rear differential ratio

[JakeP]

Purchased this 1992 SVX several months ago. Have put new steering rack lines on it, removed transmission for new torque convertor seal and rear propellar seal.Previous owner installed a 3.90 Legacy tranny, unsure if rear differential was replaced with matching 3.90 gears. When driving around tight turns at slow speeds it feels as if the drive train is binding like an engaged 4wd vehicle does on tight turns on dry pavement.Did not notice this before tranny seal replacement, only drove it a few miles. Any thoughts on this. Thanks

[Blacky]

It sounds like a duty solenoid C (transfer solenoid) issue. The wire may have gotten pinched during the tranny work.

[jeskolesk]

If the binding is slight it could be that you need friction modifier or "shudder fix" additive for your transmission fluid. Fixed mine right up after a 4.44 swap.

Check to see if there are any codes first though.

[longassname]

Assuming you didn't open up your transmission while it was out the only thing that changed and could thus be suspected as the cause is your transmission fluid.

A good inexpensive fluid to use is the Valvoline max life multi-vehicle full synthetic atf: http://www.valvoline.com/our-product...e-dex-merc-atf


Add lubegard to it eliminate the binding during turns and extend fluid life: http://lubegard.com/C-112/LUBEGARD+A...uid+Protectant


Your transmission may have performance modifications. The same modifications that make it last longer and shift better can make it shudder on fast turns.

[JakeP]

Thanks, I did find out the rear differential is a 3.90 ratio. Will follow up with what I find causing the bind!

[longassname]

by fast turns I of course meant slow turns.....not sure how the word fast got in there.

[JakeP]

4. Transfer Clutch Driven Plates (Metal) and Seal Rings - Refer to Figure 4
Modified Clutch Driven Plates (P/N 31589AA041) were installed to reduce rear axle
binding starting with transmission number 389607. Additionally, new style Oil Seals
(P/N 31377AA131) have been installed on the transfer clutch output shaft. These updated
seals are black in color with a "notched" design on their inner diameter and are cut
diagonally on the ends. The purpose for the change was to reduce the chance of these
seals rotating in their grooves and cutting into the rear extension housing.
If you experience a case of rear axle binding on turns, with a transmission that has the
updated transfer clutch driven plates, it is recommended that you install another set of the
updated driven plates. After installing these new driven plates, it will be necessary to
drive the vehicle in several figure 8's to break them in. As always, the first thing to check
when diagnosing an AWD binding complaint is tire size. All tires must be of the same
size and brand name.
Also, major differences in the tire wear patterns between front and rear, can cause
binding in tight turns. Found this info in 4eat modifications, bulletin #16-58-94. Tires are same size front and rear with very little wear. Also FSM calls for Dexron-11- ATF. From Lubegard:
CAUTION:
Use LUBEGARD HFM-ATF Supplement (Black Box) ONLY for applications that require
highly friction modified fluids. Also do not use in CVT applications. Use in transmissions
that do not have this requirement may cause excess wear and clutch slippage. Use
LUBEGARD Automatic Transmission Fluid Protectant (Red Box - 60902) in all other ATF.

[longassname]

dude......

You don't need to research obscure stuff. If you don't have a bad transfer clutch or bad transfer clutch solenoid you just have bad fluid. It's also possible your transmission has performance modifications--in which case it probably had lubegard in it before you drained it and now you need to add lubegard.


I would suggest changing your fluid to the Valvoline maxlife multi-vehicle atf and putting lubegard atf protectant in it. You can use the platinum if you want; a lot of auto parts stores carry that one now but the regular red bottle of atf protectant is the tried and true gold standard and costs less. If it still binds you need to open up your extension housing and plan on replacing your transfer clutch and or solenoid.

[longassname]

dexron 2 is an old standard which has been superseded many times. If you want to run the genuine Subaru fluid you can. It is a very good fluid. The Valvoline maxlife multivehicle atf is also a very good full synthetic fluid for our transmissions and you can buy it at Walmart by the gallon for $17 something

[longassname]

You might also check your adjustment of your throttle and cruise control cables to make sure they aren't holding your throttle partly open when not pressed.

[longassname]

Did you figure it out?

[JakeP]

No, thanks for asking

[longassname]

did you try changing the fluid and adding the lubegard?

[92 SVX]

Originally Posted by JakeP

No, thanks for asking

Generally speaking if you had the wrong gears in the rear diff even on straight driving you would feel a binding.

If you are having a bind on tight turns, especially figure 8's Solenoid C is either not doing its job or is unplugged.

the dash has a green power light that will light up on first ignition (bulb check) but if the tcu detects a problem it will also flash 16 times when you turn on the key that just tells you there is code stored, you will then need to perform the diagnostic procedure to determine the actual code.

[longassname]

Theoretically you should also have a TCU chip modified for the different gear ratio. That's not the problem causing your binding but the car would drive better with the TCU programmed correctly.

It might help to clarify a few things.

Did you open the transmission at all?
What fluid did you fill it with?
Do you have a flashing power light at start up?