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6.9 #521 Restoration

Started by wbrian63, 28 August 2013, 06:40 AM

oversize

I'd like to design a engine stand that supports the engine by it's normal mounts and not by the bellhousing bolts.  I'm sure they're strong enough but it doesn't seem right...
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

wbrian63

Quote from: oversize on 31 October 2013, 06:09 PM
The M100s are such an impressive engine; they're just enormous!  And it must be a very scary task to have it hanging so far off the ground....

Indeed it was scary. At the peak of the lifting process, the engine hoist started making very scary noises. PING!!!! or POP!!!!! and I'd jump every single time. We traced it to tension on the main pivot point of the lifting arm, which is nothing more than a square tube with a big bolt through it. The tension was so high that the metal was grabbing...

Quote from: oversize on 31 October 2013, 06:09 PMLooking at it I don't think they were ever designed to come out that way, but without a hoist any other option is near impossible.  Unless you had 2 engine cranes to lift the body from the subframe/engine.  But then you'd have the whole body suspended high in the air which could be just as dangerous....

Unfortunately, the W116 chassis isn't designed like it's predecessors - there is no separate subframe to disconnect from the chassis. The main cross member that joins the left and right fenders is welded to the car.
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

wbrian63

Quote from: oversize on 31 October 2013, 06:12 PM
I'd like to design a engine stand that supports the engine by it's normal mounts and not by the bellhousing bolts.  I'm sure they're strong enough but it doesn't seem right...

Interesting idea, but the "industry standard" has always been to hang the engine from the bell housing bolts. A stand that holds the engine from the mounts might get in the way of any bottom-end work. Plus, the precision needed on such a fixture would be far beyond my abilities as a novice welder. I can purchase flat plate all day long. Making a frame that holds the engine on the sides is wayyy beyond my abilities.
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

wbrian63

Quote from: oversize on 31 October 2013, 06:11 PM
Great work BTW; any pics of the empty engine bay?  What is now easily accessible?

Just because you asked....

Now that the massive bulk of the M100 has been removed from the engine bay, cleaning operations are at full speed - or at least my speed.
Here are a few "before" pictures - remember that a lot of the engine compartment forward of the strut towers was already cleaned - things were really a LOT more nasty than they appear here:






Just like the PVC in the wheel wells can hide a massive amount of rust, the sound dampening mat on the firewall can do the same - so off it comes.




Hurray! No rust!

The "off it comes" seems like it was an easy task, and frankly it was, once I'd removed everything from the firewall that was in the way, which includes, but is not limited to the following:

  • Fuse box (this comes with a special prayer that I can get it reinstalled and all the wires hooked back to their proper positions when the time comes)
  • HVAC low and high pressure lines. This required first the removal of the driver's seat, which typically had frozen height-adjustment slides which are required to be free-moving to gain access to the rear screws, then about 4 or 5 trips in and out from under the dash to get the right size wrenches.
  • Vacuum line grommet adjacent to the fuse box - easy.
  • Hood release cable - easy.
  • Heater control valve - this would have been easy if the idiot that installed (or likely replaced, given the age of the car) the hose that's inside the cowl connecting the outlet of the valve to the inlet of the core would have put the band clamp on the valve oriented such that it didn't require removal of the wiper motor...
  • Wiper motor - reason noted above. Turns out this was a good idea, as the grommet for the power cable had perished and there was evidence of water incursion (small amount) in that area under the dash. This also took a couple of trips in and out of the dash.
  • Hose for heater outlet on passenger side - easy.
  • Windshield washer nozzles. I marvel at MB's ingenuity. My modern W220 and predecessor W140 cars have electrically heated washer nozzles. The W116 engineers solved the problem of freezing nozzles by wrapping the pipe that starts in the engine compartment and terminates at a swaged end to form the nozzle around the heater core inlet and outlet hoses.
  • Oil pressure line - easy.
  • Suspension control line - easy.

