TheSamba.com :: View topic - CV Joint Boots - Finally found some quality made boots that last

Fri Jul 29, 2016 7:00 pm

Since so many of us bus owners have been screwed, buying garbage quality parts under the pretense of being respected brand names (Meyle Germany comes to mind, but also Bosch, Beru Germany, and other brands that outsource manufacturing), this bit of intel on a quality CV Boot replacement may be of interest…

Last year, I had to replace yet another pair of CV Boots that came with a set of brand new Lobro CV joints (part#251 598-101) that I got from Bus Depot 3 years ago; this was for my passenger side axle. Since the boots were out of warranty by that time, and because the “supposedly” quality German made boots had lasted no longer than the Chinese crap from Meyle and others, I decided to try another brand from my local O’Reilly store. The new boots were from Precision Axle (part# PRE 2401), and made in Tiawan, but the box listed the boot material as neoprene, so I gave it a shot. So far, these are holding up well and look as good as the day they were installed (less the dust and dirt).

This week, I’m having to replace a torn CV Boot on my driver side axle, which I had installed on another set of Lobro CV joints only. The separate boots I purchased in this case have been in service about 2 years and 18,000 miles, but when I replaced them, the boots were different brands. I believe one of them was a Victor Reinze product sold as part# 251 598 201 from Bus Depot (purchased when I got the Lobro CV joints), and the other was left over from a complete axle kit I got from Advance Auto Parts (Something like Quality Axle). I’ve had multiple bad experiences with failed CV joints from Meyle, and others, but that’s another story. What’s important is that both boots for my driver side axle were brand new and put in service at the exact same time and have been run under the exact same conditions. The one that is still going strong appears to be the same manufacturer brand (with the same markings and numbers) as the Precision 2401 boot I installed last year on the passenger side axle, so I checked with O’Reilly again for another pair, and they said the Precision Boots have since been superseded by Moog boots, so I bought a set of MooG 2401 boots from Summit Racing for about $12 each, and when I opened them up, they have the same MBI manufacturer Brand and markings as the Precision boots, but the Moog box says made in USA. Who knows where these parts are actually made, but I’m stoked to maybe have possibly found a source for decent quality CV Boots that last. You can’t trust the Seller’s brand anymore, only what’s stamped on the part.

Bad CB Boot

Good CV Boot (Yes zip ties holding the boot to the axle have also been in service 2 years with no problems)

Both Moog and Precision seem to offer the same MBI manufactured part

Fri Jul 29, 2016 7:12 pm

I see that RockAuto has 1 in stock for a whopping $11 :wink:

Fri Jul 29, 2016 7:30 pm

Thanks for the heads up! Still getting burned on poor rubber quality... weatherstrip, fuel line (unless using Gates Barricade FI), and gaskets and grommets.

Fri Jul 29, 2016 7:33 pm

Have them crack open the box and send you a picture. It the boot has MBI on it, you've got a winner. Wish I knew what "MBI" stands for.....

Don't even think about buying a CV Joint that doesn't say Lobro or GKN (GKN owns Lobro). I've been in the GKN factories, and they are OEM suppliers to most of the major auto companies. GKN is ISO/QS 9000 certified (industry speak for they don't cut corners with materials or workmanship) and their quality is top notch.

Fri Jul 29, 2016 10:45 pm

The Meyle boots I put on were sporting laser print on them, with
manufacturing date & everything. I took some pictures but the print
won't show, just flash from the camera.
I hadn't seen that before, print-on-the-flange, so maybe, they're tightening
quality control.....or just screwing with me?
We'll see. Clock & odo are running.

Mon Apr 23, 2018 6:43 pm

69BahamaYellow wrote: Have them crack open the box and send you a picture. It the boot has MBI on it, you've got a winner. Wish I knew what "MBI" stands for.....

Don't even think about buying a CV Joint that doesn't say Lobro or GKN (GKN owns Lobro). I've been in the GKN factories, and they are OEM suppliers to most of the major auto companies. GKN is ISO/QS 9000 certified (industry speak for they don't cut corners with materials or workmanship) and their quality is top notch.

How do your CV boots look today? Holding up well? How many miles you have on them now?

Mon Apr 23, 2018 8:15 pm

As an experiment, I've been periodically wiping my CV joint boots down with ArmorAll spray, to keep the outside surface clean, soft and flexible. Don't know if it's helping, but it definitely doesn't seem to be hurting...

Tue Apr 24, 2018 6:37 am

udidwht wrote: 69BahamaYellow wrote: Have them crack open the box and send you a picture. It the boot has MBI on it, you've got a winner. Wish I knew what "MBI" stands for.....

Don't even think about buying a CV Joint that doesn't say Lobro or GKN (GKN owns Lobro). I've been in the GKN factories, and they are OEM suppliers to most of the major auto companies. GKN is ISO/QS 9000 certified (industry speak for they don't cut corners with materials or workmanship) and their quality is top notch.

