shaft side where the boot rests and is banded.
Have you tried removing the band on the shaft side and pushing the boot towards the CV and than using just a zip tie to keep it snugged, but still able move a tiny bit if pressured.
I do this with all CV boots and haven't had any tearing issues that I can remember.

Thanks. I don't think I've done this so will try it.

One thing that I have tried is a Touareg CV boot. So far it hasn't torn but... it's made out of plastic and is very stiff! So much so that it's really difficult to secure the inner end to the shaft tightly. I've probably covered the most on this CV boot so far but it's been 18 months since I drove Limey so I'll be going over this again soon once I get back home.

MG

insyncro Sat Mar 15, 2014 2:11 pm

Curious to hear if moving the small end of the boot will relieve some of the pressure on the large end:wink:

My fingers are crossed for you as it sounds like you have as many vans, CVs, as I do :lol:

Yes, those plastic boots can be a bugger.

What I use is a DEI stainless steel tie wrap designed for securing wrapped headers.
There is a tool that will really tight them down.
I found these for the front outers.
Once secured, you can give them a whack and flatten the raised end to clear any obstruction on the upright.
They will not release from this and will need to be cut and replaced each time you have to remove the boot on that CV, but they are holding well for me.

SyncroGhia Sat Mar 15, 2014 2:13 pm

insyncro wrote: Curious to hear if moving the small end of the boot will relieve some of the pressure on the large end:wink:

My fingers are crossed for you as it sounds like you have as many vans, CVs, as I do :lol:

Yes, those plastic boots can be a bugger.

What I use is a DEI stainless steel tie wrap designed for securing wrapped headers.
There is a tool that will really tight them down.
I found these for the front outers.
Once secured, you can give them a whack and flatten the raised end to clear any obstruction on the upright.
They will not release from this and will need to be cut and replaced each time you have to remove the boot on that CV, but they are holding well for me.

I have used the straps also but didn't realise that there was a specific tool to tighten them down.

Could you post a photo or link up please?

MG

insyncro Sat Mar 15, 2014 2:26 pm

It is actually a CV banding tool that I use with the stainless ties.

http://www.bing.com/images/search?q=cv+band+tool&FORM=HDRSC2&MID=2051&PC=VZW

You grab the end of the band and crank the tool to tighten.
There are super heavy duty versions of this tool that are used for bands that secure items to shipping pallets too.
The cheaper tools will not do a very good job with the thicker bands.
Once you see what it is, you may be able to make a tool to work for your application.
Tighten the band's works best in a vice on your workbench vs with the half shaft installed in the vehicle, but still possible.

Hope this helps.

SyncroGhia Sat Mar 15, 2014 2:28 pm

insyncro wrote: It is actually a CV banding tool that I use with the stainless ties.

http://www.bing.com/images/search?q=cv+band+tool&FORM=HDRSC2&MID=2051&PC=VZW

You grab the end of the band and crank the tool to tighten.
There are super heavy duty versions of this tool that are used for bands that secure items to shipping pallets too.
The cheaper tools will not do a very good job with the thicker bands.
Once you see what it is, you may be able to make a tool to work for your application.
Tighten the band's works best in a vice on your workbench vs with the half shaft installed in the vehicle, but still possible.

Hope this helps.

Thanks I'll have to grab one :)

MG

insyncro Sat Mar 15, 2014 2:34 pm

This is the style band I use:



Here is a stock photo of the tool (the cheaper one) in action:



syncrodoka Sat Apr 19, 2014 10:16 pm

Polished machining grooves out of new CV star and body. The new out of the box CV started out as unable to articulate by hand in any direction and when done the full range of motion could be utilized. Polishing up the assemblies is a quick procedure just don't overdo it.
The CVs were all oriented correctly out of the box so that wasn't the issue.

Polished on right, factory machining on left.

SyncroGhia Sat Apr 19, 2014 10:35 pm

Thanks for the tip.

I've just got Limey home and the ride height is currently 21 inch with a further 2-3 inch droop at the rear.

I'll be checking on the rear CV boots once I've finished fixing the roof on and getting the interior all back in and working.

MG

ALIKA T3 Sun Jun 29, 2014 10:59 pm

Aloha all!

I haven't checked this thread in a while.

Let's say theorically, car manufacturers have it figured out, they must have some kind of chart depending on the length of the gap between wheel and transmission flange, how much an axle needs to be right?

Maybe could we collect datas and kind of reconstitute that chart starting from a result point of view?

Unfortunately, we don't have many vehicles like ours with that much wheel travel using Lobro joints on both sides, right ?

I'm going to have silicone boots made in the near future for Löbro joints. Stock style first :100 and 108mm, and maybe for Syncro 14" 90mm and 16" 98mm outer CV's later.
If you guys have been dreaming of anything, let me know, I can make it happen.

Cheers!

Alika

insyncro Mon Jun 30, 2014 5:25 am

I have some of Alika's reproduced power steering rack bellows currently in testing.
Very nice quality, fit and finish.
Looking forward to some new options for CV boots =D>

I will post pictures of the bellows in their own thread shortly.



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