[Mercedesist]

Hello!

So after having some weird sounds with my CV axle, I replaced it with another (used) one. Sounds are gone.

Having my old CV axle out, I wanted to disassemble it and take a look at it, what's inside.

This is not a tutorial. I will explain the way I removed CV axle from car and how I disassembled It

So, to remove the axle:

1. I removed the wheel center cap
2. "Unbended" the axle nut "security tab"
3. Using 32 millimeter head and a lot of force I broke loose the axle securing nut
4. Jacked up the car, put it on bricks (my version of jackstand ), removed the wheel
5. Using 12 star head (10mm) removed the 6 bolts, holding the CV axle to the differential (before doing this, cleaned the bolt heads so that nothing strips)
6. Removed the exaust (final muffler) from it's end rubbers; let it hang
7. Removed the sway bar link carefully, taking the load off the sway bar
8. Removed the plastic cover from lower control arm
9. Removed the large bolt, that holds together knuckle with lower control arm (In my case it was 21mm nut and bolt head was 22mm)
10. With 60 hits using large hammer and a lot of WD-40 smashed out the CV axle from hub splines (have heard that this can ruin your bearing; mine is still fine...)
11. With some thinking and maneuvering removed the CV axle completely.

With it completely removed, I installed the "new one" in pretty much reverse order.

I could not find the procedure of CV axle disassembly anywhere so I thinked through It and I did it!

So, to dissasemble this massive structure, I:

1. Using a flat blade screwdriver and hammer (hitthing the lip of cover) removed the cover
2. Removed the snap ring which allowed the balls and its ring to slide off
3. Removed the "casing" where balls ride
4. Removed the other cover, using the same technique as in 1st step
5. Removed the casing from the balls
6. Removed the balls with cage and now I had bare shaft.

In the next images you will se the state of internals. I must say, that the grease was very stinky and burnt smelling. In some areas it is rock hard and burned to the surface.

The balls and cage on the whell bearing side

The differential side

After seeing these images, how do you think - are these components reusable? Like there is no major wear. The shiny parts on components are made from balls riding on them. there are smooth and no metal is missing. I think a lot and good quality new grease will get these ones running for many more years... or am I wrong?

 

[300Dman]

Personally if the balls are still good I would reuse it. If it was were I used to work I would be told to get some 500 grit wet and dry paper and polish up the wear areas and if I wanted to go down to say 1200 grit.
When it was taken apart did it have grease in it or Oil? On my 84 300D the original came with oil similar to differential oil. When I re-booted my old axles I used CV Joint Grease.

Personally I think the Grease is better because of something comes up from the road and puts hole in the boot large enough to let the oil out there is a good chance of losing all of the oil. With grease it is not going to come out as easy and some is still going to stay in the actual joint.

 

[Mercedesist]

Personally if the balls are still good I would reuse it. If it was were I used to work I would be told to get some 500 grit wet and dry paper and polish up the wear areas and if I wanted to go down to say 1200 grit.
When it was taken apart did it have grease in it or Oil? On my 84 300D the original came with oil similar to differential oil. When I re-booted my old axles I used CV Joint Grease.

Personally I think the Grease is better because of something comes up from the road and puts hole in the boot large enough to let the oil out there is a good chance of losing all of the oil. With grease it is not going to come out as easy and some is still going to stay in the actual joint.

it came with grease. i will use grease too

 

[Hirnbeiss]

If there is no grooving or pitting, they can be re-used. However, I would only do it if you can get good quality boots on with perfect clamping. Nothing generates a higher level of DIY-disappointment than looking under your car a year later to find a torn or leaking boot on your lovingly restored half-axle.

 

[samosali]

here in this part of the world axles can be overhauled by an expert for a low cost. Adding of material on worn places is needed and then fine machining follows. I am sure you can find an expert there who will repair your both axles for 200 eur. they will make another 100,000 km then. new axles are ca 2000 eur. used on ebay are 400 eur but you must trust the seller they have no significant wear.

 

[Tracia]

Just replace 'em. I found this video helpful.

 

[daidnik]

You'll never get the hardness of those OE knuckles in any cheap aftermkt part if you can find it.

Viability of re-use of the drive axle is best evaluated while the axle is assembled and out of the car. Feel for notchiness in the knuckles. If you can feel notchiness, this can lead to vibrations.

 

[luschka]

Does anybody here know if we can still buy OEM fit CV boots? Or do we need to use universal fit boots? My rubber boots are dry rotted and need replacing.

 

[samosali]

Does anybody here know if we can still buy OEM fit CV boots? Or do we need to use universal fit boots? My rubber boots are dry rotted and need replacing.

i do not think so. i recently replaced all rear axle boots with aftermarket ones. I am sure they will be good for 5 to 10 years. originals are ok for 30 years. none of my original boot had a through-crack after 30 years.

 

[luschka]

Does anybody here know if we can still buy OEM fit CV boots? Or do we need to use universal fit boots? My rubber boots are dry rotted and need replacing.

