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Sat Feb 27, 2016 12:44 pm

I have the Meyle boots fitted on mine, they fit well. Ill report back in a few thousands miles with updates.

Sat Feb 27, 2016 12:58 pm

khalimadeath wrote: I have the Meyle boots fitted on mine, they fit well. Ill report back in a few thousands miles with updates.

A few thousand? We need boots that give us a minimum of 50k. Otherwise it will continue to be more economical to buy the pre-made EMPI axles with absolutely fantastic boots.

Robbie49kNoRipsOnMine

Sat Feb 27, 2016 1:13 pm

cdennisg wrote: raygreenwood wrote: cdennisg wrote: chimneyfish wrote: rusty busty wrote: I see cip has "off road" bus CV boots.

Any thoughts on them? They're more than 4 times the price of the cheap ones :shock: but maybe they'd last 4 times as long?
http://www.cip1.ca/ProductDetails.asp?ProductCode=C13-86-9303K
Would they even work?

Maybe the wider concertina of the boot would be desirable "off road"? They are EMPI, so I don't know how long they would last before the rubber deteriorated, not long I guess, and cable ties instead of a clip would not be my choice of fixing. However, I would expect that people who go off road with their buses would regularly strip down their CV joints (or break them), so these may be OK for that environment. I would also guess they would be popular with the beach buggy guys who cannibalize our 6 rib 091 transmissions.

In the swingaxle beetle and bus world, the EMPI urethane accordion style boots are the only thing that actually lasts these days. I have seen original style (VW brand and others) rubber axle boots split in a matter of months with very little usage. Maybe the EMPI CV boots use the same rubber/urethane compound? If so, they may very well be a great choice for us.

EMPI....does not use urethane. In fact.....no one uses urethane for an axle boot. Its heavy, its too low in elasticity even at its softest durometer....and hardens at a rate of 3-5% per year.

EMPI......uses neoprene. You can find that note on their website in their teating and material pages.

Neoprene.....is actually better than rubber in certain ways......right now.....with with Buna and other rubber formulations missing the chemicals they are lately.

Its got better elasticity wo ots good abrasion resistance. Its got excellent ozone resostance and very good high and low temperature flexibility. ....however.....it is not as resistant to some oils.

Ray

Huh. Always thought they were urethane as that is what they have always been called. A misnomer I guess. Thanks for the clarity.

So who can we get to make bus cv boots in neoprene? Same for ball joint and tie rod boots. They obviously work better than what is currently available.

I am no really an EMPI fan.....but I will say that their CV boot technical section on their web site....is very complete....and has A LOT of information.

They have design, profile, material and testing documents. They build boots for hundreds of vehicles.

Neoprene has been kind of a go to material because of other rubber issues for a while. That being said....neoprene has definite lifespan issues with certain oils. I am not sure exactly which ones ....or which formulations of neoprene have issues. There are numerous formulations.

The EMPI docs even make nkte that many rebuilding houses dont like to use silicone.....but does not elaborate why. But...I can make an educated guess......and its because many if not most of the "pourable/castable" silicones themselves (as compared to the really serious...injection mold only silicones and RTVs we use for building engines)...have a few issues with certain oils as well.......but mostly because of their cost.....and the fact that because they are so elastic.....the boot has to be greatly thicker.....again....cost.

Silicine for most boots....mof you had the right grease/oil so there are no issues.....is awesome. Abrasion and tear resistant. ...flexible. ...really good at low temps....and ozone resistant.

EMPI also made a comment. ...about their solid neoprene boots in comparison to the late (meaning currently) OEM boots that are bi-layer molded parts. These are similar to the strut boots you find now. They are a thin layer of hard polyethylene or polypropylene on the inside and a rubber on the outside. Many OEM CV boots are like this now.

The OEMS are doing this for a reason. The polyethylene or polypropylene on the inside is extremely chemical resistant. The oils wont touch it. But its too stiff to make the whole boot from.
So the outside is made from something that has good to fair ozone, elasticity and water resistance......but may have poor oil resistance....and either way may be more expensive than they want to make the whole boot from.

The problem is that with age, either the stiffer inside starts cracking or the two layers start to separate. Flexibility issues.

Now.....the problem here really...is that neoprene like any other butadiene based elastomer....is NOT ozone resistant. So in reality.....its probably a misnomer and is not,straight NEOPRENE. Its CHLOROPRENE......which is a chlorinated version of neoprene which is highly ozone resistant and in the family as viton and EPDM.

