68 Steering Arm bolts

[Michael M.]

About 3 to 4 years ago, I went through my front suspension and replaced all the worn out parts etc. I torqued everything to spec but I've determined that the steering arm bolts on both sides have loosened up. These are the bolts that go through the spindle, through the caliper bracket and then through the steering arms. The steering arms have the holes in them which connect to the outer tie rod ends. They are only accessible to service if you remove the rotor.

Not sure why they loosened up and I will disassemble and re-torque (using red loctite this time), but it got me to thinking that maybe these 44 year old bolts have stretched over time and won't hold the torque.

Does anyone know a good source where I can get new steering arm bolts and the nuts that secure them? Thanks.

[Joe L.]

Re: 68 Steering Arm bolts

About 3 to 4 years ago, I went through my front suspension and replaced all the worn out parts etc. I torqued everything to spec but I've determined that the steering arm bolts on both sides have loosened up. These are the bolts that go through the spindle, through the caliper bracket and then through the steering arms. The steering arms have the holes in them which connect to the outer tie rod ends. They are only accessible to service if you remove the rotor.

Not sure why they loosened up and I will disassemble and re-torque (using red loctite this time), but it got me to thinking that maybe these 44 year old bolts have stretched over time and won't hold the torque.

Does anyone know a good source where I can get new steering arm bolts and the nuts that secure them? Thanks.

Michael------

Do you have lock nuts on the bolts? That's what they're supposed to have. Even if you do, they may have lost their ability to maintain torque. That's the most likely cause of your problem. The original nuts were GM #9422302. Those are discontinued but you can obtain replacements from GM under GM #9442940. You can also obtain reproductions of the original nuts from AMK products. These are stover-type locknuts, SAE grade 8, and zinc finish.

The bolts were GM #3871512. They're long since GM discontinued but are available in reproduction from AMK Products.

[Michael M.]

Re: 68 Steering Arm bolts

Thanks Joe. Just what I needed.

[Michael M.]

Re: 68 Steering Arm bolts

Joe, can you confirm that both front and back steering arm bolts are the same lengtH. I think one of them goes through a bracket that the other one doesn't. Thanks.

[Don H.]

Re: 68 Steering Arm bolts

Mike,
if the bolts on your 68 are the same as those on my 65, and I will guess they are, they are the same length. I just had mine out and now back together after cleaning up my suspension parts, and they are exactly the same. One bolt protrudes one or two more threads beyond the nut than the other does.

[Michael M.]

Re: 68 Steering Arm bolts

Thanks Don. I think the bolts on your '65 are 7/16" and mine are 1/2" but I believe they are the same length, I just wanted to confirm my belief.

[Joe L.]

Re: 68 Steering Arm bolts

Joe, can you confirm that both front and back steering arm bolts are the same lengtH. I think one of them goes through a bracket that the other one doesn't. Thanks.

Michael-----


No, they are of different lengths. I should have mentioned that but I was kind of tired when I posted the last response. The longer bolt is the one I previously described, GM #3871512. It was 2-21/32" in length with a thread length of 15/16". This bolt was black phosphate finished and of GM 300M material grade (SAE grade 8). These bolts had the number "96", 6 radial lines and a manufacturer's ID embossed on the head which was the trimmed style (i.e. "non-indented"). They are available in reproduction from AMK Products, as I previously mentioned.

The other bolt was 2-13/32" in length with a thread length of 1-3/32". It was of GM #3818706 and, later, GM #1385922. It was black phosphate finished and of GM 300M material grade. The head had only the manufacturer's ID and 6 radial lines and was of the trimmed style. It was GM discontinued in March, 1975 and the replacement 1385922 was discontinued without supercession in October, 1992. I know of no reproduction source for it.

So, what's so special about the above-referenced bolts? Well, they are 1/2-20 size which is pretty common but they have a non standard un-threaded shank-to-threaded shank length. Specifically, the un-threaded shank is longer than it would be for a "standard" bolt of the respective lengths. Is this important? GM thought so and I tend to agree.

[Joe L.]

Re: 68 Steering Arm bolts

Mike,
if the bolts on your 68 are the same as those on my 65, and I will guess they are, they are the same length. I just had mine out and now back together after cleaning up my suspension parts, and they are exactly the same. One bolt protrudes one or two more threads beyond the nut than the other does.

Don------


The 1965 and 1968 steering arm bolts are not the same. All 1963-67 used 7/16-20 bolts. 1968-82 used 1/2-20 bolts.