Once all this was done, a little careful pulling and prodding with a putty knife released the mat without a single tear. I'll re-attach it later using the same adhesive used to put the hood liner in place.

Lots of scrubbing and washing reveal a more-or-less clean engine bay:






This a view down into the area where the front level control valve mounts - nice and clean:


The drivers side shows the damage that occurs with leaking master cylinders, the subsequent removal of paint and the rust that follows. All of this is surface rust. The wetness is fresh water after wash-down of the "Purple Stuff":


I'd like to have removed the suspension lines and the rear brake line from the car, but that proved impossible.

The rear brake line is a single unit that terminates at a T in the rear of the car. I can't get the nut on the line attached to the T to break loose, even with line wrenches. It's smack up against the bottom of the body, so there's no way to get any heat in there to coax it free.

The rear suspension lines run between the rear subframe and the chassis. I do plan on removing the subframe to replace the mounts and clean it up, but not this minute.

Thanks for reading...
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

oversize

When did you remove the stabilizer bar?

LOL! I forgot about the cross-member!!!  But then that raises the point of how the factory got the M100 in there in the first place.....  Perhaps without the transmission?  Would it be easier to just remove the engine?

Make sure you thoroughly inspect the cross-member for cracking.  Can you take some pics of the welds in that area so I can compare (I think someone has tried to repair one of mine before)?  Also check the frame around the steering box mounts, as there was an upgrade for that area which included a reinforcing plate.
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

oversize

I'd even go so far to say it might be wise to have a chassis welder seam-weld both cross-member ends to the inner fenders.  The factory tack welds don't look strong enough and I've heard at least one 450 let go in this area; which will likely result in a one-way trip to the wreckers!  :( :o ??? :'(  With a 6.9 this area would be under far greater stress and I'd do it just for the peace of mind (and particularly since it's easily accessible now).
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

Squiggle Dog

You're making progress! Putting the fuse box back in place looks like it will be no easy accomplishment. I've taken out a few, but haven't installed any, at least not on a W116. W116s have so many wires...
Stop paying for animal cruelty and slaughter. Go vegan! [url="https://challenge22.com/"]https://challenge22.com/[/url]

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, Heated Seats, 350,000+

wbrian63

QuoteWhen did you remove the stabilizer bar?

After the engine was removed - it's the only way, so far as I can tell.

QuoteLOL! I forgot about the cross-member!!!  But then that raises the point of how the factory got the M100 in there in the first place.....  Perhaps without the transmission?  Would it be easier to just remove the engine?

The M-100 service manual, of which I have a really sorry copy, indicates the engine should be removed with the transmission. It is indeed possible to remove the engine from the transmission and extract the engine from the car at that point, but then you have to contend with supporting the transmission in the chassis. The transmission's only attachment point, other than to the block, is at the rear of the housing via a small rubber-isolation joint. As my intent is to fully scour the car for hidden rust, having the transmission out is part and parcel to that effort.

QuoteMake sure you thoroughly inspect the cross-member for cracking.  Can you take some pics of the welds in that area so I can compare (I think someone has tried to repair one of mine before)?  Also check the frame around the steering box mounts, as there was an upgrade for that area which included a reinforcing plate.
I've never heard of the cross member being a weak point in the W116 chassis line. That doesn't mean that the tin worm, if allowed free reign, won't cause a failure. Having cleaned the crossmember thoroughly, I find no indication of rust. I do have some dents to remove in the underside of the crossmember from previous damage due to overzealous jacking of the car without proper support. Not really required for structural integrity, but "as long as I'm there"...

I'll be happy to snap some detailed pictures for you.

Also, regarding the steering box, I also am not aware of any issues with frame stability in this area. I do recall that the 300SE predecessors had issues in this area and MB did produce a stiffener plate to help with this problem.

Point well taken that it is a good idea to check these areas for potential problems. The design of the attachment point for the steering box involves 3 tubes that pass through the hollow of the frame rail and are welded on both ends. I'll check these welds for cracks. There is no problem with rust, so far as I can tell.

