I have a 92 6.5TD with a 4L80 transmission truck has 4.10 gears. The transmission has a vibration or shudder when in o.d with moderate throttle applied. If the converter unlocks the vibration stops. If light throttle is applied going up a hill it does not do this. I have added 2 bottles of Anti-shudder additive and it maybe helped slightly?
Is this typical with these or is the converter and or transmission going south? Would a shift kit possibley increase fluid pressure to the lock up portion of the converter?
This transmission shifts fine and the o.d and conveter seems to work well other than this vibration!
I know nothing about these transmissions but could eaisly change out what ever is wrong here.
Thanks in advance for your help!:help2:

In case anyone is interested in knowing how this turned out. I replaced the torque converter and that took care of all the vibration or shudder that I had been experienceing! This transmission has some life left in it after all!

In case anyone is interested in knowing how this turned out. I replaced the torque converter and that took care of all the vibration or shudder that I had been experienceing! This transmission has some life left in it after all!

the internal failure of the trans components caused this. Your new converter will not last.

Mike, what in the trans causes this? I had a very similar problem before I installed the Transgo kit. Just curious.

Justin

Justin
Age has a lot to do with this kind of failure. Not enough fluid going to the right place and valve body wear all contribute to this. Teflon rings that broke down and bad design in general. In this particular post we can picture a 95 year old person getting a liver transplant. For all you guys that are listening; if you get your 4L80s rebuilt, have the valve body bored with Transgo kit, otherwise you will be back at your trans shop and they won't know why it failed so soon. You can heed my tech info or tell me to f/o. Your problem
mike

Mike,
I understand what your saying. When my tranny was out the guy I took it to said that there were some o-rings that were cracked and broken. Surprisingly all the other internals looked fairly good after 120K. Ironicaly the Transgo went in shortly after. FYI, I think anyone wanting good life out of the 4l80 needs one of these kits. Those line pressure modules just don't cut it in my book. Thanks for the insight.
Justin

I've always heard that the when the 4L80 is good its good, but when something goes its like a nuke went off inside of it. The local trans shop said he won't rebuild any trans without a transgo shift kit and a suncoast convertor, he also gives a 1 year unlimited milage warranty and does mostly work trucks. And I don't see him with comebacks.

This is some important tech info for you guys, and probably the most important reason for a Transgo s/k. Behind the manual valve ( this is the main control valve that the shift lever moves to select your gears) is a plastic filter with a sealed o ring whixh is known to crack and fall apart. When and if this happens, mainline pressure can shove this valve into another gear ( your shift lever will fly up, possibly into reverse ) and cause all kinds of bad things. The Transgo s/k will prevent this from ever happening. No I am not a pimp for Transgo, but I don't build many transmissions without it.

I recall putting a different filter in with a roll pin or some such thing... You mind giving a complete run down of what the Transgo will do for a 4l80?? It won't help me anymore, but maybe others will listen and follow suggestions.

Hey thanks for all the replys. Now when I first asked the question on this I was looking for this kind of imformation and would have put the transgo kit in at the same time. Yes I have been to my local transmission shop and he said that if the new converter did not shudder any in lock-up mode that it would be fine. But if it shuddered any at all to put the kit in imedieately. Well I guess now after reading "Mike's" imformation I will put a kit into this 95 year old woman. Thanks!