[HWYSTR455]

I'm watching curiously, and impressed with the parts selection. Looking forward to hearing about the results! Know how frustrating stuff like this can be first hand!

.

[gearbanger]

Okay, well, you were saying that it got alot better and still vibrated in 6th a little. I hope the tranny redo will solve it. Any chance you will give it a try with the original driveshaft before swapping to the new CV shaft?

[andrewb70]

Originally Posted by gearbanger

Okay, well, you were saying that it got alot better and still vibrated in 6th a little. I hope the tranny redo will solve it. Any chance you will give it a try with the original driveshaft before swapping to the new CV shaft?

My old yoke had more run out than was desirable. I forget the exact numbers, but they are listed earlier in this thread. I swapped to a different yoke and the runout was better, but the vibration persisted, although at a lower level. I may be able to try the old shaft as a fall back if the new shaft is not ready for my planned road trip. When my transmission failed the slip yoke got damaged as well. So for me to install the old shaft I would have to swap the slip yoke. I would rather not incur that extra expense if I don't have to. I seriously doubt that the transmission was the cause of the vibration. The vibration was there even when the transmission was new.

Andrew

[andrewb70]

Originally Posted by HWYSTR455

I'm watching curiously, and impressed with the parts selection. Looking forward to hearing about the results! Know how frustrating stuff like this can be first hand!

.

Thanks! I am looking forward to the results as well. Frustration can be a very powerful motivator. In my search for answers I ran across the attached PDF from Spicer. It has some very interesting information on page 9 and 10 about compound angles.

http://www.pro-touring.com/%7Eandrew...11-1-HVTSS.pdf

If the rear end in my GTO is offset it may not cause a vibration by itself, but it can certainly contribute to the compound working angle.

Andrew

[6 Grrrs]

Originally Posted by andrewb70

Thanks! I am looking forward to the results as well. Frustration can be a very powerful motivator. In my search for answers I ran across the attached PDF from Spicer. It has some very interesting information on page 9 and 10 about compound angles.

http://www.pro-touring.com/%7Eandrew...11-1-HVTSS.pdf

If the rear end in my GTO is offset it may not cause a vibration by itself, but it can certainly contribute to the compound working angle.

Andrew

Nice find and great read.

[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

[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

[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

[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 not 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

[Motornoggin]

That looks pretty dang cool.

[andrewb70]

Hello Everyone...

I have to apologize for the less than timely update to this thread. It has been a very busy week and a crazy few days. As promised here are a few more pictures of the CV driveshaft from the DSS.





On Wednesday I headed out from Pigeon Forge to Bowling Green, KY. It was the most pleasant drive I have ever done in my GTO. The vibration that I was experiencing before is now completely gone. The car was smooth as glass at all reasonable highway speeds. I ran it up to about 90 and there were no noticeable driveline vibrations that I could detect.

From BG, KY I headed to Chicago to pick up my son. On Friday morning we headed out to the Lane Automotive Motor State Challenge. My goal for attending the event was to enjoy some time with my son and reconnect with some car friends. However, I couldn't resist taking my car on the Gingerman race track. I also figured that some track time will really test my newly rebuilt transmission and the new driveshaft. Gingerman has two long straights where the car can be easily taken up to over 120 mph.

On Saturday we headed to the track, passed tech, and were ready to go. I ran three sessions with my son riding shotgun and managed to get into the to 16 in the Pro-Touring class which consisted of any vehicle older than 30 years. My best time was 1:55.xx At high speeds the driveline was super smooth and the car performed very well. No drama, no puking fluids, 200 degree water temp.

I will post more later...

Andrew

[gearbanger]

Dude, that is awesome! I am so glad it fixed it. Shooting the money shotgun at it can be scary, but if it fixes it then it doesnt really matter what it cost, it's fixed!

[Motornoggin]

Good news! Glad you had a good time my friend!

[andrewb70]

Hello Everyone,

I thought I would give everyone an update as to what I have been up to for the last week. As I posted earlier, I spent Father's Day weekend with my son at the Motor State Challenge. We had a great time and the car performed very well.

On Monday (6-20-11), I picked up my daughter and we headed west. Our mission was to spend some quality time together and visit some of my friends. It also gave us an opportunity to see some of the most breathtaking scenery in the world. Monday evening we arrived safely in Lincoln, NE where we spent the night at my friend Brian's house. Brian is a great guy and he is actually the person that did the body work and paint on my car.

Tuesday (6-21-11) morning we continued our journey west and made our first scenic stop. Well, perhaps the word "scenic" is not entirely accurate to describe Buford, WY, but the town is certainly unique. Buford, Wyoming is the highest town on I-80 between San Francisco and New York City. It also has the distinction of being the smallest town in the US, with a population of 1. Word has it that it used to be a population of 2, but the father of the man that lives in town passed away.