That phrase - "as long as I'm there" is going to be the bane of my existence if I'm not careful to keep it in check....
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

wbrian63

Quote from: oversize on 01 November 2013, 09:44 AM
I'd even go so far to say it might be wise to have a chassis welder seam-weld both cross-member ends to the inner fenders.  The factory tack welds don't look strong enough and I've heard at least one 450 let go in this area; which will likely result in a one-way trip to the wreckers!  :( :o ??? :'(  With a 6.9 this area would be under far greater stress and I'd do it just for the peace of mind (and particularly since it's easily accessible now).

I don't know if I agree with you on this point.

If there is no visible indication of problems with the welds, I think it's best to leave things as found. Welding on the structural members of unit-body constructed cars is not something that should be done without careful attention to the cleanliness of the area being welded. When these cars were assembled originally, the metal was scrupulously clean, allowing for a quality weldment. Fast forward 37 years, adding road grime, leaking engine fluids and the addition of MB primer and paint and you don't have a good substrate to guarantee a solid weld - even if "thoroughly" cleaned with wire brushes, abrasive pads, and even media blasting. There are also risks involved with the hardening and in some cases embrittlement that can come from re-welding already welded structures.

I do agree with you that if this is a good idea, it's easy to do this type of work "as long as I'm there"...  :)

I fully acknowledge the depth of my understanding of metalurgy is not nearly complete, so if others more qualified have dissenting opinions, or can confirm my assumptions, I welcome their input.
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

wbrian63

Quote from: Squiggle Dog on 01 November 2013, 02:35 PM
You're making progress! Putting the fuse box back in place looks like it will be no easy accomplishment. I've taken out a few, but haven't installed any, at least not on a W116. W116s have so many wires...
Yep - every time I look at that bundle of snakes I get a chill up my spine. I think the hair on my head would stand up as well - if I had any hair on my head...

That being said, the risk for having major rust under the fuse box is very real, and removing the box is the only way to know for sure whether there is rust or not.

I'm glad I found none.

We shall see what the future holds regarding reinstallation. My shoulders hurt just from thinking about the contortions I'll be forced to endure to make it happen - and that's just getting the box reinstalled to the chassis.

The good thing is that I've got the driver's seat out, and have removed the brake pedal assembly. That makes under-the-dash access a lot better.

I have a crack free dash that's going to replace the current unit, and I'll likely the reinstallation of the fuse box to coincide with the R&R of the front windshield (which is cracked and needs a new seal anyway) and the R&R of the dash and R&R&R (removal, refurbishment, replacement) of the HVAC box. Once the dash is out, access to the wiring harness and bolts for the fuse box through the firewall are WAY easier.

I'm trying VERY hard to not do things that will only have to be undone, or redone later. I've got a limited number of days to accomplish the majority of the renovation to get the car road worthy. I do not have time to waste. Deadline is June 1 of next year, and while that may seem like a long way in the future, the car has already been at the shop about 10 weeks and I'm a long way from starting to put things back on the car...

My attention right now needs to focus on everything forward of the cowl/firewall area. Once the front suspension is back in place and the engine compartment is repainted along with the inner fenders, then I can look at other things.

The motor needs some work - I'm replacing everything that is rubber, including the upper-to-lower intake seals. These items harden and crack overtime and cause pesky vacuum leaks that result in rough idle. Anything rubber on the engine has turned to concrete and anything that has to come off will break in the process. I've got new parts for every known rubber item on the upper section of the motor.

I've even got a new timing chain and most of the guide rails. The timing chain replacement will be decided pending an investigation for stretch - the car and motor have <60,000 miles, so hopefully I won't find much in that area.

I don't know if it's possible to have a leak-free 70's era engine, even an MB, but I'm going to try.

The transmission is getting new seals, front and rear as well. Anything that looks like it's leaking or might leak is going to get attention. I'm even contemplating replacing the input shaft with the upgraded version, as this is a known weak point on these otherwise nearly bulletproof boxes.

