Why should you secure dangerous things well? The unforeseen is always a possibility. We all do things without thinking them through sometimes. In certain situations it is best to allow for that in advance.

It is better to be a chicken than a pressed chicken in my opinion. As one poster mentioned I have heard of some metal ramps collapsing even locally.

The models that do should not have been allowed on the market. Also the front ends of our older Mercedes tend to be heavier than most cars today.

Never work under a car where there is a potential possibility of another vehicle bumping it or hitting it.

So I was able to swap trannys without killing myself. Thing now is I can’t get the torque converter and flex plate lined up. I might have to pull this apart again....😭

Well, how much longer do you want to fight it before you pull the engine?

Recommend you set a time limit, if you don't get things lined up when that time has passed, bite the bullet and pull the engine. Mate engine to trans, and install as a unit.

Always get toqure converter bolts started before bolting trans.completely up.
LOOSEN TRANS. BOLTS separate trans. from engine a small amount,line
up converter, start bolts,now draw in trans.tighten converter bolts evenly.
No needed to completely separate engine.
SLOW Down YOUR"E moving too Fast
Oh darn,did this a fewwww times my self.

done this on both my 87 300D and one of my 85's w123s. In the end I do thing it's better to just pull the whole engine and trans together, and put them in together. Plus address that rear main seal at the same time. About to do this job myself and will be putting the 4 speed manual behind it in the end.

Is there no pictorial or anything to somewhat guide the first timer at this? I'm planning on swapping a W123 gas manual transmission in for my W123 300D automatic so I don't need to bother with all the vacuum issues I'm currently facing.

I will be getting a beefier clutch plate or something of the like from a mechanic who's done many of these swaps but lives over a 1000 miles from me. Otherwise I would maybe have him do it.

How many hours can I estimate for this swap?

P.S. Also, isn't there a wiki page with a ton of how-to articles somewhere? I can't find it again.

Yeah I try to do too much too fast and then this crap happens. A mechanic friend of mine told me to get the same M10 bolts through the bell-housing but longer so I can slide the trans back and forth a bit and wiggle it to line things up. Tighten the other bolts then replace the long ones with the correct ones. If this doesn't work then I'm popping the motor out.

@sanford It took me all day Monday to get this far. Factor another day now to line things up and reconnect everything.Obviously if your doing a manual swap there is more involved at the pedal box and shift linkages. I'm doing an R&R with the slush boxes ('76 into a '75) so other than the aligning issue its pretty straightforward. Yours is a pretty common mod and from my experience there is more on those swaps in this forum then there is information on the auto-boxes in general.

x3 on the safety shake after lifting.

I've done it in the dirt, that's no fun.

If you're on a paved surface it's much nicer.

If you're under some kind of cover, it's a walk in the park.

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I pulled my 300d in reverse onto some good steel ramps when I did my trans swap ,the frt I slowly raised with 7 wooden cribs on both sides of the car . It takes awhile to get it setup but it works and I felt completely safe. I had 6x4 blocks at the jack points as raisers for the screw jacks , again , 1 crib at a time and took 30 minutes to setup but was done with the cost of a shop at $100 an hr.I ended up with a trannie jack from northern tool for removal and install. Had to go at it twice since the yard trannie was a no go .I feel confident in this mechanical task if it came up again.

No shop cost , just my own garage at the time , to add safety each crib I screwed in place with some good deck screws so they could be easily removed when done , no Philip headed screws , just spend the money for these , you’ll not regret it.

Well I just got done doing the requisite victory lap.
I followed my buddies advice and it worked great.
-Stuck the trans jack under to support what I was doing
-Found some M10-1.50 X100mm bolts to sub in at 11,1,3 and 9 oclock positions roughly (the ones that are threaded into the intermediate flange). Removed other (70mm) bolts and nuts
-Wiggled the trans back to free the torque converter.
-Lined up the bolt holes between converter and flex plate. Placed 2 bolts in finger tight.
-Turned motor to next position and put two more in etc.
-Wiggled trans back forward again and put 70mm bolts in the other positions finger tight.
-Verified everything still moved
-reinstalled starter bolts, verified movement again
-torqued torque converter bolts.
-removed 100mm bolts from bell housing and reinstalled with 70mm bolts.
-torqued bell housing bolts and starter bolts
-verified movement one more time. Satisfied with that I kicked over the starter and all was right in the world.

That was Saturday, today I replaced/ cleaned out the cooler and lines, filled it up with fluid and took a quick hop around the neighborhood. Tomorrow I plan to stretch its legs a little with the 20 mile round trip to work.

Thanks everybody for all the suggestions.
Ultimately I performed all the work on ramps while momentarily putting the front on jack stands to slide out the trans for the new one. Once it was in the "pocket" I lowered the car back on top of the ramps so I could continue to work safely.

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DON'T MESS WITH MY MERCEDES!


1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles

Well I drove it all this past week and stretched its legs up between Clermont and Orlando today. About 60mi round trip. Trans is solid and I can run comfortably at 60mph with the AC running. Slow as hell but I like it. Finally good to enjoy it after a year of ownership. I should probably start a new thread but I'm losing oil out the rear main seal. Anybody have ideas? It looks like the crank has to come loose?