1996 Mercedes SL 600

[Hereward]

Zonergem said:

Great stuff. Did you know how many flavours of bump stop there are?



Courtesy of W124Performance.com
http://www.w124performance.com/images/W124_suspens...

Wow, that is mad! My original reddish ones and the yellow replacements are 96mm variants. Definitely a car set up more for wafting rather than storming the Nurburgring.

[Hereward]

Howitzer said:

Really interesting thread.

I was wondering how you ordered directly from MB Germany, did you do it online?

I’ve been told both the loom and parts to make my own one are NLA from Mercedes so being able to confirm that would be a benefit. Both my closest parts places have lost the very good parts guys they had sadly.

Dave!

I used these people. Been very good so far:
https://www.online-teile.com/mercedes-ersatzteile/...

You'll need to input the part numbers, though. This site is good for the parts diagrammes:
https://www.genuinemercedesparts.com/auto-parts/19...

However, there is a guy in Kent who specialises in fabricating R129 wiring looms. I can't recall his details but Zonergem will know.

There is also this guy in New York. People post him all sorts of stuff to repair:
https://www.youtube.com/user/vsandvs/videos

Edit - you have a 500E?!

Edited by Hereward on Saturday 17th February 08:29

[Hereward]

Howitzer said:

r129sl said:

Can I ask what lift you're using? Is it a scissor lift? I fancy treating myself. Apologies if this has been dealt with before.

I think it was an Automotech Services Ltd AS-7530D. I found this thread by doing a search for a scissor lift to fit a W124 and the 129 wheelbase is pretty similar.

Dave!

Indeed. I couldn't do a fraction of the work done without it. It's a no-brainer with man-maths (cringe) - you will quickly recover the outlay by being able to do the work yourself. You will also need a small air compressor for it, to operate the pneumatic safety locks.



You can just make out the rubber blocks on the R129 jacking points. For cars with a longer wheelbase (such as my E39 Bimmer) the grey ramp sections can be locked in place horizontally:


Being able to sit or kneel under the car makes life so much easier. I laid down a double layer of foam matting from Halfords so it's quite comfortable.

Dave, your 500E needs its own thread.

Edited by Hereward on Saturday 17th February 10:42

[Hereward]

f1ten said:

...How did you get on with the diff leak ? I'm told you can end up with even worse whines if you change it ? Have you had a costing yet ?

Have you done any of the suspension ?

Sorry, I didn't see this.

I had the diff leak sorted early on. Not cheap at all. Can't remember the cost but I think it was £hundreds.

I haven't replaced much in the way of suspension yet. From what I can recall I had a pair of rear arms replaced since a bush had torn and was leaking grease. The rest looks original (ie tired) so probably worth looking at sooner rather than later.

I have had an intermittent issue with the ADS suspension. The orange dash warning light would come on randomly every now and again. This defaults the suspension to a rock-hard setting, perfectly driveable but not very comfortable. The issue began to crop up more regularly until it would trigger on every journey. The random nature of the issue led me to suspect a dying accelerometer. I bought a used one from ebay for £30 and swapped out the suspect unit (from 1996) and all has been fine since. Replacement is simply plug-and-play, no calibration nonsense required.

Dying accelerometer held next to the second-hand replacement part bolted to top of the front left suspension turret. Replacement manufactured in 2008 so it's good to see the modern ones are backwards compatible, readily-available and cheap:



I also replaced the cabin air filter. This is sensibly mounted at the bottom of the windscreen and easily accessible from the engine bay:





I performed an oil change last week, using a vacuum extractor through the dip-stick tube. I keep meaning to do a "proper" oil change from underneath but just can't be arsed. Anyway I think she's had 3 oil changes in 3,000 miles, so it's not the end of the world! I pumped out about 9.3 litres using this method:



When she's parked up I always try to leave the bonnet open to cool down the engine bay quickly. It's very cramped in there and the heat build up can't be ideal.

[Hereward]

Zonergem said:

Always good to hear updates on this fabulous car. I'm starting a GoFundMe page to buy Hereward some wheel cleaner

The 600s that come up for sale are shifting and seemingly at considerably higher prices than a 500 in the same condition.

