Meph Posted June 2, 2012 Share Posted June 2, 2012 Hey guys, I was wondering if someone who's worked on a 240Z rack could let me know if there are any internal bushings to keep the rack (#13 in the diagram) tight fitting in the housing (#14 in diagram). Ive been trying to diagnose a shake in my steering wheel, and while I know the tires are probably the main contributing factor, Ive found there is play in the rack, not in and out but vertically. If I extend the rack out in one direction or the other, and reach down though the engine bay and grab the inner tire rod Im able to pull/push it up and down causing a knocking/clunk (it moved maybe 1/16 to 1/8th of an inch up or down at the tie rod so its not all that loose at the rack). My MR2 is known for a very similar issue, caused by a worn internal bushing that causes wheel shake. Is this normal for the Z to have some vertical play or has something come loose/needs replacing? Anyone who can lend a hand would be much appreciated. Thanks, Meph Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 2, 2012 Share Posted June 2, 2012 (edited) Parts 15, 16 and 17 hold the rack down. There's a procedure for tightening during assembly in the FSM. Tighten it down as far as it will go then back it off, about 15-20 degrees I believe (better check). I got an extra 30 degrees out of mine (36 years of wear) and 15 was fairly dry. I stuffed a finger full of bearing grease in while it was open. It seemed to add some tightness (the extra 30 degrees on the screw, not the grease). On a 280Z you can get the parts out (15, 16, 17) while everything's in the car, on the ground if the car's not too low. Edit - actually, I'm not 100% clear on where exactly #15 is pressing on the rack. But it can be adjusted. Edited June 2, 2012 by NewZed Quote Link to comment Share on other sites More sharing options...
zbloke Posted June 2, 2012 Share Posted June 2, 2012 I think 15 pushes the rack onto the pinion, I had a similar issue and careful adjustment of 17 and 18 made an improvement. I still have some wheel wobble though, the only place I can seem to find some free play or movement is in the top strut bearings? Quote Link to comment Share on other sites More sharing options...
Meph Posted June 2, 2012 Author Share Posted June 2, 2012 Check this out here, #15 in this PDF, Tube End Bushing! Thats what Im looking for, im sure its why the rack has play. Can anyone confirm these bushings actually exist? http://www.blackdragonauto.com/pdfcatalogs/pdf/ZR/0038.pdf Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 2, 2012 Share Posted June 2, 2012 The bushings on the ends limit travel up and down. I've never so far found that to be a source of wheel shake. Push up and down on your tie rods and see if they move-if they move up and down it is either in the inner tie rod bearing or in that bushing you are referring to. Most often culprit is inner tie rods. Sometimes outer tie rods. Check for play in steering shaft - that is where I still have play, but that shaft and its little u-joints are not available. Major fabrication job to fix that. Even with a little play, my steering has no slop when driving, but I do have a little tiny shake. I just had it aligned and that helped some. I'm thinking of having my tires "trued" on a machine that actually shaves them into round. I did that on my daughter's jeep and it made a WORLD of difference. Quote Link to comment Share on other sites More sharing options...
Meph Posted June 2, 2012 Author Share Posted June 2, 2012 Shaving is exactly what my tires need to ride smooth I believe, but Im trying to get a set of 17x10 in the near future so Im holding off spending any more on the current setup. I adjusted the pre-load on the rack (15-18 on the diagram) and it got ride of 100% of the up down travel on the drivers side. If I grab the passenger side of the rack it still has up down play, leading me to believe there in in-fact a worn bushing hiding in there somewhere. The knocking I would hear when dry steering from the rack is now gone thanks to that preload adjust so Ive got my fingers crossed that everything will ride a little better. Ive checked for play in the tie rods and they seemed tight/new, and have re adjusted the wheel bearings. Im sure 75% or more of my problem is due to tire true-ness/ballance. Thanks for the input so far! Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 2, 2012 Share Posted June 2, 2012 I've been wondering if shaving does any better than just smoking the tires a couple of times then rotating fronts to backs ? Haha. Quote Link to comment Share on other sites More sharing options...
clarkspeed Posted June 3, 2012 Share Posted June 3, 2012 I've been chasing front end shake on the race car for a long time. Most recently thought the rack was bad on center but instead traced it to the splined steering shaft just below the coupling. I removed the shaft and rotated it a couple teeth and reinstalled. Seemed to engage the splines better and the movement was gone. Quote Link to comment Share on other sites More sharing options...
zbloke Posted September 16, 2012 Share Posted September 16, 2012 I still have some wheel wobble though, the only place I can seem to find some free play or movement is in the top strut bearings? I've now fitted new top strut bearings and my wheel wobble appears to to have completely gone! HTH Quote Link to comment Share on other sites More sharing options...
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