OM617 W116 300SD Front Crank Seal Replacement--Can It Be Done With Radiator In Place? - Page 2 - PeachParts Mercedes-Benz Forum

ROLLGUY · #16 01-22-2013, 06:16 PM

Quote:

Originally Posted by qwerty

250F will be no problem at all.

If that is in fact the approved method, then maybe I will do it that way next time.

Quote:

Originally Posted by qwerty

The spacer doesn't rotate on the crankshaft because it's sandwiched behind the balancing disc, which is under the influence of a bolt tightened to a pretty high torque level. I pulled my spacer ring off with two flat screwdrivers, 180 degrees apart. Simultaneous, opposing force is the key.

I think I tried on the last one I did, and it did not budge. I used the old one, and no leaks (new seal of course).

Quote:

Originally Posted by qwerty

Considering that the dowel recesses in the balancing disc do not extend fully through the disc, that's quite the trick.

I don't fully understand the above statement.

Squiggle Dog · #17 01-22-2013, 06:41 PM

I've think 250F will be safe for the balancer, though too much could definitely harm it.

Usually the spacer ring falls off with the seal, or it can be prised off with a flatblade screwdriver at each side (this is all from what I've read, no experience). I also wondered how oil would not get past the spacer since it is not a tight fit. But, since it is sandwiched between the balancer and the raised edge of the crank, it seals one the sides of the spacer, not the inner diameter.

Maybe in fact the recessed for the pins in the spacer do not go all the way through the backside. I hadn't thought of this. But then again, maybe they do. Maybe the dowel pins could be frozen, greased, placed onto the hot balancer, then pushed onto the crank (I know, good luck doing all that wearing oven mits and the radiator in place).

I am hoping the dowel pins can be reused.

jt20 · #18 01-22-2013, 06:44 PM

Quote:

Originally Posted by ROLLGUY

If that is in fact the approved method, then maybe I will do it that way next time.

I think I tried on the last one I did, and it did not budge. I used the old one, and no leaks (new seal of course).

I don't fully understand the above statement.

Some spacers slide right up to the tip of the snout, some are fit pretty tight.

I think he is referring to how far back the dowels are when you put the disk back on. You have to constantly re-align the holes in the disk with the dowels. I have done it twice by leaving the dowels in place as you stated. ... it is quite the trick. And I would not suggest it to anyone, especially not with the engine in the car.

Squiggle Dog · #19 01-22-2013, 07:01 PM

Go to this thread and look at the pictures: Warning OM617 dowel pins now supplied with incorrect length

Apparently the holes do not go all the way through the balancer after all!

moon161 · #20 01-22-2013, 08:23 PM

Done it twice. First time, slicker n snot, second was a PIA. I left the dowels on the crankshaft. Soak to 250 F, convection oven helps. I don't think 350 F would hurt. Nothing metalurgically interesting happens until I think 750 F. Line it up visually, a mirror helps, slide it on. You might have 1/2 a second to index it and slide it on. If you get it right, it feels well, like two mating parts fitting up and slides back a fair ways w/ light force. If you're a bit off, it shrinks on and you'll probably need the puller to get it off, reheat and try again. Just plug in a toaster oven in your garage.

ROLLGUY · #21 01-22-2013, 08:33 PM

Quote:

Originally Posted by Squiggle Dog

Apparently the holes do not go all the way through the balancer after all!

I stand corrected, I put the balancer on with the dowels in IT, not the crank (it was years ago, so my memory failed). If I remember correctly, it was a little off, so I clocked it a little by tapping the cutout in the balancer to move it the slightest amount. I used the bolt to press it in.

qwerty · #22 01-22-2013, 09:45 PM

Quote:

Originally Posted by Squiggle Dog

Apparently the holes do not go all the way through the balancer after all!

I wasn't guessing when I said that they do not. It is not possible to remove the balancing disc and "leave the dowels on the crankshaft." Likewise, it isn't possible to install the dowel pins before the disc is at least partially seated.

It is the fact that the dowel recesses don't go all the way through that makes aligning the balancing disc such a challenge. It's totally unlike lining up a slot for a Woodruff key.

