Announcement

Collapse
No announcement yet.

Long (subframe lowering) Bolts. How to use them?

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Long (subframe lowering) Bolts. How to use them?

    Contemplating obtaining a set of long bolts for lowering the subframe (sump change needed) but unsure how to use them.
    Do they bolt all the way up and are then progressively slackened to lower subframe to required height, does the subframe have to be held up (jack etc) the bolts inserted then the subframe lowered to suit the bolts' length, or some other arrangement?
    Any advice welcome. TIA.

  • #2
    I never heard that youve to lower the subframe, for a sump change?

    To lower the subframe.
    Remove the undertray
    remove nut of the bracket from the brake-lines .
    Remove/disconnect the hose of the air-intake (tridion)
    Remove the rearbumper
    place a gearbox lift or jack under the engine
    remove the subframe-bolts
    place the long service bolts
    disconnect the handbrake lever
    slowly lower the subframe.

    good luck!!!

    Comment


    • #3
      You screw them in until they bottom out. This ensures the subframe is not being guided on the threads which could cause it to jam.

      Car needs to be on a lift or rear end on axle stands. Car must be pretty high for complete pulling of its power pack unless you remove the rear springs thereby allowing suspension to rest on its stops.

      Of course the power pack must be supported on a trolley jack or equivalent when you remove subframe bolts and fit lowering bolts. Various pipes and cables must be unclipped or disconnected. This will be obvious when you start lowering. Hand brake must be in off position.

      There is usually no need to drop subframe all the way down to heads of lowering bolts. Suggest you make a few wooden packers or washers. MDF or plywood is fine. I do not recommend unlaminated timber as it may split.

      Note regarding sub frame bolt tightening sequence:

      The bolt tightening sequence becomes obvious if you could see subframe from above.

      Rear subframe is held on to chassis with four M12 x 1.5 bolts.
      1. Forward left bolt connection has no lateral play and should be tightened first.
      2. Forward right bolt connection has some lateral play and is tightened next.
      3. Both rear bolt connections have play in all horizontal directions and are tightened last.

      Comment


      • #4
        Thanks all. I found a load of info on ClubSmart (including your contributions TK).
        Going to order the bolts and I've ordered some steel tube to cut into spacers to slip over the bolts to limit the height I drop the subframe to something more manageable but still more than permitted by using standard bolts (rear to front).
        Panicked a bit when I realised that the bolts wouldn't allow the front edge of the sump to clear the deDion, but with the subframe lowered I can more easily get at the front engine mount and remove it to drop the front of the engine a touch.
        That's the plan at least - and get some weatherproofing done to the subframe before they start throwing salt down on the roads - can't be far away now.

        Comment


        • #5
          How about fitting an electric oil heater in your new sump? Something I am considering just now before winter sets in.

          A 150 Watt PTC towel rail heater will fit perfectly screwed in from inboard. Price about GBP 20. You will need a 1/2" BSP adapter to be either brazed, welded or screwed on with a back nut inside the sump.

          Elements in PTC heaters are made out of some kind of doped stone. They are self regulating - Wattage drops as they warm up, hence PTC (positive temperature coefficient). There is no thermostat and no electric wire element that may fail due to vibration and when turned on dry.

          I am about to fit one of these heaters in the return tunnel pipe. 300 or 400 Watts PCT element. The heater will reduce coolant flow area by 29% which I think will be no major problem in Scotland at least in my life time.

          Comment


          • #6
            I've never needed the lowering bolts, simply remove all four bolts when car is on ground and put the two rear ones in the front holes. Use a jack on the bell housing to limit drop to desired height.

            Cheers!

            Comment


            • #7
              Originally posted by Kapt. Q View Post
              I've never needed the lowering bolts, simply remove all four bolts when car is on ground and put the two rear ones in the front holes. Use a jack on the bell housing to limit drop to desired height.

              Cheers!

              They'll be delivered to today so, as I'll have them - I'd be as well use them!
              I did consider the using the existing bolts method but propping the rear of the subframe on sticks puts me off - too easily knocked.
              At around the £30 mark, the bolts aren't an excessive cost for what they enable.

