6.3

Is it necessary to partially withdraw the steering shaft as described in the Shop Manual in order to provide sufficient clearance to drop the steering box? I was thinking that I would instead remove the air valve located in front of the box in order to obtain adequate clearance. Also I would remove the master cylinder along with the vacuum booster to gain better access to the steering coupling and the pressure fittings? My box leaks at the flange surrounding the pitman arm shaft. I have a good replacement box from a parts car.

Sheldon M. Rubin

The future ain't what it used to be. (Yogi Berra)
1961 300d Adenauer
1963 220SEb Cabriolet [280SE Conversion]
1969 300SEL 6.3 Euro #1439

Sheldon,
Unless you have some other reason to remove that left front air valve, I would leave it where it is. I believe it is easier and quicker to withdraw the steering shaft than to remove and reinstall that valve. It is a real PITA. But wait for other opinions[:)].
Art

yes,far easier to pull the shaft up than do anything else. Getting the damn box back in a hassle though. I use the engine crane and a rope to lift it up and hold it in place . REplace the three bolts with new grade 8 or greater with hardened washers .
I am a bit sleepy at the mo but you can undo the two allen bolts on the shaft coupler ,then remove the steering wheel and collapsible boss.Unlock the steering .
Under this,on top of a bearing in the column housing is a circlip which keeps the shaft in place . Undo the indicator switch and pull the shaft up in the column housing .It only needs to come up about two and half inches to clear the coupler.
This is one of the reasons i suggest all the front end comes out in one hit and all systems are checked together .Space is tight under there and once all jobs are done it's just matter or reassembling.

quote:

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12-14-2004, 11:49 PM #8
Tom Hanson
MBCA Member

What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be..
__________________
Tom Hanson
Orange County Section

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Please note, its pretty heavy for 1 person when it drops on your chest.
The coupling bushes for the steering column should be replaced. They just push in if loose enough. 5mm hex from memory on the knuckle. Whatever you do, dont tap the steering column from the driver's seat to drive it home into the coupling during reassembly. The column will collapse and shorten very easily. Any attempt to drive it back to correct length will require a lot of force and may fracture the internal nylon bushing leaving you with a rattly column. Unfortunately i speak from experience. Im in the market for a steering shaft.

regards
Michael D

Hi I am changing out the steering coupler The old one is splined on each end. The new one is splined on just one end. It’s a genuine MB part. Is this just a new design?
Thanks


Jim

Good Morning James -no -wrong coupler - that is a later version. Correct replacement is splined on both ends. The original was a two piece with relaceable bushings. These bushings are still available (a couple of bucks). I have replaced the bushings without fully removing the gear box and you also do not have a spline alignment issue as both halves stay on their respective shafts. The Genuine replacement is one piece. Note: if you purchase an after-market coupler (they are cheap) the steel is stiffer and requires much more torque to pinch securely and the thread pitch is off a slight so you should run a tap. I suggest a Genuine. Also, I leave the high pressure hose on the box as well as the return pipe -avoids having to align them for clearance on re-installation and threre is enough clearance.

mpm

I should have read Michael Davies post --Those replacement bushings and their fitment. The originals discengrate -you have to meticulously scrape out remaining debris for the new bushings to fit flush otherwise you battle trying to get it home to fit the locks back in place.

mpm

Its quite a bit hassle for such a minor part - 2 small cylinders of nylon (or such) but the difference is enormous. Another tip is to use a LARGE flat head screwdriver to spread the clamp a little to allow the spline connection to move easily during assembly.

regards
Michael D

I was watching this video on YouTube of a guy who works on classic benz, and he mentioned that there is a special screw that goes into the box and locks it in center position, does anyone know about it , does such a thing exist?

Yes, there is such a bolt (see picture). Unfortunately it's not accessible on V8 engines. See note from MB manual (46-1/4)

Note: On vehicles with V-engine the center position

checking bolt can no longer be used for reasons

of space. For this reason, make sure that the

steering coupling is mounted in the correct center

position.

