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Welllll stripped one of the star bolts that holds in the seat on my 987...anyone know what the specs are? Planning on going to the dealer tomorrow but don't have high hopes that they'll have any in stock.
The dealer will probably have them. You may want to get a tap to clean out the mounting hole. I swap my seats in and out every year and have had to do this a couple times.
The dealer will probably have them. You may want to get a tap to clean out the mounting hole. I swap my seats in and out every year and have had to do this a couple times.
Thanks! Any idea what size tap is needed? When you reinstall do you use loctite or anything or that sort? Seems like you'd want to but this is my first time doing this sort of thing.
Doubtful the size is anything too unique. There's a tap for every hole. :-)
Yup.. I removed the bolts on my 987.2 (star-etorx) and found two replacements - exactly the same thread - in my big-metric-bolts junkbox.. so special thread they're not. They are a "fine thread" (which has a definition in metric bolt terminology.)
I would not use locktite on these bolts since they are easily accessible and can be checked for tightness periodically. Wouldn’t want to gum up the threads. The seats need to come out of these cars occasionally for service. So you don’t want to make removals too difficult.
Yup.. I removed the bolts on my 987.2 (star-etorx) and found two replacements - exactly the same thread - in my big-metric-bolts junkbox.. so special thread they're not. They are a "fine thread" (which has a definition in metric bolt terminology.)
Size does matter, and so does harness. Just because it fits doesn't mean it is hard enough. you want a grade 8 or 8.8 (im not sure) bolt. putting in something else may launch the seat on impact.
Size does matter, and so does harness. Just because it fits doesn't mean it is hard enough. you want a grade 8 or 8.8 (im not sure) bolt. putting in something else may launch the seat on impact.
Absolutely.. and I'd actually be looking for a 10.9 grade.
This seemingly innocent little fellow is a factory 996 seat mounting bolt. Other than the fact that it has a 6-point external head, and a "self-centering" tip, it doesn't look much different than most bolts.
Looks are once again deceiving!
This car came to me with "regular" 10mm x 1.5 thread pitch grade 8.8 bolts in place of most of these OE bolts. Inexplicably, two of the OE type were still used in the passenger's seat. I noted that the replacement bolts did not seem to move particularly freely in the holes when I took them out, and that the threads were slightly rounded off on their edges. I ran the threads with a die, and the situation did not seem terribly urgent.
I had the seats in and out at least a-dozen-and-a-half times trying to get all of these Big Problems worked out, and by the time I could see the light at the end of the tunnel, I suddenly found that I had
concurrently reached the end of the life span of the threads in the floor!
This on top of everything else?! #@%&@# !!
After the shock wore off, I got to looking at these odd little bolts. I tried to clean one of them up by running the threads with a die. It lurched in a tight-loose-tight rhythm. Strange. I threaded it into my finger tips. This does indeed not have a regular thread! It is sort of triangle-shaped. A trip to the local pro fastener outlet put order to my findings. These bolts are not normal, not even self-tapping. They are THREAD FORMING BOLTS. "Triodal" by name, if I remember correctly (?). The holes in the car floor are blank inserts, and these bolts, with their self-centering tip and special shape form their own threads as they are FORCED into the holes in the floor. These are not normal threads, and only work to whatever degree that they do with the OE bolt in them. Other bolts will not quite interface well with them, and if they are asked to come in and out too many times... POOF! Goodbye threads!
Oddly enough, the failures only occurred on the front holes. The rear threads remain rock solid. ???
Problem solved by drilling out the inserts and re-tapping them to the next closest size... 1/2"-20 SAE.
REAL THREADS this time. SOLID!
After the shock wore off, I got to looking at these odd little bolts. I tried to clean one of them up by running the threads with a die. It lurched in a tight-loose-tight rhythm. Strange. I threaded it into my finger tips. This does indeed not have a regular thread! It is sort of triangle-shaped. A trip to the local pro fastener outlet put order to my findings. These bolts are not normal, not even self-tapping. They are THREAD FORMING BOLTS. "Triodal" by name, if I remember correctly (?). The holes in the car floor are blank inserts, and these bolts, with their self-centering tip and special shape form their own threads as they are FORCED into the holes in the floor. These are not normal threads, and only work to whatever degree that they do with the OE bolt in them. Other bolts will not quite interface well with them, and if they are asked to come in and out too many times... POOF! Goodbye threads!
Fastenating. (Pun on purpose..) Actually really interesting. It's hard to make a Google phrase that turns up lots of info - all that comes up are some references to them in other DIY websites where people were surprised to find them..
These bolts aren't cutting bolts - they essentially roll the threads into the holes they're screwed into. Since the receiving (female) thread is formed by the thread on the bolt - you end up with a very precise interface with great metal to metal contact - making the juncture stronger and resistant to backing out from vibration.
11-03-2019, 10:55 PM
Where to get replacement seat star bolt?
