Steering overhaul

[mdsalemi]

When my car was restored 20 years ago, several items were simply not addressed because the restoration house decided they did not need to be. Two parts among these were the power steering pump, and the steering gear or steering box.

Now, both of them are leaking. As they are original, they are also 55 years old with well over 130,000 miles of service on them. There are rebuild kits available, however, these generally contain seals to address leaking issues, they don’t address wear.

Apparently the power steering pump is a relatively easy rebuild with the seal kit. The gear is another story entirely. I’m told it’s a 23 page set of instructions. While I trust my mechanic I place higher faith in somebody who does this repeatedly, so I opted to replace both the power steering pump and the steering gear with rebuilts. Both of these were sourced from AutohausAZ, And both were rebuilt by C&M hydraulics out of Las Vegas. In fact, no matter where you source these two parts in the USA they are going to be rebuilds from C&M. If they are the only people doing this, they must be doing something correctly.

The high-pressure hose seems to be in short supply, but Authentic Classics in New York had them, when everybody else seems to be out of stock. The OEM part from Mercedes is NLA so this is an aftermarket hose.

In the next couple of weeks these will be installed…

[Kevkeller]

Thanks for sharing.

I’m wondering what wear they deal with. If they do at all. I’ve had my steering box apart and it’s a pretty robust unit. The bearings themselves are unique and probably not available new. The rest of the parts I don’t think can be purchased either.

One of the unique bearings had some race damage on mine. I put it back together and it seems fine for the time being. I did buy another to have as a future replacement though.

I’m guessing they just go through and clean it out, inspect it, and replace the seals themselves. Although I could be wrong.

I haven’t found much, in English publications, regarding disassembling and reassembling the 280SL steering unit. If anyone has I’d appreciate a link or copy.

I did make a couple tools to help me take it apart and install the large piston seal if anyone is interested in borrowing it.

I did take a bunch of pictures and was going to do a post on it but I haven’t had the time.

[mdsalemi]

I’m guessing they just go through and clean it out, inspect it, and replace the seals themselves. Although I could be wrong.

From their website: “Hard components are replaced when necessary, making sure that every unit falls within manufacturers specifications.”

So seals, gaskets, cleaning etc. yes. Would not surprise me if THEY can find bearings even if you or I could not, not to mention any other internal parts.

I’m confident that I have quality rebuilds that meet MB specifications.

[Pinder]

I replaced mine also from Autohaus . The unit was well packaged and you will need to send back your old unit for the core charge refund . I got mine refunded no issues.  Just be careful not to damage your old unit as they state if the unit sent back is damaged they may not do a full core refund. For example don’t damage the nose / shaft.

Bleeding the unit was easy. Follow the instructions on the website and also read the return packaging instructions.


Regards

 Pinder

[mdsalemi]

The unit was well packaged and you will need to send back your old unit for the core charge refund . I got mine refunded no issues. 

Autohaus did a LOUSY job of packing these TWO heavy units; these need to be in a triwall box (it was not) and the voids in the box completely filled (they were not). Thankfully the two inner boxes containing the goods (see my first post) were not damaged much, though there was a hole in one of the boxes. I'll probably have to pay the $25 fine as noted on a label.

The return instructions are almost as painful and laborious as rebuilding itself. Nitpicking things, like "Do not place labels or any writing on the box else you will be charged or we may not accept your return". They are just boxes after all...

I will do a better job of packing these up when it comes time to return them.

[TJMart]

When my car was restored 20 years ago, several items were simply not addressed because the restoration house decided they did not need to be. Two parts among these were the power steering pump, and the steering gear or steering box.

Now, both of them are leaking. As they are original, they are also 55 years old with well over 130,000 miles of service on them. There are rebuild kits available, however, these generally contain seals to address leaking issues, they don’t address wear.

Apparently the power steering pump is a relatively easy rebuild with the seal kit. The gear is another story entirely. I’m told it’s a 23 page set of instructions. While I trust my mechanic I place higher faith in somebody who does this repeatedly, so I opted to replace both the power steering pump and the steering gear with rebuilts. Both of these were sourced from AutohausAZ, And both were rebuilt by C&M hydraulics out of Las Vegas. In fact, no matter where you source these two parts in the USA they are going to be rebuilds from C&M. If they are the only people doing this, they must be doing something correctly.

The high-pressure hose seems to be in short supply, but Authentic Classics in New York had them, when everybody else seems to be out of stock. The OEM part from Mercedes is NLA so this is an aftermarket hose.

In the next couple of weeks these will be installed…

Michael,

My power steering pump hose was leaking so I replaced all my steering hoses a couple years ago and I sourced everything from MB Classic Center except the high pressure hose (NLA) that I bought from K & K. I would suggest using all MB hoses (except the high pressure hose as you mention) because the MB hoses were a much better quality and precise fit than the aftermarket hoses my previous mechanic installed with the cheap screw type hose clamps. I replaced all clamps with the Norma clamps.