Found some boots for my S500. Because this research took WAY too much time, I'm documenting this here. After lots of time comparing different part numbers, some of the OEM part numbers listed had seemingly inappropriate dimensions, with the axle side being as small as 22mm, but needing to strech almost 50% to clear my 32mm axles. Maybe universal fit axle kits are worth it, but those seem unnecessarily expensive.

Axle diameter on my car is 32mm. The larger diameter of the CV joint appears to be the same at both the diff and hub ends, I can't measure with the boots on but it's probably between 64-67mm based on parts information I researched below. A few mm off at this bigger end doesn't matter as much. By my measurements compared with some listings on Meyle's catalog, Part number 2103570191 or 2103570091 (dimensions ID 1: 31 mm, ID 2: 61 mm, L: 100 mm) should simply work for all 4, despite not being listed as a cross-referencing part. I will update this thread if somehow despite my measurements these boots do not fit.

After confirming axle diameter of 32mm, BUY:

4 boots $8 at FCPeuro or $6.50 at Pelican​

small clamp x4: for $2.40 from Mercedes or $3.25 at Pelican​

Large clamp x4: for $3.50 from Mercedes or $4.75 at Pelican​

CV joint grease: $1.19 from FCPeuro (I bought 2) or $8.50/100g from Pelican​

Optional:​

Axle nut x2 for $3 from FCPeuro or $4.75 or $15 from Pelican or $17 from Mercedes​

Screw x12 for $3.90 from Mercedes or $4.75 at Pelican *Needs blue loctite​

Washer x4 for $15 from Mercedes or $15.50 at Pelican​

Circlip x4 for $3.80 from Pelican or $4 from Mercedes​

*Bold indicates what I decided to buy. My total including shipping and tax was $92.

Spoiler: Some research notes (Spoiler)

Inner: Kit includes boot, clamps, axle nut, CV bolts, inner axle retaining lock ring. Some sellers are just selling boot and clamps under these part numbers.

1. S500 (140.051)​

Buy here: AutohausAZ: $105 genuine mercedes,​

eBay: $20 shipped from Latvia, $86 genuine mercedes,​

​

per a listing on rockauto: large end: 2.625 inches = 66.7mm diameter (minimum diameter of clamp)​

Part number: A1403500337, A1403501237, A1403500137, A1403501037, A1403500637, A1403501437 all per OEM parts diagram​

A listing on rockauto.com claims these parts interchange: 1293500137, 1293500237, 1293500337, 1293570191, A1293500137, A1293500237, A1293500337, A1293570191, VAICO V301519, Mevotech DX129 (they claim the same boot works for inner and outer)​

Below: A listing on Borg & Beck further corroborates that 1403500137 and 1293570191 interchange, and provides these dimensions:​

​

​

2. S320 (140.033)​

Part number: A1403500237, A1403501137, A1403500737, A2103500537, A1403500537 all per OEM parts diagram​

Outer: Part number: 1243570191, Febi Bilstein 08478 (ID1 22.5 mm, 65.5 mm, 98.5 mm), Febi Bilstein 30965 (ID1 38 mm, ID2 67 mm, L 100 mm), Meyle lists 3 part numbers (dimensions ID1 22-31 mm, ID2 61-64 mm, L: 96-100 mm) one of Meyle's has the same dimensions as their S500 inner boot kit.
available at FCP euro for $6, $9, $34 Mercedes
AutohausAZ: $46 Mercedes,
Pelicanparts: $5, $7

Parts diagram for 140.051 S500 V8
Parts diagram for 140.033 I6
Search keywords: where to buy w140 cv boot bellows

 

[Mercedesist]

Just replace 'em. I found this video helpful.

If you mean "replace the axle shafts", then, well... hell no. I doubt that they are still available new from MB. And if they are, spending 900 EUR on a driveshaft is insane. I have seen some cheap brands offering them, but knowing the "force and mass" of W140, I think they would damaged after a few "kickdowns". And why should you replace the axle, if there is nothing wrong with the main components on the 30 year old one?

 

[daidnik]

I think you are best rebuilding what you have.

If these axles are from the early S320 you cite in your profile, then be aware that there are a number of variations in those drive axles; e.g. With vs Without ASD & ASR. There is also a chassis S/N split on 140.032 chassis around 245645 (from memory looking at EPC 5 min ago).

There are also variants on the Oetiker clamps (Loom Tie in EPC-speak). I think the 320's have a smaller diameter drive axle shaft, so the smaller Oetiker clamp is different from the V-8 cars and I think there are 2 widths of the clamps (7mm & 9mm I think).

The good news is that the boots remain constant (I think). There is enough stretch that the small hole fits both the 6-cyl & 8-cyl drive axle shafts. Getting the Vaico boots seems to be the place to start, then you can measure the 'channel' width where the clamps fit and see if the later style 7mm width fits best (likely IMO), then you would order the later Oetiker clamps from MB as they aren't very expensive as cited above.

You'll need Oetiker pliers to clamp them.

The diameter of the Oetiker clamps is almost always marked on them right near the clamping ear. That might help although I'm not seeing that detail in EPC.

