Mailbu Transmission Problem

[oldrock&roller]

I have a 99 3.1 170,000 miles and a transmission problem. When shifting to 2nd from 1st its like trying to hold in 1st and them shifts hard into 2nd. It will also do this when running 60 mph and push down in passing gear, I changed oil and filter and there was no metal or clutch particles in the pan it was the cleanest pan I ever saw. Any recommendations? Thanks for your replies.

[bcopeland]

Same tyhing in my Yukon. I replaced the tranny. However, in my Bu I replaced the filter and it ran well for about 3 months. Then the same thing but I replaced the fil;ter again and it runs fine. You might want to do another filter change.

[niccaleb112602]

It might just be a bad solinoid in the valve body. I'd have a good quality scanner hooked up that gives real time data and drive it to see if maybe the high pressure switch is operating properly. Figure with that many miles you could have one going weak. Just a thought

[jimmypodunk]

My 97 Astro has a 4L60E tranny and it did this for 3 years every summer. In the winter it was fine. I got a P1870 transmission component slipping error. I finally installed a Transgo shift kit I bought last year that is suppose to eliminate this problem. It now has a nice firm shift but it doesn't kick harshly anymore and the P1870 light hasn't come back on yet. The real test will be when I take it for a long road trip in the hot weather this summer.

[markag6]

I don't know if it is the same thing or not, but last summer both my dads 97 silverado and my 96 Grand Am shifting really funny. It would rev higher then usual before a shift at any speed, then it would jolt into the next gear when it did shift. It turns out that our alternators were bad. We replaced them and problem was solved. I guess the alternator wasn't keeping the system charged and the computer wasn't getting enough power.

[oldrock&roller]

up date.. Had some error codes strored in computer low voltage at tps and low flow at egr. Got those taken care of but still got the trans problem. How many shifting solenoids are there? (2) one for 1-2 one 3-4 is this correct. I took it to a trans shop and no codes was stored for trans.. whats me to take it in and leave it for some test. I feel the big one coming... Thanks for all your replies and sugestions. Anyone else care to commet?