Fixed rough idle, 380sl and steering play, read!

I went in for a full tuneup on my 380SL hoping the rough idle would go away... Well after the tuneup the car continued with the rough idle. The mechanic after a lot of checking saw that the seals on the fuel injection were worn and letting in air, so I had a vacum leak and also the vacum advance was also shot. If you have a vacum leak your car will not idle correctly... Check for vacum leaks before spending a lot of money fixing injectors etc... Also he got rid of the play in my steering, the car is running like new. If you have play besides changing all the worn parts on the steering box a good mechanic can do an adjutment and it has to be counter clock wise. It has to be this way or you will get to much play... Counter clock wise... I hope my expensive experiece will save somebody some money and time. In the Miami area I recommend Nano Auto repair on 32 Ave and Sw 10st. The owner Emilio is very fair and I think he learned a lot with my car, 305-443-8164...

[4NDELIT]

thanks a lot for the advice... I'm sure it'll help someone when they need it!

[G-Benz]

Note the steering box issue:

I have a VW Beetle and some time ago when I replaced the steering box, I too adjusted the play by turning the adjustment bolt...you can tell by steering which way to adjust (yes, counterclockwise).

All that does however is give you a tighter "feel" since the adjustment serves to tighten the load on the steering shaft. You adjust the feel on a new or rebuilt unit to suit your taste...but it doesn't really solve the "play" issue.

The culprit is worn components, period. Adjusting the steering box bolt is a Band-Aid fix, comparable to raising the idle speed to solve a rough idle problem.

So having the steering components replaced was a sound decision. And yes, vacuum leaks plague many vehicles with rough running issues...it's a shame most owners start throwing parts at the problem first!

[DaimlerChrysler]

just out of curiosity...how much did the seals set you back...with labour?

[RickM]

Regarding the play in the steering: Which is most likely to fail first..the Steering Coupler or the steering box?

[iwannabenz]

...had a very rough idle at times, symptoms same as Hudson66, checked ALL sorts of stuff, previous owner has said new plug wires last fall (and they looked new) so didn't check them, finally clued in Mon AM driving one of the kids to school and the radio was making ominous popping sounds, lifted the hood and could actually hear one of the plug wires arcing (hence the radio interference). Decided to bite the bullet and put in a whole new set of plug wires, could not believe the difference! Runs like the proverbial top, still stinging from the dealer price for the OEM wires , $265 Cdn (or about $180 US). Lesson learned: look for the obvious stuff first, don't assume anything.

[ctaylor738]

I just finished replacing my steering box (246K miles). The coupling was fine.

But who knows if it had been replaced before? I took a good look at it when it was out and could not see obvious points where it would wear.

I have had steering boxes on various cars wear out over the years, but never a coupling.

FWIW

[sublettd]

IMO, anyone who might replace a steering box just because it has "play" in it is wasting their money. It seems to me that MB has built in an adjustment to the steering component and one should make the adjustment when the steering becomes loose.
At about $300-400 a pop for a new/rebuilt box, this could get mighty expensive...especially if you have more than one of these MB creatures.

My 300D has more than 278,000 miles on it and it still has the original steering box. However, the SL only has about 95,000 and I recently replaced that steering box. Why one has lasted so long and the other so much less is a mystery to me, but that's the case. I also replaced the coupling on the SL at the same time the box was replaced.

For anyone replacing their steering box, I highly recommend Performance Products as the source of the replacement.

[ctaylor738]

Wasting money? Mine had over a quarter-turn of play before the wheels would begin to move. There is no way that an adjustment or a new steering shock would have taken that out.

The adjustment can make the steering feel stiffer, but doesn't do much if there is substantial wear in the box, IMHO.

I paid $295 for a rebuild from Meridian Auto Parts and am very satisfied. 1-888-275-2525 or websales@meridianautoparts.com

[sublettd]

CTaylor,

Why in the world would you wait until it had a quarter-turn before you adjusted it? Perhaps waiting that long allowed the gears in the box to completely disintegrate????

Admittedly, I'm not an expert on this topic other than the fact that I have three MB's and routinely tighten the steering when it's needed. The 300D has probably been adjusted four or five times and the 300TD at least a couple. So, from my personal experience, there is room for adjustment in these boxes.

There are also instructions on doing so in every MB manual you pick up. Wonder why they might have printed instructions for the procedure???

