I went out and bought a digital angle gauge from Harbor Freight today. I verified it against a bubble level and my gravity gauge. I'm confident it's accurate within a couple tenths.

Pinion is 3 degrees nose up. Drive shaft is 1.5 degrees rear end up. Tail shaft is 3 degrees down.

Numbers are a little better I'd say but still not good enough if working angles are to be below 3 degrees.

I'm not sure why the drive shaft angle is less with the digital gauge. I put the gravity gauge right next to it and it went right back to the 3 degrees I measured the first time. I'm going with 1.5 degrees.

I'll adjust the angles in the coming days and see what happens.

Thanks

So driveshaft and pinion is in a /\?

If so dropping the rear pinion to neg 2 degrees should lower the driveshaft to closer to zero and maybe plus or minus .5 degree. If the driveshaft does go to a neg .5 them your front operating angle would be 2.5 and if rear pinion down neg 2 degrees it would make the rear operating angle 2.5 as well. Both operating angles would be equal if thafs the case

Correct. The drive shaft to pinion looks like /\.

I'm hoping to both raise the transmission and lower the pinion, but we'll see what I can come up with.

Thanks Randy

I lowered the pinion last weekend to the point that it's about .5 degrees nose down now. This got the working angle at the rear u-joint down to around 1.5 degrees. I was still slightly up in the rear. This did change the front working angle but it was still a little over 3 degrees. I took the car out for a drive anyway. Nothing changed or it changed so slightly it's not worth mentioning.

Today, I tried to raise the transmission by removing the snubber on top to gain the clearance I needed. I wasn't able to go up but a few tenths due to the reverse lockout hitting the tunnel now.

So my plan at this point is to cut the tunnel out enough to get the transmission where I need it. I'll leave it open until I'm certain I have the transmission where it needs to be. Hopefully, this will either fix the issue or allow me to rule it out.

Some maybe good news is I think I'll have the clearance I need for the headers though it will get tight in places once I raise the engine. I'm also fairly certain I won't have to raise the tunnel over the driveshaft. I'll just have to change the tunnel over the transmission.

The bad news and why I'm going to leave the tunnel open until I'm certain the angles are correct is that I'm going to have to cut out part of the factory tunnel brace that's spot welded to the floor from side to side. The drive shaft will be way too close if it clears at all once I raise the transmission. This means making a DSE style trans brace and putting in new floors which I needed anyway. I'm not willing to do all of that until after I know the drive line angles are working correctly.

We'll see what happens. I'll be back with an update later.

Might not be an issue -- but if you have a rear sump -- don't get that up so much that the oil doesn't flow in to it..... ??? Maybe the pan is already sloped enough that it doesn't matter - I don't even know what motor you're running etc.

That's a good point, Greg. I'll check it soon to make sure I'm ok. The engine is still a Gen II LT1 though it is stroked. Thanks.

Finally! After all this time playing with this damn vibration issue, I have affected it with an adjustment. It's not fixed. It's better in some ways and worse in others, but it's in the drive line for sure. Hopefully, it's only the drive line and I don't still have multiple issues. I'll play with it more this afternoon and see what happens.

Thanks!

Well ------ at least you're on to the cause. That's 90% of the battle.


Watch this video....
download this handy dandy phone app...... LOL it might help make setup easier.

Good news Trey! Interested in what you’ve found.

Thanks Greg. I'll take a look.

I raised the transmission up, Scott. Too much working angle in the front u-joint I do believe was the issue. At least that's what I was adjusting anyway.

Later in the afternoon I raised the nose of the pinion back up just a touch to see if that helps make things better as I had it about .5 degrees nose down. I haven't taken another official measurement but I should have the pinion .5-1 degree up now and the transmission 1.5 degrees down. The weather sucks today so I may not get it out to see if that helped make things even better.

Trans tunnel will eventually have to be removed entirely. I did that wrong way back in 09 when I first did the swap. I have the Hooker T56 tunnel piece coming. We'll see how that fits before I cut any more. If this works, I'm still confident I won't have to raise the driveshaft tunnel, but the factory brace in the floor I mentioned early does have to be cut for me to be happy with its clearance. It's really tight right now.