300D turbo manual trans swap problem#1: Pilot Bearing Shatters Inside Crank
 

Hey Fellas,

I was installing a brand new pilot bearing into the 617 turbo crank when all of a sudden, BAM! A segment of the outer race cracked and popped off. The rest of the race is almost flush with the surface of the crank that the fly wheel bolts. It looks like I was about 3/16" from bottoming the bearing inside the crank. Any ideas on how to get the rest of the bearing out? My day is ruined, but there always my mud toy to work on.

Thanks

Shiran

It sounds like you were trying to force it into the crank unevenly.

You don't necessarily have to have a pilot bearing puller to get
the pilot bearing out.

First, find a deep well socket with an O.D. slightly smaller than the hole
through the pilot bearing. Then fill the inside of the socket with duct tape
and also wrap the outside of the socket with duct tape, so that the
socket just fits snugly into the bearing. Fill the void in the end
of the crankshaft behind the pilot bearing with some cheap wheel bearing
grease. Place the socket into the pilot bearing hole and hit the end of
the socket firmly with a hammer until you feel the socket hit the crankshaft.
Each time you hit the socket with the hammer, the hydraulic action of the
displacement of the thick bearing grease pushes the pilot bearing outward a
bit. Once the socket hits the crankshaft, remove the socket and refill the
void behind the pilot bearing. Repeat this process until the pilot
bearing is free.

Thanks Lance, but the hydraulic method only pushed out the inner race with the ball bearings. I think it's time to go to Home Depot and find a small cut off attachment for the die grinder. :D

There is a bearing puller tool out there made by several different manufacturers, basically is a J-hook with a tang on the side. You hook the tip behind the bearing, hold the end, and strike the tang with a hammer, working around the bearing. I know MAC makes them as that's where I got mine. I have done the hydraulic method on some before in the past, had some that wouldnt go no matter what as well, and used an acetylene torch very very carefully to slice the old part out of the crank (not a novice level job) Once I finally got the tool it has paid for itself many times. I can get you the MAC number tomorrow if you want.

If you don't mind, please post that MAC tools part number. I tried my el cheapo Harbor freight slide hammer with hooks and I broke the hooks after a few blows. I could not find a small diameter cut off attachment for my die grinder, so I might try a grinding stone this afternoon.

The outer race is out. I used a heel bar to pry it out. I stuffed a 15mm socket into the crank bore so that the heel bar had something to pivot on. This swap is taking too long, but I'm learning alot.

A little ingenuity always works,lol. Well, here's that tool anyway...
It looks like its either an S12 or S120 number on it. This thing has taken all the beatings I can give it, I think I originally bought it for doing transmission pump and tailshaft seals without disassembling the trannies.

Well, after removing the shattered bearing, I measured the ID of the pilot bearing bore in the crank. I'm reading 1.358" with a set of dial calipers. The OD of the damaged bearing that I ordered is 1.378". I got a 2nd pilot bearing locally and it also measures 1.358" OD. 0.020" is too tight of a press fit. I would think .002" would be ideal. Do I flapper wheel the crank bore or do I flapper the bearing OD? What have others done? I'd like to know.

Interesting, This is the 83? I was told this was an 84+ issue. Did you read manufacturing date off the vin plate? That would make this an 84.

My solution was to take the gringer with the cone attachement and run it parallel to but run perpindicular to the race.


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This way a groove is createdin the middle. Then I ran it parallel and took off the lip i created. Did you check to see if the bearing was moveable when you installed it? I tried three times with a 5lb sledge before I found a thread on here about it. I figure its alot better to ruin a $5 bearing than a $XXXX crank.

Thanks winmutt. I was thinking the same thing. I know I have to clean up the crank bore because I scarred it up when I removed the busted race.

Yup, this is for the '83 turbo. It's a weird car because the other day I wire wheeled the back flange on the differential to confirm that it has a 3.07 rear end and it has 2.88 stamped on it. I know a mechanic owned it at one point so it might be a frankenstein benz with parts from 77-85! Maybe the engine is '84+.

If its a 2.88 you can bet they probably did swap the rest of it. BTW I have found the 2.88 + manual to be REAL slow off the line (first day in parking garage with auto it took 3 attempts to make it up the ramp, ALDA adj took care of that). I may move up to the 3.07 out of my euro. I'll make that decision once I get the eng up to par.

Hello all,

Where did you get the bearings from? Reading many posts one would think they are simple off the shelf sealed ball/needle bearings.....could that be true? I would've thought that due to the heat they may be somewhat special manufacture?

Thanks.

Yes, these are off the shelf bearings. The first one was ordered online. It's a NACHI brand made in Japan. The second was bought from a local parts supplier since I needed it ASAP. It's an STS brand bearing made in Korea. The NACHI had ball bearings. I found that out when it busted. I'm not sure what the inside of the STS contains. I hope I don't find either :D

winmutt,

Did you let the bearing spin as you were grinding it?

Thanks

Shiran

Mine is a basic sealed ball bearing from NAPA.