Speed control moutning plate/heatsink - remove broken bolts?

[eflyguy]

My speed control moutning plate/heatsink - has been rattling around on the deck for a while - all 4 bolts that mount it to the floor are sheared off. Any suggestions on removing the broken bolts? I'm about to drill them out and re-tap to a larger size, and replace with stainless steel.

Similarly, one of the bolts that mounts the solenoid support bracket is also broken off - it's been hanging on by the other bolt.

It appears the aluminum-to-steel contact has made these parts seize together.

Alternatively, can I get a replacement, perhaps from someone who upgraded their cart?
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[eflyguy]

A picture of the part I'm talking about, with the environmental cover in place (it was held on by a single bolt as well, although fortunately the holes for the others are clear. I'll just run a tap thru them..)
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[master66]

You could either drill and tap a larger size as you stated or driil them and tap them the same size also .If you find a tap chart it should give you the correct size of drill bit you would need for the current thread size .I would start with trying to spray some liquid wrench on them first and let that sit for a while .
You're other option would be to use an ez-out ,this is a corkscrew looking bit that after you drill a small hole through the center of the bolt you insert it in the hole and start turning the wrench ,the threads on the ez-out are reversed so when you turn it bights in and loostens the broken bolt .

[eflyguy]

Should have mentioned, I've tried the liquid wrench and ez-out, no way these things will budge. It appears to be more than just rust, like the steel-aluminum contact has reacted and seized them solid..

Problem with trying to drill them then tap to same size is that the bolts are steel but the plate is aluminum, so unless the drill is perfectly centered, it will trash the existing threads on the way thru. I'm using a drill press but it's still not easy to keep it perfectly centered..

I'll plug away at it.

[master66]

Well at least we think along the same lines anyway ,good luck with it .

[eflyguy]

Well, I broke 4 drill bits trying to drill out just one of the sheared off bolts! The bolts are simply too hard for anything more than a small pilot hole, and the aluminum too soft - the drills walk away from the center, then break.

Still, I was able to get a hole thru one, and will just re-tap that hole. I'm not even going to try and mess with the four on the 'feet', I've just drilled a new hole between each of the old holes (now plugged with sheared bolt shafts) and will tap those for new bolts. Picked up more stainless steel bolts (a local Ace is going out of business - 60% off everything so SS hardware is quite reasonable!)

Thx!
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[eflyguy]

Brought the bracket upstairs, in a cardboard box so I could work on it while I watched a little TV. That helped make relatively brief work of the chore of re-tapping the clean holes, tapped the new ones on the "feet", then re-tapping the messed up one that had caused me so much grief earlier.

Took me forever to get the darned thing out, thanks to seized bolts. Took less than 5 minutes to re-install it with nice, shiny, new stainless-steel bolts. All of them could be hand-tightened then just needed a quarter turn with a wrench/socket.. :) Sheesh, it's nice when things go right. I've bought stainless bolts & nuts for everything I've pulled apart so far, so I am looking forward to putting it back together. I need to pick up a tap for the seat/frame mount points, to clean all of those up as well..

Took some pics but too lazy to get back up and fetch the camera, so I'll post those in the morning..
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[master66]

Well good for you ,sounds like ya got er handled .

[dock98]

Originally Posted by master66

Well good for you ,sounds like ya got er handled .

[eflyguy]

All better..