Shortsguy1 · #23 01-22-2013, 10:05 PM

Quote:

Originally Posted by moon161

Nothing metalurgically interesting happens until I think 750 F.

Probably not relevant to this discussion, but some artificial aging can occur when you heat treat aluminum at temps as low as 350F.

See section on precipitation heat treatments at:
Heat Treatment of Aluminum Alloys

I help out with a bike frame building class, and on rare occasion, students use their kitchen ovens to adjust the strength of their frames.

jt20 · #24 01-22-2013, 10:18 PM

Quote:

Originally Posted by qwerty

I wasn't guessing when I said that they do not. It is not possible to remove the balancing disc and "leave the dowels on the crankshaft." Likewise, it isn't possible to install the dowel pins before the disc is at least partially seated.

No use in arguing for the sake of anecdotes, but that is the way I have done it at least twice.

The pins remained on the crank without force... so I left them there instead of replacing. (not factory approved)

A light source from behind the balancer helps guide it onto the pins correctly without gouging the pins. Adjust the alignment by hitting the balancer in the cutout with a wooden mandrel.

You may not approve the method... but don't tell us it isn't possible.

Squiggle Dog · #25 01-22-2013, 10:27 PM

Maybe some balancers have pin recesses that go all the way through, while some don't. The one pictured in the link above does not, and there is no way they could be left on the crank while installing the disc. However, if some discs have pin recesses that go all the way through, then this is possible.

Squiggle Dog · #26 01-22-2013, 10:35 PM

Looking at the cross-section in the engine manual, it seems that it would not be possible to have an OM617 balancer with dowel pin holes that go all the way through--they would rest against the spacer and there would not be enough metal between the pins and the outer lip of the oil seal (outer lip of oil seal rides on balancer, inner lip rides on spacer).

Conclusion: fitting the pins on the crank before installing the balancer would not work on the OM617. They must be driven in after balancer is installed, or at least started onto the crank.

qwerty · #27 01-22-2013, 10:54 PM

Quote:

Originally Posted by jt20

You may not approve the method... but don't tell us it isn't possible.

That is what I am telling you. Not possible; cannot be done.

jt20 · #28 01-23-2013, 01:44 PM

Apologies. -It has been too long. That is correct, it will not go on in that fashion.

whunter · #29 01-23-2013, 02:43 PM

Quote:

Originally Posted by Squiggle Dog

The front crank seal in my 1980 W116 300SD is leaking. I'd like to replace it, but the OM617 engine manual says to remove the radiator. I really don't want to have to drain the coolant and deal with plugging the lines to the transmission and oil cooler. Removing the radiator is a pain anyway.

Obviously the fan shroud needs to come off, but it looks like there is enough room to get the crank pulley and harmonic balancer off with the radiator in place. Even if for some reason the bolt in the center of the puller tool is too long, I could cut it down or make a shorter bolt. I can get underneath the car to work on the seal and can put cardboard or something over the radiator to protect it.

Has anyone replaced the front crank seal with the radiator still in place? I am hoping I am able to do this. There is a good 5" between the face of the crank pulley and the radiator. The width of the pulleys is about 3", and they don't need a puller tool to remove them. That leaves the harmonic balancer, which itself is only about 2" wide. By this time I'd have about 8" or so of clearance between the harmonic balancer and the radiator, which should be plenty of room for the puller tool, especially if I cut down the center bolt. What say ye?

Spacer ring puller.
Pelican Parts.com - Puller (Collet Type)

If you want to discuss this job further, feel free to call me.

.

JB3 · #30 01-23-2013, 02:58 PM

id remove the radiator just because its so easy to damage with the slightest mistake, even though you now have to deal with fluids.

However, if you do leave it in, id do what one of my coworkers used to do and showed me. He took a piece of sheet steel, and folded card board over it, then dropped it in front of the radiator and taped it in. He called it his "radiator bullet proof vest".

He was drilling, and at that point he had eaten the cost of a radiator earlier by slipping with the drill and going right through it with a half inch bit, so I doubt you need to go that far, but some thick cardboard would certainly add some protection from dropped tools and such