I changed plugs and broke the transmission!

[cris2004]

At least I hope not.
I have a 1998 1500 4wd, 350cid. I don't usually mess things up, but after swapping plugs, rotor and cap, The low idle only developed a 'lope'. I intend to check plug gap, but now the transmission is acting up.

It sounded like it was trying to kick into the front axle drive for 4 wheel, and then made a bit or a grinding noise. I can't get it in reverse, the motor just surges and it doesnt sound like it ingages. I can still go forward, but a slight unusual noise remains. Shifting to 4 high or low doesnt seem to effect anything.

I have 185000 miles from new, so it wouldnt be a shock if it's done. I just can't help but believe I didnt bump a vaac hose, or some kind or actuator wire. (I dont know how to check) A vaac leak would explain both, but I dont hear one and have checked what I can see.

Any advice on testing for a vaac leak or what I might have hit while paying around the engine surface? Thanks!

[idahogroundhog]

Sounds like a random death on the tranny, because of the presence of grinding, but an easy way to check for vacuum leaks is to take a can of carb cleaner (with the air cleaner still on) and spray a light spray around the connections of the hoses and if the engine idle goes up there is a leak present. But be sure there is a good seal between the cleaner and the intake.

[cris2004]

Thanks. It isnt so much a grinding as it is a binding or some odd thing.
I really think it is not shifting completely, or not being told to shift completely.

I did some more research, and apparently the TCM ( thinks thats it) sends a signal to the unit. It may be what I messed up.
Apparently, this is all electronic without a vacuum modulator.

I found an encouraging post from' Hallfleming' dated 12/11/04 on a 97 problem. Sounds very similar to mine. His fix was a 'pressure regulator valve'.
I havent found out what or where this is, but it's where I'm at now!

If anyone is familar with replacing this, I'd appreciate the help.
Thanks!

[94century]

Also check to make sure you did not bump the shifter linkage. It will be on the steering shaft. Sounds like it could be that.

[cris2004]

Thanks, but this one's all electric. My 66 Malibou has linkage on the column...


I have seen scan results and code on trannys. Is this a specialized unit or the OBD II? I have no codes on the latter.

My focus now is a sensor giving bad orders or that pressure regulator. I suppose pulling it out is next.

[94century]

OBD-2. If it is electric try disconnecting the battery for 15 minutes and reconnecting it.

[cris2004]

I may be out of luck then. I pulled the batt to replace it, coincidently enough, and get no trouble codes on the OBII.