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Restoration of 6.9 #496

Started by McNuggets, 16 August 2020, 06:23 PM

daantjie

Ugh ja that ring gear is toasty :o  big job to replace.  On the 6.9 you have to pull the engine and trans which in itself is no walk in the park.  Best to bang out other jobbies while it's out.  Bon chance ;)
Daniel
1977 450 SEL 6.9 - Astralsilber

raueda1

Quote from: daantjie on 27 March 2021, 08:57 PM
Ugh ja that ring gear is toasty :o  big job to replace.  On the 6.9 you have to pull the engine and trans which in itself is no walk in the park.  Best to bang out other jobbies while it's out.  Bon chance ;)
Yes, spot on.  Prepare yourself for some soul searching on how much work you want to do when engine is out.  It's such a great opportunity to do jobs you'd probably never consider otherwise! 

Anyway, if you do pull the engine make sure that your engine hoist is HUGE.  It's not just a question of weight.  The boom needs to surprisingly long or you'll eventually get stuck.  Also get a good, heavy duty leveling arm.  The cheap ones with small threads (such as Harbor Freight) will wear out surprisingly fast.  With the right equipment pulling the engine really isn't as bad as you'd expect, though it is laborious.  With undersized or cheap-o equipment there's a very high risk of something very bad happening.  Don't ask me how it know this.   ::)
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

McNuggets

Some updates since last time: I moved across town to a house with 2 driveways, into one of which I had my car towed. I didn't touch it for a few months, but recently have started working toward engine removal. I took off a lot of the easy stuff plus the ac compressor, which was tricky. I got it out without removing the RH engine mount like they do in the book, but their way is probably easiest with how little room you get otherwise. I bought some flare nut wrenches because I was worried about rounding AC and oil/hydraulic line connections with the adjustables, but can tell I will soon also be buying extensions, swivel joints, impact sockets, crows foot wrenches, etc as I suspect they would really ease working on this engine.

I haven't decided what I will do while the engine is out besides the ring gear but there's no shortage of good candidates ;D There is a long list of work that I would be silly not to do with this opportunity. Looking at the age and condition of the parts on this car is making me anxious, and the closer I look the more I want to replace. I am realizing the best would be to just set about replacing all the usual suspects in the suspension, driveline, and brakes before trying to drive it despite how slowly I am moving. I think I am in for a long and expensive period of working on smaller assemblies before I can really see the big picture but I am ok with that because it should make for a great feeling car, albeit not a looker.

To this end I am considering buying an air compressor for blasting, sanding, painting, pressure testing, tools, etc. Does anyone have a setup like this?

Nuggies

Flogrates

Air compressors are so handy, just make sure you get a big enough one

rumb

For sandblasting and painting you would really want @17 cfm compressor.  Yes thats big but you need that much air flow to do the job.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

McNuggets

I got the engine out today! I had forgotten the three sump oil hoses and the engine dampers. Lifting it out was not difficult, just go slow and try not to damage anything. I had the crane off to the passenger side slightly, which meant the exhaust manifold rubbed against the strut tower on that side, but it's not like I damaged a concours paintjob... Based on Dave's prior work in these threads: https://forum.w116.org/mechanicals/oil-sump-hose-specs/ https://forum.w116.org/mechanicals/6-9-oil-tank-hoses-and-related-issues/ I decided to cut through my hoses with a hacksaw rather than try to disconnect them with no blowtorch and the engine still in the car. I also cut the oil line from the engine to the oil pressure gauge in the instrument cluster (the fitting would not unscrew without also twisting the hardline to which it is affixed at the rear of the engine, no room for counterhold), and the diagnostic sensor on the crankshaft, which I thought was a vacuum line but does enclose two (severed) wires. Next time I do this I will remove the crank pulley beforehand. I didn't this time, and my AC condenser has flattened fins from the pulley and various hoses I did not tie out of the way.

The only real hiccup was the load-leveler I used to pitch the engine up/down. This is the ubiquitous harbor freight 2 ton model. Even with liberal and repeated application of graphite lube, the screw stripped while I was trying to pitch the engine down so that the transmission would clear the radiator support. I am lucky it only froze in place instead of letting the engine slide down the rest of the screw. They used a regular machine screw thread instead of an acme thread, which sprinkled its shavings onto my air metering plate, eek! I have got the engine+trans on a wooden crib for now, while I plan my next move.

