Power steering box removal/overhaul/refitment - MIS-ADVENTURES

[s class]

Plans for my 280SE this weekend : I must remove the steering box as it has L-A-R-G-E slop around its centre point.  I will send it in to a specialist for rebuilding, but I strongly suspect it is BER (beyond economic repair).  As a result I will also send them the steering box out of my 280S parts donor which I believe has much lower mileage.

At least now that I've posted my intended plans for this weekend, it will help to pit pressure on me to actually make it happen 

Ryan in South Africa

PS in case you think I'm lazy only donig that this weekend, I must also rebush my W140's gear linkage, reassemble its rear seat area and trunk interior after the audio install and ascertain why the driver's door electric window lift isn't working - these W140's suffer all the same maladies as W116.

Life is too short to spend struggling with only one old benz.......

[WGB]

The box can be adjusted in-situ easily on a 6 cylinder although the adjuster must be turned anticlockwise not clockwise as in most cars. Also check the coupling between steering column and Box as it has rubber in it which can perish.

If that fails then it's time for a new box

Bill Babe

[s class]

Bill,

I replaced the rubber steering shaft coupling some time ago and it's still fine.  Yes thanks I am fmiliar with the procedure for adjusting the box in situ, and as you commmented, its easy on the 6 cylinder.  And It has been adjusted a few times in the last few years and there is no more scope left.  It realy is very knackered (its done nearly 500 000km)

Ryan

[WGB]

Ryan,

I guess you have tried everything.

I found the only way I managed to adjust my 450SEL's box was to remove the exhaust manifold on that side. The rubber filled universal was shot and after replacing this and adjusting the box it steered exactly as I remembered they did when they were new - about 185,000 miles if the speedo means anything

Best of luck.

Bill

[s class]

Bill,

on the 6 cylinder access is very much easier than on the v8's.  I have removed the steering box and I will soon post a procedure description with pics.  In any case, it is leaking at the seals so it had to come out. 

To second Big R's comment about all rubber parts being past their sell-by date, although the box is leaking, there is another more significant leak from one of the rubber hydraulic lines to the box.  At least that will be easy to fix. 

I have also retrieved the spare steering box from my parts car and was disappointed to discover that it has 3.7 or 3.8 turns lock-to-lock, compared to 3.1 for my original box.  In each case the pitman arm swings the same arc, they just need a different number of turns to achieve this.  I'm not keen to go to a slower ratio box, so I will be visting my local mercedes specialist breaker tomorrow to see what I can find.  Bummer.

When I get everything ready to reassemble, I will describe how to align everything to get the box onto its high point and the steering properly centred on the high point.

Sorry I'm too busy at work this week to write it up now - next week....

Ryan in South Africa.

[s class]

Yay!!!

Yesterday I located another steering box with the correct number of turns and mointing points.  It has a nice smooth even turning force from lock to lock, except for a clean, prominent high spot in the centre.  NO play in it when on the high spot.  I felt so lucky and happy with life!

On the way home I located some replacement hydreaulic hose.  The kind fellows even crimped it onto the metal tube which goes to the steering box so I won't have to worry about crappy hose clamps on that end of the return line.  I felt SO lucky and happy with life!

ON the way home with my new treasures the W140 broke a chain guide and the debris must have gone into the sump.  Aaargh panic - no oil pressure when engine speed increases because the debris has blocked the oil pump pickup.  I limped home feeling disappointed, but at least I could look forward to fitting the W116's steering box and NEW hydraulic hose. 

No no, the guys were bastards at the hose place! they supplied me 13mm hose instead of 11mm, so I can't get the clamps to hold at the other end.  ****.  I had to cut off the beautiful crimp they put on.  But I cheered myself up that at least I could fit the steering box. 

It comes from a W123, and is the same except the pitman arm is a different shape.  I broke my hub puller trying to draw off the pitman arms to swap them.  Went to bed in a bad mood. 

Now the W140 and W116 are on stands.  This morning I set out in the R107 to locate a DECENT hub puller and 11mm hydraulic hose.  Got pulled over by the coppers who thought I had a "nice car".  They kept me there for about 30 minutes examining the car, checking lights, horn, tyres etc until they found somehting to fine me for.  A fused brakelight globe.  *!&?  Becoming an expensive morning. 

I now shelled out a lot of readies for a DECENT hub puller, and I found the right hose.  Maybe tonight the W116 will run.  I now feel a lot luckier and hapy with life.

Ryan (got till 14 August to pay my fine for "unroadworthiness").

[s class]

The saga continues - my decent hub puller was able to remove the pitman arm from the old W116 steering box, but broke  trying to remove the one from the "new" steering box.  So the 280SE is still on stands. 

Have to go back to the place I bought it and argue a bit. 

Ryan

[s class]

Things are not going well with the 280SE's steering box.  I took two nice used 280E W123 boxes to the steering specialist that does my "outwork".  The bad news is they considered the 2 boxes too worn.  I have scoured breakers yards and examined about 60 steering boxes, and found nothing better than the original 2 I got from the breaker.  At present the car is still on stands as I consider my next move. 

Ryan (I own a W116 but it doesn't run at the moment).

[oscar]

Got pulled over by the coppers who thought I had a "nice car".  They kept me there for about 30 minutes examining the car, checking lights, horn, tyres etc until they found somehting to fine me for.  A fused brakelight globe.  *!&?  Becoming an expensive morning. 
Ryan (got till 14 August to pay my fine for "unroadworthiness").

Seriously?! That's ridiculous.  Who's to say the brake light just failed whilst applying the brakes to stop for the cops?  It's unbelievable that crap can still happen.

I don't know anything about steering boxes so I'm watching and learning, waiting (hoping) for a good outcome.  My question is though that can your boxes be rebuilt or is the "too worn" comment aimed at these boxes being beyond repairability?  I only ask because I remember Big R getting his box rebuilt some time ago.

[s class]

Yes, thanks styria,

When new, the steering boxes have a "high point" - where the clearance and play is very small in the centre of the box.  Towards the sides there is slightly more play and less turning resistance.  What happens is the boxes tend to wear in the middle region until the high point is no longer apparent.  If wear is mild, you can adjust the sector shaft using the external allen head adjustment.  If wear is excessive, a lot of adjustment is needed, and usually youfind that the ends of the box (which don't see much wear) start binding before youve been able to take up the slack in the middle.  THis is what I have found with every single box I've looked at.  I was planning to find a good one and have it sent in for a paint, reseal and adjust (the so-called rebuild). 

I have encountered one establishment that claims they will be able to "build up and reshape" the sector shaft teeth to restore the proper clearances.  I am skeptical about this, and it's quite expensive.  Any experience with this anyone?

Thanks, Ryan