79 Bay, worm and roller steering box repair

Discussion in 'Steering, brakes & Suspension' started by rstucke, Mar 8, 2015.

  1. AnnaBay73

    AnnaBay73 New Member

    Messages:
    29
    Location:
    Australia
    Hi, I have now had chance to test the reco steering box. Major improvement, dare I say it, it feels like how you should expect the kombi to drive. More direct, a lot less correcting the wheel to compensate for too much freeplay. Like most people, I was in denial that the box was a major problem, no doubt partly due to the lack of suppliers of quality reco boxes and the cost. Thanks to Rick and his great post, kombi owners now know whats involved. If anyone knows of suppliers of good gear they should post it here.
    Thans again Rick.
     
    cbus likes this.
  2. jason young

    jason young New Member

    Messages:
    10
    Location:
    port hedland
    Great story & a fantastic rebuild. Love your work.
     
  3. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    A short time ago Trops Orah asked me if I'd recon his steering box. I agreed and I'll post progress over the next few days.
    After removing the cross shaft I noticed the worm was just a little gritty to rotate.
    After strip down it was obvious there had been some water in there (a killer for hardened steel surfaces) and also a fair bit of crud.
    Bushes were worn (not as bad as some) and this is what can be repaired.
    Fortunately the balls and the surface they contact are not too bad under a magnifying glass so I'm hoping it was crud around the lower worm bearing causing the gritty feeling (find out soon)
    I've tried to source the angular ball cones (specially the ones at the bottom of the worm but they are unobtainium with a 45mm outer diameter (only ever 42 and 47 available). These were specials for ZF ontop of a 45 deg contact angle. Even with the SKF part number 355904 there is no luck so I'll polish Cades lower cone as the section the balls run on is OK.
    Can't do more on this till Tues or Wed because my bus is due at Master Blaster for a light massage to remove all 3 layers of Merino Gelb and the surface rust around the engine bay and vents (had a fire at some stage)
    Here are some pics in the mean time. P4220023.jpg P4220024.jpg P4220026.jpg P4290051.jpg
     
  4. MrBubbleHead

    MrBubbleHead Member

    Messages:
    257
    Location:
    Footscray Melbourne
    This is a great thread its about time the myth of steering boxes has been exposed. I would for sure be interested in having mine reconditioned if your inclined.
     
  5. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    I'm thinking of maybe doing a couple and having an exchange set up. Maybe.
    I'll let you know
    It's just that I'm flat out on my own resto at the moment.
     
    Last edited: May 4, 2016
    marcus williams likes this.
  6. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    Ok progress as I had an hour spare today.
    cleaned the housings. P5020054.jpg

    polished the lower worm cup (the most vunerable to corrosion by water. came up ok.
    P5030060.jpg

    re-installed the worm and checked preload. aok.
    P5030066.jpg

    Machined the bush out of the end plate and cleaned it up for the new thicker bronze bush.
    P5030068.jpg

    P5030071.jpg

    More on this tomorrow (time permitting).
     
    Last edited: May 4, 2016
  7. Whitie

    Whitie Active Member

    Messages:
    136
    Location:
    Warriewood
    Great read Rick.
    This may not be relative to your thread but could I ask possibly a dumb question:confused:, what signs would you expect that indicates your steering box needs a refurb?

    I've notice when back on the suburban street after a long fwy drive my steering becomes quite tight & heavy.
    First thought it was all in my head, maybe caus id been used to moving the wheel only slightly on the fwy, but its quite noticeable, next day steering back normal.
    Could this relate to the steering box? Low on oil? ball joints heating up? or maybe the driver just needs to grow some muscle.
    Appreciate any feed back, cheers Tony
     
  8. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    Hi Tony
    I've seen this very thing. Once on a friends kombi and on my own when I bought it off a guy in Vic and drove it home. Steering got tight after about an hours driving. Both times caused by a steering damper seizing up. The steering wandered a fair bit too (goes left, correct, goes right, correct, goes left etc.). Next time it happens take it off and go for a drive. I still have the old damper, when I move it through its' stroke it feels ok but when I took it off the bus after I had the tight steering problem it was seized.
    A steering box needs work if there is play between the steering shaft and pitman arm AND the adjuster on the end of the box is all the way in.
    Hope this helps, let me know how you go with the damper.

    Rick
     
  9. Trops Orah

    Trops Orah Member

    Messages:
    50
    Location:
    Melbourne
    Hi Rick,
    Really good news with the corrosion removal in the worm cup and the preload. Do you think the steering box will be salvageable now, or is their further water damage to contend with? Also can you explain to me why the brass bearing has perforations in it?
    Thanks again for undertaking the work and especially posting the images of the work so I can follow and understand the repairs
    Regards
    Cade
     
  10. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    Todays progress
    Bearing for the end plate
    12.jpg
    13.jpg
    14.jpg
    Remove bearing from housing
    20.jpg 21.jpg
    Cade the bearing isn't perforated, it's actually dimpled. The bearing (approx. 3mm thick) was placed in a mould and the aluminium was diecast around it which made the whole thing a throw away unit. The dimples are there to help the alloy key to the bronze. Looks perforated because I've machined the bearing away and used plyers to remove what was left. As for corrosion the only problem was the lower cup and that polished up ok. the small amount of corrosion on the worm isn't on the running path of bearings and seal so this box is going to be spot on when done.
     
