Depreciation Road Racer - Mercedes E350

Got the rear half of the driveshaft clamped up in the vice.  Tried using vice grips to see if I can loosen it at all, but no dice.

Drilled a pilot hole:

Then a 3/8" hole all the way through:

Slipped a bolt in to pry against:

Made several attempts with several different tools, and the only thing I succeeded in doing was bending the bolt.  Maybe a torch will help loosen it up, but I am a little too tired to play with fire tonight.  I might also go and grab a replacement slide hammer tomorrow.  I figure the newly drilled holes should provide something to grab onto.

Kind of tempted to just do the rear one, since the front still had grease left in it, so should not have any wear.

Ran to the hammer store this morning before work, and during lunch, tried the slide hammer (no dice), and two 18" pry bars (also no dice).  Prying just bent the bolt more.  I don't have any grade 8 3/8" bolts laying around, but I do have some 7/16" ones.  May drill the hole out for them to fit.  I suspect I am going to have to heat the bushing up with a torch, then try to pry it out.  That is going to smell really bad when the plastic inside it melts, not to mention I better not wear sandals for that job.  If anyone's got any suggestions, I am listening.

Drilled the hole out to 7/16", and tried to pry it.  Didn't work, but it didn't bend the bolt this time.  Heated it with the propane torch.  Didn't work.  Heated it with the MAPP torch.  Didn't work, and actually distorted the bushing.  
 

If I can't figure something out, I may end up having to buy a replacement driveshaft anyway.

I am kind of wondering if taking a punch to it to try to deform it enough that it isn't contacting the driveshaft all the way around is a good idea, or if it'll make it harder to remove if that attempt fails.

Can you use that hole to suspend the bushing from something sturdy, letting the driveshaft hang, then hit the flange with a hammer to tap the shaft off the bushing?

I don't think I have anything that sturdy.  I could maybe borrow an engine host to hang it from, and try it that way.  Not sure it'll work well without being able to hit all three points of the flange at once.  A little worried I could damage the flange, too but that's probably not a valid concern.

What part exactly are you removing?  Is it possible to try to grind at it until it's weak enough to crack, like an inner race from a wheel bearing stuck on the hub?

In reply to wae :

The part with the hole drilled in it is press fit into the end of the driveshaft.  It needs to come out so a new one can be pressed in.  I'm a little worried about damaging the driveshaft if I hit it with any grinding blade, but I am wondering if I can cut a big chunk of the exposed part off, then use a dremel to cut into it below the surface, and chisel it out.  Just worried I am going to make things worse if I am not careful.  I am not sure the dremel grinder discs will fit very well, unless I use them up a bit first.  I won't be able to cut too deep, either.

Rockauto sells the dorman driveshaft for $550 + shipping, but it's on a 10 day delay.  At that point, I want to already have something I can trust to make the trip, so that route would primarily be to put the car back together so I can sell it.  So, I am really hoping to come up with a solution, and have the car back together this weekend.

Hmm, I think the grinding it thin trick works best when you're removing the outside bit as opposed to the inside bit...

Air hammer against the hole?

I could see chaining it up to something and whacking down on the flange with a sledge.

Try heating the flange again and then hitting the bushing with Freeze Off?

Debating whether to take a jigsaw or my hacksaw designed for tight spaces and try to cut the bushing lengthwise.  I think there is a lip on the driveshaft that acts as a stop for the bushing, and I would damage that, but I am thinking it would not be likely to cause too much of a problem.  If a tiny bit of missing material that far inboard is enough to throw it out of balance, then maybe it wasn't in balance anyway.

Can you use an air chisel to push it out, maybe using one of your holes?

Brotus7 said:

Can you use an air chisel to push it out, maybe using one of your holes?

I only have a small compressor with a 3 or 5 gallon tank anymore, but it could probably run my air hammer for a few seconds at a time.  I'll have to look and see if any of the tools I have for it might work.  With the damage it has taken, I'm concerned it might just rip the bushing a bit.  But that may not leave me any worse off than I already am.

Regarding hitting it with a hacksaw blade, I had a thought - the load is going to be carried on the outside of the flange, to where it is welded to the rest of the driveshaft.  So if I damage the lip that the bushing presses against, I don't think it will be a safety issue, just a risk of a tiny change in balance.  Still, I won't attempt it tonight, I want to sleep on this and consider as many options as possible.

Any chance you can drill it out? It would require a beefy drill bit I'm sure but if you have one large enough maybe give it a try? Or perhaps you could take a grinding bit and thin down one side and then take a punch to it?

Long shot here: freeze your grade 8 bolt before using it and heat the flange. Maybe the bolt will help keep the bushing cold enough and the flange hot enough that it will budge. 

In reply to Blunder :

Freezing the bolt couldn't hurt, and I was just about to ask about heating the flange instead of the bushing.

So, there is no lip setting the depth.  It is just set by pressing/hammering it to the correct point.  In the morning, I managed to cut it lengthwise with a hacksaw.  Got sick and went inside for a while.

Thought I had gone through, but turns out I was wrong. I hammered one part of it down into the other a bit.

After that, and a hit with some penetrating oil, I was able to rotate the bushing fairly easily, and after a few iterations of levering, then hammering the bushing into itself more, I was able to get it to come out about 1/4", but no more.  I think some of the metal is still 1/32" thick or so along the cut, and I cannot get it to split.

If worst comes to worst, I'll make another cut 180 degrees from the original, but am trying to think of anything easier first.

Went with another hacksaw cut.  That took way too long.

Shook loose debris out of the driveshaft, but there is still some shavings in there.  Think I'll see if the shop vac can pull some of them out and then call it good enough

The replacement has been in the freezer since this morning, so hopefully it won't take too much effort to hammer in.  I need to check how much it is supposed to stick out first, though.

Install was way easier than removal.  If I remember right, the old one was about 7/8" out.  Spec was supposedly about 1 - 3/32" out (assuming I am reading the directions right.  Wonder if it was not actually centering on the rear differential.

In reply to eastsideTim :

Fantastic news. Glad you were able to remove it. 

In reply to Blunder :

Thanks.  I'm definitely leaving the front one alone, since it still had grease in it.  
Installed the center bearing, and partially installed the support.  It didn't want to go on the bearing evenly, so I am going to snag some PVC pipe and hopefully hammer it in place properly.  Probably done with the garage tonight.  Headed out to a local cruise in to get away for a bit.

Nice.

"Gotta be more stubborn than the E36 M3 you're working on." - An old dude I work with

Damn, you went full caveman on that thing, didn't you?

When I did the wheel bearing on der Scheißwagen, I found that all the press-fit stuff was way more "fitty" than I've run into on other cars, so I have to wonder if Merc is using a much tighter spec in general. 

I should have some time in the evenings of this coming week if you need a hand at all.

It's reassembled and on the ground.  I need to get cleaned up after a gear oil incident, then am going to grab some dinner.  Will test drive it afterwards.

Fingers crossed!

Anyone interested in buying a heavily maintained Mercedes with a vibration issue?