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Thanks for the info. Just Perfect - The first time in my life I try to mess with the box, space becomes an issue. This whole car has space issues and MB chose to chicken out on such a small thing. Naaaa just kidding 😂

I'm planning to reseal my steering box this winter. I already purchased A1094600261S1 kit from FEBI.

I hope it's possible to remove the box somehow. I have already exchange the steering coupling last winter. So I know that steering column must be moved out the way. Last time it was enough just to lower he box without disconnecting the hydraulics.

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Well it happened - what I was afraid off. I have successfully stripped the Allen screw heads, they refused to budge even after spraying penetrating oil on them couple of times and leaving them sit for a week.

So, now how do I tackle them, are they accessible from underneath to either drill through with left hand bit or cut them with a Dremel disk cutter? But if there is another way please do let me know.

If you're really lucky, you only stripped the top half of them and you can clean the hole a little deeper to get it out.

If it were an isolated, easily accessible bolt, I'd be hitting it with a lot of heat and trying again. These are where oil and gasoline make that a dangerous proposition.

-CTH

I had the same problem when I worked on my coupe. I used an air chisel. Not recommending it but it’s what I did..


Jim

I was finally able to get the box off. One thing strange, the steering box has a fitting for the hoses on the top, which according to various part listing websites is for a 280SEL 4.5 USA version (image attached)(https://nemigaparts.com/cat_spares/epc/mercedes/1/fg/108067/68f/46/001/).

So my question is, has the previous owner done something or these early models came with such box?

My other question being, what would be the sequence to reinstall the box? Do I slip the coupling on the steering shaft and then hook up the box or do I put the coupling on the box and then slide it into place. Mind you, I have not taken the steering off or the leveling valve.

Does the steering pump fluid Reservoir have a spring in it? Each and every schematic I have come across, shows the filter ring at the bottom, then the metal plate and then a spring, which pushes on the plate as the lid is tightened.

Ahh, mine is a RHD & hoses are tightened laying underneath to the engine side of the box, so perhaps sounds like your box has been switched.

With regards to the coupling, I actually did the steering column bearing at the same time, so the shaft came out.
Please us a large screwdriver to loosen the coupling clamps to make engagement of the coupling sections as easy as possible. If you resort to pulling the column back, DONT tap back down as the column will collapse internally and be ruined.

Given the weight of the box, Id first try the coupling LOOSE on the centered shaft then try to lift and slide the box up and back onto the shaft and into the coupling then fit a bolt to the frame. This may be a 2 person job with a strap from above to relieve the load, or jack lift from below. Its a major work out if done solo.

Oh, and if draining the system, may as well change the filter in the reservoir - inexpensive. Just pull the spring, plate, and the filter beneath just lifts out.

regards
Michael

...and yes, there is a spring, which presses on the plate which seals the filter - so its vaguely important as the spring pressure is not high. Your could try a tight 'o' ring pushed down the shaft to secure that plate until a spring is available. I suspect the pump pressure draws the plate down, but leaving it free floating without any pressure may defeat the system.

regards
Michael

Thank you for the helpful tips.

For me it is going to be a one man job so there will be a lot of grunting and swearing 🤬 going on. I wonder why the box was swapped? This box layout makes getting to the hose connections impossible without removing the booster.

As for the reservoir, I am missing the spring and the filter is on the plate rather than at the bottom, which to me did not make sense. So now I know what needs to be done.

Regards

Nadir

Ok so the pelicanparts.com was not able to find the spring for the reservoir even though they had it listed. Now is it possible someone can give me some specs on the spring. I would like to know the length, ID, OD of the spring and the thickness of the wire that makes the spring. I will try to have locally made by a tool shop. Will appreciate the help.

One interesting thing, I was cleaning the frame where the steering box goes and I was surprised to find "108" stamped. Looks like early 109s were using 108 body parts.

It seems that the spring is still available here in Europe from MB 

See https://partssearch.mercedes-benz-classic.com/parts/A0019931401 or FEDER | Mercedes-Benz Onlineshop (mercedes-benz.de)

I can ask my MB dealer here and send it to you in envelope. The cost is about 16 USD + shipping.

You should talk to MB Classic centre in US as I guess they are able to order it from Germany too.