As long as I'm there....
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

KenM

Fascinating project Brian, thanks for taking the time to post your pics, most informative. I can't offer any advice but I think that your methodical and thorough approach will see the job done right.

Looking forward to the next update.

wbrian63

Thanks Ken. Words of encouragement are a good thing.

This week I'm working on pulling the undercoating off of the passenger (RHS) inner fender. This is the fender that had all of the oily mess when I started working on the car.

Surprisingly, or maybe not so, several areas of PVC that were really oil soaked to begin with had completely delaminated from the metal and just peeled off leaving pristeen primer paint below.

Or maybe there was a bonding issue from the factory?

I'm about 75% done with removing the PVC coating. I'm being more fastidious about getting as much PVC off as possible. Learning from the driver's side fender tells me that less PVC means the scouring pads last longer and work better - the PVC tends to gum up the works.
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

nathan

very very nice WBF, and very very scary!
having put together a few 116s in the last few years we revived, this one looks like a monster effort.
you are tipping me over the edge to get my mechanic to rebuild my engine, and get the engine bay painted at the same time. removing that firewall liner will give an awesome result. did it come off in one piece or tear?
keep the pics coming
nathan
1979 116 6.9 #6436
2018 213 e63
2011 212 e63
2011 463 g55
2007 211 e500 wagen
1995 124 e320 cabriolet
1983 460 300gd
1981 123 280te

wbrian63

Quote from: nathan on 06 November 2013, 06:47 PM
very very nice WBF, and very very scary!
having put together a few 116s in the last few years we revived, this one looks like a monster effort.

I don't know about monster effort. So far, things are going about as one would expect for a car of this vintage. The only thing that has surprised me is the amount of rust that the PVC lining concealed without giving any indication of what lurked beneath. I'm afraid that there are many W116 owners out there that have what appears to be a solid car, but is in reality suffering the effects of the tin worm in many unseen places.

While crawling around under the car trying in vain to remove the brake and suspension lines I discovered a rust bubble on the driver's side where the frame rails "die" into the body. I don't think it's penetration rust, but now I've got another tin worm to chase. I may end up putting the chassis on a rotisserie so I can deal with the undercarriage properly.

As an aside, I find it interesting how owning a MIG welder has changed my perspective on what can be accomplished or should be attempted. Prior to ownership, it would never occur to me to build a chassis cart, or an engine stand. I'd either be altering my work processes to avoid the need for such items, or be scraping together the funds to purchase same. Now, I just start thinking about what it will take to build it...

Quote
you are tipping me over the edge to get my mechanic to rebuild my engine, and get the engine bay painted at the same time.

eek! - rebuilding an M100 is not for the faint of heart nor slight of pocketbook.

Quote
removing that firewall liner will give an awesome result. did it come off in one piece or tear?

Not an issue at all - the contact adhesive used to attach the liner wasn't fully engaged at many places. I was just careful with a putty knife and the liner suffered no tears at all. Key to the process is removing everything one can from the firewall so there's less manipulation of the liner required for extraction. The only thing that was in the way of a clean removal was the passenger (RHS) wiring harness and the hole in the liner is plenty large to carefully snake the harness out during removal.

Quote
keep the pics coming
nathan

Will do.

BTW - looking for any new MB brochures? My S55 keeps me making regular trips to the dealer. I can fetch whatever you're longing for.
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V

wbrian63

More updates - right-hand inner fender has been scraped of all undercoating:

Reading President Dr. Love's column in the recently-received Lode Star, I see with shock and awe that I have been mentioned... I hope my efforts will be worth the cost of the typesetting.

More updates - right-hand inner fender has been scraped of all undercoating:













These pictures don't show the completed work. It's done and cleaned to bare metal.

Rust was similar to what was discovered on the driver's side.

I'm getting better at this - the whole process was about 10 hours work...
W. Brian Fogarty

'12 S550 (W221)
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'76 450SEL 6.9 Euro #1164 - parted out

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter V