The design of the CV joints has an outer "chase" an inner "spider" and a number of balls in a holder in between those parts. As the vehicle does most of it's travel in the forward direction the surfaces that make contact under that circumstance get worn the most. By swapping the axles from side to side you then put the lesser worn surfaces which where formerly only in contact when driving in reverse into position of now being in contact when driving forward.

In theory this would lead to longer axle life because you'd end up using both directional surfaces rather than just one. Of course swapping does nothing to aleviate the wear on the balls in the joint but they are pretty tough.

This wear issue is what makes rebuilt axles so undependable, usually the axle core is inspected and measured, if it's in spec they just clean, re-lube, and reboot it. If it's out of spec they regrind the chase and the spider to the next larger size ball, then clean, re-ball, re-lube, and re-boot. The problem is that when the CV joint was originally manufactured the wear surfaces of the chase and the spider are hardened as are the balls, they don't harden the reground surfaces and the axles don't last nearly as long as a result. Now when you combine that functional flaw with Chinese/Mexican/who knows what third world quality control remanufactured axles have become a disposable wear item rather than what was originally a part that might last the life, in the Benz case, long life of the vehicle.

They wear into the other side of the CV joint as they will be rotating the opposite direction.

__________________

Gone to the dark side

- Jeff

Thanks guys, that makes sense, but I wouldn't have thought of it! I'll be sure to swap them.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

I would not swap them side to side.
many many many bearing manufacturers specifically state not to swap wheel bearings from one side to the other due to the bearings wearing specific to the race. the cv joint would be the same. it's turned one direction for hundreds of thousands of miles, the grooves are mated to the wear patterns in the balls, the oil keeps everything lubed correctly, and the cleaning and re lubing gets any wear material that's developed over the years out. I vote to keep them on the original side.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

They'll be wearing against an almost virgin surface on the opposite side. It's an old VW trick, when the CV joints wear out we could swap them and get lots more use out of them.

__________________

Gone to the dark side

- Jeff

I posed this in another thread, but realized it really belongs in this one, especially in case anyone searching wants to follow the progress of this project:

The good news is, I got everything off and started to drop the subframe ... but, the back half won't drop. The bolts are all out, of course, but when I go to lower it, just the front lowers and hangs from the back. I tried gently coaxing the back mounts off the frame with a prybar, but didn't really want to go to town on it and damage something. Is there something I'm missing here? I don't think it's hung up on anything. Are the bushing sleeves just stuck to the frame posts maybe? If so, should I try torching them, or keep prying? I'm trying to be careful because I don't want it to suddenly pop free and crash down. Obviously I have the jack under it (plus an extra scissor jack) but still don't want any sudden lurches.
Help?

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Use a second jack to support the front and keep it level, them lower the main jack an inch or two, then you can use the pry tool to lever the rear mounts. With the front hanging down it exerts off axis leverage on the rear mounts and the tubular studs they mount onto making it harder for them to disengage. Sometimes they will be stuck on there pretty firmly you just need to keep trying. A spray of KROIL to the top of the mount so that it can get on and leech down the stud can probably help some, and if you can get the tip of a bar, large screw driver, chisel in between the chassis and the mount where you can make some contact with its tip to the mount's inner/upper/central metal section into which the stub fits, giving it a "short, sharp, shot" or two, such a shock will help break it loose. The metal in the mounts are some alloy that can corrode and stick to the tubular stud's steel. This is the kind of stuff what "real wrenching" is all about! Good Luck!

Thanks, I think I was on the right path at least. I did think to push the front back up since it was making the rear mounts cockeyed, but it was still sticking so I wasn't sure if that was the right method. I'll shoot some Kroil on there before I go to work, then try again when I get home (or in the morning). I guess I need to be a bit less timid with the pry bar! I'll give a chisel a try too.
To be continued ...

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

I don't envy you. I spent a good deal of time beating on the one in my parts car, finally cut it out. The subframe still has the mounts in it, ... I soaked and pounded for a while until I lost interest, even tried a ball-joint press.

__________________

Gone to the dark side

- Jeff

That's not too encouraging! Hopefully I'll have a bit more luck. I don't need to get the mounts out of the frame, since a "new" frame with new mounts is going on. But I can't cut the mount that's fixed to the car ... I'm gonna need that! I might try sticking the ball joint press I have in there ... it's about the right size.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Is BFH a b.. f...ing hammer?

I'll give it a try. Thanks.

These are not going to come off. For anything. I am never going to finish this stupid project. Should I try firing the torch up bthe bottom of the mounts? I am prying with a huge prybar, and have also tried a chisel and a wood splitter with a big hammer. They don't break because the rubber gives and can't possibly exert enough force. And I can't seem to get anything onto the metal part of the bushing to avoid that.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

That's where I decided to cut the thing out of my parts car, ... so I can't help you there.

I'd be starting to consider pouring a low durometer urethane into the bushing and leaving it there.

__________________

Gone to the dark side

- Jeff

I think my next move, after studying an old bushing, is to cut the center of the bushing out. Which I'm sure will be a bear, but that way I can lower the frame off and put it to the side, then chisel -- or very carefully cut -- the bushing core off the post. If I could get a chisel tip on the metal part of the bushing, I think it would come off. There's not that much metal coming in contact with the post, but the rubber just won't allow enough force to be exerted to pop it loose. Unless I cut a hole in the trunk floor and stick a chisel down the top ... think I'll avoid that ... .
My big fear at this point is that I'm going to damage the post itself. Then I'm really, really up the creek. I guess you could weld one back on, but that sounds like it would be pretty unsafe. So I want to be careful not to damage the post or the threads.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)