Trany Problem...Wont move in D
 

I did some search and found nothing regarding to this trany problem.
Just got this 95 SVX about 145,xxx miles with trany problem.
When shift into D, nothing(I couldnt feel the engagement and when I hit the gas, it just rev up as its in N). same as 3. But when I move the shifter to 2 or 1, it would engage and drive. When speed reached about 30, I then move the shifter to 3 and then D and everything is fine including the TC locking at proper speed.
Reverse is woking properly.
The trany fluid is dirty but at full mark. I also disconnect the resistor to see if it would make any difference(no difference at all).
Any suggestion?
Thank you

Your description is rather confusing. Please confirm.

If you select D on start up there is no drive?

Same in 3, if you select 3 on start up there is no drive?

When either 2 or 1 is selected it will engage and drive. Will it shift from 1 to 2 automatically after take off and speed is gained?

When speed reached about 30, I then move the shifter to 3 and then D and everything is fine including the TC locking at proper speed.
Reverse is woking properly.
Presumably making the shifts manually after 2 has been engaged.:confused:

On the basis of what you say, the fault is confined to automatic selection functions, which causes one to suspect faulty speed sensing or information signalling.

First off run a check for both transmission and engine codes and advise the results. Instructions available within the how too section.

Just an update
When the car is cold(sitting for over 5 hours, the trany would shift fine). Once it warms up(turn off the car after 3 or 4 miles of city driving, upon restart, the trany is acting up again)
And sorry about my description:o

If you select D on start up there is no drive? YES

Same in 3, if you select 3 on start up there is no drive? YES

When either 2 or 1 is selected it will engage and drive. Will it shift from 1 to 2 automatically after take off and speed is gained? YES

When speed reached about 30, I then move the shifter to 3 and then D and everything is fine including the TC locking at proper speed.
Reverse is woking properly.
Presumably making the shifts manually after 2 has been engaged. YES

Will check if any code present.
Thanks again for the help!

There is a difference in the power flow through the gearbox in 1st gear in Drive, and 1st selected by the shifter.
When it is in Drive 1st gear, the 1st/2nd one-way clutch takes the power flow. When it is in 1st Selected, the Low/Reverse brake is used.
http://www.subaru-svx.net/photos/files/oab_au/37225.jpg
So I would say that the 1st/2nd one-way clutch is slipping. As it is a Sprage type, it will need replacing, and the box has to come out to do it.

You can continue to drive it as you are doing, selecting 2nd with the shifter to start, then moving it to D to pick up 3rd. Of course you will have to select 2nd again when you slow down or stop.
Sorry about that.:(
Harvey.

pearlm30, special thanks for the update and confirmation.

I note that if you select 1 the car will drive.

If you select 2 the car will drive and shift from 1 to 2 automatically.

Only when a speed of about 30 MPH is reached and D is selected, will shifting progress through 3 and into D and then all is normal.

Therefore you confirm that first is engaging correctly when selected via the shifter. Also that first is engaging correctly when second is selected from rest, so that first is engaged automatically to be followed by second.

I am not sorry to say that there is no indication that the one way clutch is slipping. What is more at this stage there is no indication that the transmission will have to be removed. :)

The symptoms as you have reported, at this stage do not look ominous. My original diagnosis regarding possible causes stands. ;)

As a matter of interest, two arrangements are provided for first speed, such that manual selection of first, specifically provides engine braking for tricky situations.

Thank you everyone
I took the trany pan off and there are a lot of metal shavings and dirt paste:eek:. I will put in a new internal filter and install a trany cooler tomorrow(mainly to bypass the radiator cooler in case its blocked)while letting the trany drain over night.
I read some of the trany slip related threads and found out I can use Ford type F fluid and the Lucas trans fix to increase fiction(less slip)
I know the trany is most likely toasted and just curious if the trany drain and magic fluid would fix it.
Thanks again and I will report back.

I am now more than confused as at no time within your reports of a fault, have you previously mentioned "trany slip". :confused:

Yes give it a go if you like. Stranger things have happened.

