Lucas Transmission Fix

The Lucas product has received some favorable comments from some Caddy owners who had sticky shift solenoids in the 4T80E trannies. That being said, I think in your place I'd drop the pan and clean the screen followed by a refill with fresh fluid then evaluate before I added the Lucas. FWIW YMMV

That was already done once, with little or no improvement. We're going to have it done again, but I suspect that more will be needed to fix the problem.

== Lucas won't harm anything. I use it as preventative maintenance. Started by adding one bottle. Now since I change the fluid frequently, have scaled back to 8 oz. each time. Does sound like solenoids are sticking slightly. Might guess from varnish or deposits. ATF is high in detergents. Continue drain and fill to cleanse fluid. If you can let it drain hot and stand over night you'll get almost a quart more out. Total capacity is just under six (5.9) quarts, so some remains in the torque converter when draining. Over night drain will remove close to 3.5 quarts. No promises, but I think you may experience an improvement with the Lucas transmission fix.

Thanks for the reply. I hope you're right.

mjc13

== Shifting is controlled by the solenoids regulated by the ECM. Could also be poor wiring connection outside the case. Try clean and reconnect. Also be sure to get the fluid level right. Car must be driven at least ten (10) miles according to Toyota for the transmission to reach operating temperature. No prolonged high speed or stop and go with A/C on prior to checking. Once you get the level right, is a good idea to measure the amount drained. Makes it far easier to replace just the correct quantity.

My health forces me to have a local dealer do the work. We drive the car under pretty good conditions: either a long highway commute with a 2 minute warmup first, or a local trip of about 5 miles with a long straight stretch. We're babying the transmission in the hope that we can get rid of that hesitation.

Delayed shifts across gears sound like a line pressure problem. It may be due to varnish causing sticking pistons and valves etc as others mentioned. Another source of low line pressure can simply be a plugged strainer.

The strainer in its casing is impossible to clean with compressed air. I just replaced one with 24K miles of fine metal particles lodged in it with a $20 Fram ATF kit that included a cork-rubber gasket that helped to hold the bolts in place.

Yeah, maybe a more frequent ATF drain and refill schedule for a while.

When it does shift it does so decisively, so I don't think it's line pressure...

The dealer supposedly replaced the strainer with the first drain & fill, but I'll try to make *sure* they do it with the second one. Thanks.

...

=== Were the permanent magnets in the bottom of the pan still in place? That's where metal particles are supposed to be trapped. Maybe I'm wrong, but wasn't aware of non ferrous metal in the transmission.

You might try a different mechanic this time. Cheaper, too. At least in my neck of the woods, the dealer mechanics aren't so great. And they charge US$80+/hr.

Michael

The case it self, and some bearings, are likely to be nonferrous.

Which metals?

Any lead likely to be in the tranny, just wondering...?

Michael

When the pan is off we look for ferrous shavings that stick to the magents. These are from the gears. I clean this layer of sludge off so the magnets can do a better job attracting more gear shavings. There is quite a bit this time, so my next strainer goes back to the 15K mile interval. Aisin trannys are relatively dirty.

There are also copper/brass shavings that can come from the bushings according to the shop manual. I do try to look for these shavings but can't say I'd seen any among the thin layer of black sludge on the bottom of the pan. Which would be a good thing in the absence anyway. The shavings caught in the strainer look ferrous.

The clutch material suspended in the ATF is said to make the fluid look gray.

Ferrous from the gears, copper/brass from the bushings, and clutch material (brake bands, clutch pack) sorta like your brake pad.

== FWIW, I saw that layer of slime on the pan when I bought the car at around 80K. Replaced the gasket, cleaned the pan, and changed the fluid. A mechanic with a solvent tank did the cleaning. Since then, I've been using Mobil 1 synthetic ATF in the transmission and differential. Actually I also add that 8 oz. of Lucas also. Generally drain and fill the A140E Aisin transmission at 5K intervals when I do servicing. Had to change the gasket again not long ago to correct a leak (discovered two stripped bolts from prior work). Pan was spotless and magnets clean. I cleaned them again anyway, but there was nothing there. So for me, regular fluid changes have worked well without changing the pan, strainer or gasket.

Didn't someone mention that fillling the tranny with synthetic ATF resulted in the car not properly shifting? Something about the ATF viscosity being too low...?

I'm impressed that synthetic ATF worked for you.

I put Mobil 1 synthetic ATF in my differential, and small amounts of it (less than a pint) in my last tranny oil drain-and-fill (I still had my Mobil 1 lying around in the garage), but was afraid to go fully synthetic.

Michael