Transmission Slipping Please help

gee55987 · #1 01-31-2010, 09:44 PM

I own a 1996 with about 200,000 miles. I noticed it would like to drag the shifts from 2nd to 3rd and 3rd to fourth but never really saw it as a problem. As of now the car barley will shift into fourth and 3rd is not all there. It tends to drag under heavy loads. First and second are just fine. Im thinking it has something to do with the Line pressure. I have been doing some research on it and found that Solenoid A valve goes bad. Now if that is the problem I have no idea where to find this or how to replace it. I thought I once read something about resisting the pressure but I'm totally lost with that. Also I thought I read something about cutting a line which would give me hard shifts. Thats fine I just want to get a little more life out of her. I'm totally lost as to what to do and any info would help!
Thanks

Trevor · #2 01-31-2010, 10:42 PM

Quote:

Originally Posted by gee55987

I own a 1996 with about 200,000 miles. I noticed it would like to drag the shifts from 2nd to 3rd and 3rd to fourth but never really saw it as a problem. As of now the car barley will shift into fourth and 3rd is not all there. It tends to drag under heavy loads. First and second are just fine. Im thinking it has something to do with the Line pressure. I have been doing some research on it and found that Solenoid A valve goes bad. Now if that is the problem I have no idea where to find this or how to replace it. I thought I once read something about resisting the pressure but I'm totally lost with that. Also I thought I read something about cutting a line which would give me hard shifts. Thats fine I just want to get a little more life out of her. I'm totally lost as to what to do and any info would help!
Thanks

If the transmission is original, you/it have/has done very well and must consider a replacement. If you have evidence that a the transmission has been replaced or overhauled, that is another matter and some advice may help you. Please post again.

gee55987 · #3 02-01-2010, 03:49 PM

well i bought it with about 175,000 and as i was told it was rebuilt at about 100,000. I have kept it up pretty well. I flushed it when i first got it and have always kept tabs on the fluid level. Im hoping its something with line pressure.

oab_au · #4 02-01-2010, 05:19 PM

Quote:

Originally Posted by gee55987

well i bought it with about 175,000 and as i was told it was rebuilt at about 100,000. I have kept it up pretty well. I flushed it when i first got it and have always kept tabs on the fluid level. Im hoping its something with line pressure.

I think it is a high clutch problem, and is terminal.

You could try unplugging the resistor behind the battery, that will raise the line pressure, to see if there is a difference, but I doubt it will help.

Harvey.

Trevor · #5 02-01-2010, 08:50 PM

Quote:

Originally Posted by oab_au

I think it is a high clutch problem, and is terminal.

You could try unplugging the resistor behind the battery, that will raise the line pressure, to see if there is a difference, but I doubt it will help.

Harvey.

At this stage do not give up hope. There is absolutely no reason to accept that the transmission must be replaced or completely overhauled.

It would appear that you have been cautious since you noticed the problem and therefore it is reasonable to hope that nothing has been seriously worn due to slippage.

You are correct in suspecting low line pressure. This can be easily tested by someone with the right equipment and the test will cost very little.

If low line pressure is detected, this can be due to a faulty “A” solenoid valve, which can be checked and if necessary replaced, without removing the transmission, and at a reasonable cost.

Keep fingers crossed.

gee55987 · #6 02-02-2010, 08:37 PM

Quote:

Originally Posted by oab_au

I think it is a high clutch problem, and is terminal.

You could try unplugging the resistor behind the battery, that will raise the line pressure, to see if there is a difference, but I doubt it will help.

Harvey.

I am going to have my line pressure tested, but before I do so could you tell me where I can Find this resister. (behind battery) I have not a clue what to unplug if you wouldnt mind directing me a little bit.
Thank you all.
And yes, Im crossing my fingers! =)

Trevor · #7 02-02-2010, 09:16 PM

Quote:

Originally Posted by gee55987

I am going to have my line pressure tested, but before I do so could you tell me where I can Find this resister. (behind battery) I have not a clue what to unplug if you wouldnt mind directing me a little bit.
Thank you all.
And yes, Im crossing my fingers! =)

You should run a transmission diagnostic test. This provides a way of testing the resistor and associated circuit. Refer the how too stuff.

The resister is a small elongated metal enclosure, mounted on the panel behind the battery. It has a plug/socket connection.

The resistor circuit is there to protect the "A" relay against sudden closing shock. I can provide detailed information if required. If you disconnect the resistor, do so only to get you by meantime. If you find that it is disconnected or is open circuit (bad), you have found the reason for a faulty "A" solenoid.

Keeping fingers crossed for you.

gee55987 · #8 02-07-2010, 02:48 AM

I will have to run a test on it like you said. I did however find that connector and gave it a try. I found that with it disconnected it goes into the gears hard when moving from the park position, but didn't help my problem. I'm still hoping for the best and if any other suggestions come up...please let me know..
Thank you!

Trevor · #9 02-07-2010, 04:02 AM

Quote:

Originally Posted by gee55987

I will have to run a test on it like you said. I did however find that connector and gave it a try. I found that with it disconnected it goes into the gears hard when moving from the park position, but didn't help my problem. I'm still hoping for the best and if any other suggestions come up...please let me know..
Thank you!

Starting from the beginning, your descriptions tend to be rather confusing. ---

“I noticed it would like to drag the shifts from 2nd to 3rd and 3rd to fourth but never really saw it as a problem.”

Exactly what do you mean by “drag the shift”? It shifts too slowly? Slips when the next gear engages?

“As of now the car barely will shift into fourth.” Stays in three? “and 3rd is not all there.” will not engage third? “It tends to drag under heavy loads.” The drive slips and the revs rise?

