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WTB: New 1989 TCC

Posted: Tue Jun 26, 2012 10:16 am
by themixer
Does anyone have the GM part number of the TCC for a 1989 2.8 automatic? I am looking to replace mine with a genuine part.

Or if anyone has one new they can sell me that would be awesome.

Re: WTB: New 1989 TCC

Posted: Tue Jun 26, 2012 11:22 am
by 3X00-Modified
This is about as "genuine" as you will get for an 89... And why would you want a genuine part? they fail all the time

ACDELCO Part # 8689901

Right on rockauto under transmission and control solenoid.

Re: WTB: New 1989 TCC

Posted: Wed Jun 27, 2012 1:05 pm
by ifixalot
You don't have to buy a new one if you don't want to and if you are reasonably handy.
The reason they fail is because it is a coil of wire wound around a plastic spool. The wire
is stretched as it is wound creating pressure on the plastic spool. Inside that spool is the
metal rod that holds a ball to close the passage for the TCC to drain. While the solendoid is energized,
the rod is held up against the ball. When it is not energized, it is suppose to release the ball.
As heat softens the plastic, the spool collapses little by little until it keeps the rod from sliding freely
inside the spool. It holds the ball, which wont release fluid and the TCC sticks. Once the car cools down,
the plastic thickness of the wall decreases and releases the rod and it works until the car warms up again.
What I did on all of mine was to take the solenoid apart and drill out the plastic inside the hole
with the next largest drill bit. It's a little tricky because you have to break some spot welds
to get it apart.
On the 89-90, I had to cut my wires to get it out and I spliced the wires with wire nuts.
Don't worry about re-welding it because the bolts that hold it in will hold it together once you have it
re-installed.
The reason I took this approach was that I've heard new solenoids can fail as they age and
I wanted it fixed for good.

Re: WTB: New 1989 TCC

Posted: Tue Jul 17, 2012 8:33 am
by themixer
hey sorry i totally missed these posts, so should i be installing an aftermarket component? i would like to not modify and bolt on something that's reliable. I completely missed this on rock auto, i just put in a $400 order from them

Re: WTB: New 1989 TCC

Posted: Tue Jul 17, 2012 8:41 am
by 3X00-Modified
Just because the part is "aftermarket" does not mean it has to be modified to fit... Just buy a tcc solenoid from anywhere and replace it. Odds are you will be getting rid of the car before it fails again, or it just wont fail again.

Re: WTB: New 1989 TCC

Posted: Tue Jul 17, 2012 8:44 am
by themixer
I was referring to the comment above about drilling out the part, I plan on keeping this rust free beretta for a while!

Re: WTB: New 1989 TCC

Posted: Tue Jul 17, 2012 8:57 am
by themixer
Just called my local autoparts store that couldn't find a listing before for the TCC and they have the "control solenoid". I guess its all about asking for the right part. They can order the standard TCS20 component, would this be just as good as any?

Re: WTB: New 1989 TCC

Posted: Tue Jul 17, 2012 10:18 am
by 3X00-Modified
Yes there is only one control solenoid in the trans. I have no idea what brand they are selling so I can't say if its just as good as any, that's what you'll have to decide when you get it.