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Fixing cracks in CV boots

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Neveragain55
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Fixing cracks in CV boots

Post by Neveragain55 » Wed Oct 07, 2015 2:21 pm

This is something everybody suffers with no matter what type of car you have as long as your car has CV boots.

Regardless of where the boots are, at some point they always start to dry rot, crack, and eventually rip and/or tear.

The grease flings out, the balls go dry, and now you have serious problems.

I probably should have just taken the half axles off, and completely repacked them with new grease & put on new boots but I'm already diving into so many other areas I hadn't planned on that if I keep this up I'll wind up rebuilding the whole car and she won't be back on the road again for another year or so.

So at some point I have to stop my OCD and just stick to my game plan.

Instead of doing a complete rebuild, I opted to just coat the boots (where they were cracking) with a product from 3M called "Window Weld #08609"

The great thing about this product is that it dries to a very durable, yet flexible state, and it won't crack, separate or tear the boot apart like other sealants while the boot is spinning over a hundred miles an hour.

You can find this stuff in places like Pep Boys or AutoZone, and I can't begin to tell you how many uses it has or all the things it's good for.

Here's what you do:

1. Raise the rear end of the car by placing a hydraulic jack under the center part of the rear axle carrier so that the wheels are off the ground. (you'll need a jack that is rated to go at least 18 inches or higher)

2. Chock the front wheels.

3. Find a jacking point somewhere under each trailing arm, and raise them up just enough so that the wheels are sitting as level as possible. (you want the half axles to be as parallel to the ground as possible so that there is little to no "angle" in the CV boots)

4. Put the car in neutral, and leave the wheels on.

5. Squeeze some of the window weld out directly onto your fingers, and smear it over the surfaces where the boots are either just starting to dry rot or where you see surface cracks. (use gloves if you want because this stuff is hard to get off your skin but I find that gloves interfere with the smoothing process)

6. Place your body so that you can rotate the wheels with either one of your feet or one of your free hands and push & smear the window weld into the cracked surfaces evenly.

7. Go wash your hands with "Goo Gone" (if you didn't wear gloves) and leave the car there for at least an hour to let the window weld tack up to the point where it won't move when you lower everything.

By the next day your CV boots will be ready to travel around the country and you'll NEVER see any cracking in those areas where you applied the window weld again............guaranteed.


I also used this opportunity to spray some POR15 rubberized undercoating on the drivers side axle shaft because some of the paint had chipped off over the years and the exposed axle had some minor surface rust.

For those of you like me that are certifiable and you were cursed with having a "T" type personality.

Start the car while it's in "park", and your back wheels will spin very slowly.

While the wheels are spinning "very slowly" you can apply the window weld over the cracked areas of the CV boots.

Doing it this way gets you a much more even distribution over the surfaces, and you can massage, smooth, and shape the window weld better as if you were shaping a clay figurine on a spinning wheel.

I know, I know, I spent many years on doctors couches as a child and as an adult I'm not much better.

For those of you who can't believe your reading this and your heads are about to explode...............absolutely nobody has to do it that way.

I did because I'm mentally unstable, and I skipped the "fear" line when they were handing it out that day.

Seriously, I hope that if any of you use this product, you'll get the same results I got.

P.S. you can see in the pictures that I have jack stands under the outer end of the axle shafts. These pictures were taken after everything was done.

I placed jacks under the actual trailing arms when I did the job and the axle shafts sat more parallel than what you see in the pictures.

Lastly, I included a picture that I found on Google a of a great example of what type of cracks I was experiencing.

The picture of the dry rotted, cracking boot is not a picture of my actual boot before I started the process but the cracks in it are identical to what mine looked like.

Image

Image

Image

Image

Image

Image
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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dwcains
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Post by dwcains » Wed Oct 07, 2015 5:13 pm

10 or so years ago my wife had a Volvo T5R which had developed ripped CV boots. We found a kit, can't recall the brand name, which had a pair of split boots with a special adhesive to seal the seam. Super easy install and lasted for maybe 25K miles before the car was rear-ended and totaled. They came from the UK. There were also ones available with a seam and several little bolts to hold the seam together, but at the time, the glued ones had better reviews on the Volvo sites.
Dean
Lutz, FL

'85 635 CSi Euro #9402254
'87 Spider Veloce
'92 Spider Veloce
'08 350Z

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Post by Da_Hose » Wed Oct 07, 2015 9:24 pm

I have seen some of those split boot kits, but they make me nervous. Knowing that the window weld works great might get me to try them if I run into an otherwise sorted car that needs boots in the near future.

