Driveshaft Stud Stripped/Cross Threaded

[mooserage]

Did some work under the car recently and was inspecting things for future work, one of which was installing torque solutions carrier bearing driveshaft bushings. Looking at the rear most passenger carrier bearing mount I found this gem:

I've had this car for about 70k miles, so I guess it was this way since then at least. Anyway, I could see that some of the threads were stripped or cross threaded even with the second nut covering it up. Pulled the lower nut off and found this:

For fear of the threads coming off with it, I left the upper original nut on there. So, I have a few questions and I'm hoping wiser folks might have some advice for me before taking the other nut off to install the new bushings (the originals are shot). I searched a bit, but didn't find much for this issue.

-If I install the bushings and I can torque it to spec (FSM: 22-29 ft/lbs) is that good enough and I am overthinking this?

If the threads are really damaged after removal:

-Besides chasing the threads, is there anything else I can do to "fix" this if there is still enough threads left to make this work?

-Can the studs be replaced? (I think not from the FSM, but if anyone knows otherwise it'd be good to know)

-Could it be reinforced in anyway, like sleeved?

Despite the huge mileage on this car, it spent its entire life in Washington except for one winter in the midwest, but there are still a lot of signs of corrosion under there /ubbthreads/images/graemlins/frown.gif I was just thankful that most of it is on the surface.

Thanks!

 

[iceman69510]

I would try chasing the threads before you try to undo the nut.

Those studs can be replaced, but not an easy job, and of course requires cutting our and welding in a new one (and finding a part-not sold as a service part).

If you can achieve torque high enough up on the stud it would probably be ok. BUT, the prior mechanic probably put that nut there because they couldn't.

Drill through and use a cotter pin or safety wire?

 

[thomcasey]

Also, note that you will be introducing vibration from the driveline into the vehicle with those mounts (I know, I have them currently). So, you may want to think about that with weak threads as the vibration can be detrimental to the ability to keep that nut tight. I am moving to some Outlander bushings when I feel like crawling under the car. I have a set sitting on my shelf.

 

[89Mirageman]

Is the other side on the floorpan on the interior of the car? Maybe grind it from the top and remove the stud and replace it with a bolt. One other option and this is kinda sketchy but if you can get the bolt tightened to spec maybe clean the threads really well and throw a few tack welds on there. Of course if you ever do have to take it back off replacing the stud will probably be your only option. Also if you were to ever sell the car the new owner might not like your modification.

 

[transparentdsm]

id try re-threading it with maybe an american thread thats close to it and see if it cleans it up and lets you thread a fresh nut on. other than that i would start stripping interior to pull and replace that from the inside. its a bitch, but its the safest way to do it in my opinion.

 

[mooserage]

Thanks for the replies! In order to keep my post short, I'll just partially quote everyone:

Quoting iceman69510:
I would try chasing the threads before you try to undo the nut. Those studs can be replaced, but not an easy job...



I have a tap and die set, so I can chase the threads with that. I would prefer not to replace the stud right now if at all possible. If someday (I can dream) I really dive into refreshing the chassis then I would probably replace it. The cotterpin/safety wire isn't a bad idea as a backup, I'd feel better about that than the second nut.

Quoting thomcasey:
Also, note that you will be introducing vibration from the driveline into the vehicle with those mounts ... I am moving to some Outlander bushings...



That is interesting, I saw a few people said they found driveline noise reduced after installing these, though I don't recall any mention of vibration. I had not heard of the outlander bushings as a possibility, are they a direct drop in replacement?

Quoting 89Mirageman:
Is the other side on the floorpan on the interior of the car? Maybe grind it from the top... Also if you were to ever sell the car the new owner might not like your modification.



It's sounding like it may be accessible from the top, but as I mentioned, I am hoping to avoid that route if at all possible. It would still be a possibility if necessary though. I am at a point where I am not sure that I could ever sell the car, mileage is way up there and I know almost every little kink its got. I think I am stuck with it /ubbthreads/images/graemlins/uhh.gif

Quoting transparentdsm:
id try re-threading it with maybe an american thread thats close to it and see if it cleans it up and lets you thread a fresh nut on...



It sounds like re-threading is on the list either way, but I'm curious, why use an American thread? Just as a backup if I don't have tap & dies available, or is there another reason to try it?

Thanks!

 

[thomcasey]

Quote:
That is interesting, I saw a few people said they found driveline noise reduced after installing these, though I don't recall any mention of vibration. I had not heard of the outlander bushings as a possibility, are they a direct drop in replacement?



Yea, I had heard that too, but I talked with a Mitsubishi Master Tech that also builds DSMs and he stated those are best for track cars. DD does introduce noise. He told me they from from and Outlander, but I will verify the model and year when I see him tonight.

 

[mooserage]

Thanks for the feedback, I'd definitely be curious what the part number is for those. I might try the TS bushings first since I have them, but if the vibration is bad, then some rubber would probably help.

 

[transparentdsm]

Quoting mooserage:


Quoting transparentdsm:
id try re-threading it with maybe an american thread thats close to it and see if it cleans it up and lets you thread a fresh nut on...



It sounds like re-threading is on the list either way, but I'm curious, why use an American thread? Just as a backup if I don't have tap & dies available, or is there another reason to try it?

Thanks!



the reason i would use the closest american size is so you can pull the most metal off the stud and leave the most thread possible. with almost all the thread gone a metric of that size may not cut a full thread into the stud cause it to again strip.

 

[mooserage]

I see, thank you for the explanation. I haven't dealt with a lot of re-threading studs so it really helps to hear some of these strategies to try and tackle this.

 

[FlyingEagle]

You can always take a wire wheel on a hand held drill (brass will remove the least material but can take longer to clean out debris from deep in the crevice of each thread) to the threads before starting any tap type element in place. This helps with getting the first set of cutting threads in place before going any further, regardless of what type of chase or cutting tap you use.

 

[thomcasey]

Quoting mooserage:
Thanks for the feedback, I'd definitely be curious what the part number is for those. I might try the TS bushings first since I have them, but if the vibration is bad, then some rubber would probably help.



I checked with Brian, they are either from the mid 2000's EVO or Outlander.

 

[mjdarg]

Did that first nut come off easily? Someone could have put an SAE nut instead of a metric nut on. +1 to a brass wire wheel. If the stud looks fine and not corroded in the rubber bushing, you could cut only have the stud and weld on a section with good threads. You'd just have to grind it down so it's the same OD. That would be easier than perhaps taking out seats and carpet.

 

[mooserage]

It came off pretty easily, but also fit in the mm socket I was using pretty well. I didn't think to check the thread pitch at the time though. Hopefully this next week I will get a chance to take it all off and investigate. Agreed on ther wirte wheel at least.