Transmission/Truck Lurch at start up
Mountain Pass
Joined: Jun 2016
Posts: 154
Likes: 79
You can have some tension between the parking pawl and the rear diff out to the brakes. When you parked it, you were in gear (forward or reverse doesn't matter) and you were holding the brake as you shifted to park. That may leave torque on the driveline. When you start it again, the ABS system is holding pressure on the brakes (I'm thinking another nanny safety thing) for about 1 or 2 seconds.
This truck seems to be holding my brakes for me a lot for one reason or another. It isn't a stretch for me to think it is doing it while parked. Maybe your incline sensor thinks you are on a slight angle?
This truck seems to be holding my brakes for me a lot for one reason or another. It isn't a stretch for me to think it is doing it while parked. Maybe your incline sensor thinks you are on a slight angle?
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Laughing Gas
Joined: Aug 2021
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Bob
Lead Driver
Joined: Feb 2005
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From: The Great State of Texas
No the click..click I'm referring to is occurring exactly when your truck moves backwards.
Mountain Pass
Joined: Feb 2024
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I thought the OP knew that noise was there, it's very obvious(I forgot I have audiophile headphones lol). Yes there is a definite solenoid-sounding noise exactly when the truck moves. I assume it's a solenoid in the trans, or maybe just slack in the driveline (like my Toyota's infamous "driveshaft clunk").
Hotshot
Joined: Jun 2003
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From: SW VA
You can. Click the 3 lines at the top, go down and hit "View Full Site"
Changes it to the same layout as on a computer...how god intended the internet to be used! LoL
Changes it to the same layout as on a computer...how god intended the internet to be used! LoL
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Laughing Gas
Joined: Aug 2021
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I thought the OP knew that noise was there, it's very obvious(I forgot I have audiophile headphones lol). Yes there is a definite solenoid-sounding noise exactly when the truck moves. I assume it's a solenoid in the trans, or maybe just slack in the driveline (like my Toyota's infamous "driveshaft clunk").
If it is a solenoid it would make sense as that’s how hydraulic pressure would be applied to the clutches to move the truck.
Im sure that there is slack in the driveline but in most cases the truck has been sitting for a day or three on a flat driveway so there would be no reason for it to move.
Thanks,
Bob
Lead Driver
Joined: Feb 2022
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It more than likely is a tight drum that is getting some friction from when the pressure builds up. It might have a leaky check valve that can cause it, dropping pressure when shut off, so fluid drains out of the packs, when starting up the pump energizes the packs with new fluid. My 2018 F-150 did that for a while until the trans was fully broken in. After about 30K miles it no longer did that.
Tuned
Joined: Jan 2018
Posts: 280
Likes: 148
Unrelated to OP issue I think but wanted to join in the 10spd bashing. I can lightly rev my 23' 7.3 in neutral and it will move a little and make light clunking noises. The lurch foward after putting in park is atrocious sometimes as is putting in D or R after starting. I frequently remote start or wait for rpms to fall. I also use the N trick to ease the pressure on the drivetrain. I actually like the trans most of the time but man it does some weird *****.
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