I reckon this kind of wiggling is bad



I was quite surprised at how much movement there can be in these little cogs once the shims have worn down a bit.

The shims inside the cage go "under" the side cogs and the plastic / nylon caps go on the other gears that are held in place by the pin.

I can understand that if you haven't taken something like this to bits yourself and seen it for yourself you might imagine that this isn't important but honestly chaps once you've seen the lips worn into the shims and the wiggle from the axle in the slot...

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

With all non limited slip diffs, there is more free play between the small gears that you would expect. Generally, the gears are not shimmed to a specific backlash or even checked. The limit is usually a vague " excessive wear".

In any event, the clip keeps the axle from falling out and it is surprising it didn't at least slide out a little in the OPs case.

I was thinking about how far the axle end would have to come out before you'd start to loose differential oil - and was thinking how tight most of these axles are under the rear end of a Mercedes (so was thinking it probably wouldn't move that far and oil leakage is highly unlikely) - so went to the FSM for a schematic I remembered =>



There you can see another reason for a tight fitting shim and circlip on the end of the axle.

Not only does the clip hold the axle in position - it has to be tight enough to help hold the bearings in place. Now if set correctly the outer casing should be applying a pre-load on the bearings (which are held in place by the big circlips) =>



...but this pre-load seems to go soft after wear and perhaps relaxation of the casting. {As an aside the relaxation of the casting is a serious problem for the smaller differential casings on a W201}

So anyway the clip also helps the bearings run in their correct position on the bearing cups.

Attached Thumbnails

 

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Hmmmm. Makes you wonder...

My drive today made me wonder too; almost no vibration on the way to town, and only a little on the way back. At first, I just thought it was because the car was happy I worked on it, fixed the back up lights and got the rubber strip on the rear bumper back on tightly.

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1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)

I was under the impression that the missing clip was # 30. Can the OP confirm?

The internal snap ring in your pic ( # 29 ) is an immensely poor way to retain the bearing race. Getting proper bearing preload would be difficult and require a selection of various thickness rings.

If this ring was missing, the bearing cup would slide out on the first drive causing a lot of backlash and ring / pinion noise.

SL320,

Yep, on the very tip of the axle; does that confirm your notion that the bearing race is wandering, in my case?

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1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)

It is indeed difficult - it is a pain in the arse and to make matters worse the small W201 casings flex and relax so the pre-load gets reduced quite quickly. Not a good design for the smaller casings.

However, the same design is used for the W123 and those differentials are not known for the same trouble as the smaller W201 ones.

I see the clip as an extra bit of security for the axial bearings. A tight fitting circlip (with a decent sized shim) will help hold the bearing in place but the "primary" pre-load is made by the casing pushing against the "huge" circlip shims with the cage for the small differential gears trapped between.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I think you've got little to loose by fitting a decent sized shim and a circlip and then seeing how things are.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

The only function of clip 30 at the axle stub tip is to prevent the axle from popping out.

In fact some cars ( non MB ) use a clip that amounts to the effect you get when snapping a socket onto an extension. Removal consists of preloading the shaft outward then striking the joint to jar it out of position.

Other cars / trucks have bolt on stubs and no # 30 clip at all.

In any event, # 30 does not hold the side bearings together, clip 29 does that by holding the outer race and a press fit to the diff housing holds the inner race.

The clip also holds the side cog in the differential cage in place (as well as helping to compress the bearing race in the event the side pre-load is slack) => and now we've come full circle!

The clip needs to be fitted with more firmness than a socket on the end of an extension. I find it best to tap them in place with a hammer and punch.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Okay, looks like these bloody things are $7 apiece... Anybody have some spares I can buy?

__________________
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1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)

Yeah, they're pricey. I bought from MB SouthAtl (as reccommended by Greazzer). They don't list sizes along with the part numbers, and I didn't know what I needed.

I essentially bought 1 or 2 of everything available, and they vary in price. I think I spent close to $100 just for the shims. I didn't measure with my dial indicator, but the second shim I tried out of the ones I ordered fit nicely (got the circlip back in and no discernible play between the axle and the diff).

In my case, the previous owner's mechanic had lost the original shim on the passenger side, leading to much play between the axle and diff.

Did you sell them back to South Atlanta?

__________________
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1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)

In my defense...he was using my shop for free and he always did.....the clip could not be installed. It's a working shop, so do I allow the vehicle to sit in my shop 'till parts arrive whist said owner needs to depart to Colorado?

I understand the importance of the C clips. If it won't go in, it won't go in ! Plus, he couldn't afford to select other axles that 'may' have enabled the C clips to be installed.



.

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[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Sell them back? - no. I don't even know if they have a return policy. They're sitting in a box somewhere in my garage.