Really....the boots shoul be made of EPDM or VITON. EPDM is what brake master cylinder and caliper seals and your windshield seals are made of......but its in very high demand and expensive.....and must be injection molded and not simply pressure cast.

All that aside.....it may be worh looking at EMPIs boot profile pages. See if there is something that fits American or Japanese cars that may be able to be attached to the bus flange.

Also....its interesting to see the boot bellows rib design changes that EMPI has made. Some may have been done to not have design infringement issues....some are actually improvements.

One thing I havd noted over the years....is that the ribbed section/cavity of the average CV boot is 100% worthless and a material waste....and with many boots the shape and fit of these ribs is a detriment.

A lot of the wear that destroys many CV boots is from sand and oil getting between the ribs/folds and abrading the adjoining fold as the boot compresses and flexes. Add to that.....grease gets pushed out of the joint into this open cavity...mand when its cold the stiff grease does not miraculously flow back into the joint.

A better design would be a low profile cap shape with a single fold...much like a big ball joint boot. The single fold should be large enough to allow the boot to flex full range....and it should be made of material elastic enough....that you pump the joint and the boot full of grease...so as it flexes it constantly pumps grease back into the joint.

If things get going better this year I had thought about trying my hand at casting some silicone boots along these lines. Ray

Sat Feb 27, 2016 1:18 pm

asiab3 wrote: A few thousand? We need boots that give us a minimum of 50k.
I've got 10 years of daily-driving use on the EMPI boots I bought from Bus Boys (2) and Wolfgang International (2) in early 2004 -- bus was off the road for a year -- and while they're looking a bit dry these days, they're still not split and holding grease just fine.

But the EMPI boots of 10 years ago could be a vastly different beast from the EMPI boots of today...

Sat Feb 27, 2016 1:26 pm

tristessa wrote: asiab3 wrote: A few thousand? We need boots that give us a minimum of 50k.
I've got 10 years of daily-driving use on the EMPI boots I bought from Bus Boys (2) and Wolfgang International (2) in early 2004 -- bus was off the road for a year -- and while they're looking a bit dry these days, they're still not split and holding grease just fine.

But the EMPI boots of 10 years ago could be a vastly different beast from the EMPI boots of today...

The old ones definitely could be different. But I also know that three years ago, the boots that came on the axles were different from the boots they sold separately... :roll:

Sat Feb 27, 2016 6:47 pm

asiab3 wrote: tristessa wrote: asiab3 wrote: A few thousand? We need boots that give us a minimum of 50k.
I've got 10 years of daily-driving use on the EMPI boots I bought from Bus Boys (2) and Wolfgang International (2) in early 2004 -- bus was off the road for a year -- and while they're looking a bit dry these days, they're still not split and holding grease just fine.

But the EMPI boots of 10 years ago could be a vastly different beast from the EMPI boots of today...

The old ones definitely could be different. But I also know that three years ago, the boots that came on the axles were different from the boots they sold separately... :roll:

Thats most probabaly because its highly doubtful that EMPI either makes their new axles in house....or rebuilds any rebuilt axles they may sell.

So going through one of the many companies that make new or rebuild old.....unless EMPI somehow was able to swimg a high volume deal for the builder/rebuilder to use their boots......its doubtful the boots that come on complete axles would be the same as what they have manufactured under their own name. Ray

Sat Feb 27, 2016 7:14 pm

asiab3 wrote: khalimadeath wrote: I have the Meyle boots fitted on mine, they fit well. Ill report back in a few thousands miles with updates.

A few thousand? We need boots that give us a minimum of 50k. Otherwise it will continue to be more economical to buy the pre-made EMPI axles with absolutely fantastic boots.

Robbie49kNoRipsOnMine

Well yea, but I can only put on so many miles this year lol.

Sat Feb 27, 2016 7:16 pm

not to bust anyone but there is something that is just not considered in this thread as everyone debates. It is a little molecule named Ozone O3. Most destructive to rubber. Two people with the exact same boot can have two very different experiences based on the ozone in the air where they are, as well as the time of season because in some areas ozone is seasonal. Two guys in the same city may get completely different results because one person parks near electric motors arcing and the other does not. Motor brushes arcing is one source of ozone. One person could get 10 years out of a specific boot while someone else only six months before it started cracking. The Japanese, Honda etc seem to have mastered rubber boots and CV joints lasting a very long time. I would try to find a Honda boot from the 1990's in good shape and see what manufacture's stamp is on it, then see if they make anything for a VW.

