Update your bookmarks! This is the new version of Brian Clifton's SL guide
- The Mercedes-Benz R129 SL (1990 - 2002)
- Styled by Bruno Sacco
- 4th generation SL
- Preceded by the R107 "Panzerwagen" and succeeded by the R230
- Click here for a photo gallery
The R129 is the fourth generation of the SL and is my favorite of the series. The 300SL Gullwing and 300SL Roadster are beautiful, but they are a bit old for my tastes and I also don’t have pockets deep enough to buy (or maintain) them. The 113-Pagoda and 107-body SL are without doubt classics... but they don't have a lot of power and I think they are dated in many ways. I believe the 129-body SL offers a great compromise between power, modern technology, and the comfortable cruising you’d expect from an SL.
Before I jumped in and bought an R129, I looked quite a bit at the 230-body SL. I don’t like the look of the body style as much as the R129, but they do feature a retractable hardtop. Through all my searching, I’ve found there are several advantages the R129 has over the R230:
- You can actually fit golf clubs in the trunk; I’ve actually managed to fit two full golf bags in there! You’d have a hard time squeezing a cooler into an R230.
- The panoramic roof option on the 129-body is amazing; it offers ridiculously large views of the sky, much bigger than the panoramic roof on the R230.
With later V8 models which feature the M113 engine, you also have a lot of supercharging options. It’s essentially the same engine as what's in the R230 until the SL550 came out for model year 2007.
This guide is my attempt at helping folks who love the R129 or are interested in buying one. I've collected information from various sources and wrote most of the guide myself. Bud Cloninger, MBCA Desert Stars section President and owner of MB Motors here in Phoenix Arizona, has also helped a lot by contributing content. I've tried my best to note where credit is due.
What to look for
So you finally find a car in the newspaper, online, or for sale at a dealership. Here are the most important things to keep in mind while you are examining the car.
Does the car have a wiring harness issue?
If the car is model year 1993, 1994, or 1995 more than likely there was or will be a wiring harness issue. It’s a known problem but a recall was never issued. Repairing this can cost several thousand dollars (unless you do it yourself; parts cost roughly $500 - $700). If you are considering a 1993 - 1995 model year and can’t verify if the harness was replaced, take the car to a good Mercedes-Benz mechanic. Someone that has worked with these cars a lot should be able to quickly tell and give an estimate if the harness needs replacement.
Does the car have a wind protection screen?
Starting with model year 1993, the wind protection screen (also called a “draught-stop”) is standard equipment. The windscreen snaps onto the roll bar and helps provide a super quiet ride when you have the top down. If the car has one you’ll find it in the trunk. Pop the trunk and you should see a compartment held by 3 straps. Un-strap those and you should see the windscreen, hopefully in good shape.
Does the car have a removable hard top?
If the car you’re looking at does not have a hard top, you will have to find one that fits. The roofs for all R129s are not entirely interchangeable. Late model SLs have a much larger seal around the A-pillars and windshield surround.
Does the car have a panoramic roof?
You’ll notice the very top is black and the rest is body colored. If the car is black, you’ll probably have to jump in to notice. Regardless, you can tell the difference in the hard tops from the outside. The panoramic roof has a more round and much smoother shape to it. Having the roof from the beginning is a huge plus; Buying the roof afterwards can cost anywhere from $500 - $2500 and you may have to match the paint and interior after that. I am not positive, but I think the panoramic roof is only compatible on model year 1995+ because of the seals.
The soft top and rollover bar (tips by Bud Cloninger)
When you look at the car you should always work the soft top and rollover bar several times and check for hydraulic leaks at the front A pillars by the visors and at the pistons that lift the top and soft top boot. In my experience the tops that are not exercised occasionally have a better chance of leaking.
You can tell if the soft top is original by examining it; when you look close, you should see a checkered pattern. You can also test to make sure the soft top still works well by trying to pour some water on it and see if any water makes its way through the plastic window. The canvas top comes in two pieces and just the rear with the plastic windows can be replaced if needed.
Wiring for high mounted stoplight and alternator harness (tips by Bud Cloninger)
Check the high mounted stop light (the 3rd brake light) for function. If it does not work there is most likely an open in the wires at the right side trunk hinge. In two cases I have found the brake lights were stuck on because of a “short” had a cured instead of an “open” at the trunk hinge wires, and it melted wires together way into the wire loom up by the drivers left foot rest.
