I have been replacing a lot of nuts, studs, and bolts on my car and have noticed some consistencies with the part numbers:
90179-xxxxx = Most common for nuts
90116-xxxxx = Most common for studs
90119-xxxxx = Most common for bolts
Naturally, there are variations, but the above are the most common ones I have seen whilst working in the engine area:
With a nut that begins with 90179 it would seem the sixth and seventh digit denote the diameter of the thread of the fastener it threads on to:
90179-08059 = Exhaust heat shield nut, which has an inner diameter of 8 mm
90179-10128 = Exhaust manifold nut, which has an inner diameter of 10 mm
But I have no clue on the meaning of the final three digits. Is there some meaning, or is it just random?
I looked at many other nuts and still couldn't find any pattern. 90179-08017 and 90179-08135 from my intake manifold and plenum were both nuts with integrated washers, 90179-08040 from the EGR cooler/intake manifold had a bit of a flange.
(Disclaimer, I am not sure if the right nuts were in the right locations on the intake...they seemed to be in logical positions.)
Right now the only conclusion I can come to is that the final three digits are just sequentially assigned and have no meaning other than to make the part number unique.
As for why I am asking this, I would love to know if I could determine if a Toyota part exists that is identical in shape and size to 90179-10128 but with a thread pitch of 1.5 instead of 1.25. (Someone thought it would be fun to helicoil ONE of my exhaust studs to 10 x 1.5 and I cannot find a stud that is threaded 1.25 on the long end and 1.5 on the short.)
Thanks!
90179-xxxxx = Most common for nuts
90116-xxxxx = Most common for studs
90119-xxxxx = Most common for bolts
Naturally, there are variations, but the above are the most common ones I have seen whilst working in the engine area:
With a nut that begins with 90179 it would seem the sixth and seventh digit denote the diameter of the thread of the fastener it threads on to:
90179-08059 = Exhaust heat shield nut, which has an inner diameter of 8 mm
90179-10128 = Exhaust manifold nut, which has an inner diameter of 10 mm
But I have no clue on the meaning of the final three digits. Is there some meaning, or is it just random?
I looked at many other nuts and still couldn't find any pattern. 90179-08017 and 90179-08135 from my intake manifold and plenum were both nuts with integrated washers, 90179-08040 from the EGR cooler/intake manifold had a bit of a flange.
(Disclaimer, I am not sure if the right nuts were in the right locations on the intake...they seemed to be in logical positions.)
Right now the only conclusion I can come to is that the final three digits are just sequentially assigned and have no meaning other than to make the part number unique.
As for why I am asking this, I would love to know if I could determine if a Toyota part exists that is identical in shape and size to 90179-10128 but with a thread pitch of 1.5 instead of 1.25. (Someone thought it would be fun to helicoil ONE of my exhaust studs to 10 x 1.5 and I cannot find a stud that is threaded 1.25 on the long end and 1.5 on the short.)
Thanks!
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