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I was going to replace my shocks and unlike the rears, the fronts did not come with any bump stops or bellows. Rockauto has listings for them but all from different manufacturers (SKP, Mevotech & Moog) and not Bilstein, none of those three list the original Jaguar part numbers under their cross-reference and the pictures don't look like the one in the Jaguar parts catalog either. They're a lot cheaper than ordering from Jaguar, but I'm not sure any will work perfectly with the Bilsteins. And I can't seem to find a Bilstein listing that seems correct. So what have others ordered for new bellows and bump stops?
I've used the SKP, Moog and Mevotech bellows and bump stops from Rock Auto and also the KYB ones they sometimes have. As far as I can recall, they all fit. There's nothing critical about those parts.
The Mevotechs are a different design. You have to install a plastic washer on the bump stop, then secure the split end of the bellows around the bump stop with a zip tie. I personally prefer the types with the solid bump stop you can just work into the end of the bellows and be done with it.
SKP bellows arrived today. But they are plastic, not rubber, just shaped like a bellows, much, much larger in diameter than the shock body and fit very loose. Even the bump stop is much larger than the shaft diameter. The crumbling remains of pencil erasers that were in there already seem similar but I just assumed they were that way because they were totally worn out, damaged and maybe not even the right part in the first place. Are they all supposed to just sort of dangle loosely over the shock body like a lamp shade without a finial nut?
And the bump stops came already snapped into them, but they easily snap out with virtually no force whatsoever. I guess I could use some kind of glue to secure the bump stop into the bellows. Or are they supposed to snap together some other way that's not obvious?
In the top photo the bellows might be upside down? I’m not entirely sure how that unit goes together with the exception that the bump stop will be firmly placed inside the bellows.
The factory bellows and bump stop is supposed to be pressed up inside a metal umbrella like piece on the body but, it’s not likely to stay there unless you glue it in.
SAnd the bump stops came already snapped into them, but they easily snap out with virtually no force whatsoever.
As Addicted suspected, the bellows are upside down. The widest diameter of the bump stop should fit into the groove molded into the opposite end of the bellows.
As Addicted suspected, the bellows are upside down. The widest diameter of the bump stop should fit into the groove molded into the opposite end of the bellows.
That's going to be quite some trick as there appears to be some considerable difference in diameters. I'll give it a shot tomorrow.
Inspired by the discussion here and with an indy that I use sometimes when I'm overloaded with more broken cars than I can handle, I decided to run an experiment. I didn't like the idea of this cheap bellows just hanging over the top of the shock body like a loose lampshade, rattling around and not providing any protection whatsoever against dust or debris. Apparently the original design was supposed to hang from the underside of the shock mount somehow. That would provide some protection against debris hitting the polished section of the rod/shaft, but being open at the bottom would still not provide any protection from dust. As Addicted spotted that the bellows was upside down in the first photo above, I thought, "Why not?"
The bellows are actually a little too long to fit upside down with the shock compressed. I worked it out that I needed to cut off and discard the skirt and two accordian sections as shown below.
Then using a little hook-shaped pick, I was able to stretch it over the little cup under the upper shock mount and it would hang there sort of like Addicted described that the OEM part was supposed to. The photo below shows the bellows with bump stop installed "upside down" with the shock fully extended.
The next photo below shows the installation with the shock compressed to ride height and there's still a ways to go when it hits a bump. You can better see the little cup I mentioned above in this view. I think the two pics are different sides of the car, but its the same either way.
Throughout the shock travel, the rod/shaft should be completely covered and though its not hermetically sealed at either end, should provide better dust exclusion than if it were left open at the bottom.
Now I don't know how this is going to work long term. It may eventually dislodge the bump stop from the bellows and just hang there. I'll have to try to remember to report back in a year but I don't think its going to hurt anything. My indie told me that the Bilsteins have a double wiper seal and that the boot or bellows is not really necessary. They just install a bump stop with no bellows at all, so if this doesn't work, I'll just cut the bellows off and leave the bump stop in place. Fingers crossed.
On the X100 top mounts, I have been able to use a heat gun to stretch the boots around the little "cup" on the underside of the mount so the molded ridge that I think is where the widest diameter of the bump stop is supposed to fit is instead stretched around the slightly wider "rim" of the "cup" I don't know if the same idea could work on the X308, but your method looks great, and you don't have the lower end of the boot just hanging there with no real seal around the shock.
Looks very good. My only concern would be whether, if any water seeps into the bellows from top (splash when driving on wet road), it would have a way to quickly drain out at the bottom.
I thought about that, but it doesn't appear that the bump stop is smooth enough to seal against the top of the shock body anyway. However, what I kind of suspect is that bellows is eventually going to kind of take a set at the default ride height and when the shocks extend, it'll actually open up, at least briefly. What I don't know is if at that point its also going to start making some noises every time the shocks are compressed again and make contact. Actually, I'm pretty sure it will but whether I will be able to hear it above all the other road noises or whether it will be obnoxious I don't know. But just trying to figure out a way to make use out of what is obviously a very generic bellows. I thought about shopping online and try to find a gaiter for a small hydraulic cylinder or something that is the right diameter at both ends to ziptie but then what to do with the bump stop? There may be no good solution except for the OEM jaguar parts.
Well, that didn't work out very well. The plastic bellows isn't quite flexible enough to keep up with the rapid up and down of the damper and what it did was to pound the bump stop out of its snapped-in position at the end of the bellows and I discovered it sort of lodged halfway up in the bellows. The bump stop really needs to be secured at the top where it won't get pounded. Sooooooo, version 2......
I used a dremel tool to put some tiny holes in that little cup at the top of the strut and secured the bump stop with stainless steel safety wire. Then blew the chips away and replaced the bellows as I had it before. Now the bellows is basically just hanging like a lamp shade from the cup. It's not going to protect the shaft from getting wet or dusty so much anymore, but at least it should protect the shaft from getting pitted by rocks and gravel being thrown off the tire tread.
If I'd thought about using safety wire before, I'd have cut the bellows off at the next wider "outside" rib and bound it too just above the lip of that cup with safety wire or a ziptie. The bellows does hang a little loosely from the cup now that its been stretched over a second time but hopefully it will last a while. It won't hurt anything if it comes loose, just rattle around.
Bilstein bellows and bump stops
