Svenska Posted January 5, 2010 Report Share Posted January 5, 2010 I replaced a few of these on a number of 850s (in this case it's a 1995). In some of them (whether I use the OE Sachs/Boge or Bilstein replacements), after the job is done and everything is put back in order, with the car sitting on level ground, I notice that the black rubber coated metal "washer" leaves a gap between itself and the strut bearing. It's like a 1/4 inch gap and doesn't look right. This is after replacing the rubber spring mount and the bearing. I tighten the X-shaped nut down as far as it will go on the threaded shock piston. The black rubber washer goes over that and then the large 22mm nyloc nut is tightened until you run out of threads or until it's at the torque spec. I can't find any pictorial tutorials addressing this. So, basically when the car has been driven after the front end strut replacement, the car sits level and there is a gap between the washer and the bearing. A gap wide enough that you can fit your little finger in between. Other times on 850s, that same washer sits flush right on top of the bearing. Has anyone seen this? What gives? Link to comment Share on other sites More sharing options...
erikv11 Posted January 5, 2010 Report Share Posted January 5, 2010 There should be a gap. The big "washer" is there to limit the travel when you lift the car up in the air, think of when you begin to lift the car off the ground with the jack, the wheels don't lift at first. They start to lift when the struts have expanded to close that gap. Then there is resistance to the springs. Anyway, normal is for there to be a gap, so the wheels have both up and down travel. If there is no gap, there is no down travel. Link to comment Share on other sites More sharing options...
Svenska Posted January 5, 2010 Author Report Share Posted January 5, 2010 So if there's no gap with the tires on the ground, then the struts are failing/have failed? Link to comment Share on other sites More sharing options...
erikv11 Posted January 5, 2010 Report Share Posted January 5, 2010 No, bad struts would mean the car is more free to bounce on the springs, maybe it will bottom (or top) out more easily, but when the car is at rest the gap should be the same. The struts don't determine where the car sits, that is all dictated by the springs. Think about when you compress a strut outside of the vehicle, it only barely/slowly re-expands. The strut bears almost none of the weight. So maybe in my other post I should have said "the wheels start to lift off the ground when the springs have expanded the struts enough to close that gap." I have never seen zero gap after a strut job so I can only speculate about what would cause it. Possibilities: 1. springs are too stiff, so the weight of the car is not able to compress them. So this might only happen when you put in new/other springs. 2. car is on a hill so more weight on the front end (?) 3. springs were over-compressed on reassembly so the cross-shaped nut was tightened way too far down. If these are stock springs, there is a spec on the spring. It is supposed to be compressed to 11.81 inches (which is 30 centimeters), then you snug the cross-shaped nut to the hardware, without continuing to compress the spring while doing so. I know this 11.81 does not have to be exact but the whole reason for that 11.81 inches, is to ensure that the strut is in midrange when the assembly is all back together. If you tighten the x-nut way too far down the shaft, maybe you could put the strut at end range. That would pull the washer down and close the gap when you get it back in the car. This possibility makes sense but I don't know if the threads on the struts extend far enough to make it possible to put it at end range. 4. strut towers somehow not put back together right so the tower is too tall, I seriously doubt this because you would know it pretty quick. 5. ? Either of (1) or (3) (but especially number 3) would cause the car to have a (very) harsh ride, because the strut can compress but it can't expand e.g. over a pothole. And probably wear out the struts faster, because they are not engineered to work at end range. Link to comment Share on other sites More sharing options...
Svenska Posted January 5, 2010 Author Report Share Posted January 5, 2010 YES! It's #3. I remember I just cranked down on the spring compressor (probably beyond 11.81 inches) until it was able to release the strut easily. I was going by a pictorial which said to compress them 11.81 inches - but didn't specify how important that was. I actually figured I tightened that X nut down too far, which pushed the rubber strut mount down on the spring too far. Thanks for confirming that. That's the only thing it could be since I reused the springs. I've been wracking my brain going over the steps involved and how I could have botched that. That X nut dictates how far the spring is allowed to expand when seated. Thanks, that confirms my suspicion. Link to comment Share on other sites More sharing options...
the commissar! Posted January 5, 2010 Report Share Posted January 5, 2010 Hmmm...So if you replace springs with aftermarket how much do you tighten this down...same 11.81 inches? What if they are not that long in the first place? Link to comment Share on other sites More sharing options...
erikv11 Posted January 6, 2010 Report Share Posted January 6, 2010 Hmmm...So if you replace springs with aftermarket how much do you tighten this down...same 11.81 inches? What if they are not that long in the first place? yeah, the length will likely be shorter for lowering (shorter) springs, I have never seen a recommendation plus it will depend on the spring. Most people use struts that are matched to or known to work with aftermarket springs, don't compress much more than needed to put it together, and it works out fine. And really that will usually work out fine for stock setup, just don't overcompress. The point is the strut should be somewhere in midrange when the tower is all back together. Link to comment Share on other sites More sharing options...
Svenska Posted January 13, 2010 Author Report Share Posted January 13, 2010 I just had a weird idea that I have yet to try out with replacement struts... Could you not install the stock spring on the new strut, install the rubber mount/bushing and bearing, then turn that X-nut a few revolutions (so that the strut unit is safe to move) without measuring 30cm/11.81"? My thinking is that you would then install that strut with the three nuts on top, then lower the car/load the suspension, then turn the X-nut until enough clearance (like a little finger's width) is present? I just tried doing my struts. I compressed to 30cm, replaced yadda, yadda, installed with that large nut on top of the strut piston, and there's still too large of a gap. I then took off the rubber washer/disc and discovered the X-nut could easily be turned by hand. I think I tightened the X-nut with an IPD wrench, installed the rubber disc/washer and final nut, and it seemed to look "normal". Wouldn't the car seek out its own height? I don't think I'm thinking this through all the way though. Can someone chip in??? Link to comment Share on other sites More sharing options...
Guest tonyg Posted January 18, 2010 Report Share Posted January 18, 2010 hi i ve just had struts & rear shocks replaced with standards boge gas, on a 850 t5 wagon, the car is sitting higher at the front by at least 1" and lower at the rear by about the same could it have something to do with the front thread adjustment being out of spec? Link to comment Share on other sites More sharing options...
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