Front engine mount nut damaged

I have just had a new front panel welded on. Refitted the engine and tried to bolt up my new motorsport mount but it wouldnt fit. Taken it off and you can see the bolt on the right screws in at a horrid angle. The nut welded on the inside is off centre but i cant tell if the thread is also damaged…



Can anyone give me some advice of the options I have  :dontknow:

Absolutely gutted as i thought a brand new panel and mount would get rid of any potential problems like this!

 

The engine mount (part that bolts to the front panel) should have oval cut outs, to allow adjustment, rather than circular holes in an exact location. Does your aftermarket mount have this?

The bolts should go square into the panel, otherwise the clamping force won't be properly applied. It looks like either your front panel was very poor quality or you managed to cross thread the bolt as it went in - possibly from misaligning it on fitting, due to the aftermarket mount having circular holes and not ovals???

your right about the mount, it has circular holes much smaller than the oval holes on the original mount which probably contributed to the cross threading of the nut. If i can get the bolt to go in straight i will put the mount on in 2 halves next time to avoid any unnecessary pressure on the bolts.

Dont think the panel was at fault although the nut isnt completely central which cant of helped. It is definitely cross threaded. Im going to go buy a tap and die set now and see if i can retap it. Bu there isnt enough space to drill it out first so dont know how it will go…

Yeah its a bit of a tricky one to resolve, now that its cross threaded. Options include:

- cutting out the area of the panel and putting another section in with a new captive nut
- re-tapping the original thread back into the captive nut
- tapping a slightly larger thread into the captive nut

If its any consolation, that engine mount doesn't actually support any weight, its a 'torque reaction link' and its a common area of weakness for corrosion too. So it isn't subjected to that much load. Having said that, with uprated mounts and fast starts, it will get more load than standard.

thanks for your advice. Just bought a tap and die set, but they only had a cheapy one. Should i use a tap the same as the bolt. Or a larger one like you said? If I used a larger one would i need a different bolt?

I'd start with the same size tap (M10 isn't it?) and see how that holds. The problem if you go up a size is you're 'eating' into a captive nut which is sized for the M10 thread size, so there isn't that much material left on it. So you'd either need to use an odd size (eg M11) or go up to M12 with the risk that there's not enough metal to adequately support it any more.

TBH I think you'll be fine with the standard size re-tapped.

thanks for the dude.

Basically I didnt have the option of a good tap as i was home alone. The hardware shop where i work only had a rubbish £20 set that looked like it was made of cheese but thats all i could get. Retapped it as m10 only to find that the tap was genuinely made of cheese and had ruined itself. But it had also flattened most of the thread in the nut. So i managed to retap the nut using the original bolt and got the mount on in the end.

I will be talking personally with the company who made the mount though as the reason it cross threaded in the first place was, just as you said, the two holes drilled in the mount are not big enough for any adjustments and are too close together so the bolts were going in at an angle. Using hammers and blind ignorance I got it on eventually but in future they should definitely make those 2 bolt holes larger like on the original mount, so that there is room to move a few mm left/right. I live local to them so once the caddy runs i might pop down and have a chat in person.

Otherwise im chuffed to bits the engine is all bolted up properly!