HOW TO: Strip a 16v KR Throttle Body

Discussion in 'K-Jetronic OEM injection' started by !wvw!, Mar 19, 2017.

  1. !wvw! Paid Member Paid Member

    Joined:
    Dec 20, 2003
    Likes Received:
    5
    I thought I would do a guide for dismantling a 16v throttle body (I had promised I would). I have missed a couple of the dimensions out by accident (mainly on the first stage), so be aware. Also, I have tried to describe the components as best I can, but I have included pictures as a backup. My advice is to take plenty of pictures as you go along - I have included what I think to be the most useful ones here, but its better to be safe than sorry. Also, make sure you measure the distance of the grub screws when you take them out - that way it should work the same as before!

    Usual disclaimers apply - i.e.. not my fault if you balls it up.

    How to Dismantle a 16V KR Throttle Body

    1. Remove throttle body butterfly screws (for both butterfly's) - these are shot peened from behind, so can be quite tough to remove. The larger of the screws correspond to the smaller butterfly (for when rebuilding). The stamped numbers and screw heads face towards the engine. Note that the smaller butterfly is notched on one edge.
    i6l2E93h.jpg

    2. Undo 13 mm bolt on large butterfly shaft - on the underside of the throttle body.
    Remove small serrated washer.
    Unclip spring from washer with catch on (note that the washer has a notch for the spring) - remove washer.
    Remove plastic top bush.
    Untension spring and remove.
    qcaOovUh.jpg
    Eh46BUWh.jpg

    Remove thin washer (didn't get the dimensions - apologies!)
    Remove plastic bush (inverse of previous bush - like an upside down hat)
    84u8Kvph.jpg

    3. Now, working from the top of the main (smaller) butterfly.
    Remove nut (14 mm)
    Remove serrated washer (16 mm o/d)
    Remove second serrated washer (20.5 mm o/d)
    Remove plain thin washer (12 mm i/d, 20 mm o/d, 0.5 mm thick)
    Take tension of the spring and remove accelerator cable arm - note the there is a sleeve in the middle of this - it may or may not come out with the arm - its dimensions are i/d 9.8 mm, o/d 12 mm, depth 10.7 mm.

    Image of spring end locations.
    2twNuHlh.jpg

    Remove spring - upward facing hook goes over accelerator cable arm, the other end goes over the next bracket on the mechanism.
    Remove thin washer (i/d 12 mm, o/d 19.6 mm, 0.5 mm thick)
    O1IKCdfh.jpg

    For the next step, I wedged the throttle in what would be the open position to allow for the removal of the next piece of the mechanism.
    Release the tension on the small spring which is hooked onto the next piece of the mechanism (large butterfly - note that there is a notch of the spring).
    yFB6ERQh.jpg

    Remove the large butterfly spindle - should just pull out - it pushes through some roller bearings at the top and bottom of the throttle body housing.
    mtoHU72h.jpg

    Note - there is a small washer at the top of the spindle - on the two I have dismantled, it did not fall out, but it is there. Its dimensions are o/d 15.4 mm i/d 8 mm and 0.5 mm thick.

    Remove plastic bush (top).
    Remove metal sleeve (o/d 12 mm, depth 4.9 mm)
    Remove thin washer (o/d 17.8 mm, i/d 10 mm, think this is 0.5 mm thick)
    Remove thicker washer (o/d 17.8 mm, i/d 10 mm, 1mm thick)
    Remove bottom plastic bush (inverse of previous one).
    lGHHcgjh.jpg

    4. Spin over the throttle body housing.
    Remove the smaller butterfly spindle. You can remove the now empty throttle body for the time being. Careful not to lose any parts!
    Remove washer (o/d 17.8 mm, i/d 10 mm)
    Remove plastic bush - note that the previous washer sits inside this.
    Remove spring (hooked end is down)
    Remove washer (o/d 17.8 mm, i/d 10 mm, 0.16 mm thick)
    Remove plastic bush - inverse of previous one.
    Unhook bottom spring from next part of the mechanism.
    Remove bracket with plastic bush - bush end toward the bottom of the mechanism.
    Unhook the bottom spring. Hooked end towards bottom of the mechanism.
    Remove plastic bush.
    RQRETQzh.jpg

    5. Done!

    Rebuild in reverse order - use your pictures to help locate the springs - its actually not as bad as you think to get them tensioned in the right position - this is where your pictures come in. Note that some of the pieces of the mechanism have been stamped to make sure they grip the spindles - they will come off, they just need a little lubrication and a bit of a wiggle!

