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Installing Late bay steering box into an early bay

Discussion in 'Steering, brakes & Suspension' started by SunnyJim, Mar 26, 2020.

  1. SunnyJim

    SunnyJim Well-Known Member

    carindale Brisbane
    Installing a late bay steering box into a early bay 71 kombi

    My son lost steering in his 71 bus. Pretty scary, lucky it was at low speed not on the M1.
    Once the kombi was towed home investigation showed that the steering wheel shaft clamp had simply come loose from the steering box shaft. We could have just tightened it again but decision was made to overhaul all aspects get the best steering possible.

    How? We decided to retrofit a late bay steering box to the 71 Lowlight. Feedback indicated the late bay box was a better box than the early bay version.
    the new box.jpg

    We first put sunnyjim up on the car ramps, but in retrospect it is better to put on 2 car stands, as eventually the 2 front wheels do need to freewheel e.g. be off the ground. 2 car stands one on each side of the front beam.

    Special tools needed
    36mm socket to loosen tighten the late bay box lock nut
    push centre punch
    gear/steering wheel puller to remove the pitman arm
    grinder, cutting wheel, dremel
    2 car stands
    torque wrench

    We removed the steering column so i could look through the kombi floor and see the top of the steering box.
    We removed and inspected the bolts and nuts on the rubber coupler. I was fully prepared to replace the rubber coupler but as it was only about 7 years old and in excellent condition, I was told it was probably better than current product quality. I think it was important to note that all nuts were the lock type with nylon insert. I am not sure if this original or not. We loosened the nut and bolt holding the clamp on the steering box shaft. Now here was the main source of our problem. This clamp was found to not grip the splines on the steering box even though it was not loose when we first found it, it was still tight.
    See the picture below, this is what we think has happened. The bolt that goes through the clamp sits in a horizontal groove in the steering box shaft. The bolt has now narrowed enough that it no longer grips the steering box input shaft. It has narrowed because the bolt threads are worn away. I found out this is not the correct bolt. The correct one should have a solid shaft in the middle where it parks against the steering box shaft notch .
    probelm bolt.jpg

    Below is the correct bolt. More meat in the middle.


    See the groove in the shaft where the clamp bolt will locate .


    Removing the original early bay box. This was straight forward as per the books. I did need to use a puller to get the pitman arm off. You also need to remove the old pitman arm from the Drag link. Mark the drag link threads so as to know the length it was screwed into. On our drag link I found it was obvious, as surface rust had clearly marked this for us.

    Comparing the new late bay and old early bay boxes. If possible lay them side by side and appreciate the physical differences.
    - Both have 4 mounting holes but only 3 are common, you will have to drill a new 4th hole in the chassis rails (this was my biggest challenge)
    - the steering output shafts are different, so this means increasing the hole size in the 2 chassis rails.
    - You will need a new late bay pitman arm and larger lock nut
    - The late bay box uses a lock washer unlike the early bay, it does not have a hole for a split pin.

    Lying on the ground under the kombi try to position the new steering box in its new position. You will see it obviously wont go in. But we found the box touched on the inner valance, so we used a hammer to flatten out the valance metal to give more wiggle room

    Making the cardboard template to drill the new 4th hole.
    - get a small square of cardboard and neatly cut it so it sits over the output shaft of the new steering box. use a pen or drill to mark the 4 holes by poking thru the cardboard into the steering box holes
    - now the old steering box is removed place the cardboard stencil on the chassis rails. Put 3 of the 4 bolts thru the cardboard into the chassis. It should sit flat, if it doesn't tape it down flat. I started on the drivers side of the chassis rails but it doesn't matter as you need to mark both sides of the chassis rails. Now use a pen/paint/ or a push centre punch to mark the spot for the new 4th steering box hole. Now while the cardboard is still taped to the chassis use a felt pen and mark out the area that needs to be cut out of the chassis rails. you will do more cutting on this side due to the shape of the new steering box.
    Now remove the cardboard stencil and place it on the other side of the chassis rails. Put 3 bolts thru the stencil into the holes. Remember to reverse the cardboard stencil or else it wont line up. Once again use a pen or centre punch to mark the new 4th hole. Now a quick check before you drill the new hole, measure the distance from the old 4th hole to the new mark. They should be the same on both sides. Make sure they are. Whilst you are still on this side you need to mark the hole for the steering box shaft. On this side you won't need to remove as much metal.You are just increasing the size of a circular hole by a little bit. I measured the hole at 52mm, the new box shaft is 54mm so you need to enlarge this hole by about 3mm all around.
    cardboard template.jpg
    design the template.jpg

