wonkey eyed barmaid Posted March 4, 2004 Share Posted March 4, 2004 Hi, I am planning to do this conversion to my car next weekend - just testing the waters to find out any problems i might encounter, or any tips to make life easier... the plan is to remove the upper suspension and arb assemblies (which currently comprise top-links and a rubber-bushed 1/2" arb that is bolted through the top-link to complete the wishbone) - and replace with a complete solid wishbone and a 'proper' ball & cup type 5/8" arb. the car is '99 VX Classic, liveaxle and standard-track. i have sourced and purchased a narrow-track de-dion arb with all mounting brackets and bushes. I have also sourced a pair of standard-track de-dion wishbones, complete with bushes and cv joints. From redline I purchased the additional pivot brackets, as used to add a secondary top-link to old-style academy spec cars. so apart from cutting the hole in the bodywork for the forward leg of the new wishbone to go through, and replacing said parts with new parts, what else is there to do?? Can I reuse the existing damper mounting bolts etc? do I need spacer washers or anything? and lastly; are the upper wishbones handed? I know which way round the longer and shorter legs should go, obviously, but I mean are there a few degrees of difference in the angles of the pivot bushes that require them to be fitted on a particular side? cheers in advance. grant. Link to comment Share on other sites More sharing options...
Jingers Posted March 4, 2004 Share Posted March 4, 2004 Grant, as far as I can remember there are two tapers used for the upper ball joint on the wishbones these were the original triumph upright (trunnion type) and the later upright. Other things to think about are aluminium blocks for the anti-roll bar instead of the inboard rubber ones originally fitted and plastic shims that can be fitted where the wishbone bolts go through the metalastic bushes. Gary may is the guy to talk to at Freestyle for the best advise IMO and parts should you need them. FTD Moreton in Marsh 1994 Q500 HPW Link to comment Share on other sites More sharing options...
Joe 90 Posted March 5, 2004 Share Posted March 5, 2004 I'm more than a little surprised that a '99 car doesn't have the proper wishbones as standard. I did this on my '88 car without any problems (that I can remember, it was some years ago). SEP field working not spotted in 100,502 miles. Photos here Link to comment Share on other sites More sharing options...
ChrisHawkins Posted March 5, 2004 Share Posted March 5, 2004 Grant, I did this conversion a couple of years ago and it is quite straight forward, However I originally planned on retaining the lower trunnion type wishbone and drove the car like this for some months and it was noticeably better than the original live axle setup. But on advice from Mark at Ratrace I changed the lower wishbones and uprights to the spherical type. This is because trunnion type do not allow the upright to line up with the upper wishbone ball joint without forcing it or filing the hole in the lower wishbone Changing these wishbones matched with the upper wishbones transformed the front end of the car. Other than that the conversion was resonably simple and well worth it for the result. Cheers Chris K93 AMJ jetped-boarders.co.uk Link to comment Share on other sites More sharing options...
Casbar Posted March 5, 2004 Share Posted March 5, 2004 Done this to death previously but as a quick resume - You should change the top rod ends to a different one (motor factor number QR1572S) as the tapers are different on the uprights from the trunnion one to the one Caterham currently use. This part is off a Fiat 132 I believe. You can of course just use the ones that come with the upper wishbones, but Caterham will tell you that they haven't tested this configuration Link to comment Share on other sites More sharing options...
wonkey eyed barmaid Posted March 5, 2004 Author Share Posted March 5, 2004 jingers - cheers for the advice, what more can you tell me about the differing tapers of the upper ball joints? my car is fitted with the trunion-type uprights, which i am planning to retain, along with all current lower wishbone parts. whats this about plastic shims for the metalastic bushes? why are they needed? ----------- chris hawkins - thanks for that, "trunnion type do not allow the upright to line up with the upper wishbone ball joint without forcing it or filing the hole in the lower wishbone" in what way will it 'force' the ball joint? and what do you mean by 'filling the hole' in the lower wishbone? Link to comment Share on other sites More sharing options...
Casbar Posted March 5, 2004 Share Posted March 5, 2004 What more do you want to know about the tapers - they are different! I converted my live axle car to de-dion adj top wishbones a couple of years ago, had a problem getting the nut done up on the rod ends. Spoke to Caterham who then informed me that the tapers were different, and although they sold me the kit as a live axle upgrade, they had never tested the de-dion rod end in the trunnion upright. Only solution if I wanted a "tested solution" was to change the uprights or just go with the wrong taper Do some digging and found out that the part number I posted earlier, has a triumph taper at one end, and a metric thread which fits the adj wishbones, so I changed the rod end - all fits ok, and its the correct taper! Didn't have any probs lining it all up though, so can't comment on that. I know several people who have now used the different rod ends to upgrade with. It would be easier if Caterham would just supply them though. Of course you can stick with the originals - they can't come off, but I prefer things to be correct. If you wan't to know anything else give me a call - 07879 621157 Link to comment Share on other sites More sharing options...
ChrisHawkins Posted March 5, 2004 Share Posted March 5, 2004 Grant, Don't get me wrong they will fit the and I did drive my car like this. But if you think that the trunion will only move in a "camber" direction and not in a "castor" direction then if the upper wishbone ball joint is not in the exact same position as the old type, be it forwards or backwards (I can't remember which) Then it will not line up correctly regardless of the ball joint. This is why it was surgested to me that I file the holes that secure the trunion in the lower wishbone to make it line up. Which is why I changed to the spherical wishbones and uprights. Cheers Chris Link to comment Share on other sites More sharing options...
wonkey eyed barmaid Posted March 5, 2004 Author Share Posted March 5, 2004 thanks casbar, "What more do you want to know about the tapers - they are different!" forgive my ignorance, but what i do not know is what are the tapers, and what do they do? you talk about having trouble doing up the nut - is that the nut that secures the setting of the ball joint thread into the wishbone, or the locknut that secures the ball joint through the top of the upright? why not just change the nut? sorry if these questions seem totaly obvious to some, but uprights and ball joints is not something ive ever mucked about with before. im new to upgradeitis, and normally have a garage set my geometry etc... Edited by - granteuk on 5 Mar 2004 13:50:43 Link to comment Share on other sites More sharing options...