Alternatively you can buy the original NOS spring from https://www.mercedespartz.com/store/0019931401/

This shop is in Iran/Teheran! But he is fine. I bought some parts for my W114 and W115 from him. Don't worry as the payment is by PayPal and only once you receive the parcel. Talk to him by WhatsUp. His shipping costs are reasonable.

Filip

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Thanks for the info. I actually did send Information request to the shop in Iran few days back, still waiting on a response. I stumbled on his site by chance. As for the part available in Germany I will check with Tom at classic shop and see what he can offer, as I can not find the spring on any mercedes dealer websites.

Again thanks for your research. I will bother you for the spring if I can not find it here.

Well looks like classic benz has few PS reservoir springs available. Initially Tom came back with NLA, but when I mentioned the link shared earlier by Filip, he searched some "dark database too"🤫 😉and found few springs floating about. So, if someone needs them this would be a good time.

That's great news. BTW I got message from Iran shop today. He said he already replied to you.

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Thanks for letting me know, I will check spam to see his email.

I need some advise.

After the trouble I had to go through to get the damaged allen head bolt out, I have been able to find a 12 POINT Flange Bolt 12.9, similar in size as the torx bolt MB now supplies for the coupling. The heads are the same size. Would it be a good decision to use the 12 point flange bolt instead of the torx bolt?

Link to the 12 point Flange bolt - https://www.belmetric.com/8mm-12point-c-2_1989_1991/btp8x35blk-12-point-flange-bolt-129-p-14244.html?zenid=bpqatajvhs3qhs74ub86qu2tq0

One more thing, is it safe to run the engine with pump hooked up to the steering box without the pitman arm being attached? The reason I ask this is, because it will help me turn the steering side to side to evacuate any air from the system without putting any load on the steering mechanism.

I was running it without anything attached to it. No problem.

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Need urgent advise.

I was able to put the steering box with the coupling back, but to my bewilderment the coupling, after I installed the missing bushing, has somehow gotten short. Now it is not able to hold both steering shaft and the steering box shaft at the same time. I did not even open the steering wheel just to avoid collapsing the column. Can the steering column retract if there is a slight bump while pulling the steering box up.

If the steering column intact has retracted/collapsed, what will be the indication and how can u fix it?

Some guidance will be greatly appreciated.

Let's be very calm here. Is the coupling loose so it can slide up and down AND the box properly mounted?
Please relax everything, use a big screwdriver on the coupling so it is free, relax the box and test for the best position, as it may easily drop a few cm and may need to lift up and back.
It's unlikely that the shaft has collapsed, but the impact required to do so is not great.

If so, the solution is to replace the shaft as the nylon collapsible element will snap.
Removing the shaft, putting it in a vice, and beating it back to length with a large mallet and chisel will give you a shaft of correct length, but with with internal damage and a 'click' and slack in the steering wheel, forever ,that feels like... a bad coupling!

Regards
Michael

Thanks for the detailed advice. I checked the spindle today and the end that goes into the coupling has collaped as it is inside the tube flush with the open end. When I touch it with a screw driver it sort of wiggles, so I am thinking the previous owner applied the mallet solution.

I will take the spindle out, does not look to be a big deal. Can I find a new spindle or can they be re-built? I would rather avoid the "standard" solution.

Removing the spindle is not a big deal. Bit of messing about with the indicator (2 screws) round of bolts on the steering column, perhaps a few on the floor.
Lemme know how you go on the 'rebuild' as I thinks its an item for the scrap heap.
regards
M

...its a critical safety item and i expect that rebuilding a collapsible steering column is a negative.

regards
M

I agree, that I should not try fixing the collapsed end of the steering spindle, but it is a NLA item so there is no option, unless any of you know where to get a new one.

If I can stretch the end and fix it back into the coupling, then I think the collapsing feature should still be intact but with a missing part that collapses in case of an accident.

