Clutch slipping, transmission slipping, or something else

[GShail]

Clutch slipping, transmission slipping, or something else?

I just pulled off of the highway about fifteen minutes ago from transporting some cars. On the highway the truck flys right along like a mean machine. However when I pulled off the exit and up a steep hill going into town I started getting a herky-jerky motion from the truck, much like you might experience if you were going over a bad washboard road or perhaps had a flat tire. Got out and looked at the truck and crud, no flat tire.



The herky-jerky motion is barely and I mean barely pronounced in first gear, it is quite strong in second, and fairly strong in third. In fourth, fifth, and sixth it seems pretty nonexistent but I kind of think I ran out of hill plus momentum puts a different load on the clutch and trans.



I took a spin around town and went down a hill using my exhaust brake and get the same herky-jerky motion in third and second going down hill.



The trailer has only one heavy car on it, a 61 Deville, and I estimate my load with trailer and car to be about 11,000 to 12,000 lbs.



I got under the truck and don't see any fluid leaks or broken U-joints that I can detect. I have been meticulous about changing fluids in the transmission and the differentials. I am about due for a new clutch.



Please tell me I probably just need a new clutch and that my transmission is likely OK. My transmission has about 90,000 miles on it and the clutch has about 110,000.



Help I need to go to work this week and need to know what you fellas think I am probably up against.



I sure appreciate all the help I have received as a member of this forum.

 

[MMeier]

Hey George, up for another round of fun I see. Does the center support bearing " appear" to be O. K. ? Sometimes when loaded I get something similar in 1st and 2nd. trans shop says everything is O. K. Just put the 6 speed back in after pulling it wednesday and running it up to SLC then picked it up friday morning. just put this unit in 5 weeks ago, second week it started making some kind of noise after it warmed up. Guy in SLC said he found a " chipped " tooth and replaced a shift rail, bust our balls on this thing, put 1700 miles on my buddy's duralax and guess what..... ??????? IT STILL MAKES THE SAME DAMN NOISE!!!!!!!!!! #@$%! #@$%! Heading out for the containers yards of SoCal tonight, lets see what kind of fun I can have this week!

 

[GShail]

Just went out and crawled underneath the truck again with the flashlight, the center support bearing seems to be OK.

 

[GShail]

After some food and a shower I went back outside and disconnected my truck from the trailer and took the truck for a spin. Everything seems normal. I ran the truck uphill and ran the truck downhill. I took it on the freeway and really lit her up. Nothing abnormal. No herky-jerky motion. No wierdness in any gear. I suppose to duplicate the previous symptoms I will have to reconnect the trailer. I'll try that again in the morning.

 

[Little Bill]

Could be your rear springs wrapping up. I had similar experience in my '01 that was cured with a set of ladder bars.

 

[JCleary]

I had similar symptoms with my truck.



It would only happen while loaded and hot.



Turns out the stock u-joints were shot. All of the bearings were dry and two had turned to powdered metal.



I replaced them with greasable Precision 351's and have not had a problem since.

 

[NIsaacs]

I would check everything on the trailer, from the frame, to the hitch, to the axles/suspension. Also, maybe the placement of the one car, in relation to the hitch/trailer axles.





"NICK"

 

[GShail]

The trailer is absolutely perfect right now, just changed out the equalizers for brand new ones and everything else is legit. The placement of the cars is also sound, I know what I am doing when it comes to loading the cars and placing them properly. Do not believe it is the rear spings wrapping up either, I have airbags on the rear and everything is cool there also.

 

[DPKetchum]

First thing that hit me after reading was a u/joint binding.

 

[GShail]

Well after a closer examination i think that it is the center support bearing as MMeir has suggested. The rubber part is fairly torn , I coudn't see it very welll last night in the dark. I have an appointment with the driveline guy at Six States in the morning, and have my new center support bearing on hand. Hope this will rectify the problem.

 

[jelag]

I'm an owner of an 04 with almost 200K miles pulling a 22K lb trailer... .



We put a clutch in the truck at 100K from the noise your talking about... the ujoints seemed tight and good... . got the clutch back in... . and had the same problem... and we're in the business... the old clutch was due... the disc had some severe damage to the hub and springs... we put a HD unit in... .



The real problem was the ujoint and carrier bearing..... as we pressed the ujoints apart. . we noted that the needles were rust... . we couldn't feel it by hand... .



We replaced the ujoints with greaseable ones and a new carrier bearing as well... .

 

[GShail]

Replaced the center support bearing and still have the herky-jerky symptoms. The carrier bearing and the center support bearing are one and the same aren't they?

 

[Money Maker]

updates???



what was the fix????