Weird mostly speed-based vibration i cannot brain
#41
I have not verified that yet, though i would find it weird that that would be loose on two diffs. But it IS me, so i should just go ahead and expect lightning to strike twice.
#45
Cpt. Slow
iTrader: (25)
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,224
Total Cats: 1,145
I think I'll put our intern in the car, try a PPF alignment, try rotating the current rebuilt driveshaft 180*, try the new rebuilt driveshaft we have, try your old driveshaft sitting in our scrap bin, and then finally we have a carbon fiber drive shaft to try as well. Hopefully one of those things fixes it.
#46
I think I'll put our intern in the car, try a PPF alignment, try rotating the current rebuilt driveshaft 180*, try the new rebuilt driveshaft we have, try your old driveshaft sitting in our scrap bin, and then finally we have a carbon fiber drive shaft to try as well. Hopefully one of those things fixes it.
#47
Cpt. Slow
iTrader: (25)
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,224
Total Cats: 1,145
I don't know much about it, I think it's this one?
https://www.rallysportdirect.com/par...hoCZA0QAvD_BwE
owner of the car bought it mostly because we get a fairly sizable discount afaik.
https://www.rallysportdirect.com/par...hoCZA0QAvD_BwE
owner of the car bought it mostly because we get a fairly sizable discount afaik.
#49
Played with lots of dial gauge last night. Here's some general numbers. Wheel measurements are lateral runout, i did not have access to really check radial, though the one with the worst lateral looks pretty gross barrel-wise, radially.
Driver rear wheel in driver rear location: ~0.015"
Driver rear wheel in passenger rear location: ~0.012"
Passenger rear wheel in passenger rear location: ~0.005"
Passenger rear wheel in driver rear location: ~0.008"
Driver front wheel in driver rear location: ~0.008"
Driver CV: < 0.005"
Passenger CV: ~0.015"
Driveshaft: ~0.020"
The crappiest wheel is the one i'm 99% sure we had some issue getting to 13-14lbs road force, the other three we got in the 5-7lb range.
Driveshaft is pretty suspect, going from Curly's video above. I'll double check measurement by hand to make sure the base isn't moving at all (did it with car in gear in the air) before swapping driveshafts for funsies. I don't love the passenger CV either, but don't know what "spec" is.
Driver rear wheel in driver rear location: ~0.015"
Driver rear wheel in passenger rear location: ~0.012"
Passenger rear wheel in passenger rear location: ~0.005"
Passenger rear wheel in driver rear location: ~0.008"
Driver front wheel in driver rear location: ~0.008"
Driver CV: < 0.005"
Passenger CV: ~0.015"
Driveshaft: ~0.020"
The crappiest wheel is the one i'm 99% sure we had some issue getting to 13-14lbs road force, the other three we got in the 5-7lb range.
Driveshaft is pretty suspect, going from Curly's video above. I'll double check measurement by hand to make sure the base isn't moving at all (did it with car in gear in the air) before swapping driveshafts for funsies. I don't love the passenger CV either, but don't know what "spec" is.
#50
Played with lots of dial gauge last night. Here's some general numbers. Wheel measurements are lateral runout, i did not have access to really check radial, though the one with the worst lateral looks pretty gross barrel-wise, radially.
Driver rear wheel in driver rear location: ~0.015"
Driver rear wheel in passenger rear location: ~0.012"
Passenger rear wheel in passenger rear location: ~0.005"
Passenger rear wheel in driver rear location: ~0.008"
Driver front wheel in driver rear location: ~0.008"
Driver CV: < 0.005"
Passenger CV: ~0.015"
Driveshaft: ~0.020"
The crappiest wheel is the one i'm 99% sure we had some issue getting to 13-14lbs road force, the other three we got in the 5-7lb range.
Driveshaft is pretty suspect, going from Curly's video above. I'll double check measurement by hand to make sure the base isn't moving at all (did it with car in gear in the air) before swapping driveshafts for funsies. I don't love the passenger CV either, but don't know what "spec" is.
