Truck Shudder
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Senior User
Joined: Jan 2004
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From: Carmichael, ca
Truck Shudder
Just got back from a 10,000 mile vacation accross our great nation. Due to a 5th wheel hitch accident that dropped our 5th wheel on our original truck's bed, we bought a new '06 F350, dually, crew cab, 4 wheel drive, Super Duty 6.0 turbo diesel with the 'Tow-Haul' package. Basically the truck is a dream to drive and we had no problems with it. We were pulling a 38' 5th wheel 'Toy-Hauler' that weighed around 13,000 lbs, plus 2 large 16 year olds. The total GVW was 24,000 lbs.
The only thing that bothered me was that the drive train would shudder whenever we would start out. A very light throttle would help eleminate this and once moving, there was no shudder at the shift points. I am going to talk to our local Ford dealership to see what they say about it but I thought that I would check here to see if anyone else has experienced this.
Thanks
The only thing that bothered me was that the drive train would shudder whenever we would start out. A very light throttle would help eleminate this and once moving, there was no shudder at the shift points. I am going to talk to our local Ford dealership to see what they say about it but I thought that I would check here to see if anyone else has experienced this.
Thanks
Fleet Mechanic
Joined: Nov 2003
Posts: 1,372
Likes: 14
From: West Cornwall, CT
I think that rclarke nailed the cause of the shudder that you feel. When the trailer is not connected your F350's rear end probably sits 4 inches higher than when loaded. The driveshaft and pinion angles are probably set mostly for this unloaded condition.
When loaded and accelerating from a dead stop, the rear pinion rotates upward and the resultant angle can cause the shudder you feel.
When I load my backhoe forward on the trailer far enough to set the back of the truck down over 4 inches, I see the same shudder that you are describing when accelerating hard from a dead stop. Trailer tongue weight under this condition is about 1500# (class 5 hitch installed). With less tongue weight (1000# or so) there is no shudder.
Lou Braun
When loaded and accelerating from a dead stop, the rear pinion rotates upward and the resultant angle can cause the shudder you feel.
When I load my backhoe forward on the trailer far enough to set the back of the truck down over 4 inches, I see the same shudder that you are describing when accelerating hard from a dead stop. Trailer tongue weight under this condition is about 1500# (class 5 hitch installed). With less tongue weight (1000# or so) there is no shudder.
Lou Braun
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From: Carmichael, ca
Thank you everyone for the responses.
Yes it is an automatic transmission. I the guy I talked to at the dealersip also mentioned the pinion angles too. The truck does "squat" when hooked to the 5th wheel so I will be adding air bags between the frame and springs to correct it.
The other thing that the dealership guy mentioned was to do some figure 8's with the truck to get the limited slip working a little bit better, that the new limited slips may not be working smoothly. But since the shudder happened whether I was going straight or turning, I think that the pinion angle makes more sense.
I have a '79 3/4 ton that I have been thinking about traction bars due to the 545 engine that I put in it.
Yes it is an automatic transmission. I the guy I talked to at the dealersip also mentioned the pinion angles too. The truck does "squat" when hooked to the 5th wheel so I will be adding air bags between the frame and springs to correct it.
The other thing that the dealership guy mentioned was to do some figure 8's with the truck to get the limited slip working a little bit better, that the new limited slips may not be working smoothly. But since the shudder happened whether I was going straight or turning, I think that the pinion angle makes more sense.
I have a '79 3/4 ton that I have been thinking about traction bars due to the 545 engine that I put in it.
