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It's really strange. Lets say I'm in 5th gear on the highway and coasting, if I mash the pedal I get a loud thump noise. Happends every time. The shifter also bounces up and down a good amount. Would this be in the tranny or what?
I've changed all the mounts.
The car has 40,000 miles.

Thanks in advance.
 

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Sounds like it's a combination of backlash between the diff and transmission. Happens all the time on mine. Seems normal form what I hear.
 

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I know exactly what you mean. I get that sometimes in my 96. I'd like to get rid of it, but don't know what to fix (if anything). I've just learned how to get back on the gas without getting the thump. Doesn't happen very often.
 

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My car also does this currently.
But it happens to me in every gear and its very load.
I have read many articles about this and looked thoroughly through the service manual. It does sound like that the backlash is not set correctly.

This usually happens to cars that have had a new gear set installed and the backlash was set incorrect or not set tight enough.:(

This weekend I will be breaking into my differential and looking for anything loose. I have heard that this could get so bad and start breaking or chipping the gears (darn new gears then go with 4.10). :)
 

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Mine does it as well. Ive heard others say it was normal and that Ford said there is nothing you can do about it but who knows.
 

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Yeah, it's the slack in the shaft. It only happens on mine when I'm slowing down to coast speed from high speed. I compensate by slowing it down slowly myself rather than to cause the shock. In your case, you would have to ease the gas on so it picks the slack up, then hammer it.
 

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i have no idea what i'm talking about

i have the same problem (driveline slack being taken up) and have posted here and on stangnet as well as my explorer forum and have gotten bout ten different answers.

1 - bad Torque converter - but i'm not getting any shudder
2 - bad trans - but its not slipping gears - perfect 1234 even when hot
3 - bad u-joints - but no bang @ a stand still
4 - bad torque boxs - but visible cracks or tears
5 - bad U/L CA's & or bushings - put it up on a rack and push/pulled/pryed and it all felt fine/solid
6 - bad gears - but it ain't howling at all
7 - bad posi unit clutchs - this one still concerns me but - i can't find any info on this one
8 - bad input shaft adjusters in the rear end? - but i'm not getting any driveline vibration
9 - bad axle bearings - but no leaking
10 - bad axle dampeners - but rearend doesn't feel squirrely

frankly i've just given up and started carrying my cell phone more well waiting for it give way - WHATEVER IT IS !!!:barf:
 

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In this list, all of the mechanical failures have been ruled out. The driveshaft has it's own inertia...take a puff and think about it.
 

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i really DON"T know what i'm talking about!!!

i wasn't kidding - if someone could narrow it down i'd appreciate it - as for the drive shaft having inertia - could you please explain - i'll be happy to check that out also - as for the puff comment the AVATAR picture is not me - i value my brain cells - they make me to much money :)
 

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While it could be any component in the drivetrain, for me it was the T-45. When mine was replaced (out with the B/W, in with the Tremac), the {Thump} disapeared.
 

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I took my car into a transmission place to have a quote done because of this problem and they said it was in the differential but they would have to break into it to find out exactly what the problem is.

After I break into my dif either today or this weekend I will find out more then get back on the forum and update everyone.

I am really sure it is the backlash setting.

And if you wait to long it will not be a simple tighten a bolt. :(
 

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Backlash!

Sounds like bad factory backlash.

Mine used to do that-- when we installed my 373s the factory backlash was really off.

Installed the 373s and got the backlash perfect, no more thunking.

Bad Ford! :eek:
 

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my car does it really bad. i just had my rear diff worked on by mechanics that have never worked on an american car before. i think it is probably my back lash. it is getting progressively worse over the last 1000 miles though. i need to take it in soon.
-Frosty
 
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