Title: ok, the control arms ARE funny.... Post by: fiero308 on April 09, 2003, 10:53:57 am well, Don and I have decided that the lower control arms, for the 84-87's at least, ARE funny. Funny weird, that is. We looked at both my lower control arms last nite and the main pivot bolts - that the bushings go on- are NOT lined up; in fact I would guess they are 'unaligned' by a good 1/2" or more. This means that the control arm, when moving up or down, is trying to rotate about two different centres at once. Something has got to bind here. I have never seen anything like it. I don't understand how this can work, much less work well..... now I REALLY want to talk to someone with poly bushings!!!! to see if they have 'revisited' them to see what shape their suspension is in!?!?!
Don and I discussed mods and I am pretty sure I will go ahead with them. Very strange, especially when in all other respects this is a very good suspension design; essentially unequal length A-arms which VERY few other cars have. (but is popular in formula one....) 8) 8) 8) Will take pix and keep records of what I do. Any feedback from anyone who has installed poly bushings?????? ANYone? Title: Re:ok, the control arms ARE funny.... Post by: 34FieroGT on April 09, 2003, 11:29:44 am Graeme,
I have poly bushings installed at all four corners, but I didn't install them. I had David Power from Power Automotive do the installation. I used a spare set of front control arms from a parts car to minimize down-time and I don't recall the mounting points being out of alignment as yours are. Unfortunately, I can't find the extra set of control arms at this time. I have some parts in storage at my sister-in-law's, and I'll take a trip over tomorrow evening to look for them. As for the ride feel, I didn't notice much difference at all, but that could be because I had a set of Eibach lowering springs installed the year previous. One thing that I did notice was that the car is much smoother on rough pavement. I had a "clunking" noise when going over bumps disappear! I'll post a picture of the control arms once I find them. HTH tyler... Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 09, 2003, 12:09:22 pm decided to call a shop to see what they had to report. The Fiero Shop in Toronto confirmed that YES they are out of alignment but that is "just the way they are made" unquote....... Said he has installed on 'lots' of cars which I expect he has.
Still shaking my head on that one but what can I say??? I AM pretty surprised that your car seems better on rough pavement; that seems to defy logic too, but I am starting to get used to that - LOL. How much did you lower? Special shocks too? Are the springs a lot harder; do you know the spring rate? Thx for the input and reply; if you get a chance, check out the other control arms and see. If they are NOT misaligned let me know right away!!!! :o I will stop work! :-\ PS; the top arms seem to be aligned ok; it is just the lowers. Title: Re:ok, the control arms ARE funny.... Post by: FieroDough on April 09, 2003, 12:12:48 pm if the "hinges" on the frame are miss aligned as well, then all is good. :)
Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 09, 2003, 11:36:28 pm welllllllllllllll, ...........
it isn't that simple. If you look at them and do a little geometry, you will know what I am talking about. THEN you will wonder too. ??? :o Title: Re:ok, the control arms ARE funny.... Post by: FieroDough on April 10, 2003, 07:06:28 am you have to think in 3d geometry, if axis x and axys y are the some as axis x1 and y1 and the oposite side, axis a and axis b are the same as axis a1 and b1, then you are ok.
I beleive the offset x and y axis on the a-arm and fram are to help prevent possible for and aft movement. I wish I can draw a picture.. sec... Maybe the pic helps. with those axis, the a-arm still moves freely, mind you the arm only has to move so much. it never goes all the way down or all the way up. cheers! Eric Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 10, 2003, 07:55:17 am I'm not really sure what you are getting at but will try to describe it this way; see pic below; it shows the offset between the poly bushings reasonably well, so at least you can tell that the holes don't line up.
The lower bushing in the pic has the longest arm and so will be the 'master' centre of rotation, if you will. Since the entire control arm is a rigid assembly, it operates as a unit. Let's pretend/assume there is no planned or intentional distortion of the arm (by the designers). SO - when the control arm goes to move either up or down (end-to-end movement should be negated by the bushing ends, washers, nuts and bolts) it means that the ENTIRE arm is trying to move thru an arc defined by the radius of the long arm. This INCLUDES the rear bushing! However, it is 'held' in place by the bolt of course, and thus I can only assume that something distorts somewhere. IFF both bushings were aligned; ie on the SAME axis, then there is obviously no problem. But they are not, so they are trying to define two different centres of rotation every time the control arm moves. The shorter arm will not act as a centre of rotation because it is effectively a 'support' that is 'mid-beam' - that is, the wheel is acting as a fixed point to one side and the longer control arm acts as a fixed point to the other side, so it is a 'stabilizer' at best, but still in conflict with the long arm. Don't know if that spells out my concern any better but it is a try. Don? Do you want to try? Still a mystery to me what they were thinking of. I will be doing a mod and taking measurements, pix and logging info just for the record. And I hope to go autocrossing or at least do a pylon grand prix somewhere. Maybe that will be the proof in the pudding......... ??? ;) I will see if I can do a pic in AutoCAD and post it to show the two radii of rotation (ie from the front). Have to get measurements....... that will follow. Title: Re:ok, the control arms ARE funny.... Post by: FieroDough on April 10, 2003, 08:39:20 am I understand your point of view, and if the brackets were parallel to eachother, that would in fact be correct But the brakets have that same offset. The "prooff of the pudding" would be to mount them without any spring ect and move the a-arm up and down. Looking for "different" resistance or binding. (resistance is somewhat normal because of the bushings, friction ect.. ).