Sun Feb 28, 2016 8:02 pm

asiab3 wrote: tristessa wrote: asiab3 wrote: A few thousand? We need boots that give us a minimum of 50k.
I've got 10 years of daily-driving use on the EMPI boots I bought from Bus Boys (2) and Wolfgang International (2) in early 2004 -- bus was off the road for a year -- and while they're looking a bit dry these days, they're still not split and holding grease just fine.

But the EMPI boots of 10 years ago could be a vastly different beast from the EMPI boots of today...

The old ones definitely could be different. But I also know that three years ago, the boots that came on the axles were different from the boots they sold separately... :roll:

At some point, maybe three years ago, no one seemed to have EMPI boots. I did find one source where there were four boots being sold on one card, but these boots were very thin so I didn't bother to install them. It sounds like EMPI boots are now available again, but I can't say whether they are the same as the earlier EMPI product or not.

Sun Feb 28, 2016 8:38 pm

SGKent wrote: not to bust anyone but there is something that is just not considered in this thread as everyone debates. It is a little molecule named Ozone O3. Most destructive to rubber. Two people with the exact same boot can have two very different experiences based on the ozone in the air where they are, as well as the time of season because in some areas ozone is seasonal. Two guys in the same city may get completely different results because one person parks near electric motors arcing and the other does not. Motor brushes arcing is one source of ozone. One person could get 10 years out of a specific boot while someone else only six months before it started cracking. The Japanese, Honda etc seem to have mastered rubber boots and CV joints lasting a very long time. I would try to find a Honda boot from the 1990's in good shape and see what manufacture's stamp is on it, then see if they make anything for a VW.

I mentioned it two posts back.m..and the correct materials.....but you are correct. Overall most people are not thinking about it.

From what I am seeing...none of the OEMS.....are having ozone or age issues with NEW boots they install on the cars as built. Most of the 2000 and on vehciles I have worked on in the last 3-4 years have high miles and original boots in surprisingly good shape.

And these are in VERY high ozone cities like Dallas Texas and Washington DC....and high salt and freezing cold areas like Iowa where I am now. This includes Ford, VW, Audi, BMW,Mercedes, GM and yes....Honda and Toyota. I have seen that original build rubber parts are pretty much rock solid.
As one of the OEM suppliers that I am doing work for mentioned this past year.....the car manufacturers demand and get higher quality in huge quantity. They dont plan on installing anything on the production line that wont at least last through warranty.

Most of the OEM boots are being made of EPDM or at least EPDM outer layers with inner layers of something else. EPDM in even skme of its crappiest formulations.....or lesser variants like EPR....are highly ozone resistant. ....but also as I alreafy mentioned...they are in demand and expensive.

Its the replacement boots that are not the same.....and have different formulations .

Even EMPI noted that its boots are neoprene. ...which...also as I noted.....I hope is,just a misnomer.....because NEOPRENE. ...while being tough, flexible and reasonably chemical proof...is NOT known to be particularly highly ozone resistant.

However....CHLOROPRENE is. Thats chlorinated neoprene.

Most of the boot manufacturers seem to be trying every combination of rubber and plastic known to man EXCEPT what is known to work.....which points to either cost or supply chain issues. Ray

Sun Feb 28, 2016 9:50 pm

So it sounds like every year we need to find a new car being made with boots that work for us, so we can buy them before the OEM supplies run out and cheap boots fill the shelves for that car. Like Ray said a few pages ago and just now, new cars don't have this problem, and I just wish we could pay $200 for a set of boots with the quality of the new OEMs.

Sun Feb 28, 2016 10:07 pm

asiab3 wrote: So it sounds like every year we need to find a new car being made with boots that work for us, so we can buy them before the OEM supplies run out and cheap boots fill the shelves for that car. Like Ray said a few pages ago and just now, new cars don't have this problem, and I just wish we could pay $200 for a set of boots with the quality of the new OEMs.

It is my understanding, maybe it was mentioned earlier in the thread, that some Ford boots will work on T2 VW's. Don't have any experience with them at all so it would be nice to have someone buy a set and then give us an report each year as time rolls on.