I have heard of a 1993 600SL in Lincolnshire that the owner might want to part with "because it's just too fast". On about 100k, apparently in good order. A pre-facelift 600 is a scary proposition - wiring looms, throttle bodies, ADS, timing cover case oil leaks and all the other thousand natural shocks that R129s are heir to - but I am quite tempted to follow up and just see what it's like.

Hehe, funnily enough I washed the car (and even the wheels!) just this morning. They have to be the easiest alloys on the planet to clean so I have no excuse. The car doesn't get driven in the rain so the bodywork just gets dusty rather than dirty. I think I last washed it in Q3 2017. Anyway, she looks much better for it and I even waxed the bonnet in a fit of detailing madness.

Yes, the pre-facelift cars have a few more potential issues but once those are checked/sorted then normal service resumes. For some reason I am getting a real hankering for buying a tatty very early 500SL. There's something massively appealing to me about cruising around in an 1989/G R129 and not being too precious about it...

Speaking of being "too fast" I received my first ever speeding ticket earlier this year, for doing 67 in a 50 in the Merc. 3 points and £100. Oddly enough my insurance company weren't too bothered and my annual premium then went down 20% at renewal. Erm, okay...

[Hereward]

MOT passed last weekend, no advisories (or whatever they are called now the MOT has been revamped).

If you have ADS2 suspension make sure the red button is pressed if any wheels are going to be jacked up off the ground with the engine running. This is to prevent over-pressurising of the hydraulic reservoir (this happened to me in last year's MOT).



I treated the canvas hood to a coating of Fabsil Gold, which is easily applied with paintbrushes in about 25 minutes. This stuff smells pretty fruity until it's dried out so best to apply in a well-ventilated area or outdoors. My hood hasn't been wet for 2 years but good to know it's ready if I ever get caught out.

I forgot to mention previously that Panasonic Japan were unable to provide replacement parts for my head unit so I purchased another one on Ebay. It works fine apart from the display, which resembles Predator's watch. Happy to live with it for now since I can locate my Top Gun sound track CD easily enough. At least I don't need to look at a broken cassette flap anymore.

[Hereward]

.

Zonergem said:

Hereward said:

For some reason I am getting a real hankering for buying a tatty very early 500SL. There's something massively appealing to me about cruising around in an 1989/G R129 and not being too precious about it...

Not a G but close. Advert is, um, concise.

https://www.ebay.co.uk/itm/Mercedes-SL500-converti...

Oooh, ya bugger, that advert has triggered something in me. What an adventure that car could be. Especially buying it unseen for added excitement! Its recent MOT history shows a somewhat volatile range of mileage recordings.

I like the colour and the solitary photo suggests she might have been tucked away from rain and ultraviolet light.

Oooohhh, what shall I do?!

[Hereward]

Thanks for your insight. The poverty spec only adds to the appeal.

Shame about the additonal pics; I was hoping the brevity of the original ad would deter bidders.

I will mull this some more but I was thinking of a cheeky £2.5-3.0k bid. But I guess the breakers would happily pay that too?

It would be great to save this car rather than see her broken for parts.

I will assume the roof doesn't work and that she's been jump-started. I will also assume ~£3k to then get her to a basic level of roadworthiness.

[Hereward]

Zonergem said:

Sod the H plate, here's a real live G and it sounds not too bad.


https://www.carandclassic.co.uk/car/C1000331

Oh farrrrrkkkkk. Seriously, faaarrrkkkk, that's the one! Thank you.

She's absolutely perfect, my favourite wheels, beautiful two-tone paint...

I'm going to sleep on it...reverting.

[Hereward]

jke11y said:

Zonergem said:

Sod the H plate, here's a real live G and it sounds not too bad.


https://www.carandclassic.co.uk/car/C1000331

And they’re still turning a profit

https://www.historics.co.uk/buying/auctions/2012-0...

Great find!

[Hereward]

Sorry to report that I won't be proceeding with the G. I ran the proposal by Management but was met with a resounding No and I suppose the logic of "You've already got one and you hardly drive that" made sense.