I pulled the spindle out,very very straight forward - whew. The spindle is made such that for testing it can be collapsed by applying atleast 100 kg of force. And then can be stretched back by hitting a rubber mallet to an old coupling tightened to the coupling. What I have noticed is, the thing that restricts the coupling from collapsing is a plastic sleeve that fits in between the two moving tubes. As long as it is stuck there the coupling is in good shape.

well done. Mine busted after the mechanic smacked it with a club mallet and clicks.

regards
Michael

Mine was short too. Previous owner had no clue how to do it right. I'm sure that mallet was used. No worries. I used plastic reverse-hammer to extend it back to length specified in documentation. Plastic sleeve looked intact. Unfortunately after about 1000 kilometers and I can hear and feel a little click during heavy steering. I'm planning to use column from my spare 6.3 that look virginal. It's absolutely OK to adjust it back with plastic hammer. It's the way how it should be done! See MB docs bellow. The issue is the age of the plastic sleeve not the adjusting process itself. Stay calm and hope you sleeve will make it.

My suggestion is to give a try and pray. You should be fine. Here is the MB document about it.

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

A hint for bleeding the steering fluid. Leave filter out, fill resorvoir, have steering in the straight-ahead position, DO NOT Start Engine, gravity bleed system using bleeder on steering gear box. This will take awhile but you will not be introducing air or making it worse by turning the steering back and forth --that just induces air. Eventually you will see air bubbles -after it is pure fluid, lock down the bleeder -start engine with full resorvoir -do not turn steering wheel (!), let idle a minute or so; shut engine off -bleed again to verify the flow is good. tighten bleeder -install filter and you are good to go. No muss, no fuss.

Thank you for the the helpful advice. As a matter of fact I was thinking on these lines, but was not sure if the pump would let the oil flow through it without turning it. This makes my life very easy.

Thank you all for providing helpful tips on getting the job done. I am, with all your help, at the point where I can fill the PS fluid, get it bled and test my work out.

This much is sure, if I have to this job again (aaaaagh God forbid) I will definitely pull the spindle out in the beginning, much easier to pull or reinstall the steering box, plus no chance of messing up the steering spindle.

Other than the steering box, one more thing that I have noticed odd with my car is that the steering spindle extension requirement does not match the shop manual. In the shop manual the upper inspection hole closer to the steering wheel is for cars with power steering, where as the lower one for mechanical ones. But on my setup if I use the PS length the spindle is not long enough to reach the coupler, so I have to use the mechanical setting (In the manual they are represented by 15a and 15b respectively). Has anyone come across this situation before? I am thinking this could potentially be because of the odd ball steering box fitted on my 6.3.

To bleed after replacing all the hoses, I just filled and ran it while turning the wheel lock to lock while up on jack stands. Top up & seems fine.

Oh, and if pulling the column to do the coupling, its worth changing the bearing on the shaft up by the steering wheel. Mine seized and made a horrible noise while making the steering extremely heavy. Very odd.

regards

Michael D

Hello.

Here is picture of my box right before restoration. It's original, never changed. Is yours different?

I have many more pictures of box guts to share. Just let me know if somebody is interested.

Filip

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

This is how steering box on my car looks like. I only see it listed under 280SEL 4.5 USA.

It's the same one. Just the hoses are different. There was never a correct picture of W109 6.3 in EPC. I think that 280 SEL 4.5 reuse our housing and aluminium plate with hose ports. The metal pipes are specific for 6.3 and pressure hose is special too.

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

that makes sense to me, as these special bits are required to shoehorn a V8 into that chassis. -CTH

I just remove the box. I do not remove booster or steering shaft -the return hose is disconnected at the steering box pipe, high pressure hose remains on the box and coupler remains on the box with the ignition key removed, locked in center position. Pitman arm removed from box -there is just enough room for all of this and have been doing it this way since the 70s --left hand drive cars-

I'm old now but still don't have a problem man-handling them for refit.

-unless the subframe is is back because the frame is bent, there is just enough room to clear the leveling valve
--the only issue I run into is the fuel feed metal pipe that runs along the frame rail.--

M.

I have some oil leak from the cover where the shaft comes out on the steering box. I have never worked on a steering box, just wanted to know if I open the ends just to replace the seals do I have to be careful of anything jumping out/