Thread: Project Sebring GT Spyder

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Those removable covers are definitely a time saver. You hope you never have to use them but it's so sweet when you have to. Nice work on fixing those holes.

As promised next up was making up a driveshaft. I needed a driveshaft in order to locate the safety loops.



This is the original driveshaft that came in the car. It's obvious from the oversize yoke and goober welds that this end didn't quite fit the tubing. Someone doctored on the yoke in an attempt to get it to fit. I didn't want to trust it to hold the potential power of the LS engine, so I had to build a new one.

I had started not to get the driveshaft that was in the Explorer that the rearend came out of since I had several driveshafts that I have collected over the years, but I was glad I did. The Explorer shaft had two good yokes that fit 3” tubing and took Spicer 1330 size u-joints. The 1350 size is stronger, but at over 1600 pound feet of torque rating, the 1330 will be more than enough to destroy the transmission in theory.

The only real downside to the 1330 u-joint is that it's design life is shortened if it is ran more than 5000 RPM for extended periods. With the 3.55 gears I plan to start with, that limits my top long distance cruising speed to around 110 MPH. Dang, I guess when I'm crossing Europe on the autobahn, it will have to be a little slower than most other super cars!



The Explorer shaft was 3 ½” OD in the middle and swaged down to 3” at the ends. Pretty common stuff for Detroit, but not really able to be correctly shortened more than a few inches without buying at least one larger yoke. I looked through the small pile of driveshafts that I had and found one that was straight 3” OD. I could combine the straight tubing with the Explorer ends and come up with something that was workable.









I did have to buy a transmission yoke that fit the T56 and took a 1330 u-joint. Turns out that is not a common combination as most folks opt for the larger 1350 joint. I could only locate the 1330 size in a forged 4130 part from Sonnax. It wasn’t cheap, but it is probably strong enough to destroy the transmission with no damage to the yoke. In the end, it was still much cheaper for me to use the stuff I had on hand and buy the yoke, than buy everything to fit the transmission yoke I had.

I used to build and shorten driveshafts regularly when I worked in the oilfield service shops. We didn't do a lot of hot rod stuff. Most of it was heavy oil field service trucks and 18 wheel log haulers. The regular car stuff we did was for jacked up 4 wheel drives and Jeeps. We never balanced them since we didn't have the equipment. We just built them as straight as possible and sent them out the door. This shaft turned out pretty good. It’s very straight and this was verified with a dial indicator after it was installed on the car. It will most likely work fine for normal driving as is, but I will get it balanced eventually.

I decided from the beginning of this project that I would install driveshaft safety loops. This car should have the potential to be fast enough to be required to have at least one on an NHRA track, but that's not the main reason for them. The driveshaft will be spinning inches away from mine and my wife's hips and thighs separated only by a single thickness of 14 gauge sheet metal. I have been known to hammer on my toys occasionally and the last thing I want to think about is an errant driveshaft deciding to crash the party. A spinning and flopping driveshaft could cut through the floor and tunnel almost like it wasn't there. I had them on my T bucket for the same reason.





The safety hoops started out as a piece of 5" tubing that I pack ratted from somewhere. It has a 3/8" thick wall. I cut off a couple of 2" long pieces and split them in half.





Then I welded in some 2" x 3/8" flat bar to form the loop. I tig welded the inner welds just for appearance and mig welded the main parts. After some grinding, they were passable.

I have to say that I probably wouldn't make loops like this again unless I had to. They are plenty strong, but I think it would have been faster to just make a quick bending form on my welding table, break out the rosebud tip to heat and forge them from a single piece of flat bar. I've done them both ways now and this way just seemed to be more work. Live and learn.

It's pretty cool that you can make your own drive shaft, I would never even try that.

A wise move.
A broken driveshaft is not a pretty sight.
I had an old unroadworthy A5 Bedford truck that I used solely on the farm. I sold it to Tom Reddin, a good mate from three roads over. He came over one arvo to A frame it home. He rang me an hour or so later.
"That truck you sold me, well it's not going to be a truck now; it's going to be a trailer."
Oh?
It turned out that the driveshaft had broken at the gearbox and had beaten the cab to death.
The damage had to be seen to be believed, and this was at the slow speed of perhaps 30mph. Had anybody been in the cab when it broke they would most definitely have been very severely injured.
It was just good luck that it broke under those particular circumstances. Quite frightening really to think of what could have happened.

So yes; a wise move on your part.

As always, top notch work from your shop! And thanks for sharing the pics/write-up.

I've done a couple shafts like you, never had them balanced and they never gave a lick of trouble.

Very nice work. Another instance where having a lathe saves the day. Nice loop too! I've made several for pulling trucks. Back then steel was the norm now everyone has to have aluminum because the weight savings is tremendous.

Well folks, I have been putting this post off, but felt like I needed to update everyone on things that have been going on.

My dad passed away on Father's Day. I had gone to visit him in the nursing home and he was complaining of stomach pain that quickly turned into severe chest pain. Long story short,15 minutes later, he was gone. He was 83.

Much of my last month has been spent helping my mom with all the various things that have to be done when someone passes. Dad wanted to be cremated and there was a memorial service at the church. There will be a military graveside service next weekend. Mom also wants to take some of his ashes to be spread at a place that he was very fond of. That will be a trip of several days in the near future.

I wanted all of you folks that have been following this project to know that my updates will be thin for awhile. I've been tinkering around in the shop, but not much is getting done. I just can't seem to get back in the groove. Family is way more important than this car.

Sorry to hear of your and your family's loss.
Our thoughts and condolences are with you.

Chris and I offer our condolences Mike..
Of course you are right, Family is way more important. Tend to yours and when you're ready c'mon back and say hello.

My thoughts and condolences also.

"..... Family is way more important than this car......"


Your priorities are exactly in the right place.



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Thanks guys. Dad and my grandfather were the 2 men that taught me much of what I know about building things. Most important is they taught me not to be afraid to try something and fail, but learn from your mistakes. Dad was the builder and my grandfather was the hot rodder (although he might not have like that handle). They are both gone now and I miss them both. I'm hoping that one of the grandkids will take an interest in this stuff so I can pass it along.

Originally Posted by Hotrod46

I'm hoping that one of the grandkids will take an interest in this stuff so I can pass it along.

I have nobody in my family that has any interest in anything except video games and cell phones, so I hang around on forums like this one to teach strangers about things mechanical. Thanks to you Mike and to others who try to keep the hobby going. I'm sorry to hear about your father. May he rest in peace. Richard.
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Mike very sorry for your loss. Like everyone else now is time for family and grieving. When my mom passed we also took part of her ashes to a special family place. There is still a huge void that only she was able to fill 22 years after her death. It seems I too have no one to pass my mechanical/building skills onto. Instead I share my projects with like minded friends and here when I actually do something! A friends father passed away last spring. Last weekend he had a big get together and did a celebration of life gathering. By waiting a few months they were able to get people who otherwise wouldn't have be able to attend share stories about his life and send pictures. It was an amazing salute to his father and a great way for people to learn about a fantastic man's life thru shared funny stories.

Sorry for the loss of your dad, sounds like he was a great guy.