M103 Help How Do You???
 

I am in the process of taking off the timing cover to replace the guides and I cannot get the 27mm bolt on the crank to move??? How do you remove this?? I have the pulley already off and the timing plate that rotates behind the pulley. Thank you
George

The crank bolt is very tight. YOU need a special tool to counter-hold the flywheel so the the bolt can be broken loose.

Where Can I Buy The Tool??????m103 Engine

http://www.baumtools.com

Once at this site, use SEARCH function.

Look for -> Flywheel Lock

today we used a
 

today we used a battery operated craftsman drill
that had an impact setting... so you could call it an electric impact thing..


it worked just fine.... :D

Or you can throw a breaker bar on it, turn it over with the starter, and use that to break it loose. The starter has enough juice to do it easily.

I've seen this approach used successfully a number of times on motors whose crankshaft bolts were torqued in the 100-150 lb. range.

I forget the exact torque figure for the MB 27mm crankshaft bolt, but it's somewhere upwards of 300 lbs. on the 126 cars, be it 103 or 116/117.

In this situation, I'd bet a buck that the "bump starter" approach would snap the socket-connection end of a lesser-quality breaker bar right off. I wouldn't chance my high $$$ Snap-On using the bump starter technique. In a few cases, people have mistakenly set the breaker bar the wrong way and ended up tightening the crankshaft bolt, breaking it off. Stuff happens.

I've also seen the "bump starter" approach wreck expensive inerts when the breaker bar got loose and went sailing.

I'm sure others have employed hill-billy strategies that worked. Getting it off is one thing; getting it back on and torqued to spec is something else.

I'd buy the flywheel lock, but that's just my opinion.

Hillbilly techniques, I like that one Mike. Personally I would get the flywheel lock for two reasons, as stated before, so nothing goes flying out and hitting someone or breaking something else that would have to be fixed AND so that the engine doesn't turn while the chain is off or loose. My 2 cents

That's amazing! Removed a 200-300LB bolt with a battery powered impact drill.

Most real pneumatic impact guns would have failed to loosen that bolt.

Yeah.....I'm the one that just "stated" it....duh....

Brewtoo - yes siree! I was taken back by that as well. No way anyone got that bugger loose with a battery operated gadget unless it was loose to begin with.

TOUCHE', I think I'll just keep my thoughts and comments to myself from now on.....Mike, did YOU notice the 2005 date on this one ??

Home made flywheel lock 103 engine 1991 190E 2.6L
 

Had a real difficult time locking the flywheel on a 1991 190E 2.6L to remove the front crack bolt, the starter is really difficult to remove with the upper bolt needing a 2 foot ratchet extension, the sanstagtool.com site sells the locking bracket for $185 so I bypassed this expense, glad to hear that there is a tool sharing program at this site.

I made my own flywheel locking tool or rather a combination of tools. Several DIY suggested placing a screwdriver into the starting ring behind the plastic flywheel cover. Well, no one screwdriver would stay put when the magnitude of the crank bolt breaking torque that was in play. Pinning/gripping a lone screwdriver was also unsuccessful, possibly because once the driver moved to touch the xmission case, the driver was not that snug under the one flywheel tooth.

I used from left to right facing the openning at the xmission housing: 1st a skinny 6" screwdriver small enough to fit under one tooth, 2nd a fat cold dice ground at the point to fit snuggly ( could not turn on its axis) under one ring gear tooth, 3rd a 6" nail set (smaller in diameter than the screwdriver) which fit loosely under a 3rd tooth, and last a visegrip to grab and hold in place the above three. Each metal object was pinned under one tooth and although 2 of the 3 were small in diameter and loose the locking visegrip made the set of three snug.

The hydraulic jack was used to leverage the 2 foot long 1/2"-drive bar and loosen the crank bolt. The nail set on the third tooth, the front tooth as the starting ring moved CCW, and was bent at the end when wedged against the bell housing, but since it's diameter is much smaller than the tooth, it was easily hammered out using the visegrip. The nail set was bent a little and got stuck such that it could not be pulled out by hand.

I have some photos and will load them when I get a chance.

Another Way
 

Here is another way. I used this on a 124 with M104 motor which is supposed to have the harmonic balancer bolt torqued to 400 N-m (yikes).

Place car on jack stands, then get under the car and remove the plastic inspection cover plate on the front side of the bell housing. Yours might be missing - mine was. Rotate crankshaft until you see the M8 bolts that attach the 'spider' carrier to the flywheel (flywheel to torque converter) visible in the opening. Remove one of the bolts and in its place screw in the following tool:

Get an M8x60 hex bolt, at least grade 8.8 but preferably 10.9 or better. Fabricate up a thick tube/bushing to go around the OD of the bolt using a 3/8” NPT schedule 40 pipe nipple, 3” long. Cut off the two threaded ends of the nipple so that the overall length of the nipple is 1-1/2” long. Then, into the ID of the nipple, drive in a 21/32” OD x 3/8” ID steel spacer bushing into the pipe nipple. The bushing just fits exactly in the nipple ID. The pipe nipple and bushing both came from the hardware store. Place two 3/8" or 5/16" hardened SAE washers under the 8.8 bolt head and then slip on the bushing. Mark the 60mm bolt so that you have a net 50mm bolt length available under the washers and then cut the bolt to this length. Dress the cut-off thread on the bolt so it screws in easily, i.e., file off the burr. Now screw in this assembly into the hole in the torque converter that you took the other M8 bolt out of. Now rotate the crankshaft until this bolt and bushing catches on the bellhousing. This will lock the crank. Now use a pipe snipe with your ¾” drive breaker bar to bust the harmonic balancer bolt loose. It takes a lot of mustard to bust that bolt loose.

This is a good method because it doesn't require you to have a helper to hold a screwdriver in place under there while you rotate the crank. You can screw in this tool and work solos at your leisure and you don't have to worry about flying tools. This job is not something to muss around with.

Don't try to do this without the bushing on the bolt because the bolt is not stiff enough. You will just bend it when you apply all that mustard to the breaker bar. Pete