1970 GTO Version 2.0

[Scott LaPointe]

I just spent quite a bit of time catching up on this build. Some nice ideas here. When you set your weights did you check the frame heights to see if they are parallel side to side? (Same height difference front to rear on both sides) And, if you know, how much lower is the left side than the right with a driver in the car?

[andrewb70]

I just spent quite a bit of time catching up on this build. Some nice ideas here. When you set your weights did you check the frame heights to see if they are parallel side to side? (Same height difference front to rear on both sides) And, if you know, how much lower is the left side than the right with a driver in the car?

Thanks for the compliments. The corner weights were set with the car sitting on a 1" steel plate that had been leveled, with me in the car. We never took any measurements from the plate to the frame, because those measurements are irrelevant as far as the corner weights are concerned.

Andrew

[Motown 454]

Thats a slick set up. They do some nice work.

[Scott LaPointe]

You're right, the heights don't affect the weights, but keeping the frame level keeps the suspension geometry the same side to side. Chances are you are still pretty close because you don't have adjusters on the front. Getting the cross weight back to 50% is probably the bigger deal.

[gearbanger]

I ran into this on my car too. This is not real technicle, but in trying to level my car, It took about 1.5" of shims to raise the drivers side rear of my GTO .5" I was really scratching my head on that one. But once I thought it through, I assumed it was because the paasenger side front spring was a little longer than the driver side was, and what I was doing was trying to fight the front spring with the much weaker back spring so it took alot more shim. That is where coil overs would definitely be nice.

Andrew, do you have any updates?

[Scott LaPointe]

[QUOTE=gearbanger;804500]I ran into this on my car too. This is not real technicle, but in trying to level my car, It took about 1.5" of shims to raise the drivers side rear of my GTO .5" I was really scratching my head on that one. But once I thought it through, I assumed it was because the paasenger side front spring was a little longer than the driver side was, and what I was doing was trying to fight the front spring with the much weaker back spring so it took alot more shim. That is where coil overs would definitely be nice.

Alex, You are correct on why you needed 1.5" of shim to correct .5" of height. Did you just level the car without checking cross weight? If so you probably have a car that will turn left better than right. It's trickier to balance cross weight with keeping ride height correct. I am used to doing it with height adjusters on all four corners. I'm not sure it's possible to do both with just adjusting spring height in the rear.

[andrewb70]

My transmission was rebuilt and sent back to me on Friday. I'm hoping to receive it this week and get it installed over the weekend. Once it's installed I can measure for the driveshaft. I'm really hoping to get it back on the road in time for the Motor State Challenge. I took my son last year and he had a blast. This year I promised him that I'd do all I could to attend with my GTO. Fingers crossed.

Andrew

[andrewb70]

The freight company just showed up with my Richmond 6 speed. I will be heading out to Pigeon Forge tomorrow morning to get it installed and measure for the driveshaft. So far so good.

During my internet search for information about driveline vibrations I came across this very informative document published by Spicer. It is full of important information about driveline alignment, etc...

Spicer Tech Paper

Andrew

[TomT]

The freight company just showed up with my Richmond 6 speed. I will be heading out to Pigeon Forge tomorrow morning to get it installed and measure for the driveshaft. So far so good.

During my internet search for information about driveline vibrations I came across this very informative document published by Spicer. It is full of important information about driveline alignment, etc...

Spicer Tech Paper

Andrew

Hey Andrew, the Spicer Tech Paper is great - thanks for posting it!

[JEFFTATE]

The freight company just showed up with my Richmond 6 speed. I will be heading out to Pigeon Forge tomorrow morning to get it installed and measure for the driveshaft. So far so good.

During my internet search for information about driveline vibrations I came across this very informative document published by Spicer. It is full of important information about driveline alignment, etc...

Spicer Tech Paper

Andrew

Andrew , thanks for posting this article.
It is chocked full of relevant information.

[andrewb70]

Bill Howell and I installed the transmission last night without too much fanfare. I also measured for the driveshaft, which came out to be 55 3/4" from the face of the yoke where the CV mounts to the center of the u-joint on the pinion yoke. Speaking of pinion yokes, after much deliberation I decided that it would be wise to reset the preload on the pinion bearings. This is something that I am not comfortable tackling myself, but one of Bill's friends will handle the task. He has set-up several rear ends for Bill and knowing how hard Bill beats on his cars, I am sure he will do a fine job.

Today I am tackling some minor tasks. I need to pick up a new crush sleeve and pinion seal, an 0-ring for the back-up sensor, and ship the slip yoke back to the DSS so the new driveshaft can be balanced as an assembly.

Andrew

[gearbanger]

Hey man, I'll be in Pigeon Forge in the morning! Ther is a Pontiac car Show at the Music Road Hotel right behind the Ruby Tuesday. You should come by and/or I would love to come out to Bills and meet you guys and check out your car and all of Bill's stash!

I don;t mean to invite myself but I don't get a chance to meet to many pro touring guys hanging out in the Pontiac crowds.

[andrewb70]

Here are a few of pictures of the transmission and how the new slip yoke sits in the tunnel. You can see in the pictures where my old, 1350 yoke used to make contact with the body. Since the front driveline angle is of no concern, I can safely lower the back of the transmission slightly and get enough clearance for the CV joint.







Andrew

[DRJDVM's '69]

I'd be interested in the price of that thing too...

So the CV adds about $450.....so how much for the whole set up?

You can PM me if you dont want to post it

[andrewb70]

I'd be interested in the price of that thing too...

So the CV adds about $450.....so how much for the whole set up?

You can PM me if you dont want to post it

I don't mind posting. My complete shaft will run about $1450. That includes the modified Spicer yoke, and the CF tube. The CF tube adds substantially to the cost of the shaft. The tube alone runs almost $11 per INCH! An aluminum version would be less and coupled with the CV will provide the same benefits as the CF shaft.

Andrew

[andrewb70]

So far, everything is going according to schedule. Since I was replacing the pinion yoke, I chose to have the pinion bearing pre-load reset. That procedure went smoothly, so the rear end is all set.

The DSS made my driveshaft last week and it is on its way to me. The shipping weight on the driveshaft is 25 pounds with the packaging. I suspect the finished weight of the driveshaft is right around 20 pounds with the slip yoke. I would guess that is easily 15 pounds less than my previous driveshaft. While weight saving was a not a primary concern, it is certainly a nice side benefit. The lighter weight will also be gentler on all the bearings in the transmission and rear end. With some luck I should be taking a test drive on Monday evening. Wish me luck!

Andrew

[Motown 454]

Good Luck with the first ride. I'll be watching for your post on how it went. Sweet Ride.

[andrewb70]

The driveshaft arrived this evening and I got right on installing it.



It looks amazing. I will take more pictures tomorrow with a better camera.

Once the shaft was bolted up, I measured my driveline angles. Since the front u-joint has been replaced with a CV joint, the front working angle is now irrelevant. The rear angle needs to be as low as possible without being zero. I adjusted my rear control arms so the rear working angle is .5 degrees with the pinion slightly down. This way, under power the pinion will want to climb and the angle should get less or increase slightly in the other direction.

Test drive tomorrow.

Andrew

[Ron S]

Very cool stuff Andrew, I'm still amazed how far the automotive aftermarket has come, carbon fiber CV drive shaft, how exotic is that. Have you driven it yet? Vibration free?

[gearbanger]

When are you going to drive it?! I can't wait to hear what the deal is!