Truck shakes when accelerating
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
Nothing to do with the LS.
I have determined that it is the engine missing now. Its very weird. I have been around these motors/trannys for 10 years now. I know my way around for the most part.
Haven t had these issues yet without a CEL. Im thinking its gotta be a plug/plugwire/ or coil pack. Well just see. Like i said, theres now CEL. no codes.
I have determined that it is the engine missing now. Its very weird. I have been around these motors/trannys for 10 years now. I know my way around for the most part.
Haven t had these issues yet without a CEL. Im thinking its gotta be a plug/plugwire/ or coil pack. Well just see. Like i said, theres now CEL. no codes.
JL
Thread Starter
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Posting Guru
Joined: May 2006
Posts: 2,486
Likes: 0
From: Iowa
I ended up pulling the rear diff cover off and finding that the differential was cracked all the way around. Causing it to get into the pinion gear under hard acceleration. I highly doubt you have the same issue though.
Your truck would be equiped with the 9.75 rear end, and is considerably tougher.
Your truck would be equiped with the 9.75 rear end, and is considerably tougher.
New User
Joined: Oct 2010
Posts: 1
Likes: 0
Just a suggestion but check the pvc hose where it connect to back of the intake behind the throttle body. the hose/elbow there wears a hole and causes a vacuum leak that can cause shudder as well. This has happened on my 97 expedition and my 98 f150. The hose is a dealer item and a better design than the original. good luck.
New User
Joined: Apr 2010
Posts: 3
Likes: 0
From: Highlands, TX
I ended up taking my truck to a transmission guy and they said it wasn't transmission problems. It ended up being one of my spark plug wires was almost burnt in half and one of my cylinders wasn't even getting power. So they fixed it, and ever since it's been just fine.
New User
Joined: Nov 2008
Posts: 19
Likes: 0
From: Glendale Az
I'm Shuddering too - F250 1999 V10
Having same problem on my 1999 F250 SD 4X4 V10. It only shudders on acceleration, like passing someone or getting on the interstate. (Not normal acceleration, when taking off from a light) It idles nicely, but when i jump on it I get shudder. It doesn't shudder at normal operating speeds, ie.. once I get passed the shudder it will cruise just fine, it's just that acceleration.
I would think it has to be motor related and not drive shaft or transmission. I'm thinking a possible vacuum leak somewhere? If it was the coil wouldn't it idle rough?
Also, I only get a check engine light occasionally, and then it goes off.
Any suggestions?
I would think it has to be motor related and not drive shaft or transmission. I'm thinking a possible vacuum leak somewhere? If it was the coil wouldn't it idle rough?
Also, I only get a check engine light occasionally, and then it goes off.
Any suggestions?
New User
Joined: Oct 2013
Posts: 2
Likes: 0
Are the clutches in the rearend something that must be fixed right away or can it be put off for a little while?
Laughing Gas
Joined: Jun 2013
Posts: 1,094
Likes: 514
From: Yokosuka Japan
as long as you have the proper amount of oil in the diff then it will not be anything more than a nuisance (generally speaking) and you simply will not have the LSD as it will not engage properly. Other than that no worries. Oh as you noticed you get an annoying shudder when it tries to engage.
now if you do not have enough oil in the diff, it will cause other problems.
kenn
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Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
It sounds just like the 2011-2014 Eco Boost and 5L new truck issue they are having from the factory.
It is turning out to be a driveline issue with an out of axial rotating drive shaft and soft rear trans mount.
On engine torque the drive line is out of line such that the torque tries to pull he driveline even more out of line.
As the rpm rises and torque is reducing on the driveline centrifugal force begins to find it's own way back into a balanced rotation condition until the next time.
During the shaking, the trans is moving in it's mount and being bolted to the motor it's akin to about a 1200 lb weight shaking the whole truck.
I would never think an engine miss would act quite that bad.
May be something may be nothing.
I have been pushing Ford to look into this on the new trucks and it's now beginning to pan out.
It's a quality control issue on the new trucks.
Good luck.