  11. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    More
    New bearing is much beefier than the original one.
    22.jpg 23.jpg 24.jpg 25.jpg 26.jpg
    nice and clean inside.
    More tomorrow.
     
    Last edited: May 4, 2016
  12. Trops Orah

    Trops Orah Member

    Messages:
    50
    Location:
    Melbourne
    Looking great Rick and great news regarding it being rebuildable,
    Also that makes sense regarding the dimples being there to stop the bearing rotating in the casting. However why would the original manufacturers just press fit a tight tolerance bearing as per what you have done? Was it to save time for assembly, or planned obsolescence ?
     
  13. Trops Orah

    Trops Orah Member

    Messages:
    50
    Location:
    Melbourne
    Also how was the condition of your van after the sand blasting!
     
  14. Trops Orah

    Trops Orah Member

    Messages:
    50
    Location:
    Melbourne
    Also meant to say " NOT just press fit" in the post above.
     
  15. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    the bushes ZF used were pre finished and very thin. The would have distorted if pressed in. The process and materials they used was quick and cheap. Zf manufacture components for the auto industry like transmissions and steering boxes (amongst other things). They make really good robust stuff for the top end of the market but can also supply crappy cheap components to the industry that wants it and at the time VW was looking to cut costs.
    The bus is still at the blasters but I've just been told the polyester hi fill primer I want to use isn't available till the 23rd. Apparently its in a container on a slow boat from the US. I'm trying to shift the bus back in the line up.
    You better PM me your address because your steering box will be ready tomorrow
    Cheers
    Rick
     
  16. Whitie

    Whitie Active Member

    Messages:
    136
    Location:
    Warriewood
    Thanks Rick, Ill keep you posted
    Tonyh
     
  17. rstucke

    rstucke Well-Known Member

    Messages:
    559
    Location:
    Wamberal NSW AUS
    Final bit
    New seals
    30.jpg
    Pic of the cross shaft and roller (strongest part in the box)
    31.jpg
    Assembly
    32.jpg
    I machined the adjusting lock nut to take an o ring (no leaks)
    33.jpg
    It's important to line up the pitman arm to the correct marks (L-left hand drive. R- right hand drive.)
    34.jpg
    In the box heading home.
    35.jpg

    Important things when re installing
    Fill with 90 weight or higher gear oil. With the box held in its normal installed attitude the oil level should be just the same level as the top of the cross shaft you can see through the fill hole. This leaves some air space for expansion (avoids pressure caused oil leaks)
    Line the pitman arm up to the correct mark on the cross shaft.
    Hold the pitman shaft with a gal pipe when tightening. don't let it rotate to the end of the box.
    Find the exact steering centre in the box and adjust the mark on rubber that sits over the steering shaft seal (you can turn it on the shaft) on the box to line up with the raised section on the seal housing. This is the only position you can adjust the box in. Feel for play in the pitman arm by moving back and forth with your hand. Turn the cross shaft adjusting screw in till the play is zero and lock it up. This is the best way to adjust the steering box (with the drag link disconnected). Some say adjust till you can feel a slight tight spot tuning the steering wheel through the middle of the box. The tight spot you are feeling is the cross shaft being forced hard into its' bushes, and even though its only a slight feeling if you do the calcs for the mechanical advantage from the rim of the steering wheel to the cross shaft in the box the force on the bushes is substantial.
    Now with the box in its' mid position and every thing connected make sure your front wheels are in the straight ahead position, if not when you are traveling in a straight line your steering box will be off centre where there is normally some play and you'll be wondering in and out of your lane and changing direction with the wind.
    Don't forget to check steering joints ball joints and centre pin for slop also the damper because the steering box is only 10% of the steering problems that Kombi's face.
    Cheers
    Rick
     
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  18. john doherty

    john doherty Well-Known Member

    Messages:
    798
    Location:
    adelaide
    Rick,
    Totally love your work.
    There I was thinking Kombi maintenance and repair was complex and only for the highly skilled?!?:eek:
    Didn't understand any of it..... But by God,.... Read it all.... Studied the photos ........ and loved it!
    Thank you for sharing...... and teaching.
    JD in Adelaide:cool:
     
    Mordred likes this.
  19. Trops Orah

    Trops Orah Member

    Messages:
    50
    Location:
    Melbourne
    Rick
    I can not thank you enough. Your workmanship is exemplary and it has been great to follow through the build.
    I also now understand the steering box assembly ( which I had no understanding) and how to install it to get the best " feel" out of my steering. I will keep you posted of the install as it goes in
    Thanks
    Cade
     
    Mordred likes this.
  20. rays76bay

    rays76bay New Member

    Messages:
    26
    Location:
    Grange,Adelaide,South Australia
    Hi Rick
    A First Class Rebuild ... is all I can say and thanks for sharing your work !!

    I read in your thread of " having a exchange set " and " I'll let you know "answer to Mr Bubble Head of Melbourne
    Can I also ask the question for a rebuild of my 76 Kombi Box . The box in the Kombi leaks oil and knocks.
    I have 2 others on the shelf and one of those I believe is the best of all the 3 for a rebuild.
    I too am in the process of a body / rust repair / repaint of our camper.

    Could you " let me know "as well if the "exchange unit" system unfolds.
    Enjoy your resto

    Ray
    Adelaide
     

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