FloridaF150,

Yeah, I continue to have it as well. My SCrew is 1400 miles and 13 days old. I do a bit of in town driving and always in 2wd mode and the clunk is there. I'm not going into the dealer till first oil change at 3k that they pay for. Then I'll discuss the tranny thunk issue.

I did get underneath last night and nothing is loose. Checked every connection. It definitely is the tranny.

 

after reading all these posts, i tried my darndest to get my truck to "thunk", and i couldn't.

you guys could try something. instread of putting your truck in drive, put it in second gear. it will then start off from a complete stop in 2nd gear and then won't upshift to third. see if your thunking goes away or is still there. i'm supposing if it is still there, it has nothing to do with the tranny.

also, not sure if this will work on a ford, but try disconnecting the battery for a half hour. also turn on some accessories to totally get ride of any residual power. then hook the battery back up. this might cause the tranny to have to relearn its shift program. i know this is true of the 4r100, but not sure about the 4r70w. this little battery unhook/hook up procedure works well on some chryslers.

good luck!

 

I think you are right. It is normal to get a clunking sound while in four wheel drive when turning sharpley.

It amazes me sometimes how little they know about their own product and how little some of the service technicians actually listen or understand what the customer is telling them.

They probably did a search for "clunk" and got that special bulletin not even reading it. Lets give this to the customer and say it is normal (said with a giggle)

argh!

 

one thing i always do is make a mechanic drive my truck while i'm in the passenger seat. that seems to work the best for me, that way i can directly point out what the problem is and they can't deny that i have a problem...

 

I think you guys are giving up too easily...If there is a noise there and there should not be then you can find it...

Unload the driveshaft and block your wheels so that you can turn the driveshaft....It should have minimum play...spin it quick one way and back the other and see if it thuds...

This is were 90% of driveline noises originate from...

the driveshaft, u-joints, diff, transmission and diff yoke, and the slip yoke...

If it is spring thud then you can space them or isolate them...

How about the in drive with the brakes held and shift into reverse and drive, reverse and drive...listen for the thud...

 

I will try what you are suggesting. However, the tranny only thunks after you have breaked to about 18 mph in stop and go traffic then accelerate. Or after coasting aroung a corner at 18 mph then accelerating. It does not thunk when putting the truck in gear or going from drive to reverse. You can really make it thunk if you increase acceleration after breaking to 18 mph. There does not seem to be any slop in the drive train. It seems more like the torque converter is disengaged at around 18mph then takes about a second to reengage after accelerating.

I'm sure this must be a common problem. It also must be expensive to fix or Ford would have already fixed it.

 

has anyone tried the locking it into second gear approach that i suggested a few posts back? if you put the gear selector in 2, the truck will start off from stop in second gear (not first) and then won't upshift. the thunk you guys are getting could be the tranny languishing between gears as you coast, then slamming back into gear when you apply some throttle. almost like it goes into third when coasting, then jumps back to second when the gas is appied. anyway, leaving the truck in second gear and then doing your test could at least give you some more clues as to why your truck is thunking...just a thought. give it a try. i'd do it on mine, but mine doesn't thunk for whatever reason.

 

You are right. when you force the tranny to stay in second it doesn't create the noise. My guess is that it is the tranny jumping from third to first... wham!

Since these transmissions are electronically controlled it should be easy for Ford to fix with a little code change. The tranny shouldn't be in third at 25 MPH anyway!

 

I asked this several months ago, but is anyone experiencing this with an aftermarket chip. The chip changes the shift patterns, firms up the shifts and shortens the delays between gears (Up and down). It seems these trucks will coast to a near stop in third, then when you hit the gas, goes to first and "thunk".

 

Do I get a prize for my 100th post?

 

i've also noticed that my tranny will upshift from 1 to 2 very quickly upon light acceleration. i wish it would wait a little longer before upshifting. i suppose this is to help fuel economy...

 

I had the same problem it was the 1st to 2nd up shift from slow to a little extra gas then BAM! into second it would go. I believe that is why if you force 2nd it won't do it.

1st the dealer said it was a problem with the valve body whish I later found out that because it is under waranty they try to replace the valve body 1st because it is cheaper when in reality you need a new computer!

I will not go into the long details on how the dealer handled this but the ford engineers that consult for the dealers knew it was the computer all along!

So don't give up and tell your dealer to call the engineers and not do the valve body first because it is a hasle it doesn't fix the issue and requires 2 seperate trips to the dealer!

Mine no longer "Thunks" and actually runs better with the new computer!

Just a thought but I wonder if a chip would fix this too?????

Good luck!

 

I had asked the same question some time ago. The response I received from one user was no, the chip does not fix the "thunk!"

 

At least installing a Superchip did not fix mine.

 

I'm coming to the conclusion that a lot of this programmed DIGITIAL stuff is crap.. and this comes from a programmer with 30 years of experience. My d@mn tranny insists on 'clunking' when its cold and I put it into reverse. "Program is correct says", says the Ford tech. "F#ck the program", sez I. The electronics are good in many ways, but very imperfect. Give me the old C6, please... simple mechanical, ANALOG sutff