tuko Posted March 2, 2012 Share Posted March 2, 2012 With so many here that have done the Defender 4 bolt PAS conversion on their series, I'm looking for some advice on the size of the crush tube to use. I have blue tube that has an inside diameter of 16 mm but using that with the M12 bolts is there too much of a gap of 4mm ? I called Designa Chassis last week and Ian recommended to use over size tube, but he didn't say what inside diameter to use. As it is, I can't find any 14 mm inside diameter tube (tighter 2 mm gap) in my garage, so I'm wondering if the larger 16 mm inside diameter will be OK ??? Thanks, Todd. Quote Link to comment Share on other sites More sharing options...
Daan Posted March 2, 2012 Share Posted March 2, 2012 I would use hydraulic tube, 1/2" inside if you can find it. the problem with an oversize tube is that the holes you will drill in the chassis will be massive, so there wont be much left of it. daan Quote Link to comment Share on other sites More sharing options...
tuko Posted March 2, 2012 Author Share Posted March 2, 2012 Thanks Daan, Thats very tight if I use ½ inside diameter tubing. Even if I used the 16 mm inner diameter tube that I have now, the outside diameter is only 20 mm. All Designa Chassis chassis's are made with 3 mm plate vers Land Rover's 2 mm frames. Therefore I think that there will be plenty of meat left to weld. Todd. Quote Link to comment Share on other sites More sharing options...
Gremlin Posted March 2, 2012 Share Posted March 2, 2012 I belive i used an old trackrod..........or was it polybush sleeve................errr i cannot remember......... but you get the idea. As for large holes in the chassis to weld them up, yes, i recall using a hole saw............, but that was on the chassis, i then plated the chassis up with 4mm with right sized holes at 12.5m, so the box is located snug. G Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 2, 2012 Share Posted March 2, 2012 Old jack handles are pretty good for this too I've used trackrods and polybush sleeves as well! Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted March 2, 2012 Share Posted March 2, 2012 I used 12mm inside diameter tube - and measured very carefully! I think it came from B&Q... Quote Link to comment Share on other sites More sharing options...
Daan Posted March 2, 2012 Share Posted March 2, 2012 Thanks Daan, Thats very tight if I use ½ inside diameter tubing. Even if I used the 16 mm inner diameter tube that I have now, the outside diameter is only 20 mm. All Designa Chassis chassis's are made with 3 mm plate vers Land Rover's 2 mm frames. Therefore I think that there will be plenty of meat left to weld. Todd. I wouldn't fance drilling 4 20mm holes in my chassis, if you find 1/2" tube with a wall of 2mm, it is only 14.7 dia. 1/2" is 12.7, so if you think that this is tight for an m12, what kind of tolerances are you thinking of achieving, it is a steering system after all. Daan Quote Link to comment Share on other sites More sharing options...
tuko Posted March 2, 2012 Author Share Posted March 2, 2012 Old jack handles are pretty good for this too I've used trackrods and polybush sleeves as well! I measured an old track rod and it's 16 mm inside diameter. The local metal shop had nothing that fell within 12 - 14 mm inside diameter. Todd. Quote Link to comment Share on other sites More sharing options...
tuko Posted March 2, 2012 Author Share Posted March 2, 2012 I wouldn't fance drilling 4 20mm holes in my chassis, if you find 1/2" tube with a wall of 2mm, it is only 14.7 dia. 1/2" is 12.7, so if you think that this is tight for an m12, what kind of tolerances are you thinking of achieving, it is a steering system after all. Daan I was hoping for 2 mm clearance, 1 mm both sides for slight drilling errors. I'm thinking that 2 mm both sides of the bolt maybe too much, or is it ? Todd. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 2, 2012 Share Posted March 2, 2012 I measured an old track rod and it's 16 mm inside diameter. Todd. Yep, I was using M16 bolts Quote Link to comment Share on other sites More sharing options...
ejparrott Posted March 4, 2012 Share Posted March 4, 2012 Last time I used tubes, I drill some steel bar to suit, but being a turner i do have an advantage. Quote Link to comment Share on other sites More sharing options...
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