Lizard: Yea, I have had the same noise since truck had about 1500mi on it. (my first post on this site was a question about this) Took it to two dealers three times and all tell me that the clunking noise on downshift and when coming to a complete stop is "normal". Quite frankly, I don't believe that Ford would make such a noisy tranny for such a nice truck. Locking out the O/D does nothing to change the clunk when slowing and stopping, but leaving it in 2nd gear and driving around town helps this problem to quiet down. Is this mechanical or electrical, (i.e. solinoids actuating harshly) I don't know but I would like it to be looked at. The tailshaft has a lot of up and down play in it, and the techs all say that this is "normal". Frustration is growing on this mellow person, and I may have to quit being a nice guy and diagnosing their problems for them. Please re-post when you find out something, I think this could be a loose mainshaft or torque converter as the yoke splines are greased and slide smoothly, which has been a Ford problem in the past...j.b.

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99 SC Sport, Silver color everywhere, 4.2 auto,3.55 rear gear, split bench, stock AM/FM @ 2 cheesy speakers w/Ford brand bedliner. Keep'n stock from the factory because we love it for what it is...One fine ride!

 

My 99 XLT seems to have a problem somewhere in the drivetrain. At 40 mph or slower, when
you let off the gas it sometimes makes a loud
"clunk" type of noise that can be heard and felt. It also does it sometimes when it down-
shifts. I will be taking it in under warranty
but would like to know if anyone has had this
or a similar problem. Thanks for any response


99 XLT 4.6L 4-SPD Auto 3.08 Axle

6050# GVWR Package

 

THE NOISE YOU HEAR IS THE SLACK BETWEEN THE DRIVESHAFT AND THE REAR-END U JOINTS. I TOOK MY TRUCK INTO THE DEALER FOR THE SAME REASON AND THEY TOLD ME THAT IT WAS "NORMAL".

 

Thanks for the help guys. My u-joints seem okay but I have what feels like too much backlash in the ring gear. I'm sure the dealer will do the same thing to me and I also feel that's bull to make such a nice truck and have it make noises like that. I refuse to accept this as normal. I've owned too many vehicles in my life and none have ever done this. When I find a solution I'll write a post. Later.

 

Good Luck!!!

 

Had a similar noise and it turned out to be the stearing joint up front. Sounded like someone smacked it with a hammer from under the front somewhere just one loud bang but you could feel it. That joint was locking up when the truck went from accelerate to decelerate only momentarily. Maybe? There was a TSB on it and thats how they found it but this was a 97.

 

Hey Lizard: Just got our truck back from Ford this evening after almost a week in the shop. Looks like they may have fixed my clunk by replacing the transmission tail housing which holds the output shaft bushing. In my previous post I commented about the excessive up and down movement of the output shaft. This was due to the failure of the tailshaft bushing which supports the shaft and yoke assembly. Do not know if the "bushing" is a machined area in the aluminum housing, or is truely some kind of bronze or other bearing material. Apparently there is a TSB on this from Ford which relates to "oil slinging from the output shaft seal". Do not know if this covers just the 99 models with the 4R70 tranny or what. (The service manager became vague when I mentioned that information was shared on the Net.) After installation of the tailshaft housing, there was still a light knock and the S.M. called Ford again for more help, and their reply was to replace the driveshaft because they had some noise problems associated with those units. Not having one in stock, and after keeping the truck for almost a week, he sent a mechanic onto the lot and took a shaft off of a 2000 model and put it in our truck. Fixed the problem, went beyond the call of duty to do so, and took a new vehicle off a retail lot until a new shaft arrives! I have a good dealer working for me, I think I'll keep him...j.b.

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99 SC Sport, Silver color everywhere, 4.2 auto,3.55 rear gear, split bench, stock AM/FM @ 2 cheesy speakers w/Ford brand bedliner. Keep'n stock from the factory because we love it for what it is...One fine ride!

 

Lizard Man
J.B. has got the solution my truck had the same problem and my Dealership replaced the whole driveshaft. I haven't herd a peep since. Good Luck Rex

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Rex 99 F150 XLT S/C S/B 4.6, Auto, Solid Black, Dark Graphite. Santa Monica Ca.

 

Good luck. I have been there. If you can find the post it was called "clunck on stopping." 98 F150 has been in at least 13 times since day one for a clunck while slowing down. Also does what yours does. Ford replace tranny, transfer case, rear end gears, reprogrammed the computer, which seemed to help, (improved MPG too) but the noise always came back. Finally was seen by the Factory twit, I mean engineer. He determined that the noise was normal for this make and model. Once he says "normal" you are shafted. Ford will not do anthing else for you. They told me "thank you and if there is anything else we can do. We knew you would not like this answer, but... oh well. I contacted Ford too who basicly said they would document it and there was nothing they could do, since the engineer says it's normal. Now everyone I have talked to before will not return calls and produce copies of service records or anything like that. VERY DISAPPOINTED. Hoping it holds together untill I can affored a super duty. I now have 38k on it and it still runs fine but the clunk is there. It concerns me. I hope you have much better luck than me.

 

I don't have this clunk issue, but this kind of run-around crap really makes me mad! I consider my truck to be "normal" and it doesn't make this sound. Would this Ford engineer/twit accept this clunk as "normal" in his own personal vehicle?

I am currently going rounds with my local dealer about a rough idle -- they replaced the MAF and it's still there. They say it's "normal". Bite me!

signed,

PO'd in CA

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'99 F-250 LD 5.4L SC XLT 2WD 3.73LS in White/Silver (w/ EVERYTHING 'cept leather and engine block heater) -- added: SnugTop Hi-Liner & carpet kit, Donnelly electrochromatic/compass mirror, K&N filter, SuperWhite 9007 bulbs, IAS shocks, 3" Induction Airbox Mod, Mobil 1, more to come... (Flowmaster 70 cat-back exhaust is on order, Westin side bars, electric fan, Superchip, and silver fender/wheel flares are next)

http://hometown.aol.com/jimorama/myh...ollection.html

 

I had the same clunk, particularly on acceleration from a stop. My dealer replaced what he called the "slip-yoke" and it's been fine ever since, no-clunk!

 

Does this seem to be an intermittent problem? I think I've noticed something somewhat similar with my 99 5.4L 4x4 automatic. Every once in awhile, if I'm just leisurely cruising along and let off on the gas, the tach drops a couple hundred RPMs and it almost feels like something is pulling on the truck from behind, slowing it down slightly...it's not really a smooth deceleration though as there is a bit of a small jerk. The same thing has also happened when I've had the cruise on going down a hill. I guess I haven't really noticed much of a clunking noise though...maybe I should listen a little closer. When it does happen, it seems to go away after the truck warms up. Anyway, does this sound similar to what you guys have experienced?

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99 F150 X-Cab 4x4 SB, 5.4L V8, Deep Wedgewood Blue/Dark Graphite, ORP, 3.73 LS, Tow Pkg, Captain's Chairs
AIRAID, Luvernve Stainless Nerf Bars, BedRug Bed Liner
Lund: Frontrunner bug deflector, Eclipse taillight covers, Eclipse quarter window shades all painted to match

Sony: Mobile ES CDX-C7850 head unit, Mobile ES XDP-U50D DSP, MDX-65 MiniDisc changer
Rockford Fosgate: Punch 600a5 amp, 2 Punch XLC 4 Ohm 8" subs
Infinity: Kappa 63.1i's in the front, Kappa 62.1i's in the rear
StreetWires: Zero Noise 5.0 patch cables, UltraFlow Power cable, Power Distribution Blocks, speaker wire




[This message has been edited by MattT (edited 10-27-1999).]