How do your CV boots look today? Holding up well? How many miles you have on them now?

Hey buddy. I just got 40k of service out of a set of EMPI boots and replaced them with another set of EMPI. Not what the OP posted but thought info it might help you. Good luck.

Tue Apr 24, 2018 1:21 pm

From what I can find, the EMPI and MOOG are both MBI. Same part # made of neoprene. I found 4 shipped for $48. I'll give it a shot.

Tue Apr 24, 2018 1:37 pm

The problem with boots is that if you bought a boot (cheap or expensive) 10 years ago and it worked great all that time and you buy another today of the exact same brand you may well find that it lasts only a few thousand miles. I have been going through this battle of the boots for the last 30 years, and it is always a crap shoot when you have to buy new ones.

Tue Apr 24, 2018 1:47 pm

babysnakes wrote: From what I can find, the EMPI and MOOG are both MBI. Same part # made of neoprene. I found 4 shipped for $48. I'll give it a shot.

I have been running a rubber and grease compatibility test since about November for an automotive gasket manufacturer.

I have been inspecting and compiling data about every 10 days. I am just getting close to being able to get enough results to graph it.

This simply is looking at grease compatibility across a broad spectrum of temperature.

And all I can tell you at the moment....is what I have been saying for a few years now. Attack by the grease formulation is a significant factor in deterioration of certain rubber types.

Almost as much as ozone.

Also....neoprene...is NOT an ideal rubber for grease retention. While it has outstanding resistance to the metals in the greases.....in CV grease its primarily molybdenum disulphide, graphite and Antimony.....it has very poor resistance to many hydro treated oils.....paraffins etc.
The only neoprene with good long term resistance to most petroleum based greases is Chloroprene (chlorinated neoprene).
I will release what I am allowed to.
Ray

Tue Apr 24, 2018 1:49 pm

I know. My Rockfords lasted about 20K but were the wrong size (bellows touched the bolts). A generic one I bought lasted maybe 5K. But the MOOG/EMPI (if they are the same :? ) are neoprene not rubber. I'll take the shot and see.

Tue Apr 24, 2018 3:34 pm

ozone is a big component in boot rot. If you can keep some form of flexible coating on it that doesn't cause rot, it will help. I found out on my 1977 while restoring it that the parts of the boots and tie / ball joint boots etc that were still healthy had Cosmoline, waxoil. or equal coating still over the good rubber.

Tue Apr 24, 2018 3:41 pm

babysnakes wrote: I know. My Rockfords lasted about 20K but were the wrong size (bellows touched the bolts). A generic one I bought lasted maybe 5K. But the MOOG/EMPI (if they are the same :? ) are neoprene not rubber. I'll take the shot and see.

And Im not saying you should not use them. Its very hard to say which neoprene they are made from. They may last....but be prepared that they may fail just as well.

For example.....Its a known issue that basic neoprene does not stand up well on ball joints and tie rod ends. But....thats a totally different grease type than CVs.

By the way....Neoprene.....IS....a rubber. Its a synthetic rubber and in fact one of the first synthesized in 1931.

Virtually no "natural" rubbers have been used in automotive or aeronautics since the late 1940s.

Every CV boot ever installed on a post war production VW...has been a synthetic rubber.

In the past.....and somewhat still.....the problem many engineers run into when they are researching a seal or gasket for oil or grease compatibility....is that they research compatibility with "types" of greases or oils instead of either exact products....or individual ingredients in certain greases or oils.

They would need to test both the oil or grease product...and the individual ingredients....and at different temperatures....and over a long period of time. Thats a LOT of expensive testing. So.....it usually is not even done or at least not completely.

The engineers go off the testing results of the oil/grease manufacturers......and their testing can almost never include every type of synthetic rubber.....or every formulation of it.

So they also rely on the test results from rubber and plastic manufacturers....who also can never test for every environment....or with every formulation of oil or grease.

And.....the oils and grease formulations change all the time. What may have worked on a certain rubber.....5 years ago....may eat it now.
And....the rubber formulations change all the time (many times because of changes in the raw chemicals that go into them). An oil or grease.....even if its unchanged....may no longer work with a rubber because the rubber itself has changed.

The rapid changes in oils and lubricants over the past two decades is why auto mfgs.....like VW/Audi for instance......have a very specific and stringent list of approved oils. And.....a new one comes out virtually every year with big changes to the list. Ray

Tue Apr 24, 2018 3:48 pm

Glad the question was asked about how the Moog / Precision Axle 2401 Neoprene CV Boots I purchased are holding up. I went out and took these pics just today.

Looks like they're about toast. Right now they have 4 years and 38,000 miles on them. They are not leaking, but with all the surface cracking (one of which is fairly deep), it won't be long before they are. $hit..... looks like back to the drawing board for a CV boot solution that lasts.

