108 complete strip down and rebuild

[enginah]

Gidday guys,
i finally got the kick in the pants i needed and have taken Betty my 72 280 SEL3.5 off the road for a hard earned rest.
She failed her warrant on rust in the firewall on the outer edges up against the flare where the side of the engine bay meets the fire wall so will need to be stripping all the dash and wiring etc to be safe when welding etc.
once i started digging around a bit i found a bit more rust in the boot so the floor there will at the very least need some attention.
along with a whole lot of other minor jobs that need doing i thought that it would be a good time to start stripping out and starting from scratch.

just how far im planning on going depends on what i find as i dismantle her, but at this point the major bits are :
- engine and gearbox removal,
- steering and suspension removal and re-bushing / balancing etc etc
- interior removal and replacement/re-covering incl sunroof, seats, carpet, trim and cabin lining
- replacement of entire wiring harness - have managed to source one online that builds to spec with modern wiring etc for about $900nz at my door. interested to see if anyone has had any luck with them http://www.kabelgross.de/Automobiles/Me ... :6972.html
- bringing all the crap that has been done to her over the years back to original or as close as practicably possible. Except my pertronix kit which i will not let go!
- tidy up and remove dings from brightwork

If anyone living in or around the Auckland NZ area knows of any reputable panel and paint guys please let me know.
i will be doing 90% of this myself but if and when it gets above my pay grade id like to be able to take it to someone that i know will treat her right.

im sure ill have many many questions in the months to come.
and given that i do this kinda stuff for a job (marine engineer) i should be a lot more worried than i am about the task ahead!

[CraigB]

Great to hear a 108 getting the 'treatment' . Soon to get stuck into one myself. Have you removed the front guard inner panels and checked out your front jacking points etc, and bottom of front guards. Popular spots for rust. Have done firewall rust once and swore never again! Removed dash etc but still had the wife watching with a series of squirter bottles and fire extinguisher. Sound deadening just lights up and don't walk away because even after you stop will light itself up again. Make sure it is nice and cool after you finish. And a couple of less obvious spots - had one with rust in rear chassis members, like at the side and rear of petrol tank. Also seen one with rust in the front panel at base of radiator, behind bumper. Probably in none of these spots, but if you are going over it properly worth checking everywhere.

the loom looks interesting, shame they can't then put the original looking wiring cover over the whole lot - or maybe they do and that is just a file photo?

[enginah]

Thanks for the hints on the rust Craig,
i have not yet got to the point of doing the inspections, but ill be getting into everything with a fine toothed comb. i only want to do this once!
i got dragged away to sea until christmas so lots of time to sit and plan.
one of the biggest issues will be the sunroof and the associated rust, i have a feeling the drains are at least partially blocked.

ill let you know how i get on with the wiring. but i am going to try and request that it comes with original colouring to some degree.

once i get back into reasonable internet range ill try and follow up with some before pictures.

cheers

brendan

[CraigB]

and I forgot to mention my 'top tip' for 108 rust - after seeing so many rust out in front sill/ jacking point and finding mud in there, the only place it can really get in is via these 2 slots on top of the sill behind the mudguard. They are there so a captive nut can slide in place for the 2 screws in the bottom of the guard behind the trim at the bottom. I don't see why they have to be open so after I have painted everything and sealed and then screwed the mudguard in place, I have then reached in and put some seam sealer in to cover them before bolting the guard inner in. I was careful to make sure that mud and water that gets behind there sill has a chance to drain forward or back along that 'gutter' and if anything does leak into the sill somehow the drain by the jacking point is still open. And of course with any car it is good to remove those inners say at the end of winter and give it a good hose out, check for rust and maybe tectyl or fish oil in there. I don't have any long term evidence but from any car I have had, mud gets behind those inners and to me it makes sense if you put two slots at the bottom of that which lead into the sill cavity of course the mud will go in there, hold water and of course rust. I should take some photos some time to make that clearer.

[Mercmad]

do you really need to replace the wiring? in most cases the replacement of the plugs on the end of the wires is all that is required. It's hard to beat the quality of the original wiring in W108's . The front of the sills (and floor edges) rot out because water got into the sill box via the jack point. Also,stone chips in the front of the box turned into rust holes making the matter worse . it's a common fix and even in the 1960's Mercedes sent out a bulletin giving instructions on how to repair rusted front sections and jack points.