[ctaylor738]

This is the $1200 380SL "rescue" project - do a search on "Wayward Woman" if you want to see the whole story. The steering was like that when I got it, and it was simply a matter of time and money before I could fix it.

The adjustment on the 107's is extremely hard to get at, requires special tools, and the manual specifies that a torque measuring device be attached. It is much more of a pain than the 123's.

We had an '82 300D for sixteen years, and had the steering adjusted at the dealer several times. It was never really right, and I wish that I had replaced it.

[RickM]

Can anyone outline the procedure for adjustment and/or replacement of this unit? Thanks!

[ctaylor738]

Replacement.

This sounds a lot worse than it is. It took me about four hours. I bought a five-tool "front end set" from JC Whitney. From it, I used a spreader to force the drag link and tie rod off the pittman arm, and the pittman arm puller to get the arm off the steering box.

The best I could do at a shop was $500 for a rebuilt box and $350 for labor. I paid $305 for the box with shipping and the tools were $105. Cotter keys for the castellated nuts were $.39 and the new steering box bolts were $6.

Telephone or web:

Order rebuilt steering box

Top of car:

Remove air cleaner, disconnect, unhook left plug wires and move them out of way
Siphon/pump out PS fluid
Remove steering wheel
Remove boot, disconnect the two horn wires, and remove turn signal/wiper switch
Remove 4 screws holding steering column
Loosen/remove clamping screws on steering coupling
Pull steering column up into car about six inches

Under car:

Jack car up and put on stands, but support left wheel with jack under control arm
Disconnect left tie rod from pittman arm
Disconnect drag link from pittman arm
Remove left exhaust pipe (not manifold)
Disconnect PS pump lines from steering box, allow to drain, plug holes in steering box
Remove three bolts holding steering box to frame and maneuver box and pittman arm to floor (helps to have one person on bolts and one holding box.

On workbench:

Remove pittman arm and install on new steering box, aligning the mark on box and arm
Remove/install PS hose fittings

Under car:

Using new bolts, install new box (with helper) and re-connect and re-intall components from previous "under car" step

Back on top:

With wheels straight ahead, slip steering coupling onto steering box
With paint mark on steering column straight up, slide column down and into coupling, install and tighten clamping screws
Secure steering column with the four bolts
Reinstall turn signal and steering wheel
Fill PS resevoir, turn wheels full left/right at least twenty times, watching fluid level and adjusting as air is pumped out.
Reconnect plug wires, install air cleaner
Start car and with engine idling, slower turn wheels full l/r to verify no air in PS fluid
Put cap back on PS resevoir

Almost done:

Drive car, make final adjustments to align wheel direction with steering wheel position - steering coupling or steeriing wheel

[sublettd]

Chuck,

Understand regarding the "wayward woman".

Agree that it's much easier to adjust the steering box on the 123 than it is the 107. In spite of what the book might recommend, I've never seen anyone put a torque wrench or any other instrument on it, but just turn the screw counter-clockwise until resistance is met. However, I've never had a complaint about "feel" after an adjustment on one of my 123s.

I haven't looked under the hood of the 380SL with a critical eye toward making the steering adjustment on that vehicle, but it's EXTREMELY difficult to make the adjustment on my 500SL. It's absolutely impossible to get a wrench on the screw from the top without loosening the motor mount and jacking up the engine to create work space. I observed this procedure at the dealership when my normal mechanic told me by just looking that there was no more room for adjustment. I thought he was just trying to sell me a new steering box. Should have listened to him though, because it cost me a hundred bucks which I could have applied toward the cost of the new box that I wound up having installed.

FYI, three or four times a year Performance Products (http://www.************************) will offer a 15% off sale on almost all of their items. They just wrapped up one the 16th, but will probably have another around Father's Day. I usually save the 'big' items to order during one of their sales. I've never had a problem with anything I've ordered from them and they have one of the best return policies anyone could offer: don't like it or don't need it??? Send it back for a full refund with no questions asked.

Regards,

[RickM]

Chuck: Thank you very much for taking the time to develop the write-up.

I'm tempted to see if an adjustment might help out. If not I'll do the replacement using Chuck's instructions.

Luckily I have access to a friends shop with lift and tools.

Where is the adjustment screw located on the box? Should I access from the top or bottom?

Thanks again.