There is a grease fill spec. It's not super sensitive IMO, I think it's around 100 grams. I like MoS2 filled grease and these CV axles are almost always filled with that stuff, BUT I did buy 2 new drive axles from MB for late W140 S500 about 5 years ago and they did not have 'moly' grease, but some red colored synthetic stuff. I left it alone. They were almost $900 each, but I'd already been thru rebuilding my old ones with new moly grease and just wasn't happy with some notchiness that I could feel in the knuckles AND this car had been messed around with in the rear with H&R lowering springs and lowered down by improper adjustment of the SLS system in the rear, etc that probably screwed both the drive axles and the SLS shocks.

$3000 in parts later, all that was replaced with new shocks, accumulators, bushings, spring pads, springs, etc.

For the grease fill, you don't want it too sticky or too runny. Too sticky and it just gets pushed to the sides and stays there and doesn't lube the ball/knuckle interfaces. Too runny and it could be more prone to leakage. Oetiker clamps in general are a very leak-free joint seal. I wonder about sealing at the metal caps, but I don't see any o-rings for that in EPC, so maybe a little Dirko might not be a bad idea.

I generally use a mix of moly grease and heavy synthetic gear oil like 140 wt and get a consistency that just runny enough.

You reassemble the units dry with the boots pulled back toward the center of the axle shaft, then load the grease fill in to the knuckle and boot then clamp them on.

One should be very cautious about modification shenanigans on a W140 unless you really know what you are doing and have a very specific goal mind.

 

[Mercedesist]

I think you are best rebuilding what you have.

If these axles are from the early S320 you cite in your profile, then be aware that there are a number of variations in those drive axles; e.g. With vs Without ASD & ASR. There is also a chassis S/N split on 140.032 chassis around 245645 (from memory looking at EPC 5 min ago).

There are also variants on the Oetiker clamps (Loom Tie in EPC-speak). I think the 320's have a smaller diameter drive axle shaft, so the smaller Oetiker clamp is different from the V-8 cars and I think there are 2 widths of the clamps (7mm & 9mm I think).

The good news is that the boots remain constant (I think). There is enough stretch that the small hole fits both the 6-cyl & 8-cyl drive axle shafts. Getting the Vaico boots seems to be the place to start, then you can measure the 'channel' width where the clamps fit and see if the later style 7mm width fits best (likely IMO), then you would order the later Oetiker clamps from MB as they aren't very expensive as cited above.

You'll need Oetiker pliers to clamp them.

The diameter of the Oetiker clamps is almost always marked on them right near the clamping ear. That might help although I'm not seeing that detail in EPC.

There is a grease fill spec. It's not super sensitive IMO, I think it's around 100 grams. I like MoS2 filled grease and these CV axles are almost always filled with that stuff, BUT I did buy 2 new drive axles from MB for late W140 S500 about 5 years ago and they did not have 'moly' grease, but some red colored synthetic stuff. I left it alone. They were almost $900 each, but I'd already been thru rebuilding my old ones with new moly grease and just wasn't happy with some notchiness that I could feel in the knuckles AND this car had been messed around with in the rear with H&R lowering springs and lowered down by improper adjustment of the SLS system in the rear, etc that probably screwed both the drive axles and the SLS shocks.

$3000 in parts later, all that was replaced with new shocks, accumulators, bushings, spring pads, springs, etc.

For the grease fill, you don't want it too sticky or too runny. Too sticky and it just gets pushed to the sides and stays there and doesn't lube the ball/knuckle interfaces. Too runny and it could be more prone to leakage. Oetiker clamps in general are a very leak-free joint seal. I wonder about sealing at the metal caps, but I don't see any o-rings for that in EPC, so maybe a little Dirko might not be a bad idea.

I generally use a mix of moly grease and heavy synthetic gear oil like 140 wt and get a consistency that just runny enough.

You reassemble the units dry with the boots pulled back toward the center of the axle shaft, then load the grease fill in to the knuckle and boot then clamp them on.

One should be very cautious about modification shenanigans on a W140 unless you really know what you are doing and have a very specific goal mind.

Thank you for your amazing and detailed reply.

The axle shafts have different diameters indeed. My 300SE comes with shaft which is for example 2 cm in diameter. The diesel one comes with shaft that is 3 cm in diameter. I think the same shaft is used on high-output engines too. BUT - you CAN fit the "fat" shaft where the "thin" was. I have tested that and measured the overall length of the shafts when they were side by side.

Boots - nope. "thin" shaft has different part # than "fat" one. When I did rebuilding on "thin" ones, I could get FEBI boots and OE ones were in acceptable price. On the "fat" ones there was different story. The only boot option was MEYLE and OE replacement boot from MB costed f**** 68 EUR a piece. And you need 4 of them...

Clamps - when you remove old ones, there are numbers on them. Mine had 76 or 78 on the BIG clamp and 26 on the SMALL clamp. I purchased replacement clamps which have OETIKER written on them too. Spent 15 euros on clamps. And the clamping tool costed only 25 euros, but it is a lifetime investment. The same clamp from MB costed around 7 euros a PIECE. And you would probably get the same product, just with MB logo on it...

 

[daidnik]

Looked up some repair docs on your drive axle refurb'ing.

These are attached.

There is a note about sealing the inner end cover with sealing compound to prevent leakage.