my mojave's oil plug is stripped, what would be the best way to fix it. I retapped it, but it is not sealing and oil is dripping

 

buy a helicoil kit from your local auto parts store. you may not find one for your specific thread used on your plug but you should find one big enough to work. any coarse thread helicoil in the size you are looking for with a short bolt to match the thread of the helicoil will work. you may want to get a size slightly bigger than your hole so when you tap for the helicoil you'll be cutting into not-so-messed-up metal. Buy some Loctite too, the stuff for high temp applications, and put that on the outside of the helicoil when you run the helicoil in. This will help keep the helicoil in place. If you cant find a helicoil to match the thead of your plug and have to use a short bolt, I would suggest finding a high temp rubber of teflon washer to put under the head of the bolt to help keep it from leaking. Hope this helps....

 

Are you familiar with the HELI-COIL rethreading system? If you aren't, go to your local parts store and ask them about it. You need to measure the thread dia. of your oil plug. You will have to get a metric heli-coil kit for that size. What you do is drill the stripped threads out with a bit size that is specified in the heli-coil kit. The kit includes a spiecial size tap to rethread the hole. Then you simply screw a stainless steel coil that is included in the kit, into the new threads. That installation tool is includes in the kit. And with the new threads, you will never strip in again. Just make sure the threads on the plug are in good condition. If not, you will need to get a new plug too. Look at the pic labled Heli-coil in my bio to see what the kit looks like. Hope this helps you. venforcer.

 

I may be as wrong as can be on this but:

I seem to remember being told by a mechanic friend that Heli-Coils were not a good option for most plugs. The reason being that oil pans and other such applications do not offer enough thread area to insure a good hold for the coil. I don't know what the casting on your Mojave is like but I just looked at our grandaughters Bayou and any oversize hole would take it out into what appears to be a very thin part of the engine case.

Loc-tite and a couple of other firms make products that are well suited to this kind of repair. The Loc-tite product is a two part epoxy that sets up over a 24 hour period and can be drilled, tapped and machined just like steel. The company salesman that showed us this product made the statement that it was "stronger than aluminum" and, after drilling a couple of holes in the sample he had, I believe him. I would suggest going to Loc-tite's web site and asking their help on this.

You would probably have to order this thru NAPA or other parts store as it is fairly expensive but a lot cheaper than a new engine case or, for that matter, a new engine if you loose your drain plug.

 

Hello,

The best and simplest way I could think of is to use some pipe thread tape and wrap a little around the bolt this should stop the leak?

 

I would NOT buy the heli-coil tool and helicoils and do it yourself. Take it to local small repair shop that knows what they are doing and they should only charge you about $20 and it will be properly fixed.

Some auto stores and good hardware stores sell oversized drain plugs that retap the hole slightly bigger. I'd advise against these as well.

Why risk causing more problems? The last thing you want is for the plug to fall out or the hole get too big to be fixed. Then you'd have to split the cases and that's a major job.

I would take it to a local shop (I wouldn't take it to a dealer because most are greedy and will tell you that you need to replace the case for big $$$). A good repair shop can properly put in a heli-coil or thread repair kit easily and for cheap. Then the repair should be permanent and you won't have to worry about it.

Good luck

 

I agree with 92lt, take it to a shop and have it fixed right. If you have to spend a few dollars to get it fixed by someone who knows what they are doing, it is better then spending a lot of bucks to replace the case. If you have never used the heli-coils before, now is not the time to start. They will work, but like other things,you must know what you are doing before you try them.

 

I also think that you should take it to someone that is used to fixing such problems. There may not be enough room to drill out a amount of the drain hole wall. You also have to make sure it's drilled straight. (same angle as original hole) So the drain plug head and washer sits against the bottom of the motor correctly. The original hole might also be angled a little.

If you take it to a garage and it keeps dripping. Then you can take it back to the garage to have it corrected.

If it will tighten down at all. You could try using a plastic washer with the plug. It might compress a little to hold back the oil. The best way to insure that it won't leak is to replace that part of the motor.

 

A nutsert would be a better choice here than a helicoil. A nutsert is a deal that has threads on both sides. You thread the case to match the outer threads on the nutsert and screw it in. Then use a bolt for the inner threads.

 

I second the vote on the nutsert. Be careful taking it to a dealer, because they might use a heli coil instead of a nutsert.

If you use a nutsert, make sure it isn't too deep or it will prevent the oil from draining out all the way.

Also, it is a good idea to use a tapered tap and not tap until the threads are fully cut so that the nutsert will press hard when inserted. I would use a high strength thread locker to hold it in place and seal it. That means let it harden for a few days to make sure it is good and dry.

When I was a mechanic, I saw many heli coils fail that were done by other mechanics. They didn't seem to work well in aluminum, especially where there wasn't enough depth. Many of them came loose. I had to replace hundreds of heli coils with nutserts. I never had to replace any nutserts.