Transmission Slipping

[Klaatu55]

Good Morning All, Problem again,recently changed transmission fluid,and filter, (month ago) Noticed that transmission is hanging between first and second gear,It seems to get better as car warms up. What could I have done wrong? What can I check now? I changed filter and fluid because it was time,had no previous problem.Thanks

[4.3LXJ]

Is it slipping or just not shifting?

[Mudderoy]

Yeah does it keep increasing in RPM until about 4k then shifts?

[Klaatu55]

You,re right. It's shifting late,as opposed to slipping back. It revs up to about 3,000 rpm as opposed to the usually 2,000,before it shifts to the next gear. Also I had forgotten that my jeep had thrown a code P0751. (Shift solenoid A check performance or stuck off) I wrote it down cleared it and forgot about it because it never came back. I just remembered it and am going through past post now. Good information from orderdene and White Rabbit. not sure how to reference past post yet. I do remember two sets of plugs on transmission when I dropped transmission pan to change filter. Wonder if I ..... Oh No. Driveway is very cold today. It seems to go away once engine get thoroughly warm. I'll soon get use to the new shift point and back off the gas. Maybe wait for warmer day,if it won't harm anything in the meantime. Thanks all

[4.3LXJ]

You may have answered your own question. But also you might have some throttle position sensor issues too here. Pull your battery cables and touch the two together just for giggles. Might cure it. Since it straightens out when warm, I suspect that the shift solenoid is functioning. That is the thought here. You might drive it cold and then check for codes too before warming up to see if you get one.

[dagod16]

Hey, my transmission seems to something very similar lately. But mine is garage kept and I let it warm up every day. between 1st and 2nd it seems like it revs up just a little bit more before shifting., I will watch the RPMS when I leave work today and see. Once it's warmed up then its fine.

I also changed my transfluid and filter a few months ago.

Any thoughts as to what it is?

[4.3LXJ]

I think both of these issues are throttle position related. Any check engine lights?

[dagod16]

I checked it out today when I was driving. My rpm's never really go up, but when I get to that 1st to 2nd gear range it feels like it has a little bit of hesitation. do you guys still have the same thoughts?

[4.3LXJ]

So you are talking engine hesitation?

[dagod16]

kinda feels like shifting hesitation, and its not bad, I only notice when everything is cold , right at start up. And a stranger would never notice it, but thats because I listen to my vehicle

[Klaatu55]

Transmission seems to have straightened itself out. Since it's cold out and I have remote start I have been letting car warm up longer then usual,and last weekend I snatched drive shaft out to grease spline which I had recently discovered should be part of scheduled maintenance. Once off the jeep I found that even though drive shaft had no apparent play while on car,once off, the back universal Joint (while not froze) was 10 times stiffer than the front one and needed to be changed. One or all of these things may contribute to the jeep shifting better.