Hello All,
I have a 2001 5.4 F-150 SuperCab Lairet. I believe I have the 4r70w auto. Will check later (can I tell from the sticker on the door, or do I ahve to crawl underneath?). Anyway I have about 60k miles on it and I have noticed somebad behavior. Here is the run down:

"Clunk" at about ~22MPH when accelerating after slowing down.
Shudder when accelerating from a dead stop.
Shudder when stopping from speed > 30MPH just before the truck stops completely.

I have noticed the "clunk" ever since I got the truck. Dealer says its normal, but it is more pronounced now. I have heard of other people having this issue. Did anyone get it resolved? As for the shudder, I have heard this could be the yoke issue or a torque conv. problem. I have changed the trans fluid at about 32k, I know its due for another soon. Any feedback from people who share these problems would be great!!

Thanks for everyones help,
Rich

 

Some other sypmtoms I forgot to post:

I get the "clunk" a lot in stop and go traffic. Turning off overdrive seems to help the problem. It does not "clunk" as much.
It seems the clunk occurs around the 1-2 shift or the 2-1.
When I have a heavy load in the bed >200lbs. the clunk stops.

Rich

 

The yoke issue happened to me as I was coming to a stop.

The hard shift(clunk) between 1-2 is partly? normal depending on how hard you push it. The harder you push, the more it clunks.
Mine started to clunk and the transmission was starting to slip. Yup. It was the torque converter. Even with a new TC it still clunks once in a while.

Depending on how you use the truck, 30K might be a long time between transmission flushes. When I first got mine back in 1997 the dealers had warnings posted all over the shop to change fliud every 15-20K. The fluid not being changed is most likely the shudder problem. Make sure you get the total change method. This gets 99+% of the fluid changed. Don't let someone just drop the pan. This changes less than half of the fluid.

 

Thanks for the reply. Last time I got the trans fluid changed was at the dealer...I do believe that they flush it out and change all of the fluid. My transmission doesnt slip, other than the clunk it drives just fine...its just highly anoying. I will check the U-joints and slip yoke first, then see about a new torque convertor if that does not fix it. I have heard that there is a TSB about this problem and the fix was replacing a spring in the transmission. The dealership however, will not show me the TSB's!!

Rich

 

When I had my "clunk" it sounded very similar to what you described. I too noticed it did not do it if I had any kind of load in the bed.

After I got my truck used with 62k miles on it, I also noticed the TC shudder as well.

I had the trans fluid changed not long after getting the truck. The shudder stopped at that point. I did just have the pan dropped and a normal trans service done.

I've done a trans service every year since I've owned it. The second year, I did have the TC drained in addition to the normal trans service. That was about the time I started to tow a #4500 travel trailer. I've since added a trans temp gauge and the last service was just another pan drop and service (third year of owning the truck). Next year I plan on having the TC drained again......

Anyway, I've never had the shudder again with this schedule. I've got almost 128k miles on it now!! On the trucks last trans service, the tech asked if I had a new transmission..... I said not in the three years I've owned it, and I don't think before either... He commented that it was "very clean inside" and the old fluid looked brand new.......

Ok, now for the "clunk"...... Mine has not clunked ever since I added the Hellwig overload springs.... They also cured the annoying wheel hop the truck had if the tires spun on wet pavement or on gravel.....

I only added the overload springs because the truck would go to the bump stops with a whimpy #1000 payload in the bed... Now, the same #1000 load only drops the rear end about 2".... When it also seemed to cure the clunk and the hop, that was just added bonus and there fore the best mod I have done to the truck!!

I've heard the clunk is either the yoke or the leaf springs.... Whatever the overloads do to put extra tension on the springs seems to keep the axle twist in check as well..

Here is how they attatch to the leaf springs



This is just what seems to work for me....

Good luck!

Mitch

 

Hi Mitch,

Where does one buy Overload Springs ?

 

I wonder if Add-a-leaf would give the same results??

 

For your shudder when starting out. That could also be the rear diff if you have limited slip. This is a known issue. I had it on my 01, but it never got worse.

 

I got mine from a local 4x4 shop. I've also seen them in any of the auto parts online stores or catalogs.

I got mine for about $150 which included the mounting hardware.... The ones I've seen online all seem to run about the same price, but you have to PAY EXTRA for the mounting hardware and that's been like an additional $50 or whatever..... Then you have to pay for shipping too.... They are HEAVY, so that'll run some major $$$ as well....

I'd try to see about finding them locally if you can. Like I said, I found mine in a 4x4 shop, but you might also check into RV stores and the like, as they usually have stuff like this as well...

Good luck!

Mitch

 

The guys probably know better than me, but if what they said doesn't work - check the plugs. Had the same problem and flushed and took apart the tran and after all of that a tune up fixed it. - And found one very bad plug.