Hey, I am new here but I did search the forum for this problem with no returns.

Here it is, between 40-60mph the torque converter is locking and unlocking. Only when in 3rd or overdrive, and it kicks in and out routinely about every 5-6 seconds. It also shakes the truck a bit when it does it.

I have a 98 K1500 EX-Cab Short bed. 5.7L 4L60E. 177,000 miles

I want to know your thoughts on the possible fix's, I think it is the TCC solinoid. But the torque converter seems to be getting weaker at lower speeds around town. But a buddy of mine said it could also be a computer thing.

I just serviced the trans and transfer case about 2 months ago after this problem started. (wanted to rule it out)

Please let me know what you guys think.

Thanks, Gary

 

I have seen this issue many times. Usually the issue is with a lock up valve in the valve body and also a check ball that is stuck in the separator plate. The valves in the valve body can be pinned using a longer spring from a 4l60e pump and the separator plate will need to be replaced. You could also install a trans go shift kit to address this issue and get a new separator plate. HTH Vince

 

Thanks sir, so that will address the locking and unlocking issue, how about the sluggish shifts at lower speeds than the locking problem. I would gather the shift kit would fix this as well, but trannys are not my specialty.

Also can the shift kit and seperator plate be replaced with it in the truck? And where would you reccomend getting the parts from?

 

Looking at the mileage your trans might be a bit tired! The kit might help however if the trans is damaged it might not help for long. When you dropped the pan last how did it look? If it had a bunch of debris then I would say to start thinking about a trans or if you want to take a chance install the kit and hope for the best. I'm not saying that the advise above is the exact problem but in my opinion from what you have said is where I would look. HTH Vince

 

Thanks for the advice. The trans looks great. The fluid wasnt bad and the only reason it got changed was because of the converter. There has never been any more debris in the pan than what would be wearing off the plates and clutches. So I am not worried about the internals. The bottom passage plate looked fine, i didnt see any discoloration or anything I thought was out of ordinary.

As far as the sluggish shifts well hopefully the shift kit fixes that too.

Thanks for all the help. I think I will stick around here.

 

My truck started doing this same thing about a week ago. Mines a 99' with the 5.7 4L60E with about 116,000 miles. When it happens the truck is warmed up and cruising around 50mph. It doesnt happen every time I drive though. It also seems to be driving much looser than it did before too. Between shifts, especially going from 2nd-3rd the RPMs hardly drop at all.

 

Yep, mine didn't start doing it till about 174,000 miles though. I will definetly be doing the fixes that were recommended.

I will post the results when completed.

Also to Chevyman90, it will get worse quick, but then it will flatten out. Mine started it and got worse and worse within a few months. Now it hasnt gotten much worse, and is still driveable, allthough I have changed my driving habits a little to help prevent the truck from doing it too much. Mainly just accelerating and decelerating harder and more often in the MPH range affected.

 

Which kit would you reccomend?
SK®4T60E-Jr
Or SK®4T60E
Both are from transgo.
Also get the seperator plate from transgo?

Lastly can this all be installed with it in the truck or will I need to remove it to do it right?

Thanks, Gary

 

I believe the HD2 is the one everybody usually gets for 60e.

 

There all from transgo but I believe the kits u mentioned were the orange box. That's a really mild shift kit. I st do the hd2. U might want to becareful on the 1-2 set up and try to go soft. Or else i'll notice ur shift really hard. U might not like it. Im use to it