              Comment


              • #8
                Originally posted by tolsen View Post
                How about fitting an electric oil heater in your new sump? Something I am considering just now before winter sets in.

                A 150 Watt PTC towel rail heater will fit perfectly screwed in from inboard. Price about GBP 20. You will need a 1/2" BSP adapter to be either brazed, welded or screwed on with a back nut inside the sump.

                Elements in PTC heaters are made out of some kind of doped stone. They are self regulating - Wattage drops as they warm up, hence PTC (positive temperature coefficient). There is no thermostat and no electric wire element that may fail due to vibration and when turned on dry.

                I am about to fit one of these heaters in the return tunnel pipe. 300 or 400 Watts PCT element. The heater will reduce coolant flow area by 29% which I think will be no major problem in Scotland at least in my life time.

                I'd worry about the whole thing (doped stone) breaking up with the vibration, and besides, running a 240V cable outside doesn't really suit where I'm currently staying. Anyway, my running patterns tend to see the car run at proper temp for several hours so ample chance to boil off any condensates in the oil.

                The thing more on my mind is dealing with the handbrake on dropping the subframe. More 'net searches today....

                Comment


                • #9
                  Info on some of the sites is wrong.
                  Hand brake equaliser rod with rack at top end will drop with subframe as long as hand brake lever is off (lowest position). Rack is to be pointed towards left when lifting power pack to engage rack with hand brake lever.
                  More info on OnSmart: https://forum.onsmart.co.uk/viewtopic.php?t=3172

                  Remember to grease the equaliser mechanism when you have access.

                  Comment


                  • #10
                    Cheers TK. I'd bookmarked that page yesterday and was going to look at it in more detail today. Appreciate the clarification on removal procedure though, and yes, grease absolutely everything I encounter - including the upper surfaces of the subframe, before the roads are covered in salt.

                    Incidentally, I cribbed some of your reluctor ring press idea the other day. Initially I used a sleeve and hammered on the rings (I didn't have an appropriate bolt at hand, only a sleeve) and the ring on one side didn't go far enough onto the shaft - which I only discovered after reassembling everything and on tightenening the driveshaft bolt found the ring fouling the wheelbearing retaining bolts. So, rather than dismantle everything, merely slackened the shaft bolt enough to slide the shaft in far enough to slip the old reluctor ring (cut into two pieces and held with BluTak) between new ring and axle - then tightened the bolt which pressed the ring on far enough to clear the bearing bolts. Saved me a shed load of time. The idea wouldn't have come without seeing your press. Cheers!

                    Comment


                    • #11
                      You can if careful, lower the engine using the bolts without having to remove and disconnect all of those things, but it depends on what work you are planning on doing. When I want to extra space to get behind the engine or get to the front spark plugs you can fit the bolts and lower the subframe on a jack until just before it starts to get difficult sliding down and that will give you access to loads of things without the extra work. Its what I do all the time and Ive only ever actually dropped it all the way once. But I have to admit they make life a hell of a lot easier.

                      Comment


                      • #12
                        Bolts arrived today (ordered yesterday and delivered free - not bad for a MB/smart dealer...) and a length of steel tubing due on Tuesday. With the long bolts, and spacers cut to my choice of length I can have as little or as much space as I need so worth the effort I think. They'll get used again and again in years to come as the car needs more parts and work done on it. Useful addition to the tool kit.

                        Comment


                        • #13
                          I'm confused. Why are you lowering the engine?

                          Comment


                          • #14
                            Originally posted by Evilution View Post
                            I'm confused. Why are you lowering the engine?

                            The sump needs changing (leaking) and the bolt heads are buggered. Need it dropped and then clear of the deDion to get at them with something I can get hold of them with, or to cut them. Not looking forward to it - it's going to be an absolute pig of a job.

                            Comment


                            • #15
                              I would definitely fit stainless steel bolts. Available from Toolstation for a small fee. Only GBP 2.68 for fifty M6 x 20 cap screws. How much did Smart charge?

                              Comment

                              Ad Widget

                              Collapse
                              Working...
                              X