Casbar Posted March 5, 2004 Share Posted March 5, 2004 A taper is a cone joint that another piece of cone fits into, they mate exactly and hold together by friction and being an exact fit. If the taper is wrong, when you try and do up the nut to hold the taper in place, it just spins! You do sometimes have to put pressure onto the top of a taper to make it fit correctly, but not a massive amount. That is a very simplistic explanation, I suggest you do a search on "how things work" to get a detailed explaination of what a taper is! Or you could always use a garage! Might be safer! Link to comment Share on other sites More sharing options...
rjc Posted March 5, 2004 Share Posted March 5, 2004 The taper is the slightly conical shape given to the locating surfaces of the wishbone rose joints and the upright ends. These provide a self centering action and ensures a friction force which locks the end of the upright into the ball of the rose joint in the wishbone. This ensures precise rotation of the upright and hence the road wheel. This is very important because the precision with which the front wheels swivel allied to the castor and camber settings play a vital role in the steering response and straight line stability of the car. If the tapers are different the upright may move about within the rose causing small sudden changes in wheel alignment. Doing up the joint really tightly is not the solution as you can introduce stresses on the differing tapers that can shear or split the rose joint in the wishbone. I know someone who ran like this for a while and he was never able to get the front wheels aligned to his satisfaction, the previous settings had changed each time he re-measured them. At some prompting he changed the uprights and lower wishbones so that the front suspension was all pukka and the alignment problems went away. Using uprights and wishbones with differing tapers is extremely poor engineering practice, tapers were engineered into these components because they are necessary. The proper working of your steering and the reliability and stress calculations done on the suspension (that guarrantee the wheels stay attached to your car) assume they are assembled properly. You want to be totally sure of your car when cornering hard and I advise not adopting any half measures. Change all the suspension parts to get the pukka approved, tested, setup. Regards Rowland Link to comment Share on other sites More sharing options...
wonkey eyed barmaid Posted March 6, 2004 Author Share Posted March 6, 2004 casbar and rowland, thank you for the full and detailed descriptions of the taper and its purpose.... you learn something everyday as they say. i will source and fit the other ball joints as previously advised by casbar. anyone want a decent pair of standard de-dion narrow track ball joints...? 1 remaining question now: "plastic shims for the metalastic bushes? are these required? and where do i get them? part numbers?" ta. grant Link to comment Share on other sites More sharing options...
rjc Posted March 6, 2004 Share Posted March 6, 2004 The 99 car de dion front suspension has room for the lower front wishbones to move backwards and forwards to control the 'leaning' of the upright in the direction of the cars length. This is done by shimming the wishbone but I used washers for mine rather than plastic spacers. This leaning is called the Castor setting and it controls the force with which the steering wants to turn back to centre during cornering. The problem with just changing the upper wishbone ball joint is that you will be mixing upper and lower wishbones from different designs of suspension. I think (but I'm not sure) that the two suspensions have different alignment relative to each other. You'll need to ensure that the Castor and camber settings are within acceptable limits once everything is bolted up. Regards Rowland Link to comment Share on other sites More sharing options...
Jingers Posted March 6, 2004 Share Posted March 6, 2004 Grant, Ref: plastic shims, for advise, supply and further advise about the camber and castor angle I would contact Gary May at the folowing site: http://www.freestylemotorsport.com or contact via e-mail here: info@freestylemotorsport.com Regards FTD Moreton in Marsh 1994 Q500 HPW Link to comment Share on other sites More sharing options...
Bare Posted March 7, 2004 Share Posted March 7, 2004 I don't believe it is possible to Simply substitute Upper links from a different design. There used to be "proper" upper link upgrade Units..(Use those if humanly possible.. the ones you bought are not suitable if your car has Trunnions)...that did not realign the Castor angle at all.. a purpose designed fitment... which on a trunnion type car is fixed at 5 degrees and is non adjustible as the Trunnions simply cannot accomodate the angular movement. Enlarging theTrunnion Mounting Holes to allow for a bit of movement is a genuine Bodge, potentially Dangerous, as the angle/missfit increases significantly when the A Arm moves up or down. That in a nutshell was the reason Caterham was forced into adapting a Spherical joint onto the Upright's Old Trunnion mounting stub when they added Anti-Dive (lowered thw Front A Arm mounting point an Inch and a Bit Lower. As for Differeng Tapers for the Upper BallJoint.. the upright's taper can Easily be 'altered' to the 'new' taper by the use of an appropriate Reamer.. problem neatly solved.. permanently. Link to comment Share on other sites More sharing options...
Casbar Posted March 7, 2004 Share Posted March 7, 2004 It is possible to substitue the adj upper wishbones from the de-dion setup to the live axle setup. In fact Caterham sell this as an upgrade to allow the use of the latest anti roll bars. Caterham have stopped selling the bold on front link in favour of the standard adj setup. As for the angle of the castor, you are not adjusting the castor by massive ammounts, so won't make that much difference. Why use a reamer to adjust the taper, when you can buy a correct rod end, that will do the job. The company who gave me the part number for the correct rod ends, have been supplying them to Japan for about 8 years, and was a well respected seven specialist, although they have now closed up. Like everything make your own decision Link to comment Share on other sites More sharing options...
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