Drivetrain vibration

[ViperPete]

hey all

So I recently installed the T56 and lowered the truck.

For the last 400 miles or so I haven't been past 80 mph or so because I have not been driving on the highway. No vibrations. Feels like it's factory.

Then, on the highway I was returning home from Universal Studios and beginning at 95 mph, most intense at 99 and gone at 102- there is a drivetrain vibration. It is only felt/heard when under acceleration. Not when I let off the gas.

Draining and replacing the tranny fluid today anyway because I hit 500 miles on the tranny.

Any ideas?

 

[VPRPWRD]

Don't drive that fast, you must be crazy to drive at speeds like that!

 

[BigRed460]

hey all

So I recently installed the T56 and lowered the truck.

For the last 400 miles or so I haven't been past 80 mph or so because I have not been driving on the highway. No vibrations. Feels like it's factory.

Then, on the highway I was returning home from Universal Studios and beginning at 95 mph, most intense at 99 and gone at 102- there is a drivetrain vibration. It is only felt/heard when under acceleration. Not when I let off the gas.

Draining and replacing the tranny fluid today anyway because I hit 500 miles on the tranny.

Any ideas?

I have been chasing this vibration for a few months, not a clue. Vibrates like hell from 90-105, and changing gear doesnt help. I think my drive shaft is fubar. (I have a steal one) it. Mine gots worse and worse, I figured when I get it back together I'll look at it more.

 

[ViperPete]

I have been chasing this vibration for a few months, not a clue. Vibrates like hell from 90-105, and changing gear doesnt help. I think my drive shaft is fubar. (I have a steal one) it. Mine gots worse and worse, I figured when I get it back together I'll look at it more.

Mine is a brand new aluminum shaft... :dontknow:

 

[BigRed460]

Mine is a brand new aluminum shaft... :dontknow:

Mine is brand new also...

 

[JRSVIPR]

hey all

So I recently installed the T56 and lowered the truck.

For the last 400 miles or so I haven't been past 80 mph or so because I have not been driving on the highway. No vibrations. Feels like it's factory.

Then, on the highway I was returning home from Universal Studios and beginning at 95 mph, most intense at 99 and gone at 102- there is a drivetrain vibration. It is only felt/heard when under acceleration. Not when I let off the gas.

Draining and replacing the tranny fluid today anyway because I hit 500 miles on the tranny.

Any ideas?

http://www.vtcoa.com/forums/f8/pinion-angle-54679/

Go to the search button for more info.

 

[JTS VENOM PERFORMANCE]

the length of the shaft at speeds will cause a whip affect,
imagine holding a string end to end, then twirl it, the center will whip outwards

same as with a driveshaft, many chevys have tossed theres on a dyno because of this, the same reason we haven't offered a single
Our driveshaft builder says there only safe up to about 118mph

reaching those speeds the shaft may want to start wobbling in the center.
be careful and keep an eye on the joints and retaining bolts on the rear axle

 

[ViperPete]

the length of the shaft at speeds will cause a whip affect,
imagine holding a string end to end, then twirl it, the center will whip outwards

same as with a driveshaft, many chevys have tossed theres on a dyno because of this, the same reason we haven't offered a single
Our driveshaft builder says there only safe up to about 118mph

reaching those speeds the shaft may want to start wobbling in the center.
be careful and keep an eye on the joints and retaining bolts on the rear axle

Hmmmm. Maybe that is what I am experiencing then.

Goes away right after 102mph. I only went up to around 120 and it didn't vibrate at that speed either.

I'll check out the joints tonight.

Other than at that 5 MPH spread, the truck is smooth as hell.

 

[BigRed460]

the length of the shaft at speeds will cause a whip affect,
imagine holding a string end to end, then twirl it, the center will whip outwards

same as with a driveshaft, many chevys have tossed theres on a dyno because of this, the same reason we haven't offered a single
Our driveshaft builder says there only safe up to about 118mph

reaching those speeds the shaft may want to start wobbling in the center.
be careful and keep an eye on the joints and retaining bolts on the rear axle

So how do I fix it? My stock drive shaft didnt do this, is this just a result of having a steel drive shaft made by a dumbass?

 

[VENOMOUS1 RACING]

hey all

So I recently installed the T56 and lowered the truck.

For the last 400 miles or so I haven't been past 80 mph or so because I have not been driving on the highway. No vibrations. Feels like it's factory.

Then, on the highway I was returning home from Universal Studios and beginning at 95 mph, most intense at 99 and gone at 102- there is a drivetrain vibration. It is only felt/heard when under acceleration. Not when I let off the gas.

Draining and replacing the tranny fluid today anyway because I hit 500 miles on the tranny.

Any ideas?

Was flywheel, pressure plate, clutch balanced? Driveshaft balance? Pinion Angle?

 

[VENOMOUS1 RACING]

Was flywheel, pressure plate, clutch balanced? Driveshaft balance? Pinion Angle?

Had my one piece alum shaft at 150+ and many 1/4 mile passes as well as Mexico passes and not an issue one in 20,000+ miles. Yes the shaft can "whip" in the middle as all one piece with length tend to. Chevy/Dodge/Fird have alum. and composite shafts over the years and lengths longer than our QC. They do not vibrate or shed shafts at 120 I assure you. Rode in plenty Cammed, SC and nitrous trucks and based my decision of a one piece years ago around these personal experiences. I wouldn't turn back to a carrier bearing if I had to. :chain:
My .02

 

[ViperPete]

So I looked under the truck the other day.

Retaining cap bolts on the diff were tight. But something that I did notice was that there was a line of black on the drive shaft. Apparently at some point the rubber exhaust hanger near the driveshaft comes in contact with the driveshaft and rubs slightly on it.

It is about an inch away. I am not sure how it can come into contact with it, but it has.

Any ideas?

 

[stealth78]

Was flywheel, pressure plate, clutch balanced? Driveshaft balance? Pinion Angle?

If the clutch or flywheel had involvement it would be rpm sensitive as well. If it is vibrating at say 100-105mph in 4th, 5th, and 6th gear then I'd be looking towards tires/wheels, axle, or driveshaft!

 

[SRT2SLOW]

I had the same problem for a while. it went away when i stop listing to people on the forum. I have zero vibrations now.

 

[JRSVIPR]

I had the same problem for a while. it went away when i stop listing to people on the forum. I have zero vibrations now.

Bwaaaaaaahaaaaaahaaaaaahaaa

 

[VIPER-INJECTED]

I had the same problem for a while. it went away when i stop listing to people on the forum. I have zero vibrations now.

[ame]http://m.youtube.com/watch?v=-eSN8Cwit_s[/ame]
Jk, in to find out what's wrong with the truck issue.