seanof30306

iTrader: (4)

OK, so I've been chasing a drivetrain vibration for years. It starts vibrating at 65-70 mph, and gets progressively worse as you go faster.

If you're driving at say, 80 mph, and push the clutch in and hold it, or put it in neutral, the vibration worsens.

Several years ago, I got an aluminum driveshaft out of a 2002 Camaro, had it balanced, and new Spicer universal joints put in. It didn't help the vibration.

There's a bearing noise in the tranny, so I took it to a transmission shop, they pulled it out and disassembled it. Nothing major wrong in the transmission, so they're putting a bearing and seal kit in it.

The guy said the driveshaft is not going far enough into the tailshaft; it's 1 1/2" too short.

I'm confused. I thought 4th gen driveshafts were a direct bolt-in? If the driveshaft is indeed too short, I know it's not the cause of the vibration. It was vibrating before the driveshaft, and the vibration was unchanged after it.

battman

iTrader: (2)

4th gen drive shaft is the same length, I've been running one for years in my 87 GTA.

Sounds like you need to focus on the rear diff now that you have eliminated the transmission and driveshaft..

seanof30306

iTrader: (4)

I was pretty sure the driveshafts were the same, too, yet there's the fact that the driveshaft is not going far enough into the transmission housing.

seanof30306

iTrader: (4)

Let's assume the guy who sold the driveshaft to me off of ebay had the application wrong.

I know it was a 4th Gen driveshaft, it had that balance ring thing on it. Are there any 4th Gen driveshafts that are shorter?

Are the V6 shafts aluminum?

battman

iTrader: (2)

Do you have adjustable lower control arms?

seanof30306

iTrader: (4)

That's a good thought. They're Lakewood LCAs; I honestly don't recall whether they're adjustable, or not.

Regardless, the rear wheels are centered in the wheelwells. If the LCAs were 1 1/2" too long, the wheels wouldn't be centered, would they?

seanof30306

iTrader: (4)

Does anyone know the correct length of a stock driveshaft? I can go down to the shop and measure it.

battman

iTrader: (2)

a lot of good information here, including length:

https://www.thirdgen.org/forums/tran...h-82-92-a.html

seanof30306

iTrader: (4)

OK, check this:

https://www.thirdgen.org/forums/tran...ml#post5907799

The 4th gen driveshaft I bought had the do-nut on it; like the one at the top in the pic.

The guy at the driveshaft shop I had balance the driveshaft said the donut was not necessary when you had them balanced, and sometimes caused problems. He recommended I leave it off; I did so.

With that donut off, with the driveshaft installed, would you not see more of the yoke? If so, could that be what the guys at the transmission shop are seeing, and thinking the driveshaft is too short?

battman

iTrader: (2)

I would say that's exactly why they are seeing more of the yoke if the dampening ring has been removed.

seanof30306

iTrader: (4)

OK, was the guy at the driveshaft shop correct, and the damping ring is superfluous on a balanced driveshaft, or is there a problem running this driveshaft without the damping ring?

battman

iTrader: (2)

Well they put it there to reduce vibration but I'm pretty sure its not the problem since you had the issue before the driveshaft swap.

seanof30306

iTrader: (4)

Yeah, I'm not concerned about the lack of the damping ring causing or contributing to the vibration. It was there before the driveshaft swap, and the vibration was unchanged afterwards.

I'm just wondering whether the additional yoke exposed by the ring being missing could be problematic. I would think not, I just want to be sure.

BrutalGTA

iTrader: (2)

Had the same issues in my 92formy. Turned out being front control arm bushings and strut plates. What is your driveline angle?