Also have found on early V8 cars the alternator wire harness can chafe on heat shields when the engine mounts are collapsed from age. This can lead to serious alternator and electronic control unit failures from voltage spikes and short circuits.
Does the car have any non-standard packages?
The SL600 includes should include all options standard. If the headlights aren’t Xenon, maybe they were replaced because of an accident. For other vehicles, you’ll want to see if any packages were included. There are two main packages: SL1 package which features an AMG body kit (bumper, side skirts) and 18 inch AMG alloys with sport tires. The SL2 package offers Xenon headlights and heated seats.
Is the car a special edition?
There are several different special editions of the 129-body SL. These could significantly affect the long term value of the car. It’s possible the owner doesn’t know what they have. Here is a list of the editions to keep an eye out for: Mille Miglia Edition, Designo Edition, 40th Anniversary Roadster Edition (1997), Special Edition (1998), Final Edition (2000), SL Edition (2000), Silver Arrow Edition (2002).
Is the car an AMG model?
Inspect the car closely, because it’s easy to buy AMG badging and put it on the car, and it’s easy to buy AMG wheels. An AMG is distinguished by its hand-built engine with a distinctive serial number a badge on the engine signed by the builder. There are only four types of AMG-modified SLs and they are rare. The SL55 (65 units made), the SL60 (633 units made), the SL70 (150 units made), and the SL73 (42 units made). Most of these cars live in Europe. Keep in mind that only 204,940 total units of the R129 SL were made so the AMG models are extremely rare and valuable. If the buyer is questionable, most likely it’s not really an AMG original.
were the first to have the new designation. For example, 500SL is now SL500.
featured minor facelifts for the car:
- V8 and V12 upgraded to 5 speed electronic transmission; previous transmission was hydraulic 4-speed
- Bumper and side panels are now body color
- Grill now only has 6 slats instead of 7
- Front fender vents updated; only 2 rounded slots, rather than 3 squared slots
- Panoramic roof is now an option
- Xenon HID headlamps standard on SL600, optional on SL500
- Clear front turn signal indicators
- Addition of side airbags
- A new front-seat occupant-detection sensor could deactivate the right-side airbag when it determined that the passenger seat held less than 26 pounds
- "Sport" package became an option
- Rain-sensing windshield wipers standard
- Three-way programmable garage door opener HomeLink transmitters built into the rear-view mirror
- Replaced the earlier climate control panel with one with a much larger LCD
- Remote control uses dual infrared (IR) and radio (RF) control
featured a second facelift occurred for models which included:
- V8 engine switch from M119 to M113
- Body color door handles
- Side mirrors in the SLK style
- Soft Nappa leather seats replace the perforated leather seats
- Tail lights with curved faces replacing the classic square stepped lights
- New engine vanity cover
- Instrument cluster now has chrome rings around each gauge
- Fiber-Optic digital audio links to the CD player instead of analog copper
- 17-inch wheels standard: Wheels are now 8.25 x 17" with 245/45ZR17 tires. Sport package is 8" (front) or 9" (rear) x 18" with 245/40 (f) and 275/35 (r) tires.
|Model||Chassis||Engine||Horsepower||Produced from...||...until||Units made|
|Model||Chassis||Horsepower||Produced from...||...until||Units made|
For the inline 6 engines
- 300SL/300SL-24/SL280: 5-speed manual gearbox, 4-speed automatic optional
- 300SL-24/SL280: 5-speed automatic optional from 1989
- SL320: 5-speed automatic standard
For the V6 engines
- SL280: 5-speed manual gearbox, 5-speed automatic optional
- SL320: 5-speed automatic standard
For the V8 / V12 engines
- 4-speed automatic standard, 5-speed automatic standard from 1996.
- To save these to disk, right click the links and pick "Save Target As..."
These are the original owner's manuals in PDF format. They have everything the real manual has.
|1996||1998 Technische Daten|
|1999||1999 Technische Daten|
ADS II shop manual
- "The WIS is woefully incomplete regarding this system, as is alldata. For the most part, ADS-I diagrams and components are shown, and are mis-labeled as ADS-II. This creates a huge problem with shops not knowing what they're doing. Even the bleed points shown in WIS are not accurate."
- '"Steve Brotherton was apparently aware of a german-language version of this thing and managed to track the english one down, so now I have come into possession of the entire 162-page ADS-II factory manual. This material is pre-labeled for insertion in WIS, and was apparently slated for inclusion, but for whatever reason MB never actually did put it in. So accordingly, 95%+ of this is not found in WIS."
