Shudder when shifting up, what do I do?
Thread Starter
Junior Member
Joined: Sep 2010
Posts: 10
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From: Salt Lake City, UT
Shudder when shifting up, what do I do?
Checked the forum and can't find the solution, any suggestions appreciated!
I recently bought a 2002 5.4L, 7700 package, with 145k miles. 20% of the time my automatic transmission shifts up, I get a shudder that sometimes is barely noticeable and other times lasts up to 2 seconds. It is a vibration that is similar to going over a rumble strip. I can't tell if it is a connected problem to my positraction going out or if it originates from the transmission. It happens only when shifting up. The shudder happens more often when I'm flooring it or under a load.
The dealership claims my torque converter is slipping. They said although my transmission fluid doesn't look bad, it is definitely old (not the Mercon V), and a Technical Service Bulletin from Ford claims changing the fluid might fix a torque converter slip. Otherwise, I'll just have to replace or rebuild the whole transmission. Others claim servicing a transmission this old with no history might just cause more problems.
I had another transmission tech drive it and he thinks it's probably just the positraction slipping in the back. Gears shift well and strong otherwise with no spikes in RPM's from slipping.
At this point, I don't really care how much it costs as long as I'm fixing the right thing. Any ideas on what it could be or what I should do?
I recently bought a 2002 5.4L, 7700 package, with 145k miles. 20% of the time my automatic transmission shifts up, I get a shudder that sometimes is barely noticeable and other times lasts up to 2 seconds. It is a vibration that is similar to going over a rumble strip. I can't tell if it is a connected problem to my positraction going out or if it originates from the transmission. It happens only when shifting up. The shudder happens more often when I'm flooring it or under a load.
The dealership claims my torque converter is slipping. They said although my transmission fluid doesn't look bad, it is definitely old (not the Mercon V), and a Technical Service Bulletin from Ford claims changing the fluid might fix a torque converter slip. Otherwise, I'll just have to replace or rebuild the whole transmission. Others claim servicing a transmission this old with no history might just cause more problems.
I had another transmission tech drive it and he thinks it's probably just the positraction slipping in the back. Gears shift well and strong otherwise with no spikes in RPM's from slipping.
At this point, I don't really care how much it costs as long as I'm fixing the right thing. Any ideas on what it could be or what I should do?
Senior Member
Joined: Nov 2010
Posts: 103
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From: Fl
If its the differential when you make a sharp right hand turn real slow it will chatter and I recommend to service the transmission cuz it won't hurt it and when you change the oil change the filter as well inside the transmission inside the bottom of the pan. If it chatters when you make the right hand turn they have an additive for a limited slip for the friction.
Thread Starter
Junior Member
Joined: Sep 2010
Posts: 10
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From: Salt Lake City, UT
Thanks. Yeah, it chatters when I make the right hand turn from stop. I have serviced the rear diff with new fluid but that didn't seem to make a difference for either problem. The mechanic I talked to claimed I needed to replace the posi-clutches and go from there but I think I'll start with your suggestion with the friction modifier. What additive should I use for the friction modifier for the rear? Can I just purchase that and do it myself or do I have to re-drain the fluid again? I will probably service the transmission like you said and see if that helps the shudder problem when shifting.
Senior Member
Joined: Nov 2010
Posts: 103
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From: Fl
You can buy the "Friction Additive" at Ford or Chevy. and it comes in like a 4 once tube. One should fix it and you should notice a difference in a couple of days. If it doesn't fix it run it for about a month before adding another tube. But don't forget when you service your transmission that you must change the filter inside the bottom of the pan cuz its probably stopped up.
Senior Member
Joined: Sep 2010
Posts: 330
Likes: 2
From: Middleburg, FL
My brother's jeep does the same thing. Took it to the transmission shop and they said that there are 3 or more clutch plates in an automatic transmission that are applied when shifting. If you have done alot of towing a boat up a ramp, mudding or pulling people out and don't use the 1st gear on your transmission it will put alot of wear on those plates. I don't think that its your torque converter.