    MOST IMPORTANT THING - When you get to step 2 on the rebuild - DO NOT TIGHTEN THE SHAFT BOLTS UNTIL THE BUTTERFLYS ARE BACK IN! I did, and twisted the shaft, as there is no strength in them due to the slot through the middle. With the butterfly's back in, you can nip them up (not too tight) and they will be fine.
    bkYbsqch.jpg

    I hope this helps somebody - there isn't much on the net about stripping these - its actually not too bad as long as you are methodical. Here's how mine turned out in the end.
    ueQbFY5h.jpg s2wprCWh.jpg JjhqImlh.jpg
     
    erreesse, HPR, Coakers and 2 others like this.
  2. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    nice one, stickied :thumbup:
     
  3. Sirguydo

    Sirguydo Fastest milkman in the West Paid Member

    Joined:
    Nov 7, 2012
    Likes Received:
    1,203
    Location:
    Bolton
    Lovely work , thanks for sharing :clap:
     
  4. dubztubz Forum Member

    Joined:
    May 4, 2009
    Likes Received:
    19
    Location:
    ireland
    wonder you be able to use mk1 shaft to use mk1 accelerator cable
     
    MUSHY 16V likes this.
  5. MUSHY 16V

    MUSHY 16V Moderator Staff Member Moderator

    Joined:
    Jan 26, 2008
    Likes Received:
    800
    Location:
    aberdeen
    Not sure all the ones I did didn't have the micro switch worth looking at though
     
  6. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    not really worth the effort, just use a mk2 golf gti 8v/16v cable fits nice in the mk1 with 16v :)
     
  7. HPR

    HPR Administrator Admin

    Joined:
    Aug 11, 2009
    Likes Received:
    1,819
    Thanks, great post !
     
  8. spyrock Forum Member

    Joined:
    Oct 4, 2012
    Likes Received:
    5
    I dismantled my 16V throttle body because there is an air leak from around the butterfly shaft and I can tell you that above how-to misses some critical infomation. If you looke very closely you will see that the needle bearings hide a very small rubber shaft seal.
    It's easy to miss it, especially because on the top side of the throttle body, the shaft seal hides on the inside of the bearing where you can't see it. But it's there.

    On the bottom bearing, the seal is on the outer side. See my picture:
    Seal2.png

    Now, where to get these [:?:][:?:][:[]
     
    erreesse likes this.
  9. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
  10. spyrock Forum Member

    Joined:
    Oct 4, 2012
    Likes Received:
    5
    Thanks, I will have a look.
    Original part is INA F-95776. It's a needle bearing with incorporated seal into the outer race.Never seen this before.
     
  11. spyrock Forum Member

    Joined:
    Oct 4, 2012
    Likes Received:
    5
    I've tried to measure it and identify it on the INA web catalog. Looks to be this one with inner seal on one side (yellow marked on picture).
    https://ibb.co/T12pT9R

    It wouldn't surprise me that many people have this leak but might've never found out!
    I've also noticed the butterfly plates are not sealing the throttle body throat when closed. You can see clear gaps. This is a common defect and could be solved by coating it with Molykote 321. Very special dry film lubricant.
    Bearing-Identification.jpg
     
    erreesse likes this.
  12. oaky16v New Member

    Joined:
    Sep 10, 2021
    Likes Received:
    0
    Is there such a thing as a rebuild kit for these? When you put the screws back in the butterfly did you secure them in any way. I believe they are deformed at one end to keep them in place?
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice