1970 300sel 6.3

[RR3]

I am considering buying a 1970 300sel 6.3 with 100,000 miles.
I would be the 4th owner. Current owner has all maint records.
I have not seen the car yet, will look at it on Sunday.
Apparently it has no rust.
What should I look for.
I know air suspension is a problem and the tranny.
Anything else?
Or should I go for a 280SEL instead?

[Jim Anderson]

Make sure the headrest is in good shape so you don't get whiplash when you step on it.

The rear ends tend to be a bit fragile on this model. Anything M-100 engine specific will probably be $$$$. The 280 SEL, with steel suspension and more commonplace drivetrain components would be less expensive to repair/maintain.

BTW, unless this car has been driven exclusively in a dry climate, no rust more likely means no obvious rust. Check the usual suspects, floorpans, rocker panels, wheel openings, etc., the bottom of the spare tire well and the front edges of the front fenders, just above the headlight assembly.

[Q45Denver]

Have it checked out by a shop or someone that knows these cars and what to look for. How do you know the mileage is correct?

[el presidente]

Fuel pumps are $$$$$$$$

[Emmerich]

Have a knowledgable mechanic that you can take the car to when needed. I live in Dallas and have yet found somebody I trust to work on it. Check with m-100.org or m-100.cc and check the safety net pages for M100 people in your area.

Where are you located?

Fred

[RR3]

I'm in Toronto.

[deanyel]

Originally Posted by RR3

Or should I go for a 280SEL instead?

I think the more practical alternative to a 6.3 is a 300SEL 4.5. The 300 has more wood, leather standard and other nice touches. They always seem to be floor shift as well. 4.5 parts and service are easier than the 6.3, although the M100 engine itself is quite durable. The transmission in a 4.5 is going to more reliable as well - not overmatched by the engine. The 6.3 is a 4 speed, and then they went back to a 3 speed on the 6.9. I once had a 6.3 with a 6.9 transmission, because the 6.3 transmission just wouldn't hold up for the previous owner.

A 300SEL 4.5 is a great car - fancier than a 280, and still pretty easy to take care of. Another great thing about it is that you can convert it to coil springs with some 108 4.5 parts, if you get tired of taking care of the air susupension. I've never heard of a successful coil spring conversion on a 6.3 - the engine just weighs too much. A 300SEL 4.5 with coil springs is a very practical and desirable classic car - assuming your not too hung up on originality.

[wbain5280]

Be careful if you want to convert a 300 to coil springs. The front lower control arms would have to be replaced because the 300's are curver for the extra room needed for the air bag.

[gerryvz]

Originally Posted by RR3

I am considering buying a 1970 300sel 6.3 with 100,000 miles.
I would be the 4th owner. Current owner has all maint records.
I have not seen the car yet, will look at it on Sunday.
Apparently it has no rust.
What should I look for.
I know air suspension is a problem and the tranny.
Anything else?
Or should I go for a 280SEL instead?

Look carefully for rust. The main places would be on the undercarriage, the inside of the wheel wells and the wheel well lips (if the car has chrome edging around this wheel wells, this is often added to hide rust); bottom of the door panels, and inside the trunk (remove all mats and look down the sides of the trunk). I have only seen perhaps 5 6.3s in my life that DID NOT have rust in some manner, and I've seen a couple hundred of them all around the world.

The suspension isn't a problem if it's been properly maintained. Unfortunately, most owners don't put the maintenance required, every 5-10 years, into keeping it operating properly. So it's probable that you should count on $4,000 for a suspension rebuild (this mainly entails a set of 4 new rubber airbags, set of 4 suspension control valves, any air-line work, and labor). If the car "settles" down in anything less than two weeks, then the air suspension needs attention. Again, unfortunately, 90% of 6.3s need attention in the suspension department. Deferred maintenance.

Transmissions are pretty reliable, though most suffer the common "leakdown" problem inherent to MB fluid-coupling units whereby the seals harden, and gravity causes the fluid to leak past the internal seals into the bottom of the fluid coupler. This causes slippage upon startup. What you have to do is let the car idle for a minute or two after starting in order to let the fluid circulate, and the seals to saturate with tranny fluid. What it REALLY means is that a rebuild ($5,000) is in order, but you can get away with not doing this for a while. Otherwise, the transmissions are pretty reliable.

