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Old 08-13-2007, 03:15 AM
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Thm700R4 problems

It is a 700R4 -87 from a Camaro an the Tpi engine, in my -31 4door Ford.

When driving in about 60mph, and made a kickdown, ....to 3rd. There are no 3rd gear. The rpm is only running up. When I slow down, I got the 4rd gear again. Why? ...sometimes it works normally!

The lockup is running in and out all time, when the speed is in the correct "position". When I remove the electric connection, there are no lock up. Why do the lock up work like this? Is it the electric valve that is bad, or is it other things that can made the problem?

Is it somebody that can give some hints about the problem?

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Last edited by TpiRegal; 08-13-2007 at 06:57 AM.
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Old 08-13-2007, 06:37 AM
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700r4

At 90 mph [shouldn't that be kilometers?] you go for passing gear [kickdown], wow!

Does the engine rpm's just go up, relative to how far you push the gas pedal, will they keep going up if you don't let off the gas? As if the trans is slipping, or not holding in gear?

Or does it feel like it does go down to a lower gear, maybe lower than 3rd?

What is your differential ratio?

Did you use everything from the camaro in this car,especially relative to the lockup, or do you have an aftermarket lockup setup?
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Old 08-13-2007, 06:56 AM
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yes, kilometers or 60 mph!

The rpm is going up, but very much. Mostly like a manuell trans in free position.

I do not get the -2rd gear. The engine is running up, and the speed are going slower.

The ratio is 3,73 together with 295/50-15.

The transmission is not from the same car but schold be from a Tpi. In the identification, I found that it the letters is similar with type "police". Why? ..I don't know.
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Old 08-13-2007, 09:13 AM
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700r4

So it may be slipping in 4th. When it does this, can you pull it down to manual 3rd, to see what happens.

If you feel a bit of a jolt or bump when you do this, I would suspect it is slipping in 4th.

Does it seem to shift, 1-2, 2-3 3-4, at the speed it should, or does it shift too soon?

I'm wondering if the TV cable is set correctly, as in not enough TV pressure.
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Old 08-14-2007, 12:52 AM
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I mean he is slipping in 3rd. Because it is in those cases when I made a kickdown he feels like goes to neutral instead of 3rd gear. I can also see it by a testlamp at the electric connection for the ECM, when he is in 4rd or not.
Somebody told me that it is problem with the "forward sprag". ...?????? is it possible to repair this part?
Sometimes the kickdown works ok.
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Old 08-14-2007, 06:51 AM
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700

Well, the input sprag is overrunning in 4th gear and must hold, or 'lock' on a 4-3 downshift.

If you know for sure that you are feeling a 4-3 downshift and a subsequent slip, then yes, there is a good chance that the input sprag is a problem, as this has been a common failure.

Yes it can be fixed, however, the trans must come out to be repaired, if this is the problem.

In Norway, if you need a transmission repair, are there shops that would be considered specialist with transmissions. Or would you take it to a repair shop that does all types of repairs on vehicles?
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Old 08-14-2007, 07:29 AM
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Thanks!!!
It feels like that the 4-3 downshift slips, so it looks that the input/forward sprag that is the problem.

We have some companies in Norway, that are specialists, but it cost a lot.....

I was thinking that I schould try to fix it by my self. After a complete rodproject, this is the only thing I never have done before.

So I think I had to by a new sprag, and maybe there are some other parts I schould change when the trans is out. I have seen that there are some overhoulsets, ....maybe I schould by one of these?

Is it some other parts that it is smart to check when the trans is out?

Do you have some tips about the lockup problem I described in my first post. It could be the ECM, but instead I made the signal manually by a switch, when I have the 4 gear. It could be problem with the lockupvalve that is connected to the ECM? That is easy to check, ....when the trans is out

The 4rd gear signal is ok.

It's good to see that there are specialists "inside the pc"!!
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Old 08-14-2007, 10:37 AM
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700

Remember I asked you if you used everything from the camaro.

Did you use the computer, diagnostic link, etc?

If you have a diagnostic link, ALDL, diagnosing this lockup situation will be easier.

By plugging a test light into the ALDL, you can watch the computer bring on the lockup.

Connect your test light between terminal A and terminal F [ALDL] then go for a drive.

As you drive, the test light should be on, touching the brake pedal will turn the light off, this is power to pin A, at the transmission.

Stay off the brake, drive the car down the road. When the light goes out, this is the computer grounding pin D, at the transmission. This will bring the lockup converter 'ON'.

So you can see, as you drive, if the light goes off and on as your converter goes in and out of lockup, this will help you qualify the source of this problem.

I've seen computers intermittently lose ground. I've seen faulty brake switchs create your problem as well. Loose connections, Throttle position sensor problems, a lot of things will create this concern you have.

Try this diagnostic method I have described, I hope it helps you find the source of your lockup distress. Good luck!
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Old 08-15-2007, 01:18 AM
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I have done some teste last week. Here is the result:
The trans is from another camaro than the engine, it schould be from a Tpi.

Did you use the computer, diagnostic link, etc? YES.

I have power to A at the trans, when driving.

I ground pin D, but the lockup converter will not be 'ON'.

The Tps schoul be OK.

....any other hints???

Thanks!!!

Last edited by TpiRegal; 08-15-2007 at 08:17 AM.
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