Evaluating the 129 series SL

2001 Mercedes SL500
Evaluating late series 129

2001 was just about the end of the line for the W129 series SL. Introduced in Europe in 1989 and presented to us in the States in 1990, the car marked a return to power and the methodical correction of all that was perceived wrong with the aging 560 SL (W107) it replaced. With 322 hp, one touch fully automatic retractable soft-top, a slick muscular design with integrated front and rear bumper impact covers and increased overall build quality, the car was an instant hit.

Buyers were basically the usual suspects Mercedes had courted for this range since the 230 SL began the move away from a true sporting brief toward the boulevard cruiser of choice: 45-65 year old high income males and well supported wives. Superb build quality and leading edge technology marked Mercedes’ desire to march straight up market distancing themselves from the Japanese who were beginning to make serious inroads into the luxury segment.

Price no object

And distance themselves Mercedes certainly did, particularly in the price department. In 1990 , the V-8 cars listed for a whopping $85 grand! But how has this car aged? Out of production since 2002 and replaced with the stunning W230 series car, the last W129 SL500s are inexpensive used cars. Are they fun to drive? Will you feel like a grey haired old fart (like me) tooling around town in one?

We decided to find out by taking our 23k mile Brilliant Silver (744) 2001 example out for a cruise on one of those ‘only in California’ 70 degree crystal clear December days. And of course we set sail for the territory where any SL on the planet is most at home – the California coast – for a blast down Highway One.

“I think you would have to be very aggressive and obnoxious on the street to begin sliding this car. The brake pads are obviously very soft and would quickly disappear with sustained hard driving.”

Our test vehicle is a Sport model with deepened front and rear bumper covers, sculpted rocker panels and the 18? AMG wheel and tire combination. This package is a must as the standard cars had silly flat face five spoke alloys that look vaguely ’70 s era hot rod familiar. Without these additions an already mature car looks even more dated. Xenon headlamps and a 6 disc CD changer complete the options on this particular car. As one would expect the list of standard equipment is enormous as it should be with the price new for this car hovering around 90 grand. The heated seats are particularly appreciated by the ladies.

Improving the original design

While the car looks vaguely like the original 1990 design, the 2001 looks more harmonious and sleek without the contrasting colored lower side cladding and the parallel symmetry of lower front and side grilles of the first generation cars built through 1995. Overall, the look of the Sport edition is very muscular and masculine due largely to the enormous 245/40 ZR18 front and 275/35 ZR18 rear tires mounted on the ‘staggered width’ AMG wheels. The fit and finish is just fabulous and in some areas, particularly the interior, various switchgear and surface finishes actually have a nicer feel and look than the next generation SL. Everything you touch reinforces the Mercedes tradition of overbuilt quality. This is why the car weighs a whopping 4165 lbs!

The interior layout carries forward the logical, legible, gauge and switchgear layout that anyone who has owned a post 1981 Mercedes will instantly recognize. Your level of comfort in this car is largely a function of how you are proportioned. The inertia reel seat belt system is fully integrated into the beautifully engineered magnesium framed seats. The male portion of the seatbelt is always accessible and vertically adjustable with the power headrest adjustment.

It will never end up pinned between the seatback and rear bulkhead as was common in the 1989 and earlier SLs. Accommodating all this seat technology dictated a seatback that is just over 6″ thick which limits the extent of available travel when you recline the seatback. I like to get my shoulders well back from the steering wheel and I’ve never felt fully comfy in these cars. I’m only 5’11″ and slightly long-waisted for my height.

I find myself wishing that the engineers in Stuttgart had managed to integrate just 2 inches more overall interior length. When the seatback contacts the rear bulkhead as you recline it, the seat automatically creeps forward to allow more rearward reclining space. And the reverse is true as you extend the fore and aft and the seat back touches the bulkhead. You can cheat this system somewhat with quick clicks of the fore and aft switch and gain a half an inch or so before the seat back automatically rises.

Other cool functions are rear storage compartments that lock when you lock the car – very handy for valuables when you leave the car with the top down – a factory alarm system, CFC free climate control system and windows that automatically drop ½” during door opening to help seal the cabin up tight. And you can program 3 sets of mirror, seat and steering wheel adjustments. The early 500 SLs also had power inside mirror adjustments.

So when you loaned your SL to a pal and forgot to tell them this fact, the first thing the new driver did was to reach up and manually adjust the inside mirror. Ooops! A few of those episodes and it was time for a new power inside mirror assembly for a $1000 or so! The 2001 has the manual mirror and everyone is happy. You’ll find a cup holder in the center console, front and side airbags, 6 speaker Bose sound system but no conventional glove box due to the passenger side airbag.

The center console has a flip-up/slide forward cover that reveals more storage. The simple failure of the button on the leading edge of this cover that allows the cover to slide forward for better arm support leads to a surprising repair. If the release button falls apart (which they seem to do with regularity) the button is not available as a separate item hence you have to buy the complete console from Mercedes which means $1,600 ish plus labor to install the complete center console. OUCH! We learned that lesson the hard way.

