Author Topic: steering box  (Read 422 times)

mauro12

  • Full Member
  • Senior
  • ***
  • Italy, Sicily, Messina
  • Posts: 112
steering box
« on: March 31, 2020, 09:58:13 »
hello guys, during this hard time I decided to spend more in garage. I've noticed a small leak from my steering box, I have to say that the steering wheel fells tight and without play so far, but I wanted to know if this leak can be fixed only with new seals or maybe it is worth to overhaul. What do you think? what can be the cost of an overhaul of the box? thank you
Mauro Pisani
250sl 1967 5speed zf manual

Pawel66

  • Full Member
  • Platinum
  • ******
  • Poland, Mazowieckie, Konstancin-Jeziorna
  • Posts: 2537
Re: steering box
« Reply #1 on: March 31, 2020, 12:34:01 »
Power steering? If it is just a leak from the top, even I was able to fix it, based on these instructions: https://www.sl113.org/wiki/Steering/PowerSteeringBox
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

mauro12

  • Full Member
  • Senior
  • ***
  • Italy, Sicily, Messina
  • Posts: 112
Re: steering box
« Reply #2 on: March 31, 2020, 14:37:56 »
No it is not from the power steering but from the steering box. I see some drops coming on the floor and also when you look from the hood of the car it is quite oily the box.
Mauro Pisani
250sl 1967 5speed zf manual

MikeSimon

  • Full Member
  • Gold
  • *****
  • USA, OH, North Royalton
  • Posts: 876
Re: steering box
« Reply #3 on: March 31, 2020, 14:54:11 »
The seal that is most likely to leak in a power steering gear (box) is the seal for the input shaft. Both heat and pressure will wear this out. I am not sure if you will achieve much with an "overhaul" .
Other than paying someone money for basically nothing. Replacing the seal is the only service a gear will need, other than a flushing job, which you will do anyway when the seal is replaced.
1970/71 280SL Automatic
Sandy Beige
Parchment Leather
Power Steering
Automatic
Hardtop
Heated Tinted Rear Window
German specs
3rd owner

Pawel66

  • Full Member
  • Platinum
  • ******
  • Poland, Mazowieckie, Konstancin-Jeziorna
  • Posts: 2537
Re: steering box
« Reply #4 on: March 31, 2020, 17:01:42 »
No it is not from the power steering but from the steering box. I see some drops coming on the floor and also when you look from the hood of the car it is quite oily the box.

I meant steering box with power steering.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

yves

  • Full Member
  • Senior
  • ***
  • France, Poitou-Charentes, LA ROCHELLE
  • Posts: 141
  • Happy owner of a 69/ 280 sl , 63 Etype FHC
Re: steering box
« Reply #5 on: March 31, 2020, 17:06:32 »
Hi Mauro , i have done that job some months ago with no particular skill but i have specificaly followed the instructions from the forum manual . You must follow the torque rules of each bolt  . Y'll have the link below:

https://www.sl113.org/forums/index.php?topic=29637.0

And keep cool even if you have some issues... ;)
Happy owner of a 69 blue 280SL ,  63 FHC  osb E-type , 55 FHC XK 140 to be restored...

Aaron h

  • Full Member
  • Senior
  • ***
  • USA, TN, Knoxville
  • Posts: 242
  • I don't need a new Mercedes....I have class. ;)
Re: steering box
« Reply #6 on: April 01, 2020, 03:38:25 »
In the picture below, note the two highlighted parts.  The cylindrical valve has 5 o-rings that go around it, and are internal to the gear box.  These o-rings are notorious for getting hard and leaking.  The leak will come from the weep hole on the bottom of the lower sector shaft cover plate.  When this happens there is no way around removing the gear box and disassembling it. 

If the outer sector shaft radial seals are leaking those can sometimes be replaced in situ, but can prove to be difficult.  If the worm gear shaft radial seals are leaking (where the steering wheel shaft connects to the gear box) that will also require removal of the gear box. 

The top of the gear box where the pre-load for the power piston to sector shaft is set has one o-ring around the metal disc and two copper crush washer between the nuts.  This area can also be repaired in situ. 

Bear in mind that replacing a few seals will usually cause the other old seals to start leaking, and that it may be worth taking the gear box out and re-sealing the whole thing.

Regarding seal kits.....Meyle and FEBI make kits, but I've had some problems with them not including all of the necessary seals in the kit.  I've also experienced failed seals in 2-5 years time.  I don't know what they're using to make their seals with, but it's apparently inferior to whatever Mercedes uses.  That's where the catch is though.  Far too many customers refuse to pay the price of the Mercedes kit, so I'm left with having to use aftermarket.  The trade off is whether you want the re-sealed gear box to be leak free for another 15-20 years or 2-5 years. 

Currently, the seal kit from Mercedes retails for $248 and wholesales for around $180.  Aftermarket kits range anywhere from $30-$60.  I understand wanting to save money, but given the aggravations in removing  and re-installing the gear box I'd fork out the money for the Mercedes kit. 

