Tyger255

Hello, I have a 2003 suburban and the transmission has started to slip (revs up high before going into gear) when shifting from 2nd to 3rd. I had someone tell me that there is nothing you can do but a rebuild for this issue. Is this correct? I was going to change the filter and do new fluid but if its not going to help I don't want to waste the money. Also I did not know if it could be a shift solenoid that I could replace that could be the issue. Let me give a bit of back info...

About 6 months ago I had the rubber section of one of the transmission lines split and I lost a bunch of fluid. Trailered it home, found the problem and repaired the line. Added several quarts of fluid back into the transmission until it was close to the full mark. Let it sit for a day, drove it the next day till it was warmed and checked the fluid, did this over the next 2 days adding a little fluid at a time till it was full. checked it about a week later, still full so at this point I didn't check the fluid any more. No issues when using driving, everything seem to work with on issues. So about 2 weeks ago it started slipping, so I checked the fluid it was reading that it was over full. Got it home, made sure I'm on flat ground ( same spot as before when filling) still reading over full. So I pulled almost 2 quarts out of it before its showing the correctly level. I have a bottle of lucus stop slip for transmission that I was going to add this weekend to see if it would help.

Not sure if any of this info helps, but there it is. Is there anything I can do, or is it rebuild time...?

Irish_alley

i would try the lucus but other than that theres prob not much you can do. if you change the fluid then it may shock the trans and kill it. on my impala when warm if i dont shift it to 1st at a stop it will slam into gear but if i down shift to first then build up the rpms to 2k or so then shift it wont have any issue. this might work for you, but a column shift this would be a pain to do at every stop. but if it solves the issue it might just be a sticky solenoid. does it slip ones it finds the gear and you try to take off?

Tyger255

taking off from a stop it goes into 1st with no issues, shifts into 2nd gear perfect, when shifting from 2nd to 3rd you hear the RPMs go up and feel the accelaration stop for about 3 or 4 seconds, then the RPMs drop back down and it goes into 3rd. if I let off the gas when it starts to shift it seems like it goes into 3rd gear better. After 3rd it shift to 4th and OD with no problems. Feels like its starting to slip going into 3rd, or its just really slow to shift from 2nd to 3rd.

Cusser

I would check for ATF leaks first; if level was OK, I would do the ATF and transmission fluid change to see if that helps

This helped years ago when I had similar issue with transmission on my 1988 Suburban. On that, we were scheduled to go on vacation in two days; I actually filled once with ATF with no help to vehicle, so I did a 2nd drain and fill, and it was OK.

Our 2005 Yukon Denali did need a new transmission at maybe 150K miles, cost $2K. Now at 220K so it was worth it.