Hmmmm ... I am looking to rebuild the head on my Saturn wagon. Perhaps I will give a close eyeball to the CV boots on that guy. :-k

Jose
1987 M6 - My dream car

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Neveragain55
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Post by Neveragain55 » Wed Oct 07, 2015 10:33 pm

dwcains: I now exactly what repair kit your talking about. I've used those split cv boots with the nuts & bolts that hold them together on front wheel drive cars and they do work..........for a while, but it's always been my experience that at some point down the road the grease winds up weeping & flinging out anyway and then the "clicking" starts when you make a turn.

I've never used them on rear boots like in our BMW's so I wouldn't know how well they'd hold up, who knows maybe they would work pretty good.

What I "really" like about the 3M product is that you could buy a tube of this stuff ($25.00) and literally find hundreds of uses for it.

I've used it to fill in the cavity areas of transmission mounts, motor mounts, as well as several other things, and it just doesn't disappoint.

It's messy as Hell I won't lie, but it gest the job done like nobody's business, and it's completely impervious to water, salt and all other types of road grime that would break lesser materials down over time.

My boots were just dry rotting but none of them were completely torn, and quite honestly if they were I probably would have just rebuilt the half axles and put new boots on them.

This 3M Window Weld is great for boots that are "starting" to dry rot or "starting" to crack, but I don't know how well it would work on boots that were already torn & separated.


Jose........all of this goes for you to my friend, get this stuff and you won't be disappointed, but be prepared to be cleaning your hands for a week or so if you don't use gloves.
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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Post by sansouci » Thu Oct 08, 2015 1:57 am

After all that work, you still don't know whether 30 year old ball bearings need to be greased. I'm told that reman half shafts are cheap.
Sansouci
84 E24 633Csi Auto, Bronzit/PearlBeige 6997510
93 E32 740il M60 Auto, Alpenweis/Ultramarine
60 528i M30 5-speed Green/Beige (crushed)
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Neveragain55
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Post by Neveragain55 » Thu Oct 08, 2015 2:27 am

I understand your point but there are a few other points to consider.

1. Rebuilding the half shafts weren't on my master list for this "semi-rebuild".

2. The reason why the half shafts weren't on my list is because I've never had a lick of problems from them.

3. I've drifted into many other areas during this build that wasn't originally on my list, and all of those constant "side tracks" ate up a bunch of money that I didn't have as it is so...........

4. My cv boots weren't torn or empty of grease, and in the 45 cars I've owned it's been my experience that regardless of how many miles a car has - if it's cv boots are in tact you can pretty much bet the farm that the grease inside them is still viable and the balls are still in tact.

5. Yes the grease within the boots is 26 years old, but if that grease is anything like the differential fluid or the transmission oil that I changed (that was never changed from day one) then I have nothing to worry about because those fluids looked like they were two weeks old. (seriously)

Bottom line, I happened to notice the surface cracking when I changed the rear sway bar bushings, and I felt perfectly comfortable coating them with the window weld because I've used it before on many things and I knew it would be more than adequate in covering & sealing the cracks.

I'll eventually get around to putting on either new or remanufactured half shafts down the road but I'm very comfortable with how everything is so far.

I only made the post because lots of people have cv boot issues and I just wanted to share what I thought would be a viable option to replacing them.
Last edited by Neveragain55 on Thu Oct 08, 2015 1:13 pm, edited 1 time in total.
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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Post by dwcains » Thu Oct 08, 2015 6:41 am

FWIW, I'd never use those split boots on my E24 or 350Z, but I hated that damn Volvo so much I didn't care about shortcuts. When that car got totaled, with my wife uninjured, I was quite happy to see it go.
Dean
Lutz, FL

'85 635 CSi Euro #9402254
'87 Spider Veloce
'92 Spider Veloce
'08 350Z

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Neveragain55
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Post by Neveragain55 » Thu Oct 08, 2015 12:48 pm

I understand, and I'm glad your wife didn't get hurt.

