stilealive

So it locks-up perfectly in both 3 and D when engine is cold....and it locks-up for a little while as it warms up....Once it’s all the way up to operating temp after driving for 20 min....it will not lock-up in either gear.

Everything else is in 100% perfect working order.

4L60E
3200 Vigilante Stall Converter
Full fluid.....very clean

What could it be...?

EDIT-UPDATE: Changed the internal wiring harness with new lock-up solenoid. Thats it. All fixed.

Jays_SSZ28

iTrader: (2)

Could be a 4L60E. 4L80E. 700R4. 200 4R. TH350C.

In other words more information might help.

stilealive

damn....sorry.

4L60E
3200 Vigilante Converter

stilealive

A couple people said it’s the lock-up solenoid.

Can it work perfect while cold and then not work after hot???

mk3cn4

iTrader: (3)

I think there are a lot of things that will cause it to not lock, first thing I'd do is get a scanner and see if the computer is commanding it to lock. If so and it's not locking, then I'd say it's something mechanical. I think that would throw a CEL though when it saw the slipping, not sure. Next thing, if the computer isn't commanding lock, then the computer is seeing "bumpy road" or other criteria that it thinks it better to not lock. I think misfire detection being misconfigured can also cause it to not lock, especially if you have a lightweight converter. I'm not a pro so take with grain of salt, that's how I would tackle it..

98CayenneT/A

Wore tcc valve

Jays_SSZ28

iTrader: (2)

How long has it been installed?
If new it might need tuning. If it's been together a while it could be the tcc regulator valve as mentioned.

stilealive

It was rebuilt last time about 6 years ago.......never been touched since. Just started doing this about 2 weeks ago.

Does the TCC valve get replaced if I buy a new internal harness......is that part included in the harness? I can get a brand new harness for $40.00, I know it includes a new Lock-Up solenoid. But they never mentioned what else it has....

Jays_SSZ28

iTrader: (2)

The solenoid comes with the harness.
What you describe is a worn tcc regulator valve in the valve body.
Very common.

stilealive

My transmission guy said the harness with the lock-up solenoid is an easy swap......1 hour he said.

What about the TCC....can that be done at the same time? How long will that take to relace the TCC.....?

Jays_SSZ28

iTrader: (2)

The valve body would have to come out and the tcc regulator bore reamed and an oversized valve installed, usually a Sonnax valve with a sleeve.

Or a TransGo valve, maybe even a Fitzall. Some builders can rig it by installing the valve backwards.

This might be the most common problem with this transmission. Sometimes it sets a code, sometimes it doesn't.

What happens is the oil is slightly thicker when you first start out, then it gets thinner and leaks past the valve more.

Could be other things like a misfire. I've seen a bad TPS sensor do this also.

But, like I said, it might be the most common problem with this transmission so it's going to happen sooner or later so it wouldn't hurt to take care of it.

I wonder what was done during the last rebuild, most builders who know what they're doing add a better valve at each rebuild to prevent this problem.

stilealive

My builder just told me he put a Sonnax valve in last time he rebuilt it.

Can we rule out mechanical issues.....since it locks-up strong in both 3 and D when its cold, and since there's zero slipping and any other shifting or operation problem?

There are no codes showing right now.

Jays_SSZ28

iTrader: (2)

I guess if your transmission guy thinks it's the solenoid or harness have him replace it. And if thats not the problem he'll have to dig further.

stilealive

So....can hot transmission fluid cause the Lock-Up solenoid to stop working like it does the TCC valve?

stilealive

I think I'd rather just do both the harness (lock-up solenoid) and the TCC while its opened up.

How much longer is the job to also do the TCC valve?

Jays_SSZ28

iTrader: (2)

You said your builder put the Sonnax valve in it.

My best suggestion, since you're not doing the work, is drop it off and have it fixed. Let the guy working on it get his hands in there, figure it out, and fix the problem. Easy.

stilealive

Yup....Saturday its getting done at the dealership he works at.

Thanks for the info.....

stilealive

Couldn't do it Saturday, my friends dealership got too busy.

One other question: I was driving today, it locked up at about 60mph.....but as I sped up slowly it would then unlock. I would slow back down and it would struggle to lock up, but it did. Then after 15 minutes it would not lock up again.

So before we waste our time.......the TCC valve. Is that a part that will act like that when failing?

Lock-up solenoid.......will that act like that?

I would hate to just do the harness and lock up solenoid and then the problem is still there.

stilealive

UPDATE: Changed the internal wiring harness with new lock-up solenoid. Thats it. All fixed.

MaroonMonsterLS1

Look at that. You had the solution and could have had it fixed in a jiffy.
glad its together