From Buford, WY we traveled a little further west and reached our final destination, Laramie, Wyoming, where my good friend Rory lives. I've known Rory since high school and he is a dear friend and a fellow car and motorcycle enthusiast. Rory's current car is a very neat 1966 Corvair Corsa. The Corsa has a turbo charged engine that makes 180HP. It's a very clean, low mileage (25K miles) car that was repainted (by Brian) and has been slightly lowered. Very cool car! (fukk Ralph Nader. These cars are super cool.)



On Wednesday (6-22-11), my daughter and I made our first trip over the Rocky Mountains. We headed west and reached the town of Centennial, WY. While Centennial is 100 times the size of Buford, it is still no more than a clearing in the road and the last stop before heading over Snowy Range.



On our way up over Snowy Range we had a chance to make some stops at various scenic outlooks. The Rockies have received an exceptionally high snowfall this year and there is still much snow on the ground at higher elevations. In fact, Rory told me that as recently as two weeks before our visit, Snowy Range got over 6 inches of fresh snowfall.





As we climbed higher in elevation, the snow pack got higher and more dense. We eventually made it over Snowy Range pass and had lunch in Saratoga, WY. The North Platte river runs through Saratoga, and it was very high and moving very fast. Quite an amazing sight to see.

On Thursday (6-23-11) Rory took the day off and we headed to Estes Park, Colorado. Rory and I graduated from Park High School in Estes Park and he many of his close family reside there. Estes Park is a little tourist town with a population of about 5,000 in the winter and 50,000 in the summer. Many people have summer homes there, and millions of people pass through every summer on their way to Rocky Mountain National Park. We headed up Trail Ridge Road which connects Estes Park with Grand Lake. About a third of the way up we stopped at an outlook point to take some pictures. The scenery is simply breathtaking.



Don't try this with your carbureted muscle car kids! This picture was taken at an altitude of about 9,000 feet. Modern day fuel with ethanol is prone to vapor lock in low pressure fuel systems. I doubt that my car would have made it up that high if it had a carburetor. My wideband O2 sensor showed a constant 14.0-14.9 AFR the whole way up.





My daughter and Rory were having a good time, goofing off. I think the thin air was getting to them....LOL



The drive over Trail Ridge road is even higher than Snowy Range. Trail Ridge road is the highest continuous road in the USA, reaching a peak of over 12,000 feet! The snow pack on the way up was even higher than Snowy Range.



Passing just over the peak and heading down the western slope there is a little store that sells all sorts of souvenirs and trinkets.



We headed down the western slope of the Rockies and reached the town of Grand Lake, CO. From there we headed to Walden, CO and eventually towards the road to Saratoga, WY. We crossed back over Snowy Range and ended up in Centennial, WY where I took the following picture.



Before heading back (6-24-11) to Lincoln, NE, I snapped the following picture. It shows all the bugs we killed on the day before.



We spent the night at Brian's house again and headed back to Chicago, IL on Saturday (2-25-11). While visiting Estes Park, Rory's father suggested that we make a stop at the Strategic Air and Space Museum, which is located between Lincoln and Omaha, NE. I am so glad we went. I always loved airplanes and actually wanted to be a pilot when I was younger. We pulled up and were greeted to the sight of several Air Force rockets.



Once we stepped inside the front doors, this is what greeted us at the door!



It was simply amazing to see the SR-71 Blackbird in person. It's hard to imagine that this plane could fly from New York to London in 1 hour and 55 minutes. In fact, the true top speed is still classified!

The museum is full of really neat planes, helicopters, and space craft. I am sure that many of you eagle eyed people will spot numerous important aircraft in this picture:



Overall this was an amazing trip. The opportunity to drive my favorite car and share quality time with my daughter was simply amazing. She will be 11 in October and was a trooper in the car. I plan on doing similar road trips in the summer with my kids for as long as they will hang out with me.

My speedometer and consequently my odometer were not working for this trip, but using Google maps I was able to get a rough estimate of the total distance that I traveled. Here is a break down of the mileage. Keep in mind that this doesn't include minor trips here and there and the racing miles around Gingerman Raceway.