I used them on an old clapped out Honda Civic that had more rust than good metal.

They "did" work for a while and they served their purpose, but to your point I would never use them on my six.
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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Da_Hose
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Post by Da_Hose » Thu Oct 08, 2015 3:20 pm

Run those boots until you get back around to them.

I considered rebuilding mine, but at the time Napa Auto Parts had rebuilt halfshafts with 3 year warranty (that's better than BMW OEM) for $79 each. I figured I'd go that route and saved time/effort.

Jose
1987 M6 - My dream car

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Neveragain55
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Post by Neveragain55 » Thu Oct 08, 2015 4:58 pm

Thanks Jose'

That's my plan, and I appreciate the support.

I got some remanufactured cv axles for my Acura Legend a few years ago from NAPA , and so far they've held up great.
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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Post by sansouci » Fri Oct 09, 2015 12:06 am

Your points are well taken and is a good stopgap fix that could last a long time.
Sansouci
84 E24 633Csi Auto, Bronzit/PearlBeige 6997510
93 E32 740il M60 Auto, Alpenweis/Ultramarine
60 528i M30 5-speed Green/Beige (crushed)
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Neveragain55
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Post by Neveragain55 » Fri Oct 09, 2015 12:15 am

Thanks Sansouci,

I actually want to thank you for raising the question because that sparked me to do some research on replacement axles, and after investigating everything I found, I've definitely come to the conclusion that I'll either rebuild the existing ones myself or replace them altogether with a good set of remanufactured ones next spring after I've stored up some more chestnuts.

I've always said that: "you really have to love an older BMW to own one because these things are not cheap"
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
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Post by Brucey » Wed Oct 14, 2015 8:47 am

FWIW there are a variety of bodge-tastic means of fixing CV joint boots so that they last another five minutes.

The important thing is to remember that the walls of corrugated boots need to bend, but not stretch per se.

This means that if your perished/split boots need real help, you can use fabric reinforcement if needs be. Provided you use some kind of gloop that sticks well enough to the rubber, and will soak into the fabric too, you can make a locally reinforced 'composite boot' where it needs it.

This method seems to work well if you use smallish pieces of relatively thin quality fabric, eg from a polyester-cotton shirt or something. If you cut and set the fabric pieces so that the weave is set diagonally to the ribs in the boot, this offers the best reinforcement.

None of these repairs can be expected to last very long, but if they keep you going until you can effect a proper repair, it is 'job done'.

BTW if the boots are split at all, best to add some grease through the hole before you fix it!

Note also that some driveshafts (on FWD cars especially) are complete pigs to dismantle, so many repair shops in UK/Europe use a clever system that uses an extra-stretchy boot and a tool that will allow the boot to be slipped over the whole joint whilst it is still on the shaft. Although the boots are not as tough as OEM ones, this does offer a rapid repair.

[ Years ago I could have done with that; it took about three hours before I could get the outboard CV joint off a shaft, (and I needed the car the next day, obviously.... :roll: ). The recommended method was to hit it with a hammer, because there was no means of fitting a puller to this blind joint, which was secured with a snap ring internally. I was reduced to near-exhaustion before I managed to do 'the right hit' with the hammer and the joint popped apart...]

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Post by Da_Hose » Wed Oct 14, 2015 8:50 pm

I am with you on that last statement Brucey. I've done numerous FWD CV's and they are a bugger of a job every time.

Jose
1987 M6 - My dream car

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Post by GripGreg » Wed Oct 14, 2015 10:38 pm

Very good info dudes.

I have a stoopid question:
On my Buster, the head gasket has a leak at the RR corner.
Would this help me or hurt me? :-k

What would help me seal the corner or, is there too much pressure involved.
What about heat?
I don't think it spurts out, it just oozes.
Thanx in advance,,,,Greg
Hit the apex
in Long Beach, Cal
Buster/'82Euro6 Build Date 9/81
Rosallina/'80 528i Build Date 4/80

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Neveragain55
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Post by Neveragain55 » Wed Oct 14, 2015 11:41 pm

Brucey:

I need to make something crazy crystal clear here....my cv boots were not torn, they weren't even close to being torn.

