Changed car battery, but hit a problem...

[ben g]

I tried to change my Z4's battery at the weekend, but couldn't manage to remove the long thin bolts holding the brackets down, which hold the battery in place.

I gave them a spray earlier and manage to realise them this afternoon, although with the slightest of turns, they decided to snap at the threaded part.

I'm now left with 2 bits of thread stuck in the bottom of the battery tray, completely flush.

Would a garage be able to drill these out? I plan on getting my Z4 serviced in the next few weeks, so can ask them to sort it, but wondered whether it is actually possible?







One of the bolts hold this black bracket in place.

 

[Sidewaze Samm]

Maybe a replacement battery box from a scrapper?
Check the For Sale section, there's been a couple recently.

 

[ben g]

Maybe a replacement battery box from a scrapper?
Check the For Sale section, there's been a couple recently.

Good call. Nick_l has come to my rescue

Still need to get the threaded parts out of the hole :headbang: but I'm sure they will come out with some persuasion.

 

[road warrior]

unless you have one of those drill gadgets for removing threads you will need to drill out an tap the hole
otherwise depending on your skillset get 2 pieces of wood and wedge it - i cant go anywhere can it..

 

[mr nurburgring]

I’ve done this type of job before, drill a small hole in the bottom underside of the battery tray where the nuts are, knock out the old nuts from underside and replace with new nuts glueing them in with some epoxy resin, then buy 2 new long battery bolts from bmw.

Job done.

 

[ben g]

unless you have one of those drill gadgets for removing threads you will need to drill out an tap the hole
otherwise depending on your skillset get 2 pieces of wood and wedge it - i cant go anywhere can it..

Yeah it does seem pretty secure as it is, but I like to make sure a job is done properly, so will definitely be removing the snapped thread and replacing them.

Fortunately I work in a huge engine manufacturing plant, so have access to drills/taps etc, but it all depends whether the guy wants to do me a favour or not :lol: if not, it's going to be the indys job I suppose.

 

[Sidewaze Samm]

Still need to get the threaded parts out of the hole but I'm sure they will come out with some persuasion.

I was thinking of replacing the whole battery box. Of course I've no idea what kind of job that is - just thought it looked a straight forward option :roll:

 

[ben g]

Still need to get the threaded parts out of the hole but I'm sure they will come out with some persuasion.

I was thinking of replacing the whole battery box. Of course I've no idea what kind of job that is - just thought it looked a straight forward option :roll:

I wasn't aware the battery box could be removed easily?

If thats the case, then that seems like the most logical thing to do! Will give it a go later and report back with my findings

 

[Thrustyjust]

Those rods are only mild steel, so centre punch them and drill out and retap the threads. I dont know what size they are but you can use the threads on the new rods to tell you that.

 

[obewan]

Those rods are only mild steel, so centre punch them and drill out and retap the threads. I dont know what size they are but you can use the threads on the new rods to tell you that.

If they're only mild steel it should be easy enough to use extractor taps, save the potential hassle of re-tapping

 

[Capa]

Yeah I think I'd be looking at getting them out rather than replacing anything...

 

[kis]

I’d replace the whole box personally. Seems pretty simple to bolt off/back on.

www.ebay.co.uk/itm/264070943665
(For picture reference only - sure you could get from nick_l like the bolts)

Save all the drilling and tapping faff...

 

[ben g]

I’d replace the whole box personally. Seems pretty simple to bolt off/back on.

www.ebay.co.uk/itm/264070943665
(For picture reference only - sure you could get from nick_l like the bolts)

Save all the drilling and tapping faff...

I think that's the wisest choice now, as I've made the job even worse :lol:

I tried to remove the battery box and decided it seemed a simple enough job. Sprayed the bolts with some wd40 fast penetrant (not the standard stuff) and attempted to remove the 7 bolts holding the box in from inside the boot.

The first 5 came out easily enough. Got to the 6th and snap... Ffs :headbang: 7th... Snap.

I then went underneath to see what else was holding the battery box down, and noticed a black plastic bracket bolted onto the box with 3 tiny bolts. They looked in terrible condition. Attempted to undo them and all 3 snapped :headbang: :headbang: :headbang:

Absolutely sick of it all now. I've put it all back together and wedged some wood down the side of the battery now, to hold it in place. It doesn't move, so that will do until I can get someone to drill the top 2 bolts out. I will probably buy another battery box and just replace it, but I need to work out how to remove it completely without breaking anymore bloody bolts!!!

 

[obewan]

Feel your pain but sorry I had to smile
I thought that sort of thing only happened to me!
Hope you get it sorted soon

 

[kis]

That’s rotten luck!
Have you asked either of the two breakers? One of them surely has removed the box?

 

[ronk]

Drill and Heli Coil ?