[CraigB]

Yeah but I have had them with what appears to be sealed front (for how long I don't know) and all this mud still in the bottom. And taking gravity into account I can't see how it sucks it back up in there from the jacking point. On the other hand at the top there are these two holes/slots in an area that collects water and mud. I mean have you ever removed a guard and found it completely clean there above those holes with no mud? I could be completely wrong, but unless someone can see a clear reason not to, I would give the sealing of those top holes a go....... what have you got to lose!

[enginah]

Yes sadly the wiring is pretty woeful.
at some point in the late 80's she was rebuilt and they did a few modifications to the wiring that were never drawn in. bits have been chopped up and moved and removed
The wiring becomes a bit of a time/cost benefit analysis for me.
i have the skills to re-wire, but lacking seriously in time and energy.
generally i wouldnt even consider re-doing it, but i have had a bit of a looksie and they have just tapped stuff off +12 here and there, the fuse box is still original but the wiring doesnt match factory, i dont know what is and isnt loaded up.
im getting a few reasonable earth faults intermittently which are draining the battery.
New 70A alternator installed with extra wiring also needs to be patched in tidily. so sadly unless when i remove it all and have a look it is simple fix ill be getting in a new one.
the plus side to this is that then ill know exactly what has been done.

[enginah]

righto, here are some of the before photos,
paint wise she is in really good overall condition aside from stone chips and some paint worn where the bonnet/boot are contacting with the chassis.
painful to go to all this effort when she looks so good already. but i guess its better this way than letting her get completely run into the ground before i do it eh ?


added below in another post !!

when i get home ill put up some of the work i have already done on her.

:dance:

[CraigB]

Can't see the images - might be me though.

This sounds a bit like the wiring comment, but I wouldn't remove any paint that wasn't good. If it not crazed or faded, the adhesion of that paint onto fresh metal and the quality of the paint will be hard to beat. What colour? Metallic? Some colours and metallic are hard to blend. But if the roof is good for example I reckon you would be nuts to touch it you have a perfect join line under the trim on the c pillar. trim halfway up doors is another place to join but take the trouble to lift the trim off and join behind - sometimes you find a crash shop has masked and when polishing you see the join and a bit tacky. If it was say white I would even blend in part of a panel. But your front panel and front of bonnet will be stone chipped for sure, and of course after you strip that right back to remove the chips marks and paint back up, it will of course be chipped again within a year or so of use! Unless of course you are doing a trailer concourse job!

Anyway, something to think about. Also if paint is not crazed but say faded and painting a panel, then rubbing back to primer, but I wouldn't go any further than that and just reprime over it all. That factory bond of quality paint to panel I think is something to hang onto if you can and not the 'bare metal' that people will rave on about..... unless of course crazed and then you don't have an option.

[enginah]

Thanks for that Craig.

if you right click on the unloaded image and cut and paste into browser it seems to work. just not displaying properly for some reason.
ill look into it when i have more than dial up speed internet.

as to the paint, not intending on a full repaint at this stage, just touching up as and where i can. sunroof/any other edgings that are rusting out. As far as i am aware she has been repainted once already... to what extent i dont know

the roof lining is actually immaculate sans the off yellow stained colour which is hard to see in the photos, assuming that its from many years of dirty smokers being in the car.
im going to try and clean it up but im not holding out much hope.

again. gently gently with all of this. if i can get it to the condition i want it without replacing, more the better

b

[Ivanerrol]

Dialup? Golly I thought that had gone by the wayside.
You are better off with a smart Fone

When taking images with a digital camera set it to "web Size" in the settings or the lowest setting 1024x960 on basic.

[enginah]

5 mins of writing a list and i came up with this - all off the top of my head.
hate to think what im going to come up with when i start digging. . .

[olddog642]

G'day Brendan,
that's a reasonable list for starters, I reckon that there are two ways to attack it. One start at the front and work back or two do it in order of importance.
I managed to view the photos that you posted earlier and I must say she does look to be in pretty good nick.
Oh another thing the Kilt that you are wearing what Clan is it? I could not quite make out the finer points but it looks similar to the MacPherson.

keep up the great work
Hylton

[enginah]

10323135_10152427848552386_993345995_n.jpg

bettybren.png

betty3.jpg

betty2.jpg

I finally got a hold of some of the better photos of the car.