6.3s often have other issues such as starter, alternator, or water pump problems. Most 6.3 mechanical parts can be rebuilt by a competent shop, or purchased as rebuilt units from Star Motors (www.300sel.com) after sending your defective unit in as a core. Often Star Motors has rebuilds on the shelf and can drop-ship the same day.

All rubber window, door and trunk seals (all rubber on the car, actually) should be considered suspect and candidates for automatic replacement. This includes all rubber hoses (fuel and coolant) under the hood. 90% likelihood that all (what I call "chassis rubber") motor mounts, front subframe mounts, transmission mount, flex discs, rubber bump stops on the A-arms, and other rubber needs replacement. Budget $5,000+ to have all of this done.

The biggest issue with 6.3s and other 108/109 cars is the fact that previous owners have deferred maintenance to such a degree, that wheelbarrow-loads of money are required to bring them to a reliable condition. Combine that with the cars' age being 35 years old, and you have the natural disintegration of "soft" things like rubber parts, horsehair seat pads, and so forth.

I won't even get into items such as leather and wood cosmetics. To re-do the interior of the car to a high standard, budget $10-15,000.

Good luck!

Cheers,
Gerry

[RR3]

I really appreciate all your help and expertise.
The current owner re-iterated that the car has zero, I repeated zero (his words) rust and has always been maintained by MB.
The air bags were replaced in 1994 or 1995.
Again, I havent seen the car yet.
Interior looks great in pics.
Have to ask him about the tranny.

[vrsmith]

What is the price of the car? It sounds like it could be
a great one if the declared condition is correct. You
cannot go wrong spending more now for the best
condition vehicle you can find. Not having to import
the car into Canada will save you money, don't forget.

[gerryvz]

A general rule of thumb -- well-maintained 6.3s tend to run $15,000 and up. Below that, you are going to pay many times the purchase price over, in deferred maintenance costs, to make the car roadworthy.

There is nothing better than a well-sorted 6.3 that is operating according to factory specifications. Unfortunately, 80%+ of them, AREN'T. So owners never experience the true joy of a 6.3.

There is nothing worse, or more painful, than a cheap 6.3 (under $15K). I don't care how good of a deal it seems, or how many "individual" parts have been replaced. If the car hasn't been attended to by a competent mechanic (and most MB dealerships ARE NOT competent when it comes to a 6.3 -- few have mechanics on board experienced at working on vintage cars), it is not worth buying.

Also, if the car has resided anywhere in the world outside of the West Coast of the USA (Washington, Oregon, Idaho, California, Nevada), the US Southwest states, or the US South states, or the Australian desert, there is unquestionably rust somewhere on the car. This is a statement made with complete confidence. If the car was ever driven in the winter, and the area where the car resided at any point in its life used salt on the roads (most of the US and Europe), there is rust. I don't care if the car was only driven on salty roads for one winter. It has rust.

Download the sheet at my website (URL: http://homepage.mac.com/gerryvz/checklist.pdf ) to do a comprehensive check on the car's condition.

Owning a 6.3 is no easy thing. It requires commitment, patience, and most importantly a large wallet. You will get thrills beyond your wildest dreams from a well-fettled 6.3. But it is always best to spend the money up front to purchase a car that has benefitted from someone else's outlay of cash, time and labor.

Trying to revive a moderate running car, not to mention a basket case, is an exercise in frustration and most people end up selling it after thousands of dollars of outlay, to little benefit. Most people don't want to spend the $30-80,000 required to truly restore a 6.3 basket case. It happens all the time -- people get "6.3" on the brain and buy a $6,000-10,000 car, and after a year or two realize what they have on their hands. A money pit with little light at the end of tunnel.

Hope this all helps. Happy Thanksgiving.

Cheers,
Gerry

[RR3]

The car spent all of its life on the west coast.

[RR3]

Guys I really appreciate all the help you are giving me.
I owe you guys a drink.

Ok if I the 6.3 is really as good as it sounds, I will go for that. But I'm not crazy of the colour combo. I want a black exterior with black interior.
Painting the exterior wont be a problem, but what about redoing the interior to all black. Is it too prohibitive?