Here are some pics of two holes on the bottom of what I refer to is the frame rail. Please school me if I’m referring to the wrong area. Both are on the left side in the middle of the rail. You’ll notice the steel horizontal plate between the two areas which will give you an idea of the location. The sides of the rail are solid along with the rest of the frame rail. Suggestions please. I have the transmission and exhaust removed so now would be a good time to fix this problem. The rest of the undercarriage from what I can see is in good shape. This is a 280Z . Multiple pictures of the same two locations. Larger diameter hole is 5” long. The other 4”

That is a common problem.  You can buy replacement parts.  They need to be welded in .  Or you could cut and patch.

https://baddogparts.com/index.php?main_page=product_info&cPath=2_5&products_id=6

http://www.datsunzparts.com/

 

Grab some of this while you're down there https://www.eastwood.com/eastwood-internal-frame-coating-14oz-aerosol.html

Will do. I’ll call each of them. It would be great if they had short sections of channel I could purchase without having to buy a complete rail. Thanks for the insight.

5 hours ago, Yarb said:

Will do. I’ll call each of them. It would be great if they had short sections of channel I could purchase without having to buy a complete rail. Thanks for the insight.

Even though the hole is only in one location the chances are good that the bottom of most or all of that rail is rotten too. If you have access to one of those inexpensive bore scopes you can peer inside.  You see where the rust has crept up the side wall of the inside of the rail about 1/2", I'm going to bet that extends the length of the rail where water has been sitting.

Yarb how are your welding skills? If it was mine I would buy the frame rail part and replace the entire part. I like the idea of a bore scope since you have a large enough hole now to really peek down and see what is going on. if its limited then a patch.

Edited April 16, 20204 yr by Dave WM

I’ll find a scope and report back

I've used a pointed implement of destruction such as an ice pick and pushed, probed and stabbed frame rails. You'll find any thin spots and the inspection tool will leave little to no damage if the rail is sound. I'm betting you'll find more soft spots.

Found a good video about checking frame parts...

 

Love it. A 12 oz. b.f. frame checker. Well there's your problem there's a hole in the frame.

If we only had frame rails that thick from the factory

I did order a scope that’s blue tooth where I can view, take pics and video with your smart phone. Will be interesting to see what I find. Has a 12 foot lead which will just about cover any and everything. I’ll give that a try before I pull out the real technical equipment.