Wednesday 6-15-2011
Pigeon Forge, TN to Bowling Green, KY – 244

Thursday 6-16-2011
Bowling Green, KY to Geneva, IL – 439

Friday 6-17-2011
Geneva, IL to Watervliet, MI – 141
Cruise -- 50

Saturday 6-18-2011
Gingerman Raceway 15 racing laps = 30 racing miles

Sunday 6-19-2011
Watervliet, MI to Geneva, IL – 141

Monday 6-20-2011
Geneva, IL to Lincoln, NE – 486

Tuesday 6-21-2011
Lincoln, NE to Laramie, WY – 490

Wednesday 6-22-2011
Laramie, WY to Saratoga, WY – 79
Saratoga, WY to Laramie, WY - 79

Thursday 6-23-11
Laramie, WY to Estes Park, CO – 106
Estes Park, CO to Grand Lake, Co – 47
Grand Lake, CO to Walden, CO – 71
Walden, CO to Riverside, WY – 49
Riverside, WY to Centennial, WY – 50
Centennial, WY to Laramie, WY – 30
Total – 353 miles

Friday 6-24-2011
Laramie, WY to Lincoln, NE – 490

Saturday 6-25-2011
Lincoln, NE to Geneva, IL – 486

Sunday 6-26-2011
Geneva, IL to Pigeon Forge, TN – 601

Grand Total = 4,379

At the end of my road trip I traveled nearly 4,400 miles in my GTO. The car ran beautifully and without any high speed vibrations. Both Nebraska and Wyoming have 75 mph speed limits on the highways, which means going 85 mph is not a huge deal. The GTO does 85 mph at about 2,400 RPM and is smooth as silk. I want to thank the following people and companies for making this trip possible:

Bill Howell - Without your generous help and hospitality, this trip would not be remotely possible.

Rory and Brian - You are my dear friends and I appreciate everything you two have done for me over the years.

The Driveshaft Shop - Without Frank's innovation and attention to detail, my car would still be shaking itself apart at speeds over 75 mph.

Global West - Their various suspension components have taken a licking and kept on ticking.

ATS - Their spindles are amazing and allow me to use the very effective, OEM quality C6 Z06 brakes on the front.

GM - The LSx engine family is amazing and makes road trips like this possible. Without the modern engine and EFI my car would never have traveled over the high altitudes or gotten more than 20 MPG on the trip.

Mike Norris - Mike's tuning smoothed out a few rough spots in my tune and made the journey trouble free.

Detroit Speed and Engineering - The Midwest is plagued by severe summer storms. DSE's modern windshield wiper system kept my windshield clean and allowed me to navigate safely through the inclement weather.

In the end, I want everyone to take trips in their favorite cars. We spend years and thousands of dollars building our dream cars, and unfortunately many end up sitting pretty in the garage without having a chance to do what they were built to do: DRIVE!!!

Andrew

[Motornoggin]

Isn't that museum cool? One of my favorite places! I had a great time my friend! Thanks for coming out!

[andrewb70]

Originally Posted by Motornoggin

Isn't that museum cool? One of my favorite places! I had a great time my friend! Thanks for coming out!

It was really great to see you too, my friend!

The good folks at Lane Automotive had a photographer during the entire event and I want to thank him for taking these pictures at Gingerman.





I really love going on a road course and not just an autocross. Autocrosses are OK, but nothing compares to being on a technical road course, like Gingerman, and learning the proper line around every corner. I wish that I would have taken an experienced driver along on one of my sessions. I have no doubt that my time would have improved by seconds. In fact, I was given a quick tip on how to successfully navigate one of the corners and that tip alone was worth 2 seconds on my subsequent session.

Good times...

Andrew

[pont3]

I am SOOOO Jealous of you! Someday, I, too, will take unlimited trips in my favorite GTO ('72). My "new" GTOs have convinced me the merits of the LS engines and my "old" GTO is in line for one. Thanks for sharing.

[andrewb70]

Originally Posted by pont3

I am SOOOO Jealous of you! Someday, I, too, will take unlimited trips in my favorite GTO ('72). My "new" GTOs have convinced me the merits of the LS engines and my "old" GTO is in line for one. Thanks for sharing.

I am glad to be of an inspiration. If people actually want to drive their classic muscle cars, Pontiacs or whatever, modern EFI engines are hard to beat. If people want to cruise down to the car show and sit around polishing their shift knobs, then old technology and carburetors work just fine.

Andrew

[stobin]

Really great thread Andrew. Love the idea of taking your daughter for a summer trip in the car. I have the same aspirations with my 14 y/o daughter in the Grand Am, which is now in the process of receiving a 440 inch LS motor thanks in part to you and your GTO story.

[HWYSTR455]

Originally Posted by stobin

...the Grand Am, which is now in the process of receiving a 440 inch LS motor ....

Ok, you got my attention! Curious, what were some of the other motivators there?

Andrewb70 - Curious about the track time too. One thing that plagues the 68-72 A-body is the 'oscillation' in the rear suspension that occurs under hard power around a sweeping turn at speed. Have you experienced this? It's present in every A-body I've ever driven (hard), except one that had a truck-arm suspension. It's a hairy ride when it happens, and you KNOW it's happening...

.