Lower Shock Absorber Bolt Won't Budge

[Osmoliver]

Hi all,

The OS rear spring has snapped on my Mx-5, so I'm currently in the midst of replacing both rears.

The NS shock absorber was reasonably friendly and let me get the shock out. I've replaced the spring and refitted that. No problems there.

On the OS, I have a couple of issues:
The bolt that holds the bottom of the shock absorber into the control arm is being extremely stubborn. I managed to crack it from the nut, but it won't budge by more than a quarter turn in either direction. My mate thinks the bush inside the shock absorber is knackered and preventing the bolt from turning. Has anyone had this issue before or does anyone have any ideas how to beat it?
After spending far too long, I had to give up for the day. When re-assembling the lower control arm and hub back together the nut starting spinning on the thread and now it won't budge in either direction. I'm guessing the best option here is to cut through it and get a new one?

Any advice is greatly appreciated, cheers.

Ollie

[Oldandslow]

Notoriously difficult to get those bolts out but it sounds like you've done the hard bit if the bolt has come loose of the captive nut. If the bolt is now seized up in the bush, the bolt is probably rusted to the metal sleeve in the bush. If liberal application of plus gas down the gaps and heavy hammering are having no effect you could try heat. An induction heater on the head of the bolt is probably the neatest way to do this. Borrow or rent I'd say as they're a bit pricey. . This may result in the bush melting and you needing a replacement or indeed a whole new shock absorber. Man maths says this is a good time for an upgrade.

As for your second issue I'm not clear which nut you mean but if the threads have collapsed and it won't wind off your only option may be to slit it with a dremel and chisel it off or use a nut splitter(depending on access).

Edited by Oldandslow on Monday 26th March 11:12

[Osmoliver]

Thanks for the reply Oldandslow.

I sprayed it with some penetrating spray and lubricating oil, but neither helped. I'll order a can of plusgas and see if that offers any hope. I assume hitting with the hammer would be on the head of the bolt and hopefully it'll break the rust? Man maths says it's time for coilovers, but the annoying part is that I've already bought the springs and managed to replace one side already...

Mmm, I thought that may be the case.

[Oldandslow]

Osmoliver said:

Thanks for the reply Oldandslow.

I sprayed it with some penetrating spray and lubricating oil, but neither helped. I'll order a can of plusgas and see if that offers any hope. I assume hitting with the hammer would be on the head of the bolt and hopefully it'll break the rust? Man maths says it's time for coilovers, but the annoying part is that I've already bought the springs and managed to replace one side already...

Mmm, I thought that may be the case.

I'm not sure, the bolt is presumably still in the captive nut just unwound a little so you might knacker the threads by hammering on the head. I'd probably try hammering on the base of the shock. Use a drift to get force onto the right spot without mangling the lower arm. It'll be muffled by the rubber in the bush whatever you do but it's worth a try.

[Baskey]

I feel your pain

When the lower shock bolt on mine stuck to the inside of the bush I spent a whole day , 2 cans of plus gas and a whole canister of gas in the blowtorch trying to get it off. All without any joy

In the end the red mist set in and I ended up cutting a hole in the bottom of the wishbone and cutting through the bottom of the shock. Needed a new shock and wishbone

My advice if you value your time would be to take it to a garage

Insidently my passenger side came apart fine

[Osmoliver]

Managed to get the bolt to move in the bush, which most definitely needs replacing now. Only to find out that the captive nut has broken in the wishbone...

For my sanity, I'm ordering a new shock absorber and just taking it to the garage.

[Oldandslow]

Ah well, the joys of older cars. I saw a thing recently with the motto "All it takes is one rusty bolt to turn a 1 hour job into a 2 day ordeal". So you're definitely not alone.