I checked on the 85 GT in the garage, the a-arms do move freely and are not stressed by the brackets at all. Also keep in mind that the suspention on the fiero is not 100% vertical, it is at a slight angle (hence the reson the wheel seems to move forward or backwards when "bouncing" the suspention. From my point of vew. Your a-arms are 100%, you did a great job od cleaning them up and painting them. :) Grease the bushings with lithium grease like a mofo and you will be fine. :) cheers! Eric Title: Re:ok, the control arms ARE funny.... Post by: Boy-z on April 10, 2003, 09:20:49 am Since there are so many axis/axes just take the damn axe and cut the damn thing off. maybe you should start with a hatchet first then a Quebec speed wrench.
Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 14, 2003, 08:19:53 am latest update:
after looking at them again (and again!) it would seem that the axes of rotation thru the two bushing holes actually intersect, rather than are parallel; that would allow somewhat 'freer' rotation (less binding) than if they were parallel (but not aligned) as was first assumed/imagined, but is still not ideal. I see that Chris West put in 'Bearings' rather than bushings; that would answer this problem so maybe he recognized it then..... I am trying to come up with a suitable jig/system to make mods and thus be a self-imposed test case; will take pix and keep people posted. Of course, this has become a much bigger project than simply installing poly bushings.......... like ALL of my projects; LOL!!! ::) ::) ::) Title: Re:ok, the control arms ARE funny.... Post by: dguy on April 22, 2003, 09:25:02 am If you still have the LCA's out of the car, could you take a quick moment and measure the "hinge" bolts for me? Length & diameter are all I need--I don't really care what the thread is.
When I installed the poly bushings at the rear of the car, all four of the bolts which attached the control arms to the cradle were in questionable shape. When I start on the front arms, I'd like to have the replacement bolts in my hands before I start, rather than playing the waiting game like I am now... Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 22, 2003, 09:40:21 am i do still have them out, as I continue to prevaricate on how big a project to make out of them ..what's new..... ::) ... but my latest understanding - at least for poly bushings - if that is what you are doing??? - is that the poly bushing is supposed to 'slide' on the inner steel sleeve which means the bolt must be an interference fit inside that steel sleeve in order to lock the steel sleeve solid with the bolt, thus making the poly material slide around that sleeve. Did I make that clear as mud????? Is that a run-on sentence, too? SOOOOO, all that being said, and iff that is correct (think so) that makes the diameter of that bolt very important. Someone on this board said that you can still get the bolts from GM, so that might be the best thing; when you go to a fastener house you might get a lower tensile strength steel, etc etc so it might be best to get the original. That is what I am going to do.
AND besides, mine had to be cut out so the length is not really measurable and they are kinda rusted and corroded (into those same steel sleeves) so the diameter is a bit unsure too, IF a few thousandths of an inch are important here which I think they are.......... You should be able to measure your bushings and use that for a diam gauge and I think the bolts overall could be measured in place if you want to go to the fastener shop. Good luck; are you doing the poly thing? ;D Title: Re:ok, the control arms ARE funny.... Post by: dguy on April 22, 2003, 10:07:37 am i do still have them out, as I continue to prevaricate on how big a project to make out of them ..what's new..... ::) ... but my latest understanding - at least for poly bushings - if that is what you are doing??? Yep. I have to change the bushings on the RF wheel to eliminate a rubber-rot induced negative camber, and I decided to go the full distance and poly all four corners.Quote is that the poly bushing is supposed to 'slide' on the inner steel sleeve That is my understanding as well.Quote which means the bolt must be an interference fit inside that steel sleeve in order to lock the steel sleeve solid with the bolt, thus making the poly material slide around that sleeve. Ahh nuts... I overlooked that part of it. Come to think of it, the bolts that I removed look like they're slightly larger in diameter closer to the head, which I suspect would pinch against the inner sleeve when tightened.Quote Is that a run-on sentence, too? SOOOOO, all that being said, and iff that is correct (think so) that makes the diameter of that bolt very important. Someone on this board said that you can still get the bolts from GM, so that might be the best thing; when you go to a fastener house you might get a lower tensile strength steel, etc etc so it might be best to get the original. I didn't overlook the strength part--the replacements I ordered were 10.9 grade. :) But... I suspect that the replacements will not have that same "flare" near the head the the originals do, and fail to keep the sleeve from pivoting against the bolt. Argh... Assuming that the bolts arrive today, I'll be able to compare them to the originals when I get home this evening. My suspision though, is that I'll have four nice heavy bolts going into my nut & bolt bucket, and waiting for GM to bring the proper parts in... :(Title: bolt replacement Post by: dguy on April 23, 2003, 12:59:35 pm The supplier I was working with for the aftermarket 10.9 bolts didn't come through, and I managed to cancel the order without incident.