Advise exactly when these things occur in relation to the driving of the car.

Please look on things from a readers point of view, and try to make sure all is clear and exact. Take your time.

It is important to run a TCU diagnostic check. Refer the how too section. This should provide worthwhile information.

gee55987 · #10 02-07-2010, 09:24 PM

I'm sorry. Let me try to explain myself a little better. For starters, this can be crossed out. First and second work just fine.-- Nothing has changed there.

What is actually happening is when I accelerate and the trans wants to shift into third gear it will rev up high (4-5 grand) if I'm still accelerating at a steady rate. For instance going from a stop to a 55 I have steady pressure on the accelerator and the transmission will rev high going into third and I will have to ease off to make it engage. Once it engages and I get back on the accelerator, the trans will slip unless i use only slight pressure on it. Almost like the break band I think it is called is not grabbing to its full strength. Fourth gear is the same as third except that gear is significantly higher so it seems to be worse. (My thinking is it is only worse because it is a higher gear)

I did notice another thing the transmission is doing as well. Traveling at about 55- 60 just coasting down a rather steep hill in the drive position the tranny will grab fourth gear and I can not only see the rpms going up and down but i can feel the car slowing from the gears then allowing it to coast on and off. It does this all the way down about every 3-4 seconds. That is hard to explain it has never done that until the trans has been giving me trouble. \
Im sorry for being vague..If i can give you any more info so you can help me further please ask..Thank you!
Oh and where is this how to? Is it just one of the main forums and Ishould search and find where it tells me how to diagnose the tcu?

Trevor · #11 02-07-2010, 10:50 PM

No need to be sorry.

Disconnecting the resistor hardened up shifts but did not effect your problem. This would tend to indicate that low line pressure is not involved, but is not absolute test. A pressure test could still be worthwhile.

From what you say the transmission could possibly be slipping in second and fourth. You say ---”Almost like the break band I think it is called is not grabbing to its full strength.”, and you could very well be correct.

The band locks the drum for 2nd, releases it for 3rd, then locks it again for 4th. Keeping this in mind you may be able to ascertain whether a brake band adjustment is worth your while. I think it would be a good bet.

Top right on the home page, you will find among other things, “How Too Documents. Select and follow with “Transmission”, then “Brake Band Adjustment”.

You certainly should do a TCU diagnostic check, but like you, I cannot locate anything within the how to stuff which is all over the place. Someone reading here may know where to find it. Sorry I do not have time to scan and attach. If all else fails, start a new thread a shout.

You have been told in #4, that your fault is terminal. I have been taking time, in the hope of saving you considerable expense. Follow your nose and keep fingers crossed.

gee55987 · #12 02-11-2010, 05:12 PM

Alright some relatively good news. I had a regular engine diagnostics test done on it and found a couple things. Two codes came up. P0748 was one and I can't remember the other. They were similar. Definition for P078 is pressure control solenoid "a" electrical. Probable cause open circuit, poor electrical connection and or failed pressure control solenoid. The second code was failed TCC Solenoid and/or TPS misadjusted or faulty. Now I have not a clue what to do. If you or anyone can please guide me? I thinking this pressure control unit Solenoid A took a crap but I don;t know where it is or how to get to it. Is it even something that can be replaced. Anymore help would be more than great! Thanks!

Trevor · #13 02-12-2010, 05:20 AM

Quote:

Originally Posted by gee55987

Alright some relatively good news. I had a regular engine diagnostics test done on it and found a couple things. Two codes came up. P0748 was one and I can't remember the other. They were similar. Definition for P078 is pressure control solenoid "a" electrical. Probable cause open circuit, poor electrical connection and or failed pressure control solenoid. The second code was failed TCC Solenoid and/or TPS misadjusted or faulty. Now I have not a clue what to do. If you or anyone can please guide me? I thinking this pressure control unit Solenoid A took a crap but I don;t know where it is or how to get to it. Is it even something that can be replaced. Anymore help would be more than great! Thanks!

Yes, it is good news because the components involved can be accessed without removing the transmission.

Start with the TPS. Go to the how too section and check the instructions covering testing, cleaning and setting, Ignore the complicated stuff involving marking up a scale on a board.

Solenoid “A” directly controls line pressure and is vital. It is located on the valve body in the bottom of the tranny and can be accessed by removing the oil pan. Not too time consuming, if you have to pay for it.

Solenoid “C” controls the centre clutch delivering power to the rear wheels and again is accessible, but a little more time is involved. Do a search here.

Come back with some advice on your mechanical experience, so that we know if detailed advice is required. Please also use the shift key to make your posts easier to read.

P.S. I am sure you appreciate that you must not drive with the tranny slipping, because this will severely wear friction surfaces and terminate the works.

Was the resistor disconnected when the diagnostic was carried out?

TomsSVX · #14 02-12-2010, 06:14 AM

The solenoid A code was likely because of the dropping resistor being disconnected. A TPS misadjustment code can mess with the shift patterns but not as detrimental as what you are describing... The long and the short of it, your high clutch is dying and you will be due for a rebuild very shortly. Sorry

Tom

Trevor · #15 02-12-2010, 02:19 PM

Quote:

Originally Posted by TomsSVX

The solenoid A code was likely because of the dropping resistor being disconnected. A TPS misadjustment code can mess with the shift patterns but not as detrimental as what you are describing... The long and the short of it, your high clutch is dying and you will be due for a rebuild very shortly. Sorry

Tom

Whatever you do, get the line pressure tested before giving up hope and committing yourself to big money.

If your starter was cranking badly, would you test battery voltage, or rush out and buy new starter motor?