The Subaru SVX World Network
Page 1 of 2 1 2
Show 40 post(s) from this thread on one page

The Subaru SVX World Network (https://www.subaru-svx.net/forum/index.php)
-   Technical Q & A (https://www.subaru-svx.net/forum/forumdisplay.php?f=5)
-   -   No engine braking in 3rd gear (https://www.subaru-svx.net/forum/showthread.php?t=48610)

SuberNatural 01-13-2009 12:39 AM
No engine braking in 3rd gear
 
1st gear and 2nd gear both stay right with the engine.

D4 idles down after a few seconds of coasting as it should.

D3 goes right from pulling in gear to idle (as if in neutral) then after a second or two hits 3rd gear and then neutral until the car slows.


I have no codes on the TCU.
The trans resistor is plugeed in and good.


Any help would be appreciated. I just had the trans serviced etc.

log1call 01-13-2009 01:04 AM
Re: No engine braking in 3rd gear
 
So are you saying that the engine braking in third gear is intermittent? Also, is this in third while the shift lever is in drive or is this when you have pulled the lever to third to try and slow faster?

SuberNatural 01-13-2009 01:10 AM
Re: No engine braking in 3rd gear
 
This is with the gear selector in D3.

It is not intermittent, its mostly non-existent except for every once in a while or sometimes when driving slow. I have not found a pattern yet.

log1call 01-13-2009 02:06 AM
Re: No engine braking in 3rd gear
 
Well to start with you should go through the standard tests... stall test, line pressure tests, speed shift tests up and down, time lag test, check "crispness" of changes etc. There is a clutch and a one way sprag clutch in there that can both give engine braking problems, not to mention several valves.
It might be a good idea to see an auto trans place and get them to do a diagnosis for you.

b3lha 01-13-2009 03:26 AM
Re: No engine braking in 3rd gear
 
IIRC, engine braking is something to do with shift solenoid 3.

Have you checked the fluid level since the service?

SuberNatural 01-13-2009 11:06 AM
Re: No engine braking in 3rd gear
 
go through the standard tests... stall test, line pressure tests, speed shift tests up and down, time lag test, check "crispness" of changes etc

^^^ is there a how-to for that?


I always check where I park and have no signs of leakage but i will check here in a few minutes.

SuberNatural 01-13-2009 01:38 PM
Re: No engine braking in 3rd gear
 
(level10 trans btw)

stall test - 3000 RPM

line pressure tests - NA

speed shift tests up and down - Very Responsive

time lag test - < 1 second

check "crispness" of change - Very Crisp (but no slamming)



This morning I went for a drive, and only marginally warmed the motor. When it was cold there was no lockup as expected. However after about 3 miles or so D4 was available. So i put it in D4 and drover probably 8 miles (round trip) checking every once in a while to see if 3rd gear was behaving normally. And today it was. So im starting to think that maybe this is a temperature issue? I've never seen the ATF temp light while driving and don't drive the car very hard.

Let me know what you guys think.

michael 01-13-2009 03:40 PM
Re: No engine braking in 3rd gear
 
have you checked the resistance of the resistor by the battery.

SuberNatural 01-13-2009 04:18 PM
Re: No engine braking in 3rd gear
 
Yes, it's testing good between 12.1 and 11.9 ohms

michael 01-13-2009 04:58 PM
Re: No engine braking in 3rd gear
 
do you have any shift kits installed?

SuberNatural 01-13-2009 10:39 PM
Re: No engine braking in 3rd gear
 
Nope, just whatever level10 did. I should know more specifically what was done to the trans tomorrow.

log1call 01-14-2009 12:33 AM
Re: No engine braking in 3rd gear
 
There are a heap of variations in trans and I'm not sure which you have but, it's quite common to not have engine braking in some situations in some models/versions and specificaly in third gear... that is to say that there are models that will have engine braking in d4 but none in third in some circumstances.

I suggested you do the standard checks because, if they all look good then my advice would be not to worry. Keep an eye and an ear on it for a while and monitor the circumstances and read a workshop service manual which will describe the operation.

You could look here for a manual.. http://www.main.experiencetherave.co...ans/FSM_Scans/

Those figures you have look ok. It would have been nice to see a line pressure check but if the lag is good it is PROBABLY ok. There is a oneway clutch inside which is like a ratchet and not actually a clutch at all... I thought that could be crook but they generally reckon that will show up as a lag until it grips. It could still be slipping if it gets turned gently and grab on if it gets a jolt... but that's about the only thing I can think of that mght give intermittent/undesigned for braking fault.

Keep an eye on it's behaviour and read the manual.

stiguy 01-14-2009 02:24 AM
Re: No engine braking in 3rd gear
 
i noticed my cars does the same thing but mine does it all the time hot or cold.

oab_au 01-14-2009 04:49 PM
Re: No engine braking in 3rd gear
 
To tell what the trouble is, you have to see if there is engine braking in 2nd gear. If there is no engine braking in 2nd, and no code for solenoid 3, it is a mechanical failure in the box. If it does brake in 2nd, then it can be a few other things.

The over-run clutch is controlled primarily by the Shift solenoid 3. in 1.2.3, gears. 3rd is treated differently to the rest, as the clutch cannot be engaged when the box is driving, or it will lock-up.
In third the solenoid is on but the engagement is controlled by a shuttle valve that uses the drop in line pressure, to tell if the throttle is closed, to apply the over-run clutch.

The symptoms that you say, "then after a second or two hits 3rd gear and then neutral until the car slows. ", seems to be the way it shows up, and can be caused by;
1.Throttle position sensor.
2. Dropping resistor, too high in resistance.
3. If the line pressure regulation spring has been increased to raise the line pressure. ( Level 10 may have done this)

Harvey.

SuberNatural 01-14-2009 04:56 PM
Re: No engine braking in 3rd gear
 
Quote:
Originally Posted by oab_au (Post 582272)
To tell what the trouble is, you have to see if there is engine braking in 2nd gear. If there is no engine braking in 2nd, and no code for solenoid 3, it is a mechanical failure in the box. If it does brake in 2nd, then it can be a few other things.


I do have engine braking in 1st and 2nd gear.

The over-run clutch is controlled primarily by the Shift solenoid 3. in 1.2.3, gears. 3rd is treated differently to the rest, as the clutch cannot be engaged when the box is driving, or it will lock-up.
In third the solenoid is on but the engagement is controlled by a shuttle valve that uses the drop in line pressure, to tell if the throttle is closed, to apply the over-run clutch.

The symptoms that you say, "then after a second or two hits 3rd gear and then neutral until the car slows. ", seems to be the way it shows up, and can be caused by;
1.Throttle position sensor.
2. Dropping resistor, too high in resistance.
3. If the line pressure regulation spring has been increased to raise the line pressure. ( Level 10 may have done this)


The resistor tests in at 12.1-11.9 ohms

I guess I will check the TPS voltage and then look at getting a line pressure test. I don;t think there are any serious problems with the box its just an annoyance that i hope doesn't create a problem.

Harvey.
Thanks for your input. I just wanted to add that yesterday when it was super cold out I had engine braking in 3rd gear for the entirety of about an 8 mile run. But yesterday when it was just as cold and I went for a longer drive I didn'y have 3rd gear breaking.


All times are GMT -6. The time now is 10:47 AM.
Page 1 of 2 1 2
Show 40 post(s) from this thread on one page

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122