Can I use Lucas Transmission Fix in AUTO 02 XC70??

[XCkindaguy]

OK so a guy I work with stands by this Lucas Transmission Fix. Lucas suggest it can be used in any transmission.

In the last 6,000 miles I did an fluid change to Redline D4 ATF. Recently transmission hits gear out of cornering or hard deceleration or acceleration seems to happen only when hot.

What are your thoughts about putting in a quart of this Lucas Transmission Fix??

P.S I currently have 101,700 miles and did a IPD Transmission Torque Mount when I performed the fluid change.

[tolian2]

OK so a guy I work with stands by this Lucas Transmission Fix. Lucas suggest it can be used in any transmission.

In the last 6,000 miles I did an fluid change to Redline D4 ATF. Recently transmission hits gear out of cornering or hard deceleration or acceleration seems to happen only when hot.

What are your thoughts about putting in a quart of this Lucas Transmission Fix??

P.S I currently have 101,700 miles and did a IPD Transmission Torque Mount when I performed the fluid change.

i had a rather good luck with changing out 3 linear shift solenoids.
i had horrible clunking of gears when hot, now it's gone.
only minor flaring in 2-3 when it's getting warmed up (cold). once warmed up it's shifting fine.

[billr99]

OK so a guy I work with stands by this Lucas Transmission Fix. Lucas suggest it can be used in any transmission.

In the last 6,000 miles I did an fluid change to Redline D4 ATF. Recently transmission hits gear out of cornering or hard deceleration or acceleration seems to happen only when hot.

What are your thoughts about putting in a quart of this Lucas Transmission Fix??

P.S I currently have 101,700 miles and did a IPD Transmission Torque Mount when I performed the fluid change.

I used Seafoam TransTune with good luck. Ran a whole can thru over about 500kms, then a good fluid change and my tranny is working fairly well.

Cheers,

Bill

[Astro14]

NO chemical goop is going to fix your problem - low line pressure.

Redline D4 would not have been my choice for the transmission either - while it claims to be recommended for Toyota T-IV, it's really a DEX III, and it doesn't list JWS-3309 (the spec for this transmission) as one of the recommended applications. Look, the JWS-3309 spec is NOT the same as DEX III, the viscosity is the same, but there are different friction modifiers. The best fluid for this thing is the Toyota T-IV (available at your dealer) or the Mobil 3309 (available on line).

Back to your problem: you have valve body problems. The SLT solenoid regulates the operating hydraulic pressure in the transmission. That pressure moves the actuators to engage the gears. When the fluid is cold, it's more viscous, so the SLT solenoid can develop the required line pressure. When the fluid is hot, it's thinner, and the SLT can't keep the pressure up. So, when you coast, below 25 MPH and the trans shifts to neutral, then you step on the gas, it is slow to engage back into gear and you get the engine rev and slam/bang. It happens sometimes under hard acceleration because the engagement is slow and you're putting a lot of torque through the trans.

I will bet that when the car is hot, it often takes a second or two to go from Reverse to Drive as well...

Lucas is snake oil. You could use anything that will try to modify the friction characteristics of the fluid, a better choice is lubegard platinum, or you can try and increase the viscosity of the fluid...but both are simply going to be masking the real problem: the valve body. Tolian was lucky, sometimes it's the solenoids themselves, but this trans is known for valve body bore wear, especially in the SLT bore. A good rebuilder will re-sleeve the SLT bore, using a Sonnax reamer and kit.

Go to the resources section - read through the valve body notes. That's where your problem lies...

[XCkindaguy]

i had a rather good luck with changing out 3 linear shift solenoids.
i had horrible clunking of gears when hot, now it's gone.
only minor flaring in 2-3 when it's getting warmed up (cold). once warmed up it's shifting fine.

Did you perform the change? How much did it cost?

[XCkindaguy]

Thanks Astro14. I will look into resources section.

Damn snake oil salesmen!

[cattlecar]

The solenoids and valve body are the issue that affects these gearboxes and causes the eventual failures. There is an outer bearing race that can contribute but that is not nearly as widespread as valve body problems. VB's cause "hunting" shifts and harsh downshifts. The solenoids on this trans, and now many others, are not just on or off. The solenoids are pulsed and rapidly go open-closed to regulate pressures on the clutches and brakes they control for shifting. A clutch that is applied for one gear but will be off for the next gear will have its solenoid pulsed at a reducing rate (95% then 90% then 85%, etc) to reduce the pressure and reduce the clutches grip while the solenoid for the component that needs to be applied for next gear will have its pulse rate increased. The component for the next higher gear effectively overpowers the clutch that being released. The weak point is the trans computer does not have pressure sensors in the fluid circuits. The pulse rate is assumed to have the right pressure based on "inferring" the pressure from learning upshift completion time. When the bores of the solenoids gets worn the pressure is not what it should be every time it shifts. If the one being released goes off too quick or if the one being turned on comes on too slow then you have slip or no gear for a moment.
Nissan used AW 55-50 in several of their vehicles, maxima 2004-2006 or thereabouts and quest minivans. If you google "aisin warner 5 speed" or "AW 55-50" you'll find more than you care to read. Seversl others have used this gearbox too.
The VB issues have created a cottage industry for AW valve bodies, even the 6 speed that came out in 2005 V8 xc90 is a trans for which rebuilt VB's are offered.
Ream Man is one with a good reputation.

[cattlecar]

I'm not a believer in snake oil either but additives like Lucas can work if the problem is rubber seal related. Leaking seals making for slip can be swelled with some success sometimes. Metal missing from a solenoid bore causing it to bind is not replaced by anything out of a bottle.

[JRL]

Easier to just change out the valvebody