Post-lift driveline vibration (zero-low load situations)
#1
Post-lift driveline vibration (zero-low load situations)
After lifting my 2010 F350 Regular cab 6-speed I've experienced a vibration in the drive line.
Here are the stats on the configuration:
And here are the conditions where I get the vibration:
I went back to the shop that installed the lift. They said I need ladder bars, which I thought was a bit ludicrous. There is no hopping at take-off, which is what ladder bars are for.
I took the truck to another shop and the guy checked out things underneath and said driveshaft, u-joints, yoke all looked good. He said there was a lot of play in the rubber mount at the tranny and that tightening this up might help, but it's damn near brand new so I'd probably be doing some custom work to increase the stability there.
I'd like to hear your thoughts on the vibration because I'm not convinced either shop is right yet.
Here are the stats on the configuration:
- BDS 4" lift, radius arm in front
- 4" spring lift and 2.5" tapered blocks in rear
- Installed at 10K miles
- 14K miles on truck now
- 35" Goodyear MT/Rs on 17 inch steel rims
And here are the conditions where I get the vibration:
- Speed greater than about 50 mph
- Zero to low load on driveline; basically going down a hill
I went back to the shop that installed the lift. They said I need ladder bars, which I thought was a bit ludicrous. There is no hopping at take-off, which is what ladder bars are for.
I took the truck to another shop and the guy checked out things underneath and said driveshaft, u-joints, yoke all looked good. He said there was a lot of play in the rubber mount at the tranny and that tightening this up might help, but it's damn near brand new so I'd probably be doing some custom work to increase the stability there.
I'd like to hear your thoughts on the vibration because I'm not convinced either shop is right yet.
#2
#3
After lifting my 2010 F350 Regular cab 6-speed I've experienced a vibration in the drive line.
Here are the stats on the configuration:
And here are the conditions where I get the vibration:
I went back to the shop that installed the lift. They said I need ladder bars, which I thought was a bit ludicrous. There is no hopping at take-off, which is what ladder bars are for.
I took the truck to another shop and the guy checked out things underneath and said driveshaft, u-joints, yoke all looked good. He said there was a lot of play in the rubber mount at the tranny and that tightening this up might help, but it's damn near brand new so I'd probably be doing some custom work to increase the stability there.
I'd like to hear your thoughts on the vibration because I'm not convinced either shop is right yet.
Here are the stats on the configuration:
- BDS 4" lift, radius arm in front
- 4" spring lift and 2.5" tapered blocks in rear
- Installed at 10K miles
- 14K miles on truck now
- 35" Goodyear MT/Rs on 17 inch steel rims
And here are the conditions where I get the vibration:
- Speed greater than about 50 mph
- Zero to low load on driveline; basically going down a hill
I went back to the shop that installed the lift. They said I need ladder bars, which I thought was a bit ludicrous. There is no hopping at take-off, which is what ladder bars are for.
I took the truck to another shop and the guy checked out things underneath and said driveshaft, u-joints, yoke all looked good. He said there was a lot of play in the rubber mount at the tranny and that tightening this up might help, but it's damn near brand new so I'd probably be doing some custom work to increase the stability there.
I'd like to hear your thoughts on the vibration because I'm not convinced either shop is right yet.
Traction/Ladder bars help to prevent spring wrap, which is terrible on trucks with diesels. Big tires, gears, heavy loads, trailers, short wheelbases can exaggerate it as well.
Uncontrolled spring wrap produces 'shudder' from dead stops and if you stand in the throttle hard at low speed, but doesn't occur when the spring is at rest, such as decel.
If this problem manifested itself after the lift and no other changes, I would be paying close attention to the pinion angle, as previously stated, and the relation of the pinion to the angle of the driveshaft.
#4
Thanks guys. The pinion angle was a question of mine as well... the second shop said they thought it was a long enough driveline that it wasn't a problem, but I still wonder.
It is a one-piece driveshaft.
I'm going to snap a couple pics of the driveline and postem up to see what you think.
Thanks again for the help.
It is a one-piece driveshaft.
I'm going to snap a couple pics of the driveline and postem up to see what you think.
Thanks again for the help.
#7
Well I just wanted to comment on this one thing. I could be wrong and unclear in remembering the info. But your said you have 2.5 " tapered blocks. I thought tapered blocks would be used if you had a two piece driveshaft.
Now I could be misinformed so do not all yell at me at once. It was just a thought and maybe a solution for the OP.
Now I could be misinformed so do not all yell at me at once. It was just a thought and maybe a solution for the OP.
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#8
#9
Could you post a photo of the transfer case to driveshaft? If you have a standard U-Joint at that location, the angle should match the driveshaft-to-Pumpkin angle. That angle difference might cause a vibration.
Are you sure that you do not see any shudder when taking off from a stop? The rear pinion pitches up when that happens. If there is no shudder or vibration on take-off, it is possible that you need a slightly larger shim to point the pumkin to the drive shaft.
Also make *very* sure that the U-Bolts holding the spring pack in place are properly torqued - the torque value is high, somewhere in the 165 ft-lb range. If the spring pack is not fully secured, it can 'rock' in relation to the axle.
Lou Braun
Are you sure that you do not see any shudder when taking off from a stop? The rear pinion pitches up when that happens. If there is no shudder or vibration on take-off, it is possible that you need a slightly larger shim to point the pumkin to the drive shaft.
Also make *very* sure that the U-Bolts holding the spring pack in place are properly torqued - the torque value is high, somewhere in the 165 ft-lb range. If the spring pack is not fully secured, it can 'rock' in relation to the axle.
Lou Braun
#11
That thing has waaaaaayy too much pinion angle. The pinion should never be inline with the driveshaft like it is. You may not feel it, but when you clutch that torquey diesel off the line from a dead stop, the spring wrap will actually send the pinion over center (so it points upward, past the center line of the driveshaft).
This is obviously not good. You need to ditch the angled blocks, put in some that have minimal, or zero taper, and check the pinion angle with a magnetic protractor.
If the pinion angle is close to correct, the pinion will point down in relation to the center line of the driveshaft, rather than inline like it is in the pics.
This is obviously not good. You need to ditch the angled blocks, put in some that have minimal, or zero taper, and check the pinion angle with a magnetic protractor.
If the pinion angle is close to correct, the pinion will point down in relation to the center line of the driveshaft, rather than inline like it is in the pics.
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