It deserves to be used and cherished and I hope it finds a happy home.

[Hereward]

The amazing weather so far this Summer has been a delight. Unfortunately I was over-exuberant with the wing mirror adjuster and managed to break the knob. Not entirely sure what happened but I think I tried to turn it past its right-side limit point for some reason.



A second-hand knob was purchased on eBay and the replacement looked drastic, due to the access required to the underside, but was very straightforward.



The centre console is held in place with just 4 screws; 2 behind the climate control unit and two under the lining of the central cubby hole. I removed the climate control, the audio head unit, the trim around the gearbox selector and the cubby hole liner. The console can then be gently prised out. It has a bit of flex in it which aids removal. I was VERY careful. If I had broken it in half I would have definitely punched myself to death.

As with all these things test the operation of the new component before putting everything back together!

[Hereward]

Tyersm said:

Hey dude - I’ve got a 129 600 too. Can I bring it round for fixing ?

Of course.

[Hereward]

bolidemichael said:

Hi Hereward, fancy posting some more updates, since you might not have punched yourself to death, yet?

Self-punching was averted following successful installation of the mirror switch.

I am currently about to embark upon replacement of the rear lower suspension arms and associated bushings, nuts and bolts. A routine inspection of the underside showed the rear left knuckle bush has failed. I have the shiny new parts for fitment but I think that replacing the knuckle bushing is going to be a bugger, requiring removal of the knuckle so the old bushing can be pressed out and the new one pressed in. We shall see the true state of play when I start to take things apart.

Rear left suspension. The left end of lower control arm is attached to a failed bushing in the knuckle that the bearing and wheel hub mount to. Might be a pig to attend to. Looks like the whole suspension set up is the original 1996 vintage (apart from the ARB drop links) so it all needs replacing, really:


Nice new bits, direct from Germany:


New knuckle bushings. I think they will need to be pressed in to place...tedious:


In other news I had the centre muffler/resonator box chopped out of the exhaust and straight-piped. I have left the back-box in place. This has turned the exhaust note from a muted, distant hum to a straight-six-esque purr, building to something more shrieky higher up the rev range. To be honest I am not sure if I like it. This car is the very essence of silent wafting, with a 12 cylinder sewing machine whispering up front and a quiet hum from behind. Perhaps I shouldn't have messed with it. You wouldn't put a sports exhaust on a Rolls-Royce saloon and I sort of feel the same about this car. It's like when you try and make your elderly Dad wear trendy clothes, it just doesn't suit him.

[Hereward]

Here's the knuckle bushing in all it's glory. I don't think that will polish out - compare it to the new replacement bushing in my previous post!

It looks like it died many miles ago but I haven't felt or heard anything untoward. The rear wheels are held in place with a multitude of arms so the others (and the hydraulic suspension) are clearly doing a good job. Everything looks original so I will work through replacing them in due course.

I want to press it out without removing the knuckle from the car so I have ordered an in-situ pressing tool from the US at vast expense. In the meantime I will wire brush and soak the area in penetrating fluid and pray it doesn't put up too much of a fight. I will need to rotate the brake backing plate to gain access, I think. Bit of pain since that means calipers, discs and park bake components have to come off.

Edited by Hereward on Sunday 30th September 15:48

[Hereward]

New nearside bushing pressed in and new arm fitted. Now I need to do same again on the offside.

Old versus new:


Pressed in to position on the knuckle:


I purchased this Baum Tools pressing tool from the US at vast expense. It's very compact, allowing bushings to be removed/replaced in situ. The brake backing plate needed to be slightly bent out of the way, that's all:


I appreciate these micro-detail pics and updates are massively dull so I will endeavour to take some more out-and-about pics going forward.

[Hereward]

For those with Esprit obsessions I hope you are following "Soup classic motoring" on Youtube. Well worth checking out.

I have finished the Offside suspension work and been for a successful test drive so it's all done.

I have spray waxed the new arms, nuts and bolts. There is also a plastic cover for the lower arms (not shown in this pic) that protects the arm from stones and grot being flicked up.



