Supershafts
The diameter is 3" x 52" mild steel. I am wondering if I am reaching critical speed . I found a shop here in Houston that can spin it to 5000 or more to check it. I'm taking it tomorrow. They will build an aluminum shaft for $525.00
Bad Drive Line Vibration
- Thread starter blewbyoutobad
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Supershafts
The diameter is 3" x 52" mild steel. I am wondering if I am reaching critical speed . I found a shop here in Houston that can spin it to 5000 or more to check it. I'm taking it tomorrow. They will build an aluminum shaft for $525.00
Supershafts
Well-Known Member
525 sounds high, unless they're selling you a billet yoke which you don't need, reusing your slip though thats as much as my AL truck shafts which are much larger.
Let me know what they find, but at 52" you are going to exceed its limits at 5900, I would agree and tell you as i do all my customers to upgrade to AL, you'll gain performance thru weight lost
Let me know what they find, but at 52" you are going to exceed its limits at 5900, I would agree and tell you as i do all my customers to upgrade to AL, you'll gain performance thru weight lost
Supershafts
Yes, for $600 I can buy a Mark Williams w/ the billet tranny yoke and new joints in 3.5" aluminum 6061 .125" wall. My shop will run the shaft tomorrow but I agree it's to mush RPM for the shaft. I was wrong on the length, it is 50.4" center to center of u-joint. One advantage buying the one from MW is I get rid of the 1310 series at the tranny and have 1350 all the way.
By the way thanks for your help. I visited your web site yesterday. Maybe you want to quote on a shaft?
Yes, for $600 I can buy a Mark Williams w/ the billet tranny yoke and new joints in 3.5" aluminum 6061 .125" wall. My shop will run the shaft tomorrow but I agree it's to mush RPM for the shaft. I was wrong on the length, it is 50.4" center to center of u-joint. One advantage buying the one from MW is I get rid of the 1310 series at the tranny and have 1350 all the way.
By the way thanks for your help. I visited your web site yesterday. Maybe you want to quote on a shaft?
Supershafts
Well-Known Member
Are you using a local shop for the shaft ? or MW ? I wouldn't worry about 1310 until your beyond 800 hp plenty, not saying its bad to upgrade to another series, but for 1310 all you need to do is use the better spl version.
Supershafts
Using a local shop for the balance only. They could only run it up to 3800, although the counter guy told me 5000 was no problem. I really want to see it run at 6000. They did add a small amount of weight to the front. The shop before them removed the weight from the front. Sounds all f'd up to me. No further than when I started this post. I'll install the shaft tomorrow, measure angles and see what happens. This time I am going to measure side to side offsets. I might as well throw more variables in the equation.
Using a local shop for the balance only. They could only run it up to 3800, although the counter guy told me 5000 was no problem. I really want to see it run at 6000. They did add a small amount of weight to the front. The shop before them removed the weight from the front. Sounds all f'd up to me. No further than when I started this post. I'll install the shaft tomorrow, measure angles and see what happens. This time I am going to measure side to side offsets. I might as well throw more variables in the equation.
Supershafts
Well-Known Member
There can be side to side which can make other problems, and most mopars have that issue with the motor shifted to the side more.
Try the shaft angle and adjust the pin to meet that angle underload if the shaft is still doing it.
The shop you left sounds as if they have a different machine and it spinning at 3500 is faster than most other machines.
since they found no bends i wonder if that was it, which weight did they add, was it like 1/16 or 1/8 thick ? and 1", 1.5" or 1.75" across ?
Try the shaft angle and adjust the pin to meet that angle underload if the shaft is still doing it.
The shop you left sounds as if they have a different machine and it spinning at 3500 is faster than most other machines.
since they found no bends i wonder if that was it, which weight did they add, was it like 1/16 or 1/8 thick ? and 1", 1.5" or 1.75" across ?
furyus2
Well-Known Member
When I ran my 64 Sport Fury at the track, I had just added an X pipe. When it hit around 4800 a strange vibration started up. I let off,but ran the car again and drove through the vibration.I think it was the X pipe. Do you have exhaust on the car? I also have a slight vibration at cruise speeds. Is it possible the axles can give similar vibrations as a driveshaft/drive angle?
This whole deal has been a learning experience. I learned that low speed vibrations are usually tire balance. I had that same symptom and changed tires and wheels and it went away; however the same high speed vibe was there. This is a street car but runs through the traps at 6500. I am installing the re-balanced drive shaft tomorrow to see what will happen. I will also check angles again.
Thanks for the input
Supershafts
The weight was where the other one was removed close to the tranny end. It looks like 1/8" and 1 1/2" long. Today I am going to put the car at height on stands without the rear wheels. I will mount my dial indicator to the floor and check the runout at different RPM's in high gear. I will first check pin angles and get that set. here's what I am thinking with the SS springs. Tranny is 3 down, set diff at 2 down so a 5 degree rise under load cancels. That's where I will start. If the shaft checks out I'll install the wheels and go for a ride.
Supershafts
Well-Known Member
You can't do that, unless you have 0.0 angle at both ends, only race cars can you check for run out.
This may not come across as why but i'll try and explain it. Angles on street cars are there to circulate needles and that circulates grease and expels the old and brings in the grease kinda stored in the joints cavity.
When the shaft turns the joint oscillates, as it oscillates it is pushing the shaft forward and back, and as it does that the shaft will lets say wobble.
This is something i have gone thru and do go thru still with many shops today, i tell them all the same thing, if you check shafts like that and i don't double check you, you will be putting a new shaft in every customers car you do that with.
