While replacing the passenger side motor mount, I found that the threads in the frame were damaged. I used an Autozone thread restorer and was able to install the new mount, but they didn't seem to torque up as well as all the other bolts. Should I be excessively concerned? If I wanted to remedy the situation, what is the best course of action?
Civic Motor Mount damaged threads
- Thread starter Coprolite
- Start date
- Status
I cant picture this in my mind, what kind of thread restorer did you use? Is the bolt a spring type nut or welded nut from behind? When you say didnt toque up as well what is the torque spec and is it stripped?
No idea, they make in/out thread files. I figure if he used a tap or HC he would have just called it a tap or a helicoil.
I usually make my own thread restorer if I run into a slightly buggered but not stripped inside thread, it only takes a couple of minutes.
I usually make my own thread restorer if I run into a slightly buggered but not stripped inside thread, it only takes a couple of minutes.
I used the wording that they use. It looks to me to be a tap, butI haven't used any before, so I used their term.
Autozone kit
I think there is a good chance of it being stripped, as it gained resistance to rotation and seemed to plateau. I didn't keep pushing it, so it might have been just gaining resistance slowly and I undertorqued. A quick google indicates that this appears to be common, perhaps due to the number of motor mounts being replaced on Civics. It was difficult to get the original off, and I believe that was probably cross threaded before I got to it.
I would rather disassemble and repair than risk any other outcome. What is the easiest reliable fix? I saw helicoils, but what bolts do you use with those?
Autozone kit
I think there is a good chance of it being stripped, as it gained resistance to rotation and seemed to plateau. I didn't keep pushing it, so it might have been just gaining resistance slowly and I undertorqued. A quick google indicates that this appears to be common, perhaps due to the number of motor mounts being replaced on Civics. It was difficult to get the original off, and I believe that was probably cross threaded before I got to it.
I would rather disassemble and repair than risk any other outcome. What is the easiest reliable fix? I saw helicoils, but what bolts do you use with those?
You get the size the original bolt is, use the supplied tap and insert the threaded coil, break the tang off and use the original size bolt. Use a new bolt if the threads were buggered, the threads on the bolt are probably damaged also.
Thanks Trav. The bolt threads are what led me to believe that this was a preexisting issue, so I will get new bolts and helicals to match. The idea of trying to put a nut on the backside(the other option) had me questioning my sanity.
Originally Posted By: Coprolite
I used the wording that they use. It looks to me to be a tap, butI haven't used any before, so I used their term.
Autozone kit
Those are thread forming taps. They are made for use in stripped or buggered, already tapped holes. Since they push metal around instead of cutting it like a standard tap, they leave more metal behind, and you have a better chance of getting a usable set of threads.
In particular, that set is made in the US by Kastar/Lang, rebranded and resold by just about everybody. I got mine through Craftsman for a crazy low price via SWY points. They paid for themselves on the first use on my lawn tractor, when the electric PTO fell out of the end of the engine driveshaft, but not before buggering it up real good from being loose.
http://www.langtools.com/rethreader-tools/?sort=featured&page=2
I used the wording that they use. It looks to me to be a tap, butI haven't used any before, so I used their term.
Autozone kit
Those are thread forming taps. They are made for use in stripped or buggered, already tapped holes. Since they push metal around instead of cutting it like a standard tap, they leave more metal behind, and you have a better chance of getting a usable set of threads.
In particular, that set is made in the US by Kastar/Lang, rebranded and resold by just about everybody. I got mine through Craftsman for a crazy low price via SWY points. They paid for themselves on the first use on my lawn tractor, when the electric PTO fell out of the end of the engine driveshaft, but not before buggering it up real good from being loose.
http://www.langtools.com/rethreader-tools/?sort=featured&page=2
I just make one from a hardened bolt the same size, just cut 4 flutes in the bolt threads all the way up with a Dremel cutting wheel and that's it. This can be a real time saver for lines that didn't quite go together properly and the first couple of threads are buggered and bleed screws that the threads are corroded. These are sometimes an real oddball size and not included with any kit, just get a line fitting the correct size and Dremel away, it works like a charm every time.
For bolts I just use a thread file but for actually cutting threads and real tap and die set is necessary. This one has 8 different metric thread pitches.
Those kits may be okay but I rather spend the money on a better quality HSS tap and die set.
https://www.zoro.com/nicholson-metric-th...mp;gclsrc=aw.ds
For bolts I just use a thread file but for actually cutting threads and real tap and die set is necessary. This one has 8 different metric thread pitches.
Those kits may be okay but I rather spend the money on a better quality HSS tap and die set.
https://www.zoro.com/nicholson-metric-th...mp;gclsrc=aw.ds
To ensure that I am not off mark... I used the 12mm 1.25 tap from the kit and the Honda part number is:
95701-12040-08 BOLT, FLANGE (12X40)
So this would be an M12 1.25 40mm bolt? I am mainly asking as the helical kits I see are quoting Mx sizing and I don't size Metric bolts often, if ever...
95701-12040-08 BOLT, FLANGE (12X40)
So this would be an M12 1.25 40mm bolt? I am mainly asking as the helical kits I see are quoting Mx sizing and I don't size Metric bolts often, if ever...
Yes M12x1.25 40mm long, you can get metric flange bolt but 40mm might be oddball, 35 if there is plenty sticking out or 45mm will work okay. A good rule of thumb is a minimum of 1.5 times the bolts diameter in the threaded hole pref 2 times.
So an M12 bolt would need to be 18-24 mm in the threads to attain full thread strength, more is okay less not, it doesn't matter if its longer as long as it isn't coming into contact with anything. Ace hardware has metric flange bolts.
So an M12 bolt would need to be 18-24 mm in the threads to attain full thread strength, more is okay less not, it doesn't matter if its longer as long as it isn't coming into contact with anything. Ace hardware has metric flange bolts.
I had the heli cols on standby today, but found the drill bit would be too short to get a straight shot into the frame. I simply put in new bolts and they made up nice and tight. When I went to torque them, my 1/2 torque wrench wouldn't click. Switched over to the 3/8" and I was able to confirm they were torqued.
When I thought about it, I believe the play in the extensions combined with iffy torque wrench gave me the feeling that the bolts weren't holding the first time. Better safe than sorry though.
When I thought about it, I believe the play in the extensions combined with iffy torque wrench gave me the feeling that the bolts weren't holding the first time. Better safe than sorry though.
That's great at least they are tight. Either the toque setting is out of range for your 1/2" or it needs calibrating, keep in mind that unless you buy a wrench that specifically states its accuracy is through the whole scale it is not very accurate in the lower end of the scale the real accuracy range is approx 20-100% of the scale.
- Status
Similar threads
