Last weekend I was playing around with a deep cranking bait. I pretty much never fish deep cranks so I was throwing it around on the only setup I had with enough backbone to handle it which is mainly a frogging combo. I noticed the bait tended to want to swim on its side especially at around the halfway point.

 

Those of you who do this a lot, do these baits blow out more easily than shallow divers? I was using an 8:1 reel and even reeling as slow as possible the bait was turning slightly on its side.

I think you nailed it. I had that problem until I pulled one of my old 5.1 ratio reels out of retirement. 

I can't even imagine trying to crank a deep diver on an 8:1. That issue aside, your problem could be a slightly out of tune crankbait. This can be fixed by bending the eye of the bait. There's plenty of articles and videos online showing/explaining how to do this. 

Depends on the lure and line being used. A good deep diving crank should be able to run straight regardless how fast it’s retrieved using a reel of any gear ratio.

There is a speed point where the diver will roll over, using around 6-8 mph.

Tom

It either needs to be tuned or it's a Norman@. Some cranks will blow out at faster speeds more than others, but most can be made to run straight, or almost so. 8:1 is high for cranking, but if you slow down, while not ideal, is doable. 

If it is running on its side and not straight up and down there is something wrong with the bill, or the line tie. You can try a slight twist to the line tie and see if it makes a difference.  If it’s blowing out (you can feel when it does this) you’re reeling it too fast for the bill’s design. There is a lot of water moving over that lip, exerting pressure on it. There comes a point when the lip wants to take the path of least resistance. As soon as it does, the resistance/ pressure is reduced and it will resume its job. Sometimes you can fine tune a crank that does this, but the best remedy is to slow down your retrieve. 

 

Maybe it needed tuned? I've never really noticed them being more prone to running to the side than squarebills are, but maybe it's more noticeable when they do it.

If you tie direct it's possible to affect how a deep diver may run but with a light weight snap, not a snap swivel, today's lures run true unless damaged. Bending the line tie eye that iis molded into the bill to tune it is risky and not very effective.

Tom