Technical Putting bump stops back in

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Technical Putting bump stops back in

Wiltshire Chris

‍‍Accidental Barchetta owner
Jul 14, 2020
Using a deal of wiggling, pulling and poking I removed the upper bump stops from my rear axle, they've gone from looking this this:


to this

However, I now have come to the point I dreaded, putting them back in. So far I've tried:
  • Putting a jubilee clip around the wedgy bit, tightening it, leaving it in the freezer for a day, removing the clip and trying to poke it in.
  • Wrapping a string around the neck and trying to pull it through
  • An odd arrangement of short length of dowel down teh middle of the rubber and a big G-clamp
None of have worked. My next thought is to get it nice and warm and flexible and try the string again. Has any got any other ideas or foolproof method they think I should try?
Unfortunately I cannot attach a video of a method to remove a stuck ring from your finger so search on line for it - it's the one that uses a wound piece of string.
Maybe you could try this method (adapted to suit) if all else has failed, a bit of pushing etc at the same time - and you never know.
If it doesn't work then it's an interesting video/method in itself.

Best of luck
I can only wonder the sleepless nights you've all had wondering if I ever got the bump stops back on. Well, wonder no longer. The final solution involved two work mates, washing up liquid, wooden dowel, lengths of 2x4, speed clamps, hole cutters, threaded rod, nuts, washers and a long screwdriver.

The problem amounts to getting enough pressure on the centre part of the stop so that you can lever the flanges up and over the lip of the axle.

So, I made a little tapered dowel peg that sat in the middle of a hole cut in a piece of 2x4, it needs to stand about 2mm proud of the piece of 2x4

The bump stop can then sit in the hole, just resting on the top of the dowel, not shown is that it was then smeared with washing up liquid

Now the axle can be lowered in place

Now, the far end of the axle is clamped to the workmate with a speed clamp to stop the axle rocking. Another piece of 2x4 is then attached to the workmate with M12 threaded rod.

Note that this piece of 2x4 is aligned so you can still access the hole that allows access to the bump stop from above

Next, tighten up the nuts on the threaded rod so that the bump stop is pushed hard up against the axle

There should now be enough pressure going up through the dowel to make the flanges on the rubber bump stop want to pop out. However, they won't do it on their own so I used a long flat screw driver to poke through the hole above the bump stop to lever the cone shaped part in all directions enough for the flanges to pop out. Hooray, beers all round.

After spending hours on the first one trying many different approaches, the second one was done in five minutes. Other, better techniques may exist but this was mine and I'm just relieved it's done and I can move on with the rest of the reassembly.

Thank you to @turining for the ring tip. I hadn't seen that before but it became useful to me in another situation.
Nice job! I'd be interested to know how Fiat mechanics do this in the workshop - do they have a special tool?

(Oh, and many thanks for such a clear explanation, and the helpful pics (y))
Great - well done.

As I said an interesting video/method in itself. Looks a bit painful to me but needs must.
Nice job! I'd be interested to know how Fiat mechanics do this in the workshop - do they have a special tool?

(Oh, and many thanks for such a clear explanation, and the helpful pics (y))
I seem to recall that many of these less buffers / buttons / stops rely on a narrow width dowel insert tool. The tool easily passes into the the bayonet and barbed shaped rubber finger. The then inserted tool with applied force stretches the finger. It in turn reduces it's diameter, pops through the hole and bingo, job done. Sadly in the factory the have fresh, smooth, supple rubber at time of build and some many hours later things do not go so easily :)