I would also recommend that, since you are replacing both the box and pump and the system will be dry, you replace the fluid with MB power steering oil that is now recommended by MB.
https://operatingfluids.mercedes-benz.com/sheet/236.3/en

Tony

[mdsalemi]

Tony,

The low pressure hose is MB, ordered from Authentic Classics along with new proper clamps. All the wrong hose clamps were removed many years ago.

Also got 2 quarts of MB fluid and new canister filter.

UPDATE: I spoke too soon. Turns out that MB raised the price on the low pressure return hose into the stratosphere. Authentic Classics changed their part to a perfectly respectable Cohline 2633 15x23. They are a quality company making quality parts in Germany. Since the high pressure hose is NLA from MB, that HAS to be aftermarket. So I’m OK with the return hose being aftermarket as well…after all Mercedes themselves doesn’t make hoses…

[Harry]

I would also recommend that you replace the nylon bushings (2 ea) in the coupling between the steering column and the steering box. Now is the most convenient time.

Harry

[mdsalemi]

I would also recommend that you replace the nylon bushings (2 ea) in the coupling between the steering column and the steering box. Now is the most convenient time.

Hi Harry--boy you brought up an interesting memory from the past. THANK YOU!!!

My memory may be clouded on this, but I think this was something I tried to address more than 10 years ago. I was told there was a small U-Joint at the coupling, and then I was told there were bushings. I want to to say that my mechanic went to look for these replaceable bushings and instead found a non-serviceable U-Joint. May have something to do with early vs. later cars; earlier cars having replaceable bushings and later cars have U-Joints. I could be wrong.

Now what I'm fairly certain what was done is NOTHING. I have a vague memory (this might have been 2011 or so) that changing the U-Joint simply wasn't worth the effort as there was no play in it. But somewhere I have this new U-Joint. So, I'll dig it out and put it with the rest of these pieces and parts.

[Leester]

My July 1970 build USA model has the U-joint. I think they are over $1,000.00 now. I replaced mine even though I doubt that it needed replacing - was in there and didn't want to have to take it apart again. I'm sure someone can rebuild them - would be nice to find a rebuilder.

[neelyrc]

A few days ago I bought a rebuilt steering gear for my w108 from Pelican.  It was also a C&M unit. It is presently being installed and I should have back in a couple of days. My mechanic was favorably impressed with the quality of the C&M unit.  I packed up the core this morning for return to C&M via Pelican.  Apparently C&M dictate the details of the Core return (must use C&M original box, etc.).  A bit of a pain but hopefully it will work out as the core charge was substantial.

Looking forward to having proper steering with no leaks!

[mdsalemi]

…My mechanic was favorably impressed with the quality of the C&M unit…

They are the only people I know supplying these parts rebuilt. That’s all they do. Their website indicates they’ve rebuilt over 50,000 units (which includes other similar parts). Theres no substitute for experience.

Looking forward to getting mine in.

[Pinder]

they do include new straps to strap down the core. I had to reuse there existing metal clamps.  I pasted the new return lable over the one they had on their box.

Regards

 Pinder

[mdsalemi]

For those that may not understand the core return being such a pain, look at my first posting here which shows the gear/box and the pump as delivered. The pump is relatively light weight and is only strapped to one piece of plywood on the bottom of the box.

The steering gear/box is very heavy, and that is also strapped to a piece of plywood on the bottom of the box, PLUS includes a second piece of plywood to place on top, to prevent the box from deformation.

When returning (mine will be both pump and gear/box returned at the same time) you must place the core box(es) inside another box. If you put labels on the outside of the core box they warn you that there's a $25 charge.

As Pinder notes they give you strapping (without a strapping tool to tighten it, kind of useless) and a plastic bag so any residual fluid doesn't soil the box.

[Pinder]

Also they wanted a print out of the email sent to me for the core charge return to be put inside the box. Don’t forget that step. It’s a significant amount for the core refund.

Regards

 Pinder

[mdsalemi]

Dropped my car off on Saturday at the mechanics. Last night he removed both old PS pump and steering gear box. Rebuilt units to be installed along with new hoses and fluid, along with anything else he may find amiss.

[mdsalemi]

Well one thing begets another, that's what it is with a 55 year old car, even one restored.

So as was pointed out in another thread, the radiator needed to be moved in order to pull the pulley off the power steering pump. As long as that is happening, may as well change the coolant. I used premixed Zerex G48.

The pump and steering gear and new hoses went in without much issue.

However the mechanic noticed a couple of things...leaking from one of the pressure sensors on the auto transmission. When he pulled it, it was cracked and broken and a bad seal--hence the leaking. Got a new one from the CC, but even that needed a bit of work to fit as the threads were not long enough. Got that in also.

He also noticed some damaged rubber bits which we'll take care of in autumn. But he noticed a disparity in the fitting of the tie rods (unequal exposed threads) which he said would cause, to those sensitive to it, "bump steer" which I certainly had. Fixed that.

And while it was on the lift, could you grease all the Zerks please?

So with new steering components and a freshly greased chassis (don't ask when the last time this happened was) I had a much tighter and quieter ride home.

All done for now. Cores packed up and ready to be sent back.

Who knew. My power steering pump was Vickers, that old world British manufacturer. Didn't realize they used an British parts on our cars...