Beware of sellers offering rebuilt gear boxes online.  Many don't take the whole box apart, and if they do they have no idea how to reset the pre-load.  So you end up with a gear box that has too much play in it or is too sensitive.  On top of all of that, they all like to charge a small fortune for them. 

In essence, your gear box likely needs nothing more than a re-seal.  Internal parts rarely, if ever, wear to any notable degree.  However, you'll be better off long term removing the gear box and having the whole thing re-sealed.  If you remove/install the box yourself, then make sure you:

1) know how to center the gear box and steering wheel for reassembly,
2) that you have the centering tool or some homemade equivalent
3) Renew the steering coupling/coupling bushings for between the gear box and steering wheel shaft.....never a better time than when the gear box is out.
1966 250se coupe` black/dark olive/Macassar Ebony
1966 250se black/dark olive leather
1970 600 Midnight blue/parchment/Macassar
1972 280sel black/black leather
1971 300sel 6.3Papyrus white/dark redleather/Macassar
1973 300sel 4.5 grey blue met/blue leather/walnut
1986 635csi, M-sport, Cosmos blue

awolff280sl

  • Full Member
  • Gold
  • *****
  • USA, FL, Sarasota
  • Posts: 578
Re: steering box
« Reply #7 on: April 01, 2020, 12:05:12 »
Pierre Hedary gave me this tip:
I had a minor steering box leak, damp and with only the occasional droplet on the floor.
Pierre suggested that I put 2-3 fluid ounces of K&W TransX 75K automatic transmission treatment in my PS reservoir. Normally I don't go for additives, but within 2 weeks the box was dry.
This TranX stuff is thin, not gooey or gummy. I don't know yet if I will leave it in or flush it out eventually, but it seems to have worked for my relatively minor leak.
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo

stickandrudderman

  • Vendor
  • Platinum
  • ******
  • United Kingdom, England, Richmond
  • Posts: 2128
    • http://www.colinferns.com
Re: steering box
« Reply #8 on: April 01, 2020, 14:36:13 »
Regarding seal kits.....Meyle and FEBI make kits, but I've had some problems with them not including all of the necessary seals in the kit.  I've also experienced failed seals in 2-5 years time.  I don't know what they're using to make their seals with, but it's apparently inferior to whatever Mercedes uses.  That's where the catch is though.  Far too many customers refuse to pay the price of the Mercedes kit, so I'm left with having to use aftermarket.  The trade off is whether you want the re-sealed gear box to be leak free for another 15-20 years or 2-5 years. 
I had this problem on several boxes and found that switching to synthetic fluid instead of dexron 2 solved the issue.

I also concur that most vendors claiming to rebuild these boxes simply replace the easy to change lip seals and toss some black paint over it.
Overhauling these boxes is a skilled job best left to professionals.

MikeSimon

  • Full Member
  • Gold
  • *****
  • USA, OH, North Royalton
  • Posts: 876
Re: steering box
« Reply #9 on: April 01, 2020, 14:48:49 »
It would be interesting to see a detailed comparison between the seal kits from the Aftermarket and Mercedes. A visual and dimensional comparo would already help. A material assessment will most likely not be possible as it would involve a chemical analysis. Someone with the personal/business interest, time and funds could attack that??
1970/71 280SL Automatic
Sandy Beige
Parchment Leather
Power Steering
Automatic
Hardtop
Heated Tinted Rear Window
German specs
3rd owner

Aaron h

  • Full Member
  • Senior
  • ***
  • USA, TN, Knoxville
  • Posts: 242
  • I don't need a new Mercedes....I have class. ;)
Re: steering box
« Reply #10 on: April 01, 2020, 20:41:59 »
I'll try to lay out an aftermarket kit and a Mercedes kit soon to show what is and is not included between the two.  I agree that any further analysis without specialized testing is going to be difficult.  Though, a dial caliper could possibly help with part of the physical analysis by taking measurements.
1966 250se coupe` black/dark olive/Macassar Ebony
1966 250se black/dark olive leather
1970 600 Midnight blue/parchment/Macassar
1972 280sel black/black leather
1971 300sel 6.3Papyrus white/dark redleather/Macassar
1973 300sel 4.5 grey blue met/blue leather/walnut
1986 635csi, M-sport, Cosmos blue

MikeSimon

  • Full Member
  • Gold
  • *****
  • USA, OH, North Royalton
  • Posts: 876
Re: steering box
« Reply #11 on: April 02, 2020, 14:34:21 »
Yes! Exact dimensions are definitely necessary. Even small deviations in diameters and cross-sections of seals and O-rings always make a big difference in hydraulics
1970/71 280SL Automatic
Sandy Beige
Parchment Leather
Power Steering
Automatic
Hardtop
Heated Tinted Rear Window
German specs
3rd owner