FP

daantjie

Daniel
1977 450 SEL 6.9 - Astralsilber

raueda1

Quote from: McNuggets on 19 September 2021, 10:09 PM
I got the engine out today! I had forgotten the three sump oil hoses and the engine dampers. Lifting it out was not difficult, just go slow and try not to damage anything. I had the crane off to the passenger side slightly, which meant the exhaust manifold rubbed against the strut tower on that side, but it's not like I damaged a concours paintjob... Based on Dave's prior work in these threads: https://forum.w116.org/mechanicals/oil-sump-hose-specs/ https://forum.w116.org/mechanicals/6-9-oil-tank-hoses-and-related-issues/ I decided to cut through my hoses with a hacksaw rather than try to disconnect them with no blowtorch and the engine still in the car. I also cut the oil line from the engine to the oil pressure gauge in the instrument cluster (the fitting would not unscrew without also twisting the hardline to which it is affixed at the rear of the engine, no room for counterhold), and the diagnostic sensor on the crankshaft, which I thought was a vacuum line but does enclose two (severed) wires. Next time I do this I will remove the crank pulley beforehand. I didn't this time, and my AC condenser has flattened fins from the pulley and various hoses I did not tie out of the way.

The only real hiccup was the load-leveler I used to pitch the engine up/down. This is the ubiquitous harbor freight 2 ton model. Even with liberal and repeated application of graphite lube, the screw stripped while I was trying to pitch the engine down so that the transmission would clear the radiator support. I am lucky it only froze in place instead of letting the engine slide down the rest of the screw. They used a regular machine screw thread instead of an acme thread, which sprinkled its shavings onto my air metering plate, eek! I have got the engine+trans on a wooden crib for now, while I plan my next move.

FP
Nice work!  Good move cutting the oil pressure tube instead of trying to remove the fitting, inevitably breaking it and finding a replacement (don't ask how I know this).  Anyway, I used that same damn load leveler.  Anticipation of stripping the threads made me a nervous wreck.  Happily mine survived long enough for me to complete the job, then I threw it away.   My conclusion:  avoid Harbor Freight for mission-critical equipment. Keep us informed on progress!  It's more fun reading about somebody else doing it than doing it yourself!  Cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

rumb

Yes, those engines are big and heavy! It's quite satisfying to see the engine out of the car.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

daantjie

Quote from: rumb on 22 September 2021, 04:21 PM
Yes, those engines are big and heavy!

I recall a number of 750 lbs for the motor alone, indeed "lightweight baby!" as Ronny Coleman would say:

https://www.youtube.com/watch?v=aRz0QZc8TDE

Daniel
1977 450 SEL 6.9 - Astralsilber

McNuggets

Oh look at that, it's been another six months! I have at most three months left on my current premises for doing serious work on my car and will try to rush to have it driveable by the end of the summer. I am not sure yet where I will live next, and cannot seem get out of the habit of moving every year or so. In the meantime, I have been buying tools like it's going out of style. I have fixed up an air compressor (new belt, head gaskets, cleaned valve plate, new start+run caps, cleaned motor internals, adjusted centrifugal switch, pressure tested tank) which should be capable of about 12scfm. Its bores are pretty smooth and it looks like it had been run in a very dusty environment, but a cylinder hone costs as much as I paid for the thing... I will leave it alone for now. I've also now got a sandblasting cabinet, a filter/regulator, some hoses, and some air tools courtesy of craigslist, friends, harbor freight, and mcmaster-carr. I scored an unused parts washer from a guy who was restoring an MG but have not bought solvent for it yet.

I have also bought an old BMW motorcycle, which needed some attention too. This is my first bike and so far I absolutely love it. It looks a bit ratty because the last guy started chopping it to make a cafe racer but mechanically it is sound. I relined the gas tank, rebuilt the carburetors, fixed some electrical mistakes, changed all fluids, and registered it. Compared to the car, it is a primitive machine.

The current thing with the car: while trying to degrease the engine+trans I decided to just start taking parts off and labelling them. I think the way forward is to clean/blast/replace everything I can in the engine and suspension, then worry about the cosmetic stuff later. I need to get in the habit of spending time and money _regularly_ on this project soon, or the dream may die!

While trying to undo the inbus screws on the intake manifold, I broke the two foremost bolts as many of you warned me I would. If memory serves, this happens because they are close to the coolant passage and corrode in place. After rounding out the hex recess, I neatly drilled the bolt and tried an extractor. This sheared the head clean off on the passenger side. On the driver's side, I broke the tap socket I was using. I ordered a solid single-piece tap socket, which rounded out as it wasn't hardened. What the hell do I do now? My roommate suggested tapping the hole and using a left-hand threaded screw to try backing the bolts out. My propane torch can't be tipped over far enough to heat the head of the bolt without flaming out, as the liquid sloshes into the burner, so heating it is not an option for now.

I don't post often, but I do enjoy reading nearly everything that gets discussed on this website, how fun it is. Looking forward to a hopefully busy summer!

daantjie

https://m.youtube.com/watch?v=YqFLoq567zk

I quite like this guy  mostly he is into US muscle cars but he has tons of good info gleaned from many years of experience.
Daniel
1977 450 SEL 6.9 - Astralsilber