ed f

I had a torque arm installed by BMR while the installation was in process they noticed that my rear yoke had a lot of play.they thought that the universial was sized wrong.I brought the car in today to have them repair the play in my driveshaft.this was a 3 week time lapsed for there new lifts to be installed.the drive shaft was much worse.they took the driveshaft to a local driveshaft shop who also fabracates here in tampa.while doing the inspection there they noticed that the rear yoke on the drive shaft was very worn and could not be repaired.they offered to build me a 3 1/2 inch steel one.They told me that it would be no diffrence in vibration than a stock aluminum would.On my test ride home I felt no diffrence until I hit 85mph then I felt vibration alittle in the car but alot increase in the shifter ****.at 105mph I felt more in the shifter.The guys at BMR were very nice to me,they even gave me a ride home and picked me up when they were done.I am wondering since my driveshaft tail section had so much play in it was it hiding the road noise from my recent torque arm installation or is it because it is a steel drive shaft.I have been told by a couple of people that you can't use a steel driveshaft with a six speed without getting a lot of noise.Again I don't want to offend The guy's at BMR because they were so nice to me.please give me some advice.

jimmyblue

iTrader: (11)

Pinion angle is probably the biggest factor in driveline
vibe (presuming the 'shaft is balanced properly). If
the torque arm is nonadjustable then you get what
you get. Was the angle checked?

The heavier steel driveshafts seem to be thought to
be a prime cause of tailhousing cracking... more heft
behind those vibrations?

ed f

the guys at BMR did the install and it is adjustable,I'm sure they did the angle correctly.

ed f

well we took the steel drive shaft out and took it back to were it was made and they checked the balance they added a small amount of weight and they checked it again.we took it back to reinstall it and the car still shaked not so much in the lower speeds but once we reached speeds at 75 mph and it got worse as speed increased.I told bret from bmr that I would be happy with a stock aluminum one.So they orderd a new shaft from a local dealer and when they got it we took it to the driveshaft shop to get a universial that would connect to my 9".while installing the new driveshaft the guys at bmr was saying that this would not make any diffrence.once installed frank from bmr took it for a test drive with me riding shot gun.when we took off you could tell right a way the car was much smoother.we took it up to 105 mph and no vibrations,frank looked at me and smiled and said I don't feel any vibrations and I said me either.so if you are going to build a race car mainly then one of those steel ones are for you.those of us who drive on the street then we can stay with the aluminum.

KGSloan

good info

i hadn't heard this before but i've allways planned on staying with the stock shaft. i've never had a problem with it and you can get them used pretty cheap if you ever do happen to break one.

ed f

the john L company sells a 3 1/2 aluminum driveshaft for less than a new stock one.When this one goes that what I will buy.