1970 280 SL - New Buyer (Misc. Questions)

[70SL]

I just bought a 1970 280 SL at an estate auction with little knowledge about the car.  Now that I've got it home, I'm in love with it.  I do have a few questions:

1.  The speedometer light went out (burned out) yesterday.  Any suggestions on where to purchase parts.  I'm mechanically inclined - is this easy to install?

2.  The passenger door won't lock.  The black "lock" button on the inside won't push in.  Any suggestions?

3.  The car is an automatic and appears to operate at high RPMs above 60 MPH - more than 4500.  Is this normal.

Thanks for your patience with a new owner.

[Douglas]

1. Most likely, the rheostat (aka dimmer switch)  just needs to be adjusted. These are kind of tricky in Pagodas. Generally, I find it best to drive at a steady speed at night to adjust it. Try moving the knob on the dash next time you're driving at night & you may be surprised.

2. I can't say what the issue is, but you'll want to remove the door panels on both sides to clean and lubricate all the moving parts in the doors. This is necessary maintenance every two decades or so, particularly when you consider what a window regulator costs today. Suffice it to say it's obscene.

3. These cars rev pretty high. You might want to cite a specific speed and corresponding engine speed for confirmation.

Douglas Kim
New York
USA

[ja17]

Hello 70SL and Welcome,

Yes as Doug indicated, If all your instrument lights are out it is probably the rheostat. Exercise it by twisting the knob on the center cluster back and fourth to clean the tarnish off the coils of the rheostat.

These cars start off in second gear unless you floor it or downshift. From a stop and normal start you should feel it shift twice before you reach cruising speeds. You should feel it shift three times only if you engage the kick down switch on the floor or manually shift from lower shifter positions.

Check this item before you remove the door panel; These door latches have a first and second stage. If your door mechanism is only engaging the first position your interior lock will not work. Verify this diagnosis by opening the door and manually rotating the latch mechanism. Rotate until it clicks twice, then try your interior lock. You may find that it  works now.  Do not close the door until you release the mechanism by activating the door handle.

If you find that this is the fault, loosen the screws holding the latch reciever on the chassis and adjust it so it allows the door mechanism to "double click" when the door is closed.

Joe Alexander
Blacklick, Ohio

[Paddy_Crow]

I believe 3300 RPM at 60 MPH is normal for the auto. They do not have overdrive and the rear axle ratio is pretty tall. Nice for accelerating, but noisy at highway speed.

I used to use TV tuner cleaner to clean electrical contacts back in the day of mechanical television tuners. I don't think it's available anymore, it was freon based as I recall. There are other non-residue electrical contact cleaning solvents available, though. You just give it a good spray and then work the knob back and forth for a ten or twenty seconds.

Democracy is two wolves and a lamb voting on what to have for lunch...

[Paddy_Crow]

One more thing- find out what rear axle you have. I believe 3300 RPM is normal for the 3.69 ratio, it will be higher with the 3.92 (roughly 3500).

Democracy is two wolves and a lamb voting on what to have for lunch...

[al_lieffring]

quote:Originally posted by Paddy_Crow

One more thing- find out what rear axle you have. I believe 3300 RPM is normal for the 3.69 ratio, it will be higher with the 3.92 (roughly 3500).

Democracy is two wolves and a lamb voting on what to have for lunch...

There was also the 4.08 axle, that my car has,  I don't know why, it just does.

Al Lieffring
66 230Sl
a-cheesin with a new 85 l. tank

[paulr]

answer to number 2.

are you sure your door is shut properly as the door won't lock if it isn't.

paulr
lovely 1970 280 SL

[70SL]

Guys:

Thanks for the great advice.  

Although I haven't had a chance to check the speedometer light or axle ratio, the passenger door lock problem was diagnosed correctly by Joe Alexander.  

I'll update the other items when I have a chance to review.  

Thanks again.

Brian Carter
'70 280 SL
'48 Packard