So ... I have an 85 300DT with two problems:

1) When in cold weather the "heat" is cool at best. It gets warmer as the air gets warmer, but below 40 degrees is really weak. Any suggestions?

2) The steering has a bunch of play, which makes highway driving a bit, ah, drifty. Any adjustment on the 123 chassy's? I think my front shocks are ancient. Might that be a contributor to the problem?

Thanks alot for any input.

Hello rblookc
RE: steering problem.
Have a MB qualified mechanic check your Guide Rod mounts.

RE: heat problem.
#1. Change the thermostat.
#2. R&R the mono valve.
#3. When ambient air temp is -0C or lower; use a piece of cardboard to block up to 50% of the condensor area.
Have a great day.

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1985 300SD
1983 300D
2003 Volvo V70

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I just bought a '82 TD with abunch of play, some of which is coming from the steering box. I haven't adjusted mine yet, but there is a nut assembly on the top of the box that is adjustable

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'93 300D 200k (since Aug 04)
'82 300TD 205k (since March 04)
'02 Ford Escape 192k (bought new)
'90 Ford Festiva 310k (since '92 with under 10k)
'01 Jeep TJ Wrangler 278k (since 07 with 235k)
'76 VW Westfalia van 150k ? (since '90 with 100k)
'72 Chevrolet Corvette conv. (base not a LT1) 175k (since '84 with 100k)
71' VW Squareback (since '72 with under 9k, odo turned over, then stopped then replaced. maybe 250k)
'87 Yamaha Riva 125 scooter 7k

re lack of heat - could be monovalve or t-stat.

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1984 300D Turbo - 231k....totalled 11/30/07 RIP

re steering. My old 123 was wobbling this past week. Wife said time to condemn the car as unsafe. I looked at it and declared the tires to be seriously worn.
Replaced them and now it runs straight and true. Dear wife happy again.

old deis,
i had the same thing happen last summer- severe shaking in front end - replaced tires and it made 1000% improvement! - new tie rods also helped..

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1984 300D Turbo - 231k....totalled 11/30/07 RIP

Thanks for the advice. i think the tires are ok. it's more of a "play" than a vibration or wobble. Maybe I'll try the steering box first then delve into the tie rods and such.

Look at the tie rods, track rods (groans or knocks on speed bumps), drag link, and idler arm bushins FIRST -- if they are bad, adjusting the steering box is only going to give you stiffer wander, not good steering.

Jack up one fron tire and grab it at 3 and 9 o'clock, then alternately pull and push front and rear as if turnign the steering wheel. Any clunks, free play, or looseness needs to be investigated. Visible movement of tie rod ends inside the boot means they must be replaced. Ditto for track rod ends.

Idler arm can be check by vertical force on the drag link end -- if ti moves up and down, replace the bushings.

Steering box can be checked by standing outside the car and wriggling the wheel while watching the tires. More than about 1" of movement of the steering wheel rim before the tires move means a loose box or worn out coupler (at the top of the steering box).

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter is right. On these aging cars, fix everything in the front-end FIRST.....BEFORE anything is done to the steering box.

As for adjusting the steering box, I've recently learned that adjusting that nut does nothing but make you have a stiffer turning wheel with the SAME dead space that existed before the adjustment.

The BEST way to adjust it is to actually pull the box from the car and have it adjusted. I did this on mine and the difference is literally night and day! There is NO dead spot now. Of course, this is the more expensive option....but, if you want it done right....

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Chris
1985 300SD - 'Grace' (198K mi.)
2018 Honda Civic Sport
2018 Honda CRV LX
2010 Honda Fit Sport (RIP)
2013 Honda Accord Sport (Sold)
1996 Lexus LS400 (Retired)
1995 Ford Contour SE (Retired)
1976 Porsche 914 (Sold)
1972 Datsun 240Z (RIP)

What is the issue; Play or drift/wander?
I am getting confused here.

I believe drift/wander. At low speeds the steering is fine. At highway speeds it is a little difficult to keep the car in lane b/c it wants to wander. And there's definately a dead spot where a little turn of the wheel seems to do nothing then you feel the weight of the correction. Does that help?

Hello rblookc
Yes; that helps.
RE: steering problem.
Have a MB qualified mechanic check your Guide Rod mounts.

I agree that the tie rods and ball joints are possible also.

However; the Guide Rod mounts are over looked so often that I have started checking them first on any high mile or old age MB.

They give a sensation of random castor change = drift/wander, when every thing else is perfect.