SVX Network Forums Live Chat! SVX or Subaru Links Old Lockers Photo Post How-To Documents Message Archive SVX Shop Search |
IRC users: |
#16
|
||||
|
||||
Quote:
-Pavan. |
#17
|
|||
|
|||
Quote:
Vehicle Speed Sensor #1 Vehicle speed sensor #1 is mounted to the transmission and is basically electrical governor pressure. It is used to detect vehicle speed and it effects shift points, lock-up, and line pressure. In FWD transmissions the speed sensor reads parking gear rotation at the front output shaft. In AWD transmissions it senses the transfer clutch drum rotation at the rear output shaft. Vehicle Speed Sensor #2 Vehicle speed sensor #2 is built into the combination meter. In FWD units, it is used as a back-up for speed sensor #1. In AWD units, it is used as the front output shaft speed sensor. If I'm reading this doc correctly, #1 takes a reading from the rear output shaft while #2 takes a reading from the front output shaft before the front differential. I took a look at the wiring diagram for my 1992 SVX and it shows that the speedometer is driven by Vehicle Speed Sensor #2. Neither speed sensor would be affected by final drive ratio, so speedometer readings would naturally be inacurate after changing the final drive ratios. I emailed the tech guy at http://www.terf.com/SpeedChangerPage.htm. He indicated that the SpeedChanger box would work with the Subaru electrical system, but I'm concerned that if it wasn't wired into the correct spot on the harness it could cause the TCU to think that the front wheels would be turning at a different speed than the rear and cause a whole pile of problems. Any Thoughts? Steve
__________________
1992 SVX lsl - >111K, pearl, 4.44 gears, ECUtune stage 1 2005 Outback XT wagon - i love that turbo!!!! 2004 Dodge Ram 1500 Hemi |
#18
|
||||
|
||||
Quote:
I need to know in first place wht causes this problem and secondly how to rectify it. -Pavan. |
#19
|
|||
|
|||
Quote:
Steve
__________________
1992 SVX lsl - >111K, pearl, 4.44 gears, ECUtune stage 1 2005 Outback XT wagon - i love that turbo!!!! 2004 Dodge Ram 1500 Hemi |
#20
|
||||
|
||||
Quote:
-Pavan. |
#21
|
||||
|
||||
Gentlemen,
The speedometer sensor is driven by a gear on the passenger side of the front differential. The amount of rotations of the gear is determined by the tire diameter, and the coefficent of friction, of the tire, controling the amount of rotations, of the axles, in relationship to the ring gear. THE INTERNAL GEAR RATIOS HAVE NOTHING TO DO WITH THE SPEEDOMETER ACCURACY! It is only the sensor accuracy, the speedometer accuracy, the wireing, tire diameter, and the ability of the splined shafts to transfer power, that can show inaccuracies! That said, I would "be really interested" in joeaxial's new transmission # on the bell housing, by the starter. If the trans came from a 1996 2.5 Legacy, then it should be a 4.44 ratio trans, and his 72 mph at 3000 rpm is correct. If the trans is a 4.111, and the rpm is 3000 at 72, rather than 77 mph, there is some problem, like its not locking up the torque converter? Think about this, in first, second, third and forth, the speedometer reads the speed of the car, without reguard to the gears inside the transmission unit. The reason for this is, it only reads the speed/rotations of the front ring gear. All cars to some degree have a speedometer error. The internal ratios are not a factor. Tom
__________________
www.svxfiles.com The first SuperCharged SVX, the first 4.44 gears, the first equal length headers, the first phenolic spacers, the first Class Glass fiberglass hood, the first with 4, 4.44s in his driveway Fiberglass Hood thread My locker 4.44 Swap link |
#22
|
||||
|
||||
Quote:
-Pavan. |
#23
|
|||
|
|||
Quote:
|
#24
|
||||
|
||||
Quote:
And as I recall, on Legacy 4EAT's, the speedo is a cable, not a gear. I may be mistaken however.
__________________
-Jason (8/23/07-Present) 1995 Subaru SVX LSi (197k) Polo Green (#1102) 03/95 Mods: DDM Tuning 4500k 35w Low Beam HID, 100w H3 Bulbs, Extra Ground Cables, 15 minute $12.96 mod, svxfiles designed transmission mount (), sporting a "new" tail light bar, silver BBS rims, custom power steering cooler (one that doesn't dump ATF constantly), new negative lead cable, no more third or fourth gear (1977-Present) 1977 Chevrolet Corvette (81k) Silver (12/01/2011-Present) 2005 Subaru Outback 2.5i Limited 5MT (97k) I have a bad feeling about this. -Obi Wan Kenobi |
#25
|
||||
|
||||
I am going to pull a 4EAT apart later this week, and post pictures of the speedometer drive gear in the front differential.
Just for the record every 4EAT SVx has a three wire front speed sensor, and every Legacy 4EAT, that I have seen, has had a two wire speed sensor.
__________________
www.svxfiles.com The first SuperCharged SVX, the first 4.44 gears, the first equal length headers, the first phenolic spacers, the first Class Glass fiberglass hood, the first with 4, 4.44s in his driveway Fiberglass Hood thread My locker 4.44 Swap link |
#26
|
|||
|
|||
Quote:
I wonder if the drive gear has a different tooth angle? Harvey.
__________________
One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#27
|
||||
|
||||
Not sure if I misssed something or am ovresimplifying but. Couldn't you follow a friend going say 60 according to their accurate speedometer, set your cruise control and properly reposition the needle at 60mph. A passenger might be helpful,along with a nice straight empty road.
__________________
"The things you own end up owning you. It's only after you lose everything that you're free to do anything." 92 Pearl White Ls-l (138k) Euro Headlights & Blinkers, 97 Grill, Euro Tail Lights, SS Brake Lines, Stebro Exhaust, Slotted Rotors, Classic Registration 96 Legacy Outback (206k) 5-speed 2.2 Lightweight Crank Pulley, Group N Trans & Motor Mounts SOLD Wanted: Steering Wheel |
#28
|
||||
|
||||
Quote:
Coming to repositioning, this variation is not by a fixed value. But its a proportionate difference depending upon the speed of ur vehicle and changes according to it. -Pavan. |
#29
|
||||
|
||||
Quote:
OK, that was fun.... As long as the teeth were of the same #, and they drove each other, the angle is not important. However, the HAL effect speedometer sensor COULD be affected by the distance when seated. I do not know this for certain, but it "sounds logical" Harvey, can the third wire be a shielding wire if it does not surrond the two pulse carring wires?
__________________
www.svxfiles.com The first SuperCharged SVX, the first 4.44 gears, the first equal length headers, the first phenolic spacers, the first Class Glass fiberglass hood, the first with 4, 4.44s in his driveway Fiberglass Hood thread My locker 4.44 Swap link |
#30
|
||||
|
||||
Guys, come on, some one help us what we can do to rectify this. We are not saying that the speedo off is due to transmission faults or someother. Just we don't know what's causing this. Give us your ideas on what we can do. As far as we can say-
1) There is no mismatch of tire sizes and they are all of stock size and are same as they are on old tranny. 2) Stock speed sensor is installed we are trying to say tht the only ones that are been changed are the tranny and the rear end. Hope now you can get what we are trying to say. -Pavan. |
Thread Tools | |
Display Modes | |
|
|