W126 Steering box question
 

I have been asked to reseal a leaking W126 steering box for a customer .Stripping it down it ,I could easily spot the hardened and leaking seals everywhere but the thick mud inside the gear case was something new.

This caused the case to really badly worn and scored .
What I need to know,and it isn't in the WSM etc is ,how far can the gear case be worn before it's scrap , and has anyone tried running a hone through one to clean up the piston bore ? i haven't miked the bore yet but a rough look says it has to .50 mm worn at the end of the stroke. :eek:
The pic of the piston assembly shows some of the mud and the other shows the mud in the gear case.

I beg to differ but at the top of chapter 46-070 there's a list of limits

(I'm looking in the W123 FSM but I'm like 90% sure the information for this chapter is the same in the W126 book)

Hi, that is why I asked because it simply says to replace the needle roller in the case if the roller is noisy etc. :) Does it give any figures in the W123 book? The steering box is pretty much the same across the range from 107 through to W126.

Its been a long time since I rebuilt one, but I think you determine the wear on the gearbox based on the preload torque when you cycle the rack thru its whole rotation.

As long as the teeth are worn evenly, you should be able to revive the box.

But then again, that box has seen better days... So your guess would be as good as mine, I don't remember seeing any bore tolerance specs in the book.

Hi, yep, done that and the torque figure seemed within spec but that only measures the load applied by the 'nut'. I've asked the owner to drop in box off his parts car and i'll see if it's better. Those who have never replaced the filter and flushed the steering...beware ..:D i measured the bore and at the top of the stroke it's worn .020". A bit too far gone to bother with I think.

(Sorry I'm late) Sounds a bit nadgered - do you want a link for the book?

Hi, No I will probably write this case off . The owner has another car for parts (probably in nicer condition than his daily driver...LOL) .I might just fit another pump too, as that will be just as worn and will break down as soon as he starts driving it. :)

I might have a few rebuilt racks for the 126 but ill have to check. I know that I have a bunch of 124's and 123 racks. Thing is I think shipping to Australia would be killer.. Things are heavy:mad:

Hi,thanks for the offer but we drive on the correct side of the road here and USA/canada steering boxes won't fit. :D
There are plenty of dead W126's here to get another one from to rebuild so that's not a problem.

Well,to close this off. I got the owner to drop in his spare box from his parts car. It wasn't leaking but he still wanted it resealed . Someone has already done something to the 'new' one because i could see the evidence. Apparently they don't any tools apart from a hammer and a cold chisel.
Every nut was bashed up with notches punched into them where they had smashed them undone. 4 balls were missing from the recirculating nut and the nut inside there had been tightened up so tight the straight edge was seized solid. This has the effect of losing all the self adjusting feature and you get constant power steering .
At least the housing wasn't worn out so I made one reasonable steering box from the pair of them to give the customer steering that felt almost as good as new .
So,when it came time to strip and clean out the pump, I drained the rest of the old fluid out and found...The guts missing out of the filter ,which would explain the crap in the box .Mostly caused by years of neglect which has seen the filter disintegrate and then dirt has been allowed to circulate eventually wearing out the whole set up. So , if you want your car to keep going in the right direction....Clean the steering out every couple of years with a good flush and change the filter every time you do an oil change. it's a lot cheaper than rebuilding a steering box and pump. :D

Crazy