Hey y'all. I'm finally getting to get back into my 63 and I've got my front suspension pretty well figured out, but I realized I've lost the bolt and washer on the front of my passenger side lower control arm. I've checked parts dealers, I even took the other one to a bolt and screw vendor to get a match, but apparently it's some odd thread size that is not available. Anybody got one they'd be willing to part with?

also, looking for a solid(ish) passenger rear quarter (lower part specifically) somewhere in the southeast.

Thanks!!
-g

 

I'm not sure which bolt you need.
Can you give me a number in this illustration that is the part you need.

 

it would be part of the bushing package (6.169) but the 63 model uses a 7/16-24 bolt instead of the 3/8-24 on the 61/62. The problem is that It's virtually impossible to find a 7/16" bolt with a 24 tpi thread pitch. So far I've had no luck locating the right bolt.

 

3/8"-24 is a standard fine thread for 3/8". 7/16"-20 is standard fine thread for 7/16" bolts. 7/16"-24 would be a "special use".

Have you actually checked, using a 7/16"-20 bolt ? Or used a "thread pitch gage" on the bolt you have ? I find it unusual that Oldsmobile used a "special bolt". @Charlie Jones will likely have the correct answer.

 

Initially, I took the bolt from the other control arm, and went to get it replaced, that's when I found out about the thread pitch. I haven't been able to locate that bolt. McMaster Carr, Fastenal, Grainger, etc. are no-gos.

 

Is there a nut for the bolt ?

As I said, 7/16"-24 is "Special". You won't likely find it at those sources. Could a 7/16"-20 nut and bolt replace it ?

 

unfortunately no. These bolts thread into the end of the center bar that the lower control arm pivot on. If I had to, I might be able to re-tap the hole to a different size, but that's not something I really want to do.

Grainger offers a 7/16-24 flange bolt, but it's like $135 for 25 bolts. Seems a bit much since I only need 1 (if it even works for my application)

 

How long is the bolt? How about a pic of the other one that you have next to a tape measure? Also a shot of the head, showing the grade marking. Thanks, Bob.

 

The parts book shows it as a special bolt.
7/16-24 x 1 & 1/4 long.
GM part # 587927

 

That link is for a 7/16-14 thread pitch. I'd rather not re-tap the assembly if possible.

 

Sorry, I got the wrong thread pitch.
That is indeed an odd bolt. a fine thread 7/16 bolt is 20 threads per inch not 24.
Your best bet is to try to find someone who has a used one.
Try messaging Pat McMillan (deadds) on this forum.
He has parted out some of these cars, and may have one.

I checked my 1964 Olds parts book and I see that they went with a standard fine thread (20 TPI) in '64.
So that bolt only fits '63's and late '62's.

 

I just sent an email to a supplier that I used when I had my shop. Hopefully they can supply a single. How many lines on the head of the one that you have? The number of lines + 2 = grade. Thanks, Bob.

 

Grade 8, 6 hashmarks. bolt is also stamped "TR"