Driver rear wheel in driver rear location: ~0.015"
Driver rear wheel in passenger rear location: ~0.012"
Passenger rear wheel in passenger rear location: ~0.005"
Passenger rear wheel in driver rear location: ~0.008"
Driver front wheel in driver rear location: ~0.008"
Driver CV: < 0.005"
Passenger CV: ~0.015"
Driveshaft: ~0.020"
The crappiest wheel is the one i'm 99% sure we had some issue getting to 13-14lbs road force, the other three we got in the 5-7lb range.
Driveshaft is pretty suspect, going from Curly's video above. I'll double check measurement by hand to make sure the base isn't moving at all (did it with car in gear in the air) before swapping driveshafts for funsies. I don't love the passenger CV either, but don't know what "spec" is.
#52
Elite Member
iTrader: (5)
Join Date: Oct 2011
Location: Detroit (the part with no rules or laws)
Posts: 5,677
Total Cats: 800
After watching your video on YouTube. It makes me wonder how much of that runout is just due to the rotor to wheel surface. How true is the hub and rotor? How much is it being amplified by the distance from center?
Need more data!
Need more data!
#56
Bump
I'm having the same problem. I have replaced
The wheels and tires roadforce balanced to 10lbs
Axles
Diff (open to 3.9)
All the bushings
Alignment
Motor mounts (OEM)
And aligned the ppf.
The transmission is pretty quiet and shifts well and I have a small whine from the poly bushings at the diff. (normal)
My driveshaft feels good at the u joints but I have not checked run out. My car was in a small rear end accident that snaped the diff housing. I'm wondering if the PO tried to drive it with the diff hanging and it beat up the DS.
Did you ever replace your DS?
I'm having the same problem. I have replaced
The wheels and tires roadforce balanced to 10lbs
Axles
Diff (open to 3.9)
All the bushings
Alignment
Motor mounts (OEM)
And aligned the ppf.
The transmission is pretty quiet and shifts well and I have a small whine from the poly bushings at the diff. (normal)
My driveshaft feels good at the u joints but I have not checked run out. My car was in a small rear end accident that snaped the diff housing. I'm wondering if the PO tried to drive it with the diff hanging and it beat up the DS.
Did you ever replace your DS?
#57
Bump
I'm having the same problem. I have replaced
The wheels and tires roadforce balanced to 10lbs
Axles
Diff (open to 3.9)
All the bushings
Alignment
Motor mounts (OEM)
And aligned the ppf.
The transmission is pretty quiet and shifts well and I have a small whine from the poly bushings at the diff. (normal)
My driveshaft feels good at the u joints but I have not checked run out. My car was in a small rear end accident that snaped the diff housing. I'm wondering if the PO tried to drive it with the diff hanging and it beat up the DS.
Did you ever replace your DS?
I'm having the same problem. I have replaced
The wheels and tires roadforce balanced to 10lbs
Axles
Diff (open to 3.9)
All the bushings
Alignment
Motor mounts (OEM)
And aligned the ppf.
The transmission is pretty quiet and shifts well and I have a small whine from the poly bushings at the diff. (normal)
My driveshaft feels good at the u joints but I have not checked run out. My car was in a small rear end accident that snaped the diff housing. I'm wondering if the PO tried to drive it with the diff hanging and it beat up the DS.
Did you ever replace your DS?
#58
Hi, sorry. I did not replace my driveshaft yet. It's first up on the small laundry list of things to do when Spring cleaning hits. I had too many other irons in the fire to really give this car the attention it deserved this past year.
But like The Monkey Dude Himself, i'm pretty confident it's the driveshaft, which is why i'm going to take all 4 of mine to a shop in the next month or so and have them tell me which two are best and balance them.
But like The Monkey Dude Himself, i'm pretty confident it's the driveshaft, which is why i'm going to take all 4 of mine to a shop in the next month or so and have them tell me which two are best and balance them.
#59
I've been thinking about getting a shaftmaster drive shaft. The price is nice and I had thier alluminum one in my 6g 5.0. I'll probably go with a steel one for the Miata. With how much nvh the car has naturally I really would hate to get an alluminum ds and pick up more nvh. The drive shaft is pretty much is the last thing on my list of possible causes.