Mon Feb 29, 2016 8:23 am

Also....and I think I mentioned this a few pages back......from what the manufacturing reps tell me.....for some car manufacturers. ....they can keep quality parts with new build quality on their shelves....for quite a few years if the original parts order(s) were large enough and if the production run of the car type(s) they were destined for were long enough.

The OEMs may build something like say.....the Ford Taurus and the Mercury Sable for maybe 5 years before a change in axle design and boot happens. They obviously dont order all the boots for all those cars at one time.....because they have no idea how many cars they will eventually build, if there will be design changes or how many spare dealer parts they may need.

But they order them in very large chunks and if its an ongoing program at the parts manufacturers for a given boot or part......those large chunk orders are large enough to rate and pay for the top notch quality that new build cars require. Much of whats left over from a parts order that does not go into building new cars....goes into short term inventory or dealer spares inventory.

So.....for instance when Ford/Mercury finally changes the design of boot or axle.....as long as they have enough NEW CAR QUALITY level of inventory left in dealer stock to cover warranty eventualities on the last cars produced .....which will only stay under warranty for a maximum of 3-5 years after changing the part design. ....they cease to order large batches of these parts.

Because parts need to be available by DOT mandate for a 10 year period after a car ceases production.....they typically let the aftermarket fill the void for those last five years and beyond.
And....in many cases....some of the aftermarket parts are made by the same companies that made the original part for a company like Ford.

The problem is that orders for these "after warranty" parts will not come in with tbe huge quantities and economy of scale for manufacturing that they did when Ford was building new cars. So....in order to meet the cheaper price point that aftermarket demands.....they may cut corners in materials.....and certainly may need to cut corners when it comes to re-tooling time....which happens about every 1-3 years with injection molding.

So.....really.....if you wanted to try to be able to get new build quality over the counter from a car dealer......go to the junkyard and look at newer cars....3-5 years old....that are using a boot that is still a llve part # on new build cars.

Also.....dont just lok for complete boots and flanges. You will likely not find something that works. Look for something that the boot can be unclipped or uncrimped from the flange and be clamped or recrimped into your flange. Then go to the dealer and buy new ones. Ray

Mon Feb 29, 2016 1:06 pm

I noticed one thing about the boots in another part of my bus-
those on my steering drag link.

One end boot I sprayed with a wax based undercoat paint as it was in the firing line of my spray can, and this end is still good.
The other end was dry and it has crumbled.

As people are saying it is ozone that gets at them, I wonder if coating the outside of the boot in grease may help - I am trying a thin smear of CV grease to see what happens.

My previous CV joints and drive shafts have perfect boots (but worn CV joints ) on them - I believe they are Porsche pattern as the splines on the end are coarser than stock VW, and the circlips seem to match some pictures of Porsche driveshafts on eBay.

Mon Feb 29, 2016 1:37 pm

Does anyone have any idea what Fat Performance sells? I'm curious as to what brand they offer. I could call 'em and ask, but just wondering if any of you guys have that info first.

Mon Feb 29, 2016 6:57 pm

CV Joint Boots
https://infopart.org/audi-211501149-part

Mon Feb 29, 2016 10:36 pm

Ozone cracking:

Ozone gas attacks any polymer possessing olefinic or double bonds within its chain structure, such as natural rubber, nitrile rubber, and styrene-butadiene rubber. Products made using these polymers are especially susceptible to attack, which causes cracks to grow longer and deeper with time, the rate of crack growth depending on the load carried by the rubber component and the concentration of ozone in the atmosphere. Such materials can be protected by adding antiozonants, such as waxes, which bond to the surface to create a protective film or blend with the material and provide long term protection. Ozone cracking used to be a serious problem in car tires for example, but the problem is now seen only in very old tires. On the other hand, many critical products, like gaskets and O-rings, may be attacked by ozone produced within compressed air systems. Fuel lines made of reinforced rubber are also susceptible to attack, especially within the engine compartment, where some ozone is produced by electrical components. Storing rubber products in close proximity to a DC electric motor can accelerate ozone cracking. The commutator of the motor generates sparks which in turn produce ozone.

I have CV boots still running on my bus from 1998 when I last did the CV joints. Used Valvoline synthetic CV grease and the boots still look very good. I'll search for the brand but I highly doubt they are the same quality as those sold today of the same brand.