On the road

These late series cars are very satisfying to drive, particularly in view of their bulk. Power is adequate at 302hp and the 5 speed electronic gearbox is fairly well matched to the power characteristics. With a very tall final drive ratio of 2.65.1, 0-60 acceleration is a respectable 6.4 seconds and rolling the throttle to the floor at 40 mph will get your attention with 100 mph coming up with alacrity.

Hard and soft top operation is a breeze with power hard top release and secure functions and a fully automatic soft top. The aluminum hard top now weighs only 70 odd pounds, a full 20 pounds less than the steel top of the 560 SL, and is easily manageable by the man and woman of the house. The 560 SL top was more a job for the man of the house and a women’s discus throwing champion.

All the cars came with a detachable wind deflector that stows upright behind a lightweight cover in the trunk. It attaches to the raised rollover bar via two straps. This greatly reduces interior wind buffeting during top down cruising. If you see a car lacking this deflector, keep in mind Mercedes wants over $700 for a new one! They were standard on every W129 chassis SL.

ASR or ‘Automatic Slip Control’ is standard on these cars and senses drive-wheel slip and individually brakes the slipping wheel and/or reduces throttle until traction is regained. Should you over extend yourself on a drive in this car, you can rely on the automatic roll bar to come to your rescue if the ASR does not fully solve your predicament.

Unless already raised with the button on the dash, the roll bar will deploy itself in one third of a second if both of the following occur: the car inclines more than 26 degrees and a rear wheel extends to its full travel limit (full rebound). If the roll bar automatically deploys you will likely require a new SL and be sore for a few days.

To get a perspective from a more performance driving oriented point of view, we invited our test driver, Chris Spencer, to give us his impressions of how this 4100 lb beast feels when pushed a bit. A correct track evaluation was not possible so we headed for some familiar territory that my family has been using for the past 40 years to evaluate everything from 56 Fords to Ferrari 250 GTOs: Crystal Springs road.

“The car has a very high overall level of grip with excellent ‘turn in’ characteristics”, Spencer remarked as the scenery whistled by. “I think you would have to be very aggressive and obnoxious on the street to begin sliding this car. The brake pads are obviously very soft and would quickly disappear with sustained hard driving.” Chris wondered if the transmission would want to down shift and upset the car exiting a corner under hard acceleration and I wondered if the ASR would even allow any degree of power oversteer. The answers to those questions will have to wait until we can negotiate a free day at Infinion Raceway in Sonoma.

Living with the SL500

Here are some things to pay attention to with the late series W129 chassis. We already mentioned the center console and wind deflector replacement costs. Uneven front tire wear on the Sport models brings on an intrusive low speed rumble particularly as you bring the car to a stop. We’ve been forced to change tires with significant tread remaining to eliminate this condition on some cars. With their narrow sidewall and a wide, flat contact patch, the low profile front tires need to be regularly checked for correct pressure and alignment. This should delay the rumbling condition.

You’ll need to get on your knees to inspect the front bumper cover as it rolls underneath the front of the car. The Sport edition cover is lower than the standard car hence is more vulnerable to being ground and squashed on curbs and while negotiating driveways. Replacing a non-repairable front bumper cover can cost $1,600 although most can be repaired.

Any 129 series SL is likely to have some front valance damage. It is important to inspect the soft top for functionality and condition. Unlike the 560SL, cloudy or cracked soft rear windows can be replaced without having to remove the complete top from the frame.

The drive train is just about bullet-proof having been built since 1990 with revised ignition and cylinder heads introduced in 1999. As mileage accumulates, subframe mounts and engine mounts will progressively collapse resulting in increasing mechanical resonance transferred through the unit body. Check the seatback forward release handle functions as it is a major operation to change these cables within the seat assembly.

We look for cars that show negligible interior wear and abuse. Due to the fairly low and confined seating position, most of humanity will kick the aptly named kick panels, drag their feet on the fabric covered speakers in the door panels and chafe the seat front edge while exiting the car.

Carefully inspect the console wood for fractures as this is another very expensive item to replace. We always try to find a car that has had negligible top down cruising hence one that retains supple seat leather and rich appearing wood absent the cloudy or bleached look due to sun exposure. Oh, I should also mention the doors weigh a ton.

Looking over the MB Net vehicle history on our test car reinforces our perception of reliability. The car has made just one trip to the dealer for its FSS (flexible service system) prompted service. During this service visit which, by the way, is free for ‘ 01 models, we see only an oil level sending switch repair performed over and above the service. We did send our car to MBZ, however, as we’re aware of failing crankshaft pulleys on many of the 2000 and later V-6 and V-8 cars.

If left unchecked the wobbling pulley will slowly machine a nice groove in the front engine cover eventually requiring its replacement, a very expensive repair for a car out of warranty. We check all the pulleys and tensioners on these cars and after checking our SL, requested MBZ to replace most of these items. So there are now a few more entries in this cars warranty data bank.

I do like these SLs. They are well built, have good power and are easy to drive quickly with a minimum of fuss. There are many around and these late series cars are fundamentally reliable, well developed SLs. Soft and hard top functions are as slick as you’ll find, short of the current retractable hard top.

roy spencer/editor mercedesheritage
photography/mercedesheritage