Driveshaft length with Moser 9"
06-08-2007, 04:48 PM
#1
12 Second Club
Thread Starter
Join Date: May 2007
Location: Renton, Washington
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Driveshaft length with Moser 9" Hey Guys -
I've had a Moser 9" installed in my car for Since Feb 06 (2500 miles ago). I've had a vibration coming down my center console pretty much ever since. I've had a wheels rebalanced, driveshaft rebalanced (he said it was definately off), and my torque arm adjusted, but still have a bad vibration which is getting much worse.
Today I took it to a Drivetrain/Rear End Specialist who said that my driveshaft is too short, but I'm running the stock driveshaft and from everything I read they should be the same length. They quoted me about $1K to make a new driveline with 1350 yokes, replace my tranny bushing and my pinion seal (both which are now leaking). He also said that it looks like my rearend is moving forward and backwards, most likely due to improper bolt size in the Control Arms.
My Questions....
Is there any reason why my driveline would be too short with a Moser 9" and lowered suspension (Eibach Sportline currently in the back)?
Is it possible that balancing the driveline corrected the problem, but since it's been wobbling so long I need to replace the Rear yoke or Tranny output shaft causing the problem?
Why else would cause this vibration?
Thanks in advance!
I've had a Moser 9" installed in my car for Since Feb 06 (2500 miles ago). I've had a vibration coming down my center console pretty much ever since. I've had a wheels rebalanced, driveshaft rebalanced (he said it was definately off), and my torque arm adjusted, but still have a bad vibration which is getting much worse.
Today I took it to a Drivetrain/Rear End Specialist who said that my driveshaft is too short, but I'm running the stock driveshaft and from everything I read they should be the same length. They quoted me about $1K to make a new driveline with 1350 yokes, replace my tranny bushing and my pinion seal (both which are now leaking). He also said that it looks like my rearend is moving forward and backwards, most likely due to improper bolt size in the Control Arms.
My Questions....
Is there any reason why my driveline would be too short with a Moser 9" and lowered suspension (Eibach Sportline currently in the back)?
Is it possible that balancing the driveline corrected the problem, but since it's been wobbling so long I need to replace the Rear yoke or Tranny output shaft causing the problem?
Why else would cause this vibration?
Thanks in advance!
06-08-2007, 06:24 PM
#2
if the bolts are NOT the correct size fix this FIRST, if the rear is shifting back and forth like you said it ia a part of the problem that needs to be corrected ASAP, also a stock driveshaft will work fine with a moser 9, after that i would look at the condition of your tires i chased vibrations in my car for ever and replaced everything and when i replaced my TIRES as they were beat the vibrations ALL went away, these 17 in tires get to a point where they go to ****, but look fine that my experience take it for what its worth,
try swapping wheels/tires with someone for 1 hour and see if the vibrations go away before spending $$$$
try swapping wheels/tires with someone for 1 hour and see if the vibrations go away before spending $$$$
06-08-2007, 07:29 PM
#3
12 Second Club
iTrader: (24)
Join Date: Jan 2005
Location: Olathe, KS
Posts: 562
Likes: 0
Received 0 Likes
on
0 Posts
thechef is right. I had annoying vibration on my 3rd gen. Even though the tires were balanced they wound up having other issues. After replacing tires everything was fine.
I had some insane vibrations after swapping my 9" in. Here's what it took to fix mine, in no particular order;
- New driveshaft. Stock one wound up being slightly bent. It turns out the stock shaft doesn't like to dead hook 5K clutch drops on sticky tires.
- I had to take precise (as I possibly could) measurements, then double/triple check that the rear end was centered/squared under the car.
- Pinion angle, pinion angle, pinion angle. There are different methods that get preached and used for this. In fact many of the experts disagree. I adjusted mine experimenting with the various methods and adjusted it until my vibration settled down.
$1,000 for a drive shaft is insane!!! You can buy the carbon fiber one that's made for our cars for less than that the last time I checked. I'm running the PST aluminum shaft in mine and have had ZERO issues. DLS, Denny's and several other sponsors sell great driveshafts for half of that or less.
One question. Is your torque arm still mounted to the tranny, or is it a body mount?
I had some insane vibrations after swapping my 9" in. Here's what it took to fix mine, in no particular order;
- New driveshaft. Stock one wound up being slightly bent. It turns out the stock shaft doesn't like to dead hook 5K clutch drops on sticky tires.
- I had to take precise (as I possibly could) measurements, then double/triple check that the rear end was centered/squared under the car.
- Pinion angle, pinion angle, pinion angle. There are different methods that get preached and used for this. In fact many of the experts disagree. I adjusted mine experimenting with the various methods and adjusted it until my vibration settled down.
$1,000 for a drive shaft is insane!!! You can buy the carbon fiber one that's made for our cars for less than that the last time I checked. I'm running the PST aluminum shaft in mine and have had ZERO issues. DLS, Denny's and several other sponsors sell great driveshafts for half of that or less.
One question. Is your torque arm still mounted to the tranny, or is it a body mount?
06-08-2007, 08:43 PM
#5
12 Second Club
Thread Starter
Join Date: May 2007
Location: Renton, Washington
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
The estimate includes the price of making a custom 3" driveshaft, 1 Slip Yoke, 2 Weld Yoke (?), 2 U-Joints, Pinion Yoke (3150) and U-Bolts, Pinion Seal, Crush Sleeve, Lube, and all labor and balancing. I have broke down the price for the actual driveshaft itself which is only about $400, the rest of it is replacing seals that are leaking and labor. Which really doesn't seem that bad to me for it being custom measured. However, if I were to get a new driveshaft would probably buy one of the PST's.
Unfortunatly, my tranny still...
All 4 tires are brand new and have been tested for any runout, they are Proxes T1R 295x35x18 in the rear. I'm doubting that's the issue, but for 10 minutes of work it's definately worth ruling out right away!
One question. Is your torque arm still mounted to the tranny, or is it a body mount?
after that i would look at the condition of your tires i chased vibrations in my car for ever and replaced everything and when i replaced my TIRES as they were beat the vibrations ALL went away, these 17 in tires get to a point where they go to ****, but look fine that my experience take it for what its worth,
try swapping wheels/tires with someone for 1 hour and see if the vibrations go away before spending $$$$
try swapping wheels/tires with someone for 1 hour and see if the vibrations go away before spending $$$$
06-08-2007, 09:13 PM
#6
The stock length driveshaft should work with a Moser rear. If it was too short, I'm not sure how it could cause a vibration unless the splines became twisted. If the splines get twisted, the driveshaft won't be free to travel back and forth to compensate for suspension travel. Bob