    I drilled the new 4th hole first using just a small 3mm drill, do it on both sides. Now you are really committed. Measure again, both holes should be the same distance from the old 4th hole. If they are all good and keep enlarging this hole from both sides until you have a new hole. Access was hard, so I had to use the smallest cordless drill I could. One issue we encountered was that the chassis rails have a inner metal tube to guide/support each of the steering bolts. This guides the steering bolts but provides strength for the chassis rails so they cant be compressed. We found the new 4th hole to be right on edge of the tube. As we drilled and got near our final hole size we used a metal punch to knock the tube loose. I took the tube out cleaned it up with a grinder. We were then able to reposition the tube in its new position between the chassis rails. This part was a lot of work and I want to to highlight now there is a different way. I remember seeing on the vw samba forum when faced with this challenge someone had decided avoid this hassle and cut out a square on both sides of the chassis rails with the tube still intact. They then repositioned the tube and welded it in its new position. This looks a neater way but well above our skill level. If you want a real professional job it may be worth finding a pro to do this part for you.
    new 4th hole.jpg

    Cutting the chassis rails on the drivers side
    - Now you have marked the chassis rails via the cardboard template cut out the new shape. Initially I was worried that this might weaken the chassis rails but I don't believe so as the 4 inner tubes are still present providing rigidity between the 2 rails.
    This was just a lot of work. I tried a 100mm grinder, it was too big. I tried a air compressor cutting wheel it was not strong enough,kept stalling. I found the best tool was a dremel with small cutting wheels . It worked well but I was changing the disc every 2 minutes. I also used a multi function tool (reciprocating type with metal blade). That helped but made ugly jagged edges. Not really an issue it gets covered up with a plate on the passenger side of the chassis rails

    chassis holes enlarged.jpg
    Cutting the chassis rail on the passenger side
    This side is not as hard, as you are still keep the circular shape. As said above I measured the hole at 52mm, the new box shaft is 54mm so you need to enlarge this hole diameter by about 3mm. So you just need to nibble at the metal all around until you can insert the new steering box shaft all the way thru.

    Mounting the new steering box. If all the above steps worked for you you should be able to install the 4 bolts. I really suggest putting these in by hand to ensure you have not cross threaded them. Also inspect each bolt, clean each bolt up with degreaser and a wire brush, this will make hand insertion easier. We had to replace 1 bolt as the threads were damaged. Use a torque wrench on these 4 bolts. I have not done it yet but will take each bolt out again and put some red loctite on them to reduce the chances of them coming loose in future.
    new box installed.jpg

    To be continued part 2
    Last edited: Mar 30, 2020
  2. SunnyJim

    SunnyJim Well-Known Member

    carindale Brisbane
    Our box being new didn't have any oil in it. Once it was mounted then we filled it with oil.
    It is important before tightening the nut and drag link that a] the front wheels are real straight b] the steering box is in the centre of its travel. We found the steering box had 3.5 revolutions lock to lock. Looking through the Fred Flintstone hole in the kombi floor the black rubber notch should line up with the notch on the steering box shaft. You can test this from the centre, it should be 1.75 revolutions left and right.
    Lying on the ground under the kombi screw the new pitman arm into the drag link. Place the pitman arm hole over the steering box shaft. Now it is critical that the pitman arm 'R' mark lines up with the notch on the steering box shaft. The front wheels should still be straight and from above looking thru the Fred Flintstone hole, the notches on top of steering box still aligned. If all this is good put the lock washer on first then big nut over the pitman arm. You will need a 36mm socket and torque down the big nut and also tighten the other end to the drag link.
    pitman arm marks.jpg
    pittman arm notches and steering box shaft.jpg
    box notches lined up.jpg

    Test steering, Now from above turn the steering wheel left to right lock to lock
    . From the centre it should be equal out to left and right. Also at this stage you can check the steering wheel play. We were delighted after all our hard work we got less than 1 inch play in the steering.
    I was a little concerned that this final lock to lock was not that same as the steering box 3.5 revolutions. We found it to be less than 3, but was informed this was normal as the steering geometry underneath limits this.

    Take for a test drive
    , don't forget to remove the car stands! If it all works well send me a million dollars. If you stuffed up don't blame me! If you are happy and believe you have finished go back underneath the kombi and tap the lock washer to secure the nut. You tap one side down and the other up over the nut to secure.
    lock washer.jpg

    Seriously, the steering does seem a lot lighter and certainly less play in the wheel. My son thinks it is a much better drive. Good luck.
    Last edited: Mar 27, 2020
    roverbay, Mordred, TeeBee and 8 others like this.

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