Tue Mar 01, 2016 8:58 am

udidwht wrote: Ozone cracking:

Ozone gas attacks any polymer possessing olefinic or double bonds within its chain structure, such as natural rubber, nitrile rubber, and styrene-butadiene rubber. Products made using these polymers are especially susceptible to attack, which causes cracks to grow longer and deeper with time, the rate of crack growth depending on the load carried by the rubber component and the concentration of ozone in the atmosphere. Such materials can be protected by adding antiozonants, such as waxes, which bond to the surface to create a protective film or blend with the material and provide long term protection. Ozone cracking used to be a serious problem in car tires for example, but the problem is now seen only in very old tires. On the other hand, many critical products, like gaskets and O-rings, may be attacked by ozone produced within compressed air systems. Fuel lines made of reinforced rubber are also susceptible to attack, especially within the engine compartment, where some ozone is produced by electrical components. Storing rubber products in close proximity to a DC electric motor can accelerate ozone cracking. The commutator of the motor generates sparks which in turn produce ozone.

I have CV boots still running on my bus from 1998 when I last did the CV joints. Used Valvoline synthetic CV grease and the boots still look very good. I'll search for the brand but I highly doubt they are the same quality as those sold today of the same brand.

Straight out of wiki.....but pretty much spot on....except for a couple little items.

The note about butadiene linkage ....yes they have really had the formulas down for some time now for black synthetic rubber blends.....which is why they note that tires are so much better in the past 20 years.
These rubbers still use butadiene in the formula.....its the blending and molding techniques that have really fixed things. And.....there was (and may still be).....a,world shortage of butadiene starting a few years before the recession.
Several manufacturers that were key in that ingredient failed because of the GM bankruptcy.....and the shortage became critical. And prices have gone way up.

Now some of the problems in these same synthetic rubbers is due to further reformulations to get around the use of butadiene. ....sometimes with limited success. So its not just the butadiene that causes the ozone linkability. Without butadiene the rubber can become less stable, have solvent and weathering issues (heat, cold and water attack).....and is why companies are moving to try neoprene blends and others.

As SGKent noted.....its not just about the type of rubber.....its about the blend as much as anthing. Also.....you can moderate ozone and weathering attack to some extent. ...by how well the surface porosity of the molded part is sealed......and not just with an additive like a wax. Its about the density.....the pressure and heat its molded with.....and the surface imparted by the mold......meaning a tooling issue.

Also be careful because many of the better protective waxes and coatings have petroleum distillates that may attack the rubber in the long run. Ray

Tue Mar 01, 2016 1:02 pm

Busstom wrote: Does anyone have any idea what Fat Performance sells? I'm curious as to what brand they offer. I could call 'em and ask, but just wondering if any of you guys have that info first.

they specialize in type IV based VW racing engines among other things. Mostly for off road and drag racing. They have been a high performance staple in off road racing circles for decades. More geared toward complete engines than parts but they do sell parts.

http://fatperformance.com/home/

Tue Mar 01, 2016 1:09 pm

sodbuster wrote: Busstom wrote: Does anyone have any idea what Fat Performance sells? I'm curious as to what brand they offer. I could call 'em and ask, but just wondering if any of you guys have that info first.

they specialize in type IV based VW racing engines among other things. Mostly for off road and drag racing. They have been a high performance staple in off road racing circles for decades.

http://fatperformance.com/home/

From their catalog:

REAR AXLE COMPONENTS
RAX70 TYPE IV CV joint.
RAX70A TYPE II CV joint.
RAX71 930 Porsche CV joint.
RAX75 TYPE II and TYPE IV CV boots and flanges (set of four).
RAX76 FAT 930 CV boot flange.
RAX76A FAT TYPE II, TYPE IV CV boot flange.
RAX77 FAT 930 CV boot.
RAX77A FAT CV boot for TYPE II, TYPE IV flange (RAX 76A).
RAX78 EMPI- BATES CV boot. 930 CV boot that clamps over 930 CV.
RAX79 CV bolts. 12-point for TYPE IV CV 3/8-24 x 2.”
RAX80 CV bolts. 12-point for 930 CV 3/8-24 x 2-1/4.”
RAX80A CV bolts. Allen bolts for 930 CV 3/8-24 x 2 1/4.”