So the tranny won't shift for me, unless I shift it manually. If I put it in drive, nothing, put it in 3rd same, 2nd it will move, and 1st it will go. Once up to speed I can put it in 3rd, then OD. No lights or codes, no issues when driving otherwise. Ideas? I was thinking solenoids, but I don't know if it should be throwing a code.

 

Here's a copy/paste from what I posted at ZR2USA when I had similar issues.


Ok, blazer details first.

2002 ZR2 Blazer, 135k, automatic, 3 button transfer case switch. I have searched and read a lot but still have questions.

I got this code yesterday. Cleared it but it returned. I have no issues replacing the solenoid(s) but here's my questions.

Symptoms:
Seems blazer starts off sluggish as in another gear, 2nd - 3rd or so. Can pull shifter into first and pulls off better. Shift into drive and all seems to shift properly as long as I don't come to a stop. I can clear the code while driving and it doesn't return until I stop. Once coming to work this morning I cleared the code while moving and at one stop sign it acted perfectly normal upon take off. Next stop and pulled off, SES light came back on and started off in another higher gear. Only other strange issues I've noticed in the past is that driving down the road, turn off on side street without stopping, giving it gas to proceed, it wants to rev up briefly and then seemed to go in gear and go. It's done that for quite a while. Lately, it seems to have lost some power and wouldn't downshift when pedal was floored as it use to.

1. What parts and brands are you replacing these with?

2. Should I replace all solenoids when inside tranny? If just replacing the bad one, how do you identify them or which one it is? I'd hate to replace wrong one.
2a. What are the GM numbers if I decide to go this route.
2b. What other solenoids are in there and their GM part numbers? Would you replace these as well?
2c. I will be doing a filter change and all.

3. My tranny fluid was low. Possible fluid leaking into transfer case. I will most likely get GM seals/gaskets for this. Now would this be the transfer case intake shaft seal or the transmission tail shaft seal causing the fluid to overfill transfer case? I haven't checked the fluid level yet but want parts on hand for just in case. I know about the paper gasket. I can return these if not needed.

4. I will check and clean the electrical connections as I've seen posted and recommended in other posts.

5. I have no dash/instrument issues, just this one tranny code and what I described above. Hinting towards bad ignition switch as I've read about. No starting issues or gauge issues. It does have keyless entry.

6. If I get parts from GM, I guess they ill look them up by VIN for correct parts.

7. Filter change fluid capacity?

Thank you!




My fix:


Well it's done. Took my time. A real PITA but not difficult. Had to replace front seal in transfer case. Removed top fill plug and fluid gushed out. I used all OEM GM parts. Also replaced both shift control solenoids while I was in there. I took it as a little bit a insurance. Part numbers listed for future reference. Blazer is now code free. No more P0758. Also had to reset the TCCM since I didn't disconnect the battery. It didn't want to shift to 4 HI or 4 LOW. All ok now. Runs and shifts fine again.

24230297 shift solenoid (S) VALVE A25
14095609 transfer case input seal (S) SEAL A28
15642511 paper gasket between trans and transfer case (S) GASKET H8
24208576 transmission filter kit, gasket and seal (S) FILTER D8

 

Thanks for the quick response, wasn't expecting anything from anyone for a day or two. The unfortunate part for me is no cel or code. Seems I have a shudder at low rpm in drive, so I'm thinking tcc solenoid, I'm hoping nothing more serious than the solenoids, all seals seem to be fine, nothing leaking, fluid isn't burnt, so I'm hoping...