If they were torn, I would have just broke out my already heavily used credit card that's screaming for mercy, and I would have just bought two new or remanufactured axles from NAPA.

The picture of the axle I posted with the cat wearing the blue glove is exactly what mine looked like. (I'll post it again)

To be very exact about it, the inner boot closest to the differential on the left side and the outer boot next to the wheel on the right side each had the very beginnings of what I call "dry rot surface cracks" and they were only on the surface.

The other two boots are perfect with no issues at all. I coated them with a silicone based grease to keep the rubber flexible & pliable.

I can't stress enough how well the 3M Window Weld product works and you'll never regret using it "if" in fact you ever run across the same situation I did.

I've also dealt with torn or ripped boots on front wheel drive cars and they suck. The split boot kits with the nuts & bolts aren't bad as long as they are of the recessed lip design because the recessed lip helps to keep the grease in place.

I've had success with those as long as you put some sort of sealant that dries flexible along the edges where the boots meet.

When the boots on my Acura Legend tore a few years ago, I opted for one of those split cv boot kits but as soon as I had the money for new axles I got some..................from NAPA, and they've been awesome, really.

Like I keep saying, I'll revisit the boots on my 6 after this winter but for now I'm very happy with how everything turned out.
Attachments
cracking cv boot.JPG
cracking cv boot.JPG (68.05 KiB) Viewed 10532 times
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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sansouci
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Post by sansouci » Thu Oct 15, 2015 10:10 am

Brucey wrote:FWIW there are a variety of bodge-tastic means of fixing CV joint boots so that they last another five minutes.

The important thing is to remember that the walls of corrugated boots need to bend, but not stretch per se.

This means that if your perished/split boots need real help, you can use fabric reinforcement if needs be. Provided you use some kind of gloop that sticks well enough to the rubber, and will soak into the fabric too, you can make a locally reinforced 'composite boot' where it needs it.

This method seems to work well if you use smallish pieces of relatively thin quality fabric, eg from a polyester-cotton shirt or something. If you cut and set the fabric pieces so that the weave is set diagonally to the ribs in the boot, this offers the best reinforcement.

None of these repairs can be expected to last very long, but if they keep you going until you can effect a proper repair, it is 'job done'.

BTW if the boots are split at all, best to add some grease through the hole before you fix it!

Note also that some driveshafts (on FWD cars especially) are complete pigs to dismantle, so many repair shops in UK/Europe use a clever system that uses an extra-stretchy boot and a tool that will allow the boot to be slipped over the whole joint whilst it is still on the shaft. Although the boots are not as tough as OEM ones, this does offer a rapid repair.

[ Years ago I could have done with that; it took about three hours before I could get the outboard CV joint off a shaft, (and I needed the car the next day, obviously.... :roll: ). The recommended method was to hit it with a hammer, because there was no means of fitting a puller to this blind joint, which was secured with a snap ring internally. I was reduced to near-exhaustion before I managed to do 'the right hit' with the hammer and the joint popped apart...]

cheers
Panty hose might just be the fabric you need!
Sansouci
84 E24 633Csi Auto, Bronzit/PearlBeige 6997510
93 E32 740il M60 Auto, Alpenweis/Ultramarine
60 528i M30 5-speed Green/Beige (crushed)
71 240Z 4-speed White/Blue (rusty & sold)
65 396 Chevelle 4-speed, Marina Blue/Black (stolen)

openhill
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Re: Fixing cracks in CV boots

Post by openhill » Mon Feb 25, 2019 4:36 am

Is it still working ok or temp. fix?

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Neveragain55
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Re: Fixing cracks in CV boots

Post by Neveragain55 » Fri Feb 14, 2020 12:10 am

Sorry for getting back to you so late but I haven't been on the site for quite some time and for some reason I don't get messages in my email when people reply here in the forum.

To answer your question, the product I used is still holding up really well...... =D>
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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