The type of clutch that this is, does not have fiber linings, that the additives help.
The Sprage(Sprag, Sprague) is like a roller bearing with metal fingers that lay down and slip when turned in one direction, and stand up to lock it when rotated in the opposite direction. There is a chance that the fingers are goo-ed up in their cage, so that they don't stand up when they should. This usually makes them slip when cold, work when hot. As yours displays the opposite, I don't think it this is your case.
But when all else fails, try anything.
Harvey.

If it can be manually shifted into every gear, and pull. This doesn't sound like a mechanical fault. It sounds electronic.

Cleaning out the pan, and replacing the filter can only do a world of good. Before you change from DexIII, and go adding LSD additives, PLEASE try it with fresh, clean dexIII. You do NOT want to be changing trannies on these cars. They're WAY EFFIN' HEAVY!

As it sits, your trans isn't doing anything that would indicate you need to change it. Your TCU, on the other hand IS acting flaky.

Adding the LSD goop is a last ditch effort to save a trans that's a goner already.

I think you should believe Harvey. He's the one with the STI badge.

:rolleyes: :rolleyes: :rolleyes:

On a more serious note the symptoms that match yours in the ATSG 4EAT manual, namely

"Car does not move in D or 3 range though engine revs up"

The only suggested "probable causes" they have listed are 53: "Faulty O.W.C. (1-2)" and 54: "Faulty O.W.C. (3-4)"

This would seem to tally with Harvey's suggested fix above, I'm assuming OWC means one-way clutch.

This problem is of interest to me, because my Black Betty has the symptoms "Car does not move in D,3 or 2 though engine revs up". In the case of my problem, though, after getting it rolling in 1 there was no way I could get it to engage 2,3 or D.

The suggested fixes were, in relevance order, Valve sticking, Bad TCU and 54:, Faulty OWC 3-4.

I changed the valve chest and the TCU with no joy. I also thought along the same lines as Trevor, thinking the speed sensor was faulty, although in our VTD type the gearbox has to come out to change it, unlike your US type.

In the end, I gave up and bought another gearbox. It's probably the OWC is what I have deduced in my case. And that's what it likely is in your case too.

Joe :)

Thanks again everyone
I did the filter, bypass stock cooler with B&M cooler and fluid change this morning. I still have the same problem:confused::eek:. Dont really know what to do now. I think it could be the one way clutch thats going out. No trany code either.
BTW, when i unplug the resistor, the trany is engaging(selector in D) very very slowly shown by the rpm from the rpm gauge and the car will move forward when brake is released, but give a little gas, the rpm will go up while the car is doing like 10 mile per hour.
plug the resistor back in, selector in D, the trany just rev like in N.
I guess it will need a new trany or I can make it a parts car for my other 3 SVXs.
I really appreciate all the advice you guys provided and what a great forum this is:)

If you think about it, the TCU can only throw codes related to sensors etc that are showing values out of range.

Presuming we are correct and it is actually one or both of your One Way Clutches [spragues] that are kaput, this would be a mechanical fault, and there probably is no voltage signal that reacts to it.

What I'm saying is, it could be kaput and not throw a code.

It is sensible to try all other cheaper avenues first such as additives and so on, but probably you will have to bite the bullet and rebuild it.

Joe

Has anyone thought that maybe the inhibitor switch may be at fault? If you can, test continuity in the switch in the D and 3 ranges when shifting from park->D and then from D->3. If there is full continuity in the switch, you may disregard my suggestions. A simple suggestion would be to move the shifter all the way back to 1 and then up to D or 3 to see if this helps... Its worth a shot;)

Tom

Joe,

The merit or otherwise of the STI logo is clearly factually illustrated x 2, within this thread. :rolleyes:

Please adhere to what has been reported and the logic which should be applied, in accordance with what in good faith must be accepted as fact. The car does in fact does move in range 3 when the engine revs up.

As has been reported a second time and as a result of my request for a second confirmation:-

“When speed reached about 30, I then move the shifter to 3 and then D and everything is fine including the TC locking at proper speed.”

Protecting one in error, illustrates several errors. ;)

Joe,

“We”, remains confined to two opinions. It is notable that no real evidence has been presented which indicates the problem involves one or both, or any one way Sprague type clutch, regardless of the impressive images from Subaru manuals which have been scanned and pasted here.

Thankfully there is no reason to suggest biting any bullets at this stage. :)