The videos are part of the R129 Infoaccess Course (part number: TT-2806-CD). This course was released to the public by Mercedes-Benz USA around the year 2003; You can download the full training course (which includes all of the videos) from here: http://www.mercedestechstore.com/r129.htm
If you have any doubts, you can do a WHOIS lookup on the domain above to verify that it's owned by Mercedes-Benz USA, LLC.
The removable hard top
- Installing the hard top
- Removing the hard top
- Manually operating the hard top (if the automatic system is broken)
Roll bar and hydraulics
- Removing the rear storage compartment cover
- Removing the paneling covering the roll bar / top hydraulics
- Removing the rear carpet to get to the hydraulic control units
- Overview of the roll bar
- Roll bar components
- Roll bar operation
- Overview of seat safety
- Removing the seat cushion, back cushion, side panel, seat belt cover, and lower trim panel
- Removing the seat belts and the seat frame / rails
- Seat belt sensor
- Removing the wood trim over the center console
- Removing the center console assembly (including armrest compartment)
- Removing the eyeglasses compartment (including lock assembly) and center A/C vent
- Removing the passenger airbag, instrument cluster, side air vents, light switch, and parking brake
- About the instrument cluster
- Steering column and other areas to check before removing dash
- Removing the ignition
- About the shifter
- Removing the exterior lock and door handle
- Removing the interior door panel
- Removing the door mirror covers
- Door adjustment / fitment
Disassembling the soft top
- Headliner removal
- Seals, weatherstrip, B-pillar
- Weatherstripping, canvas, rails
- Canvas removal
- Video 5
- Video 6
- Video 7
- Video 8
- Video 9
- Video 10
- Video 11
- Video 12
- Video 13
- Video 14
- Overview of passive security
- Overview of suspension
- Overview of the M104 (300SL)
- Overview of the M119 (500SL)
- A/C Light
- Crankshaft position sensor signals
- Hall effect sensor
- Variable cam timing
- Hermann Ries (2009, Fall). Simply beautiful. Mercedes-Benz Classic. Pages 76-79.
- [Uncredited] (1989, January / February). World Premiere For New SL. The Star, Volume 34, Number 1, Page 21.
- Michael Cotton (1989, May / June). New SL Stars at Geneva Auto Show. The Star, Volume 34, Number 3, Pages 48-51.
- Frank Barrett (1989, July / August). 1990 300SL & 500SL. The Star, Volume 34, Number 4, Pages 22-29.
- Frank Barrett (1989, November / December). Mercedes-Benz for 1990............. The Star, Volume 34, Number 5, Page 36.
- Frank Barrett (1992, November / December). 600SL Leads 1993 Models. The Star, Volume 37, Number 6, Pages 46-47.
- Frank Barrett (1993, January / February). Truly Grand Tourers, The V12 Coupes & SL. The Star, Volume 38, Number 1, Pages 34-37.
- Ian Fraser (1996, May / June). Driving 40 Years of Big SLs (Part II). The Star, Volume 41, Number 3, Pages 48-51.
- [Uncredited] (1997, May / June). Factory News. The Star, Volume 42, Number 3, Pages 36-37.
- Jim McCraw (2000, July / August). SL600 Nearly Grabs One Lap of America. The Star, Volume 45, Number 4, Page 42.
- Brian Clifton (2010, July / August). Buyers' Guide - R129 Roadsters. The Star, Volume 55, Number 4, Page 56.
- David Sutherland (2006, January). Black beauty. Mercedes enthusiast, Issue 51, Pages 58-65.
- Tim Slade (2006, April). Macho Man. Mercedes enthusiast, Issue 54, Pages 46-51.
- Ian Kuah (2007, June). Original Sinner. Mercedes enthusiast, Issue 68, Pages 36-40.
- Eric Richardson (2009, March). First In Line. Mercedes enthusiast, Issue 89, Pages 36-42.
- David Sutherland (2010, August). V Almighty. Mercedes enthusiast, Issue 106.
- Chris Eckermann (2011, March). A Green Dream. Mercedes enthusiast, Issue 113, Pages 96-97.
- Karl Middelhauve (2011, May). Dream Come True. Mercedes enthusiast, Issue 115, Pages 86-88.
- David Sutherland (2011, July). More Than Metal. Mercedes enthusiast, Issue 117, Pages 66-70.
- English (US) owners manuals obtained from https://www.mbusa.com/mercedes/service_and_parts/owners_manuals
- German language manuals were sent to me via email