97 4l60E trans issue

[Gamikatsu]

I have a 97 Blazer 4 door 4.3 4x4 4L60E. Runs and drives great, with the exception of one little problem.

Once it gets warm/hot, the transmission starts banging into 1st gear, when downshifting. for example.

Driving along, 35+ mph. Come to stop sign, apply brake, stop. Let off brake and apply gas, Vehicle starts moving, slowly (presumibly in 2nd gear) then BANG 1st gear and goes as normal. 1-2 shift is smooth, as is 2-3 and 3-4. does not do it when engine and trans are cold. I had an electrical issue with the ignition switch, replaced the switch and fixed that issue. I do have a random cylinder 6 misfire popping up on occasion... thinking a carbon'd up contact inside the cap/rotor but i believe this issue is not related. if i manually drop the gear selector into 1, it does click/bang a bit into 1st but grabs hard, drives well... What are your thoughts? I have not tested the TPS yet... i switched the MAF with my wifes truck (96 4.3) just to test a MAF code i was getting with the bad ignition switch, which has sense cleared. i have two trains of thought on this...

1: solenoid sticking/weak
2: transmission mount weak/broke

any and all advise would be appreciated.

 

[Gamikatsu]

OK,

just ran by autozone and had them run codes... P1860 TCC PWM solenoid fault, and the guy cleared the code before i could write it down but its TCC clutch... is that a solenoid fault as well?

 

[rhino]

Most likely it is. It's an easy solonoid to replace, I would slap one on and try it. Would have been nice to know that other code though. If it was me, I would drive it a day or so and get them checked again. It may be the 1870 code.

 

[Gamikatsu]

Code still hasn't come back. last night i found the trans is torqing pretty bad in both directions (D and R with brake on) and the mount is oil saturated. going to do a fluid/filter drop and fill, and the mount. hope it fixes the problem. the fluid is red(ish) but is thick... not thin/wattery like it should be. I don't know what additives the previous owner has put in there..... Code has not come back yet. had it at 60+ mph, with TCC locked... it won't trip codes. i know the ignition switch being bad will throw every trans code in teh book... and i think it just hadn't cleared. i'm giving it to tonight... if the codes dont' come back, i'm going to do the fluid/pan. question however.. if i drop the pan/filter... how do i change out the fluid in the converter? i want to change as much as possible.

 

[rhino]

Good thinking...I would do the same. Let us know.