[enginah]

The kilt is clan Wilson, which is very similar to Gunn
cheers!!

[olddog642]

The kilt is clan Wilson, which is very similar to Gunn
cheers!!

I didn't associate it with the Gunn tartan as it is a much brighter tartan than the Gunn
The Wilson Clan has a fairly notable history.

Cheers
Hylton

[Mercmad]

Ahh, Pohutukawas , where was that pic taken? i miss the beaches etc living here. it's so dangerous in the water in OZ that anything will bite or eat you and thats just the other swimmers.

[enginah]

taken at hot water beach.
yes i have been over in WA for 7 years FIFO for work, never once been for a swim!!!
i save that for when i get back to NZ!

[Mercmad]

I went there with some fellow Apprentices around 1975 and spent a couple of weeks being blind drunk and tearing up the roads in a Ford V8 coupe.. youth is wasted on the young.

[enginah]

Thoughts on engine hoists / engine stands ?
First big job when i get home this time around is to remove engine and gearbox from the engine bay.
just wondering if anyone has had any success / failures with the various engine stands about and the M116 engine ?
mountings / fittings to stands / ease of removal,

assuming that i can pull the box and the engine in one complete unit ?

love to hear your thoughts guys!
also as an aside, is it worth me writing up any of this for people planning on doing it in the future ?

cheers

[olddog642]

also as an aside, is it worth me writing up any of this for people planning on doing it in the future ?

cheers

Hi Brendan,
yes it is always worth doing a write up and with photographs to accompany it. I for one am always interested on how other people do things along with the little bits and pieces that seem to crop up plus it is always with a sense of satisfaction to be able to look back at it and say I did that.
Cheers
Hylton

[Mercmad]

Be careful of the type of engine hoist you buy. Most a down right dangerous. Drew gave me one a while back which is useless for lifting engines as heavy as Merc SIX. Same goes for engine stands of which I seem to have a surplus of at the moment .



Nearly all of the online ones are too light . I modify them to suit these big engines by making a plate that bolts to the four mount bolts. This is welded to a heavy wall tube that fits into the engine stand rotating part . The engine can then mounted sideways. If you have them off the end you can't fit the dividing plate or torque convertor drive plate etc . Plus thats a lot of strain on the engine stand hanging out the front . With these light weight stands the wheels are also too small which makes it hard to wheel around on a rough floor. I would suggest you look on Trade me etc for anyone selling an older type heavy duty stand. You can always get your money back when you are finished with it..... or make your own.
I always pull the engine out with the trans. You have to get the engine to 45 degrees to clear the front axle etc so you will need an engine tilter.

[enginah]

Be careful of the type of engine hoist you buy. Most a down right dangerous. Drew gave me one a while back which is useless for lifting engines as heavy as Merc SIX.

mines the 3.5 8, but by chance have you got the actual weight of the engine ? i have been looking online like mad, and although its been an interesting "wikiventure" finding out lots of amazing things i never thought i would know about porsches making mercedes yada yada yada, i have still not found the weight of the engine and or trans

good idea about the plate to side mount it. ill have to look into it when i get home.
we have a really nice stand here on the ship for overhauling cylinder heads, good for about 1200kg, and has a really nice gearboxed rotating mechanism. such a shame i only have a 30kg weight limit for the plane home.

the other thing i am a bit dubious about the front mount is like you say the weight of the engine. not that keen on throwing all that weight on the four bolts and then onto the block... seems a recipe for dropping the engine or at the least flogging out the mounting holes.

[CraigB]

I haven't had a problem with 'cheap' stuff - but then that might have been lucky to have good cheap stuff. I think my stuff came from supercheap over time, but too long ago now to remember and it is hard to tell when you buy stuff what it is like in the box. My thinking was that when i bought stuff on special it was cheaper than my grocery bill and worth a try. But I don't use every day and i confess that while on the engine stand i had a safety line to a cable winch to the roof.... just in case, but was fine.

Engine and trans together i always think is best. I think i may have dropped the drag link to make it easier (maybe not?) - but if you buy a joint breaker ( I have a stanley one) they are cheap, work well and have had mine for years, handy thing to make a hard job easy.

