Steering Gearbox Replacement - PeachParts Mercedes-Benz Forum

#1 04-04-2006, 10:28 PM

As of a week my 1985 300D has had nearly 100% of the front end rebuilt. There is a lot of play in the steering and I am considering replacing the steering gearbox. Has anyone replaced this themselves or is this a job for a garage?
Thank you in advance.

Tom Valdriz · #2 04-05-2006, 03:13 AM

I would not replace the steering box. Most likely candidate is the
bushings and steering dampner. These are both fairly easy and inexpensive
to replace (DIY).

If you still have alot of play, I'd recommend a qualified, trustworthy Merc
mechnic adjust the steering box. Only if there is no more adjustment possible,
open your wallet wide...

Tom

#3 04-05-2006, 04:13 AM

Steering Gearbox Maval $1372.00/$541.34

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1RT04VHNX1RT091ABQ&year=1984&make=MB&model=300-DT-001&category=M&part=Steering+Gearbox

t walgamuth · #4 04-05-2006, 06:51 AM

even with tons of miles, like 300k, i have found that the boxes still offer adjustment to correct looseness.

about 13 years ago before i understood this as well, i bought a rebuilt box and had a sharp purdue student who did odd jobs for me install it. the installation took him about three hours as i remember. not a problem on t he installation. the box itself had stiff action for at least a year before it smoothed out.

it will probably adjust out for you. loosten the lock nut and turn the adjuster screw anticlockwise to remove looseness.

tom w

dannym · #5 04-05-2006, 08:55 AM

What do you consider "A lot of play"?

The manual states 24 or 25mm which is just shy of 1 inch.

You said "Nearly 100% of the front end rebuilt". Can you list the parts that were replaced?

You need to make sure everything is in good condition and an alignment is done berore even thinking of adjusting the steering box let alone replacing it.

Danny

t walgamuth · #6 04-05-2006, 11:25 PM

i dont see why you cant adjust it even though all the parts in the front end arent new.

if it is loose, it will only help the situation to adjust it.

tom w

dannym · #7 04-06-2006, 10:09 AM

Quote:

Originally Posted by t walgamuth

i dont see why you cant adjust it even though all the parts in the front end arent new.

if it is loose, it will only help the situation to adjust it.

tom w

Of course you can. you can do a lot of things that aren't right. Doing a quick fix like that will just give a false sense of security. Until his flex disc goes that is, or any of the other parts that weren't repalced.

That's what I wanted to find out. What parts aren't covered in his "NEARLY 100% front end rebuild".
I don't see how anyone can give him reliable help without knowing this.

Danny

bodyart27 · #8 04-06-2006, 11:21 AM

if you do the swap-this link might help:

Pics of Steering Box Swap

dieselbeagel · #9 04-06-2006, 12:41 PM

Before u embark on this project, u may be able to reduce the play on the steering by adding Lucas Steering Fluid.

U can get the above at ur local parts store. Check out Lucas Oil Additive and Transmission Additive. Lucas Diesel Additive actually made my car run smoother.

I have 352K on my 83 300D. There was some play in the steering after I rebuilt the front end. Added some Lucas fluid and that reduce the play enough for me to live with.

I figured that if Lucas made good steering fluid, they other products must be decent. I added the trans fluid and my trans shifts smoother.

I have it in my car for a month and am pleased with the results.

#10 04-06-2006, 01:53 PM

Quote:

Originally Posted by dannym

What do you consider "A lot of play"?

The manual states 24 or 25mm which is just shy of 1 inch.

You said "Nearly 100% of the front end rebuilt". Can you list the parts that were replaced?

You need to make sure everything is in good condition and an alignment is done berore even thinking of adjusting the steering box let alone replacing it.

Danny

Here is what hsa been replaced:
1. Tie rods
2. Lower ball joints
3. Upper control arms
4. Shocks

Control arm bushings are still good.

The mechanic who aligned the front end described the play as being in the steering box.

Hatterasguy · #11 04-06-2006, 01:59 PM

I'd do the idler arm first.

This doesn't surprise me the steering box's on these cars wear like carzy. You can adjust them a bit with that nut on top but that only helps a bit. Nothing is going to replace worn metal.

I have a steering box in the SDL out of the 420 with about 180k on it. Still more play then I like, pretty soon one of those rebuilds will be going in.

The SD seems to be on its original at 230k, lots and lots of slop. But it was mostly an around town car.

It depends what you are looking for really. You can drive these things forever with worn steering box's. But if you want it to drive like it came from the factory, well you gotta fix that then.

#12 04-06-2006, 02:37 PM

I don't mind a little play in the steering, but I have more than I care to live with. Let me see if I can measure how much play I have in degrees .

dannym · #13 04-06-2006, 02:48 PM

Quote:

Originally Posted by ncof300d

Here is what hsa been replaced:
1. Tie rods
2. Lower ball joints
3. Upper control arms
4. Shocks

Control arm bushings are still good.

The mechanic who aligned the front end described the play as being in the steering box.

I thought Idler arm as soon as I saw your list. Then I saw hatty's post!

I would do that as well as center link and steering damper and sway bar bushings.. You will more than likey need another alignment.

THEN if you need to adjust the steering box. But make sure your flex disc is still good.

I'm having the same problems. I'm waiting to replace the center link and steering damper this weekend to do an alignment. Once that's done it will be everything except the LCA's and brake strut bushing, which are still good.. I already did the brake strut bearings, which were shot.

Danny

dieseldiehard · #14 04-06-2006, 02:52 PM

I agree with Hatterasguy, if the steering box wasn't adjusted when it should have been and someone continued to drive with for a few years (or less if they drive a lot) the races get worn on the steering gear and no amount of adjustment (CCW is tighter BTW) or fluid additive is going to help. If you adjust a really worn steering gear to tight, it usually gets sloppy again real soon, all that did was put the gear under tension and it wears againg quickly and you are back worse than before. BTDT.
I replaced a badly worn box (@225K miles) with a freshly rebuilt one and as someone said it takes at least a year before they wear in before they begin to feel normal. On another occasion I found a low mileage car and bought the box, this is cheaper than a rebuild but there is some risk because the box might come with a guarantee (usually not) and if its no good you go thru all the labor to R&R again! and this is NOT a nice job, its back breaking to me I'd almost rather change a dash than swap a steering gearbox. Good low mileage 123 parts cars are getting hard to find, and unfortunately many wrecking yards don't bother putting the mileage figure on their parts, one of my peeves is these guys try to get big bucks for something they don't bother to keep the history on

All said, a tight steering 123 is a delight to drive but a loose steering one is HORRIBLE!

Hatterasguy · #15 04-06-2006, 09:07 PM

Changing the drag link is a good idea as well. The sway bar bushings don't affect steering. The steering dampner is just a shock, makes the steering feel better on the highway. They are only like $25 not a bad thing to change if its original.

It all comes down to what you want. Lose steering drives me crazy, you really notice it on the highway.