I hope Ray is on to something with grease compatibility and something that works with the $hitty rubber compounds available for type 2 bus. I've not found anything that looks remotely close to the material that all the new car manufacturers are using for their boots. I'm thinking it's some kind of multi layer EPDM, but maybe it's something else. It feels kind of like a rubbery hard plastic (much harder that anything available for a bus on the outside, but softer on the inside). Whatever it is, I have a 2005 Volvo, a 2005 Jeep, and a 2008 Honda using it, all with over 150,000 miles, and none of their CV boots are leaking or cracking, but I should also add that I've never changed the factory grease in those, so maybe it's something special.

I guess the only thing I can say for now is that the Moog / Precision Axle 2401, which also appears to be the same Neoprene as the EMPI 86-1086, is the longest lasting I've found so far. Perhaps if Ray has any grease suggestions, maybe we can squeak a little more life out of them.

I should summarize that Meyle Germany Boots have been the shortest lived, followed by Victor Reinz, and Lobro (which were probably not really Lobro, but some cheap alternative that got paired with the good quality Lobro CV joint.

Tue Apr 24, 2018 4:13 pm

I put some EMPI boots on early last summer and so far there is no sign of cracking. I have another set of boots on the other side (Put on in 2015) that are also holding up very well. (I need to check my records for the manufacturer on them). It was recommended to me to spray them a few times a year with silicon spray and I've been doing that. So far so good!

Tue Apr 24, 2018 4:21 pm

It's not the grease, if it were there would be grease leaking the moment a crack appered on the outside. It has to do with the quality of the rubber/neoprene. A coating like Steve mentioned needs to be used. Silicon...maybe. I don't like Armorall, it seems to be a death sentence. I have seen far more dashboards crack after Armorall was used than not.
If a crack starts on the outside, then the outside is the area to be addressed.

Tue Apr 24, 2018 4:56 pm

babysnakes wrote: It's not the grease, if it were there would be grease leaking the moment a crack appered on the outside. It has to do with the quality of the rubber/neoprene. A coating like Steve mentioned needs to be used. Silicon...maybe. I don't like Armorall, it seems to be a death sentence. I have seen far more dashboards crack after Armorall was used than not.
If a crack starts on the outside, then the outside is the area to be addressed.

Incorrect....100% incorrect. Exact wrong train of thought.

You are making the assumption that if a rubber is incompatible with a grease or oil that it simply eats through it. That is NOT what happens. You are also making the assumption that if you see a crsck on the outside...that it started on thrle outside or was caused by something on the outside.

If it were that simple or obvious....we would have none of these issues. Planes have literslly fallen out of the sky from that A+B must equal C train of thought :lol:

Typically when a rubber has chemical "incompatibility issues".....it means that PARTS of its structure or ingredients in its structure.....react with one part of the chemical.

It can make the rubber softer on the "chemical" side....in this case grease. That causes the plasticizers that make the rubber soft (usually hydrocarbons but not always)......to flow....or dissolve.....into the grease or chemical. In some cases it can create a totally different chemical.

And.....that pulls plasticizers out of rubber close to this area to replace those that are now migrating into the grease or oil.

This can eventually pull those solvents away from the outer surface....causing surface ckecking or chalking.....those are what most people call cracks :wink:

I have two samples doing this very thing right now. Ray

By the way......NO.....EPDM and any or its alloys.....is never and has never been used in ANY PETROLEUM based grease or oil boots. It is not compatible with petroleum hydrocarbons.

EPDM.....is what is used for brake fluid seals....and window surround seals. It works well with glycols and many synthetic lubes....silicone etc.....but fails RAPIDLY with any VOC exposure.

So....if you used your average brake cleaner to clean internal brake parts....you just f'd up. The outer boot seals on the caliper....are viton so its ok for those. Ray

Tue Apr 24, 2018 5:08 pm

Certain forms of boots have a dam that keeps the grease out of the boot very effectively, while most do not, plus it is often the small end of the boots that fails first and the small end is the least likely part of the boot to come in contact with the grease.

The mark up on boots must be pretty high because there are always so many brands of them on the market, but no one seem to want to corner the market by making a consistently superior product. Largely it is hard to even figure out who makes a certain boot, so if you have had success with a boot and it last for a decade it is hard to know what brand they even were. I have bought the most expensive boots I could find and the cheapest and haven't found that price had anything to do with quality at all, with the single exception of the Rockford boot.

Tue Apr 24, 2018 5:18 pm

Quote: Incorrect....100% incorrect. Exact wrong train of thought.
Erik - Please Note: failure to agree with Ray will elicit a negative response combined with the thrashing of a thousand words. :lol: When I lived in LA / Riverside in the 1970's and 80's, where the ozone level was off the charts, 1 or 2 years and 15,000 - 20,000 miles was it on a boot. They would fall apart just sitting on a shelf once they were exposed to that ozone. And that was without ANY grease.