Torque converter lockup

[HerbieTheMisfit]

On these wonderfully cold Wisconsin days, it seems to take an awful long time for my torque converter to lock-up on my commute to and from work. I drive about 45 min at around 60mph and it takes approx 30 minutes before it will lock. lock

My questions are:
1) Is this normal operation? If so it sucks.

2) If not, I believe lock-up depends on two things - engine coolant being warm enough and trans fluid warm enough. The coolant is getting warm (needle is at the "L" in NORMAL - where is usually is). So I would assume my trans fluid isn't heating up. Is this correct?

3) There a little brass block with 3 fittings on it that some of the transmission cooler lines run to. Is this some sort of control valve that only allows fluid into the radiator when it reaches a certain temp?

4) If so, is there a way to test it?

Thanks in advance,
Jim

 

[SHOtimer]

Here you go:

1. Yes, and yes it does.

2. The lockup depends only on Trans fluid temp. With extremely cold weather it does take a reasonably longer time to lock up. Especially for you since you are on the highway. If you were in town it would not take nearly that long.

3. Yes that is the tranny "thermostat". It bypasses the fluid back to the tranny if it is not warm enough to be cooled. Some have removed it as it can get stuck and permanetly bypass the cooling system for tranny fuild. (I have done this along with adding another cooler).

4. I'm not sure about testing it. But, I do know that my seems (to me) to heat up the tranny quicker without it, because with it bypassed the fluid is running through the radiator which speeds up the process of warming the trans fluid (which takes much longer than coolant to come up to temp).

Hope that helps.

Doug

 

[SolidState]

what he said...to the tee..

anyways, it is also worthy to note that the temp sender should be replaced in a rebuild.

If the cooler fittings are old and worn, they won't function properly and cause lengthened TC lock up..

Consider an low pressure drop cooler...it is a better solution than the half assed T-fiiting ford came up with...

 

[AutoSHO]

Once the car has been up to temperature for about 5 minutes, turn it off and restart it. The computer strategy on a cold start keeps it from locking up longer than if it is restarted once the engine is warm. You might give that a shot if there is a convenient spot in your commute to do it.

 

[HerbieTheMisfit]

I have done the restart the car after a few minutes trick a few times when it's been driving me really crazy.

So, if I understand correctly, if I route the fluid so it's always going to the radiator - it'll heat up quicker? At first glance that seems backwards to me. But I suppose going through the same radiator as the engine coolant it could do that - is that what you meant?

 

[SHOtimer]

Yes. Right now the fluid comes out of your tranny and goes to the brass 'tranny thermostat'. If the fluid is cold the thermostat reroutes it back to the tranny and it is done. If it is warm enough to open the 'tranny thermostat' and the thermostat is functioning properly the fuid then travels through the radiator, then to the tranny fluid cooler in front of the condeser then back to the tranny. The fluid running through the radiator gets both warmed (in the winter) and a cooled (in the summer). So, what you might try doing is to take out the brass 'thermostat' so that the line coming from the tranny connects directly to the line going into the radiator (So your fluid always is flowing through the radiator and the cooler, which is a much better setup). Then you must deal with the return line from the thermostat. Follow that line and you will find a "T" fitting in the fluid return line going back to the tranny. What you need to do is remove the 'T' and stick in a 1 way coupler just to connect the two rubber lines. That will leave you with the 'T' line, that used to run from the thermostat to the return line, that is no longer needed and can be left there or removed. So, I would try that and see how it goes. It will still take a while to warm up that fluid since it is so cold but this may help to speed it up.

Do you have a Helms or a Chiltons manual?

Doug

<small>[ February 16, 2004, 10:20 PM: Message edited by: SHOtimer ]</small>

 

[HerbieTheMisfit]

Doug,

Thanks for your replies - and thanks to the others too. I do have a Haynes manual.

I'll think about trying the thermostat bypass to see if that helps. From what your saying and what I've seen, I could probably set up somthing temporary with some chunks of hose, hose clamps, and something to plug up the unused return.

Of course looking at the forcast, it supposed to get into the 40's this week. We'll see if that makes a difference too.

Thanks again!
Jim

 

[SHOtimer]

Jim, really it doesn' need to be temporary just remove the thermostat and you should be good. I have a Helms not the Haynes but most workbooks have a diagram showing the tranny cooling fluid flow and how it is routed and such. It really isn't that complicated, you should be able to tackle it rather easily. I removed mine in an evening, I really think that it is pointless to be there in the first place.

Anyways, hope all of this helped and you got what you were lookin for. Anymore questions, of course post em.

Doug

<small>[ February 17, 2004, 12:29 AM: Message edited by: SHOtimer ]</small>

 

[SHOZ123]

IMHO the engine is running too cool. L is around 175F.

 

[svtman]

What I did with mine is wrap cardboard around the transmission cooler for winter use. Of course it is colder up here, so with it covered it locks up almost as fast as it does during the summer months. Otherwise I would be driving for nearly 40 minutes on the highway before it locked up.

 

[HerbieTheMisfit]

I just replaced the thermostat (with the correct Ford one) last summer, so I doubt my engine isn't getting warm enough. It's right around the "L" in the summer time too. Maybe I need a new temp sensor or something.