Camaro Subframe Alignment Pin Dimensions

[OBeer-WAN-Kenobi]

Does anyone have the dimensions for the alignment pins used to help align the subframe when mounting it to the car? I figured I'd just make a set and it would be easier to have the dimensions ahead of time instead of measuring it under the car.

I think the diameter should be about .609 correct? It's the lengths I'll need. Overall and to the step.

Thanks!

[Vince@Meanstreets]

I have a pair of alignments shafts I made years ago from 5/8" steel rod. thats .625in diameter and 10" long. Actual length doesn't matter the hole goes up into the body. It would depend on the bushing you use. I made them long to get the leverage.

[mikeextrafast]

we are getting ready to remove the front sub frame as well.... whats the proper way to reinstall it so its in the wright position?

[Vince@Meanstreets]

we are getting ready to remove the front sub frame as well.... whats the proper way to reinstall it so its in the wright position?

On a lift hoist we usually use a plumb bob to get it close. Lower the body about a 1/2" of clearance then put the bushings and bolts in loose, then shift the body around with the rods to line the frame to body.

[rsgt]

There is a hole at the front of the rear frame rails just in front of the front leaf spring mounting bracket, use this hole to cross measure to the lower front ball joint grease fittings. When you have both measurements the same the subframe will be square to the body.

[clill]

I always used old lug wrenches.

[OBeer-WAN-Kenobi]

I have a pair of alignments shafts I made years ago from 5/8" steel rod. thats .625in diameter and 10" long. Actual length doesn't matter the hole goes up into the body. It would depend on the bushing you use. I made them long to get the leverage.

If 5/8" fit's I can certainly use that. The book calls out .610 +0/-.002 if I recall correctly. Being .015 bigger in diameter, a 5/8" pin should theoretically get you closer off the bat (if it fits) but it makes me wonder why GM was so specific on the dimension if a 5/8" pin will fit.

[David Pozzi]

That might be an assembly line spec. The sub and unibody had to meet up and if the pin was too tight a fit, there could be trouble, slowing the line.

[65_LS1_T56]

If 5/8" fit's I can certainly use that. The book calls out .610 +0/-.002 if I recall correctly. Being .015 bigger in diameter, a 5/8" pin should theoretically get you closer off the bat (if it fits) but it makes me wonder why GM was so specific on the dimension if a 5/8" pin will fit.

Could have been and "attribute" or hard check fixture. 5/8" nominal hole size with built in tolerance, or MMC (max material condition) allowance. So it it would equate to a 0.015" true position allowance if 5/8" is really the nominal holes size. I'd be surprised if it was that close back in the day.

[Bowtieracing]

There is a hole at the front of the rear frame rails just in front of the front leaf spring mounting bracket, use this hole to cross measure to the lower front ball joint grease fittings. When you have both measurements the same the subframe will be square to the body.

I think this good way to get it straight.

[conester2013]

I just reinstalled my sub frame and I used the holes in the bottom at the front of the rear frame and the locating holes at the firewall on the subframe....assy manual says they should be 76" cross measurement each side. As another check I used the rear edge of the very front core support bolt hole and measured across to the center of the top fender bolt on each side..again going from driver side to pass and pass side to driver and got it within a little less than 1/8" difference on each measurement so I was good to go. I think the factory used +/- 1/8" or +/- 1/4" Either way, they didn't get them as close as we do now. It really wasn't as hard as I thought it was going to be.

Brian

[OBeer-WAN-Kenobi]

My post got lost in the missing post SNAFU so I'm just adding it again.

5/8" is too big for the alignment pins. The speck in the factory assembly manual of .610 +0/-.002 is pretty close. I had to go just a wee bit under that on my drivers side but it worked fine on my passenger side.

I haven't run a cross measurement yet but everything is looking pretty good.