If you had removed the angles like a race car you could check that, otherwise it's going to show something that isn't right, i had a shop call me and tell me a shaft i just did had .012 run out like the old one, and i told them that particular shaft has .002, i said if you bring it down because i know what i did and that im not sending my truck to pick it up and for a $50 bet i'll put that shaft in the machine and check it in front of you, if it's more than .002 the shaft is free.. I made $50 and had to show them what happens in a car.
There will always be some movement at the bushing also.
Stick it in and lets see what happened with the new bushing, balance and setting the pin to be at 0 with the shaft under load
This may not come across as why but i'll try and explain it. Angles on street cars are there to circulate needles and that circulates grease and expels the old and brings in the grease kinda stored in the joints cavity.
When the shaft turns the joint oscillates, as it oscillates it is pushing the shaft forward and back, and as it does that the shaft will lets say wobble.
This is something i have gone thru and do go thru still with many shops today, i tell them all the same thing, if you check shafts like that and i don't double check you, you will be putting a new shaft in every customers car you do that with.
If you had removed the angles like a race car you could check that, otherwise it's going to show something that isn't right, i had a shop call me and tell me a shaft i just did had .012 run out like the old one, and i told them that particular shaft has .002, i said if you bring it down because i know what i did and that im not sending my truck to pick it up and for a $50 bet i'll put that shaft in the machine and check it in front of you, if it's more than .002 the shaft is free.. I made $50 and had to show them what happens in a car.
There will always be some movement at the bushing also.
Stick it in and lets see what happened with the new bushing, balance and setting the pin to be at 0 with the shaft under load
Supershafts
More info from today's tests. Removed shims and now have the the diff at 2.5 degrees down. The tranny is at 2 down. I did a run-out test on the axles at 2000 RPM and saw .004" on both sides. I then did a run-out on the drive-shaft in high gear at 1K, 2K and 3K RPM's. See the video below. I still have the car setup so I can make more runs and videos. My next thing was to get the rear wheels balanced. I took them to NTB today and I have never seen anything like it. There are so many weights on those wheels if they were gold I'd be a millionaire. I'm taking them to Discount Tire tomorrow and have them checked before I install them and run the car. Let me know what you think.
[ame="http://www.youtube.com/watch?v=2YPJb5fsaNU"]M2U00050 - YouTube[/ame]
More info from today's tests. Removed shims and now have the the diff at 2.5 degrees down. The tranny is at 2 down. I did a run-out test on the axles at 2000 RPM and saw .004" on both sides. I then did a run-out on the drive-shaft in high gear at 1K, 2K and 3K RPM's. See the video below. I still have the car setup so I can make more runs and videos. My next thing was to get the rear wheels balanced. I took them to NTB today and I have never seen anything like it. There are so many weights on those wheels if they were gold I'd be a millionaire. I'm taking them to Discount Tire tomorrow and have them checked before I install them and run the car. Let me know what you think.
[ame="http://www.youtube.com/watch?v=2YPJb5fsaNU"]M2U00050 - YouTube[/ame]
Ok so my thinking is not right. Do I just go ahead and install the tires and road test it. Have a good laugh when you see the video. Thanks for teaching me right from wrong. Will the angles cancel now with 5 degrees up under load? I'm assuming that the SS spring move that much.
Supershafts
Well-Known Member
OMG that poor dial indicator... you're killing it...
I wouldn't make any call on seeing that, the shaft is moving forward and aft that is showing that.
Swap the wheels front to back, and take it for a ride.
5 degrees over the shafts angle ? or 5 degrees up from where it was.
The SS spring is supposed to have more spring at the power section which is the front and not have as much rise, it's supposed to be or act like a ladder bar, which is why you clamp the front section...
In that test did you feel anything, because if you didn't then either it was the balancing, or balancing and angle or you need to look at the wheels and drums....
.
I wouldn't make any call on seeing that, the shaft is moving forward and aft that is showing that.
Swap the wheels front to back, and take it for a ride.
5 degrees over the shafts angle ? or 5 degrees up from where it was.
The SS spring is supposed to have more spring at the power section which is the front and not have as much rise, it's supposed to be or act like a ladder bar, which is why you clamp the front section...
In that test did you feel anything, because if you didn't then either it was the balancing, or balancing and angle or you need to look at the wheels and drums....
.
Supershafts,
Yea I got a little carried away with that test. Thank goodness I have a spare indicator. I ran that test with no tires or drums and I did fell a small amount of vibration. The fronts are skinnys so I had my drag radials re balanced today before I did any road test. In one test I did run my new tires and wheels from my Dart and it was smooth until 5000. That's when I pulled the shaft and had it balanced a second time. I may be confusing the issue in my communication. I have read that SS springs rise 5 degrees under load so I have positioned the diff at 2.5 degrees down measured on the yoke with the drive shaft removed. The tranny is 2 down measured on the end of the output shaft. I removed the seal so I could get a good measurement. Does this setup sound correct before I run it?
Thanks for hanging in there with me.
Yea I got a little carried away with that test. Thank goodness I have a spare indicator. I ran that test with no tires or drums and I did fell a small amount of vibration. The fronts are skinnys so I had my drag radials re balanced today before I did any road test. In one test I did run my new tires and wheels from my Dart and it was smooth until 5000. That's when I pulled the shaft and had it balanced a second time. I may be confusing the issue in my communication. I have read that SS springs rise 5 degrees under load so I have positioned the diff at 2.5 degrees down measured on the yoke with the drive shaft removed. The tranny is 2 down measured on the end of the output shaft. I removed the seal so I could get a good measurement. Does this setup sound correct before I run it?
Thanks for hanging in there with me.
Supershafts
Well-Known Member
Run that and see how it is, just like you have it, just give me a idea what the shafts angle is also so i have a working angle.
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