Spoke with the parts department at a GM dealer today, and the ones I need should come up overnight from Montreal. :) So that'll be the rear bushings taken care of after tomorrow evening... then... on to the front... Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 23, 2003, 01:35:57 pm Well, that is sort of a good thing, anyway.......
how did the rears go? did they give you an awful time or not too bad. I am not looking forward to them as they look so inaccessible......... :( Good luck with the fronts; that is about all the help I can offer with them... :-\ GP Title: Re:ok, the control arms ARE funny.... Post by: dguy on April 23, 2003, 03:38:23 pm how did the rears go? did they give you an awful time or not too bad. I am not looking forward to them as they look so inaccessible......... :( All things considered, not too badly at all. The left side bolts were rust-welded to the inner sleeves, but I managed to remove them after three or four hours of persuasion. After burning away enough of a bushing to expose the inner sleeve, a combination of vise-grips & a screwdriver in the split which runs the length of the sleeve prevailed. After breaking the "weld" between the bolt and the sleeve, I used a small pry bar between the bolt head and the cradle to pull the bolt back while I turned it with a ratchet. The right side bolts were much easier, but that may have had something to do with the alignment shop greasing the sleeves after removing that control arm last summer in order to replace the ball joint. ;) Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 23, 2003, 05:01:44 pm yeah, that is about what I was thinking. Hours with vice grips.
Next time I ask - LIE to me. Tell me they fell out or something. I will probably do something like watch hockey or something instead now. GO SENS GO!!! .........now that the leaves have fallen.......... ;D Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 29, 2003, 09:13:36 am just to show what I am doing with poly bushings:
pic 1 is the bushings I will use. I verified that the inner steel sleeve rotates against the poly material. Simply tightening a nut and bolt against the ends of the sleeve is enough clamping to make it 'slide' inside the poly liner. Was pretty easy, actually. I am going to have to trim mine to length; they are intended for an 82-92 camaro, but they are the right diameter and they are poly, (just not that super cool red colour I wish I could have... >:( ) So I have driven out the inner liner so that I can put some grease grooves in the poly material (I will drill it and put in zerk fittings) and so hopefully the grease will have some place to go. The second pic shows just how smooth the inner sleeve is; except there is no place for grease...... it came with a sort of 'sticky' lube on this surface, somewhere between lube and adhesive. I am going to spot weld the sleeves that are already in the control arms (pic forthcoming) - these are the 'leftovers' from the original rubber bushings - as I have heard some people say that these steel sleeves have been known to start to slide themselves! and that would be the beginning of the end for the control arms. :o I will update this (hopefully) daily as work progresses; next - welding the existing sleeves, cutting my bushings to length and putting in grease grooves. By the way, dunking the (remains of) the old rubber bushings into a big can of lacquer thinner dissolved the rubber very nicely. The inside was 'pristine'! No scrubbing or anything; just wipe it out. Most of the bushing has to be gone, however. If anyone wants pics of anything in particular let me know; I will see what I can do. Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 29, 2003, 09:16:46 am ok so I showed the wrong pic; I was hoping it would accept two pics at once.
Attaching a pic of my bushings; left is o'all; right is with the sleeve taken out, prior to cutting to length or 'grease-grooving'. I guess that is what we are all doing, right? Grease-grooving? eewwwwwwwwww. bad one....... ::) Title: Re:ok, the control arms ARE funny.... Post by: dguy on April 30, 2003, 08:45:13 am [singing]Grease is the word[/singing]
Oh crap I think I just dated myself. ;) Just curious--what brand are your replacement bushings? The Prothane ones I bought already have "grease grooves" around the inner sleeve. Yours also appear to be provided with a new outer sleeve as well? Prothane's bushings simply sit inside the original outer sleeve. Sounds like the same grease came with each of our bushing sets BTW. Part glue, part lubricant, and nothing at all like the synthetic grease I loaded them up with after installing the zerk fittings. Laquer thinner, eh? Never thought of that one. I found a wire wheel for the drill that is a touch larger in diameter than the outer sleeves, and it cleaned them out perfectly. Title: Re:ok, the control arms ARE funny.... Post by: fiero308 on April 30, 2003, 09:01:31 am these are actually for an 82-92 camaro, but they just happen to fit perfectly and include an outer sleeve which won't hurt. They are from Energy Suspension; I bought 16 of them for ......... nah, don't ask..... a project from another lifetime.
I trimmed my testcase bushing yesterday and then cut some grease grooves in it and drilled it for zerk fittings; I also drilled my control arm 'sleeves' (the leftovers from the originals ;) ) and will be tack WELDING those sleeves in place to avoid any possibility of them rotating (heard on Pennocks that it can happen)...... more pix to come but I have to do some real work work today. Got some of my brake stuff yesterday and hopefully will have everything for "phase 1" of the brake upgrade by the wknd; and will be working away at it! My mystery brake upgrade is looking like it will work, I will also be taking pix of that and posting but that will be next wk. Stay tuned! |