Transmission or ??

[Ed Schultze]

I have a 2000 expedition close to 200,000 miles The trans was slipping and there was torque converter shudder. I had the trans rebuilt and the trans performs well. However, there was some minor shudder/vibration when a load was placed on the trans- (between gears going up hills). The trans guy is great and took it back and rebuilt it again and replaced the already replaced torque converter- he is a good guy. However, I still notice a milder shudder, groan particularly if i am going up a hill around 65 to 75. It is nowhere near what is was before. Before it really shook just like driving over the rumble strips.
I really do not want to ask this guy to have another go at it if it could be something else or if it sort of normal for an Expedition to do this. If I let off the gas the noise immediately ends. i can make it happen all the time if I am going up a hill around 65 or 70. If I let this go will I end up shortening the life of the trans?

thanks for any opinions.

Ed

 

[RonB1964]

One thing you may try as a test is to select 4x4 under the same conditions or temporarily remove the transfer case clutch fuse under the hood. If I suspected the trans was failing, I would try all the easy stuff 1st with the trans installed. Such as flui3 change, checking torque and installation of the valve body. I think if an accumulator spring is too weak, or the valve is worn, it may cause an issue like this.

 

[Ed Schultze]

Thanks very much, Can I drive with the 4X 4 at 66-7? If the noise and light rumble is absent would that mean it is in the drive train and not hte trans?/ I appreciate your help. The flid has been changed as the trans was just rebuilt a second time. That is why I was wondering if it could be something different perhaps something int eh drive train

 

[1955moose]

As far as can I drive 65 plus in 4wheel drive, Nooo! You'd have to be on snow under your tires, and that's way above any safe speed, both for you, and the vehicle. If your guy is as good as you say, pay him a small diagnostic fee, if need be, and let him diagnose it. In your neck of the woods, he's used to 4wheel drive vehicles. The chances of it doing same thing are slim, but if he misses any little thing inside your trans rebuild, or if the torque convertors are sub par, that might be your issue. These vehicles have a lot of shudder issues, 2 nd and 3rd gens in particular. Report back what He/you find.

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[Ed Schultze]

Thanks so much
I will see him later this week since yo mention shudder issues could other parts of th edrive train cause a shudder around 65 to 70 especially going up hill/ As soon as I take my foot off the gas it immediately goes away.something in the differential, four wheel drive, etc.

 

[1955moose]

Driveshaft out of balance, bad bearing or bent output shaft. CV shafts or bearings on front differential, not likely unless engaged, but maybe one or both sensors are activating front end. Where is the vibration emanating from exactly. The fact that it goes away when you back off throttle tells me it's either a bearing, or a load dependent item, as I mentioned above. Also be sure proper atf fluid along with correct level. Doesn't take much to make a torque convertor act up. Sounds like something out of alignment or balance.

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[deweysmith]

Yeah, if it's constant and only at a certain speed, I'd say a driveshaft u-joint is toast.

You can drive it in 4H at that speed, but I wouldn't recommend it on dry roads. If you have a long stretch of straight freeway you can try it on, that would be okay. It becomes an issue when cornering if the road is dry, you could get driveline windup/binding which could be catastrophic at those speeds.

My Tacoma had a bad u-joint and it vibrated like crazy in 2H from about 60-68mph. If I put it in 4H it would mostly go away, since the torque was split between the two axles. I originally thought it was a bad output shaft bearing in the front diff and basically rebuilt the whole thing and then it was still vibrating when i was done. I tried to shake the driveshaft and the u-joint yoke moved around pretty much freely inside the caps, all the needles were completely gone. It was great.

 

[rjdelp7]

Try disengaging the O/D on the gear selector. See if it makes a difference. I would keep going back until he gets right. An automatic should never be doing this. Something is wrong.

 

[Ed Schultze]

I really appreciate everyone's response I am going to go back. I like this guy and trust him. he does not get defensive and make excuses. I just wonder if maybe it is something else since he has rebuilt the trans twice. I would hate to have him rebuild it a third time if it is something else. It is also hard to be without a car but that is my problem

thanks so much

 

[briangelc]

I was convinced that I had a Transmission problem. I am a "car guy", do most of my own repairs, and am confident in my ability to diagnose problems.
I thought my tranny was going bad because of shuddering and poor shifting performance, but it turned out to be an engine misfire from several bad Coil on plugs (COP).
Side note: I did have a previous shuddering when the TQ converter tried to lockup, but 2 tubes of Lubeguard Dr. Tranny's Shudder Fixx corrected that immediately, and it ran fine for another 40,000 miles of towing 5000 lbs.
Back to the perceived tranny problem: there was NO check engine light because the frequency of misfires was not high enough to trigger the threshold for a CEL. I have been told that FORD uses a crazy high threshold for reporting CEL. Anyway, my mechanic data logged with his computer and found out which cylinders were misfiring, replaced 4 COPs, and the "shifting problems" and shuddering disappeared. it wass not in the tranny, but the motor, which confuses the logic of the tranny, and causes it to slightly malfunction