Meaner than Ymeski
Joined: Oct 2009
Posts: 23,811
Likes: 828
i would service the trans....
With the modifier you might have to take a piece of hose and run it down the fill hole...plug the end of the hose that is sticking out and pull the hose out.. then add the modifer.... if you add the modifier when its too full you might loose the modifier by it just over filling...
With the modifier you might have to take a piece of hose and run it down the fill hole...plug the end of the hose that is sticking out and pull the hose out.. then add the modifer.... if you add the modifier when its too full you might loose the modifier by it just over filling...
Land Surveyor
Joined: Nov 2008
Posts: 20
Likes: 0
From: Shelbyville, TN
Checked the forum and can't find the solution, any suggestions appreciated!
I recently bought a 2002 5.4L, 7700 package, with 145k miles. 20% of the time my automatic transmission shifts up, I get a shudder that sometimes is barely noticeable and other times lasts up to 2 seconds. It is a vibration that is similar to going over a rumble strip. I can't tell if it is a connected problem to my positraction going out or if it originates from the transmission. It happens only when shifting up. The shudder happens more often when I'm flooring it or under a load.
The dealership claims my torque converter is slipping. They said although my transmission fluid doesn't look bad, it is definitely old (not the Mercon V), and a Technical Service Bulletin from Ford claims changing the fluid might fix a torque converter slip. Otherwise, I'll just have to replace or rebuild the whole transmission. Others claim servicing a transmission this old with no history might just cause more problems.
I had another transmission tech drive it and he thinks it's probably just the positraction slipping in the back. Gears shift well and strong otherwise with no spikes in RPM's from slipping.
At this point, I don't really care how much it costs as long as I'm fixing the right thing. Any ideas on what it could be or what I should do?
I recently bought a 2002 5.4L, 7700 package, with 145k miles. 20% of the time my automatic transmission shifts up, I get a shudder that sometimes is barely noticeable and other times lasts up to 2 seconds. It is a vibration that is similar to going over a rumble strip. I can't tell if it is a connected problem to my positraction going out or if it originates from the transmission. It happens only when shifting up. The shudder happens more often when I'm flooring it or under a load.
The dealership claims my torque converter is slipping. They said although my transmission fluid doesn't look bad, it is definitely old (not the Mercon V), and a Technical Service Bulletin from Ford claims changing the fluid might fix a torque converter slip. Otherwise, I'll just have to replace or rebuild the whole transmission. Others claim servicing a transmission this old with no history might just cause more problems.
I had another transmission tech drive it and he thinks it's probably just the positraction slipping in the back. Gears shift well and strong otherwise with no spikes in RPM's from slipping.
At this point, I don't really care how much it costs as long as I'm fixing the right thing. Any ideas on what it could be or what I should do?
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Thread Starter
Junior Member
Joined: Sep 2010
Posts: 10
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From: Salt Lake City, UT
rawhite71: Did you try servicing the transmission first and if so, did it help at all? The dealership says with 145k on my tranni, if I'm going to drop it to replace the torque converter, I may as well replace the transmission. Did you only replace the torque converter? And if so how much did it cost? Thanks.
Land Surveyor
Joined: Nov 2008
Posts: 20
Likes: 0
From: Shelbyville, TN
rawhite71: Did you try servicing the transmission first and if so, did it help at all? The dealership says with 145k on my tranni, if I'm going to drop it to replace the torque converter, I may as well replace the transmission. Did you only replace the torque converter? And if so how much did it cost? Thanks.
brorip: Sorry to be so long getting back to you. Haven't been online for a while. I did service the transmission, had it vacuumed clean and added back the Merc V as the manaul states. The tranny runs great but still had the shudder/groan noise. The converter was all I replace. Bought it from a transmission part house in Murfreesboro, TN for I think about $150 to $180. Its been a while. Hope this helps.