Not sure what the next project is at this stage but I am sure something will rear its head. I may simply slowly refresh all the suspension arms but some of the nuts and bolts are so corroded it could be a right can of worms. I have also noticed the 722.6 gearbox kickdown sometimes results in a long pause before a rough engagement of the lower gear so I am wondering if I should check out the conductor plate solenoids. Perhaps I should replace the kickdown switch first. I can't really be arsed to delve back in to the gearbox again but it may be a Winter project.

[Hereward]

No dramas over Winter. I topped up the ATF and that seems to have helped smooth the kickdown.

I have performed a partial coolant flush. The system takes 20 litres of which 10 litres can be easily recovered from the radiator petcock. There are further bleed points on the engine casing but the coolant was so clean I didn't worry about chasing every litre.

Radiator petcock easily accessible from underside:


There is a bleed nipple adjacent to the petcock so a hose can be attached for mess-free draining:


Once the radiator/expansion tank have drained tighten up the petcock and refill via the expansion tank:




I had wanted to flush the power steering fluid (PSF) ever since I acquired the car. There is a PSF reservoir in the V of the engine but it was not possible to siphon much out. A proper system flush was required:

PSF reservoir located at the top of the engine under a cover, adjacent to the thermostat:


Access to the power steering pump hoses requires removal of the nearside air intake:


The pump is a tandem pump - it pressurises both the power steering circuit and the ADS hydraulic suspension circuit:


A tandem pump for those models fitted with ADS:


Other side of the tandem pump. The two male hose connections lead up to the top-up reservoir:


I made some plugs:


I disconnected the return line and plugged it. You can see how filthy the PSF is:


I connected clear hose to the return line and then jacked up the car and turned the steering lock to lock (with the engine off) to purge the old fluid. I kept the reservoir topped up with fresh fluid and turned the steering until clean fluid ran through:

Edited by Hereward on Saturday 9th March 17:24

[Hereward]

A few more excruciatingly dull pictures...

Brake fluid changed, so that's all the fluids taken care of.

I used a Gunson bleeder that attaches to the master cylinder reservoir. Pressure is provided via a connection to a car tyre that I had adjusted down to 15psi:


No need to pump the brake pedal with this method; simply pressurise the reservoir then open each individual bleed valve in turn.

The bleed valves were in reasonable condition but I replaced them all anyway:


I used some 6mm inner-diameter tubing connected to a plastic bottle to collect the purged fluid:

[Hereward]

Oh wow, thanks. None of this is difficult, it's simply swapping out bits of suspension and changing fluids. I watch YouTube videos then get stuck in. The guys who strip engines and work on electrics/electronics are the clever ones.

The brake fluid change used less than a litre, if I recall correctly. Basically the bottle shown in the picture was more than sufficient. However, I may not have fully purged all of the old fluid - it was already so clean I couldn't tell at what point the new fluid had started to come through, but at least the calipers have been fully purged. The fluid sitting in the calipers takes all the abuse (ie heat cycles) so at least get that portion refreshed.

Before you do anything use a syringe or turkey baster to draw out most of the old fluid from the master cylinder reservoir then refill it with fresh fluid. That way you are pushing fresh fluid in to the system when you start.

General rule of thumb is to start on the caliper that is mounted furthest from the ABS valve block. My car has the master cylinder just in front of the driver and the ABS/BAS block mounted on the other side of the engine bay, near the Nearside headlight. I started on the rear right caliper. You're not going to ruin anything if you do a different order but basically I think you should do the two rear calipers before the two front calipers. However, once YouTube guy I followed always starts bleeding the front calipers.

If you replace the bleed valves/nipples do so before pressurising the system. Just have a bit of towel ready since fluid will ooze out during swap over. Replacing will also be introducing air in to the system, so bleed the calipers afterwards.

The pumping of the brake pedal trick seems a popular alternative method but it can damage seals in the master cylinder if you're not gentle, or if the master cylinder is not in the best of health.

Goes without saying but don't spill brake fluid on paintwork/eyes...

When you go for a test drive afterwords be very cautious and test them at slow speed as early as possible.

Fascinating stuff is brake/hydraulic fluid. I read that as long as it's not contaminated with water or trapped air it transmits force at the speed of sound!