Torque Convertor not locking up

firecadet613 · June 17, 2004

I've got a rebuilt 4l60e in my 95 Blazer. Problem is this. The torque convertor will function properly, ie locking up on one trip, but then the next trip it will not lock up. No check engine light due to this. What should I look for and what could it be? I have no idea why this is intermitent.

Joe

firecadet613 · June 18, 2004

PS- less than 300 miles on the rebuild, I'm calling the rebuilder in the AM to find out what exactly he did and what could be causing this.

citydriver · June 18, 2004

I'm reading thru my service manual and it has a bunch of things to check..

Electrical: 12v not supplied to tranny (fuse?)

Outside electrical connector damaged

Inside elec. connector,wiring harness or solenoid damaged

Elec. short(pinched solenoid wires)

Solenoid not grounded

TCC Solenoid

Engine Speed Sensor

Bad Converter

Engine Coolant Sensor

Thats just a start,there's more that involves the valve body and oil pump and other internal parts that the rebuilder should have inspected/replaced as they were working on it.

firecadet613 · June 18, 2004

Well the problem is fixed. Here's what I did. Unplugged the 13 PIN wiring harness from the trans and sprayed both that connector and the one on the trans with QD Electrical Connection Cleaner. I readjusted the park/neutral switch as well as the brake switch. It works . The park/neutral switch still needs some fine tuning, and if anyone has any tips on that, that would be awesome!

Joe

citydriver · June 20, 2004

Glad it was only the connector

Did you reuse the old switch,you can try and line up the witness marks that the bolts left....of course they make a special tool for alignment(J 41364 A) or you can apply the parking brake and turn the ignition ON engine OFF and put the tranny in reverse and adjust the switch till the back-up lamps come on...or there may even be a hole in the switch that may have had an alignment pin (usually a plastic pin) that aligned the switch in neutral..that you may be able to use a drill bit in as an alignment pin...just dont forget to pull the bit out...just a guess

firecadet613 · June 20, 2004

Hey, where would I find this tool used to adjust the park/neutral switch on my 4l60e? It is aligned for the most part but it does not register correctly sometimes to a gear change on the electronic indicator on the dash.

Joe