Tranny shifts hard from 1-2, intermitten...

[CAT_tahoe]

my 1996 Tahoe is shifting hard from 1st to 2nd gear, very intermittenly. when it does this the "Check Engine Light" comes on and by the time i get it to a shop ot have it checked not only is it not shifting hard but on an occasion or two the light has gone off...

 

one of the tranny shops i took it too recentley told me it was probably something with my torque converter, i think he called it an 1870 code or something, but didn't perticularly like the shop very much. just stopped in cause it was there on my way home and the hard shifting was getting on my last nerve at the time.

 

any ideas?

[GetMore]

I think any shop with a scanner should be able to pull up the trouble codes, which will give more information on the problem. I'm not sure if a '96 Tahoe is OBDII or not though.

 

It could be something as simple as a bad connection to a temp sensor, causing the PCM to put the tranny in warmup mode. Possibly the speed sensor. Who knows? We need more info.

[frdfandc]

Any vehicle from 1996 to the present is OBDII. If there is a check engine light comes on, it has stored a code, but it must be checked out immediately. If the vehicle goes thru 2 drive cycles (1 startup, 1 complete cooldown, then one more startup and one more complete cooldown) without detecting any problems, the code will clear itself.

[krugger]

I own a 1996 monte carlo and it has the same problem,I ran the scanner on it and it showed that the transmision was slipping, changed the oil and saw that there was some metal ressidue showing on the magnet, 1,000 miles later I changed the oil again and there wasn't as much and it no longer shifts like that, but I have been changing the oil on it every 3,000 miles, we also have a 1998 safari and it started to do the same thing, but since it was under warranty the repairs were covered, the dealer installed a new trany on it, I also own a 2005 silverado, it has 10,000 miles on it, after 2,000 miles it started to do the same thing, not as much but it does it now and then, I guess there is something going on with gm's transmisions.

[denton_12]

Mine would also do this sometimes, unplug the Mass Airflow Sensor and see if this changes the operation of the transmission, I just had to put a new tranny in mine last week, and when I got it back from the shop they said to keep the MAS unplugged, because it giving false readings was making my truck shift wrong. The mass airflow sensor ended up making the whole tranny go out after 31,000 miles according to them.