It is turning out to be a driveline issue with an out of axial rotating drive shaft and soft rear trans mount.
On engine torque the drive line is out of line such that the torque tries to pull he driveline even more out of line.
As the rpm rises and torque is reducing on the driveline centrifugal force begins to find it's own way back into a balanced rotation condition until the next time.
During the shaking, the trans is moving in it's mount and being bolted to the motor it's akin to about a 1200 lb weight shaking the whole truck.
I would never think an engine miss would act quite that bad.
May be something may be nothing.
I have been pushing Ford to look into this on the new trucks and it's now beginning to pan out.
It's a quality control issue on the new trucks.
Good luck.
New User
Joined: Oct 2013
Posts: 2
Likes: 0
You only have clutches in the rear diff if you have the LSD option. if the clutch packs in the LSD are "burned/scorched" it will cause the shuddering problem.
as long as you have the proper amount of oil in the diff then it will not be anything more than a nuisance (generally speaking) and you simply will not have the LSD as it will not engage properly. Other than that no worries. Oh as you noticed you get an annoying shudder when it tries to engage.
now if you do not have enough oil in the diff, it will cause other problems.
kenn
as long as you have the proper amount of oil in the diff then it will not be anything more than a nuisance (generally speaking) and you simply will not have the LSD as it will not engage properly. Other than that no worries. Oh as you noticed you get an annoying shudder when it tries to engage.
now if you do not have enough oil in the diff, it will cause other problems.
kenn
Junior User
Joined: Oct 2013
Posts: 50
Likes: 0
From: Virginia
Nothing to do with the LS.
I have determined that it is the engine missing now. Its very weird. I have been around these motors/trannys for 10 years now. I know my way around for the most part.
Haven t had these issues yet without a CEL. Im thinking its gotta be a plug/plugwire/ or coil pack. Well just see. Like i said, theres now CEL. no codes.
I have determined that it is the engine missing now. Its very weird. I have been around these motors/trannys for 10 years now. I know my way around for the most part.
Haven t had these issues yet without a CEL. Im thinking its gotta be a plug/plugwire/ or coil pack. Well just see. Like i said, theres now CEL. no codes.
New User
Joined: Nov 2008
Posts: 19
Likes: 0
From: Glendale Az
Success
So the shudder was two fold. First my transmission was going out, so it was slipping when I would get to between 40 and 50. The second issue was that two coils were bad.
I hate dealer service departments, but I took it to the I can't-a-Ford you house and I asked for a Dyno tune. They called me back with a stinking code read. The same one you get at Autozone for FREE. I told the guy that the code they gave me was not the issue. It had to be in the coils since I replaced my transmission and the TPS which the code said was faulty. I still had a miss.
He said they would do more testing. Finally came back and said that two coils on the drivers side were bad.
I put in two new coils and my truck is running great.
I hate dealer service departments, but I took it to the I can't-a-Ford you house and I asked for a Dyno tune. They called me back with a stinking code read. The same one you get at Autozone for FREE. I told the guy that the code they gave me was not the issue. It had to be in the coils since I replaced my transmission and the TPS which the code said was faulty. I still had a miss.
He said they would do more testing. Finally came back and said that two coils on the drivers side were bad.
I put in two new coils and my truck is running great.
New User
Joined: Sep 2016
Posts: 2
Likes: 0
Shakes and Noise
I have a 2003 F150 4x4 with the 4.6L and currently i have the shaking problem accelerating in a straight line, the shake gradually gets bad going highway speeds (60-70mph) but when i get off the gas it no longer shakes. Is it a bad U-joint or rear pinion?
Laughing Gas
Joined: Jun 2013
Posts: 1,094
Likes: 514
From: Yokosuka Japan
check the easy one first....grab the drive shaft and see if the u joint has any play. also check to see if there are any missing balance weights on the driveshaft...I scraped one of while crawling through a rock garden
took the damn weight right off of the driveshaft shook the truck like a mother. anything dealing with a US made truck is expensive over here it was cheaper to get my brother to send me a used driveshaft then it was to fix it .