And top tip is the engine tilter - they are cheap too and you can get the engine at just the right angle and change that as you need to to clear everything - one of my favourite tools to make a hard job easy. All i would say there is to think about the angles the chains are pulling on etc to your selected points on engine - recently lent mine and they actually broke one of the hooks - I didn't see it, maybe fatigue - that tilter must have seen 20 or more engine lifts, but i wondered if it was pulling the hook on a fair bit of an angle -only mentioning as something to look out for because you don't want to be dropping engines!

[Mercmad]

For a V8 you should mount it from both sides as in this picture of a 6.3 block. A 3.5 is damned heavy probably close to 500kg with trans etc.

[AMG]

*IF* you can get one of the really old engine stands (similar to Ron's RHS side with the rotating gear) then it is relatively simple to mount it all up - except in the case of the M100, which really is a behemoth.

Notice how Ron had to extend the mount to gain clearance for rotation? That's a big torsional load on the rotisserie pivot, which is why the mount requires replication on the other side. A sensible idea for a heavy engine.

the iron block v8's are pretty damn heavy. the alloy ones, not too bad. I think the best long-term engine stand scenario is a side-mount with rotational pivot, as this enables you to hold the engine at any angle.

mine is in storage up in vegas, but is a much heavier version of Ron's and is single sided. It also can hold a holden 6 with manual bellhousing on end without any nose support - so that's about the same point load on the studs as the m100 side mount. I used it to start and run-in all kinds of engines, the main reason being that you pretty much needed a bellhousing on most to mount the starter, and protect the flywheel.

If you don't need to walk around the engine or get close to one side, then Ron's style is perfect, if you have space in your workshop. I don't have the same space, so I had to make do with the one I bought from TAFE about 20 years ago.

Nothing made in this modern era comes anywhere near the strength of the old stands. If you can hold an iron block 454 with iron heads, end-on and start it, then you know it's strong enough to hold an m100 side-on.

insofar as removing engines...... I have a gantry crane endless chain block rated to 2.5t. I don't use engine stands. It does require me to have the vehicle accurately positioned though. Something worth thinking about if your shed can fit one. I think it is the best extraction method of all. but having a hoist would make things even easier. Can't have 'em all....

[enginah]

Brilliant.
yeah that was what i was looking for !!
i think im just gonne have to make one up myself, very hard to find a decent priced one that can take a side mount

space wise its very very very tight in my garage at the moment,
i was planning on pulling the engine and doing the minor work whilst the car is away having the panel and paint done.
when it turns up ill just slide it back in after i have redone all the bushings etc etc etc.

oh yeah theres another good question .
im planning on re-doing the bushes on everything as i have it all apart and things are a bit loose and floaty seems a waste to only do part of it, so steering, suspension and all in between front and rear, been doing alot of looking at nolathane etc, but have seen first hand the issues with cracking etc when dry. im thinking of going back to rubber OEM or something to the same standard from DBdepot or Niermoller etc .
any arguements to the contrary ?


cheers

[Mercmad]

You can do it one way,and that is drop the whole engine trans and front end out of the car from the bottom. I do this by undoing the the mount bushes each side (four boltseach) .The sway bar in front (again four bolts) ,the rear trans mount and cross member ,the cross strut steering damper and the steering box (undo the coupler!) and the steering idler. You support the tranny and using an engine crane,lift the body up off the engine then wheel it out.

[stumpjumper]

For what it's worth, I remember reading that the iron block of the M116 was 60lbs heavier than the same block in alloy. MB went with the iron block (according to Rudolf Uhlenhaut) because the Eurpoean noise regs measured noise from the side of the engine, and it was very difficult to mute an alloy block. Howeve, I don't know what the M116 engine entire weighs.

I used to take the engine in and out of my Austin Healey Sprite quite regularly using a chain and a rafter. I disconnected the wngine from everything, jacked the car up using blocks of wood to get it as high as I could, then attached the chain from the rafter to a rope yoke between the lifting fittings on the rocker cover bolts. Then I lowered the car and pushed it out of the way with my foot while lowering the chain with one hand and pushing down on the emerging gearbox with the other hand. The chain ran over a single pulley and had a piece of rope tied to the far end and secured with a block and tackle arrangement to the wall of the garage. With the car out of the way, I lowered the engine and gearbox so I could work on them. Cheap, effective for the A Series engine, and fairly safe.

[Mercmad]

I think the m116 is 500 Kg. The alloy block V8 is 60Kg heavier thaqn a m180 ,which is they work so well in Finnys.