99 Lexus GS400 // Toyota T-IV // 88k mi OCI

[sky jumper]

99 Lexus GS400
104,598 vehicle miles
88,717 on T-IV ATF
single 2qt drain/fill done at 66,700 miles (8.4qt total capacity).

I'm planning the following service regimen: (in order)
1) 4x 2qt drain/fills with supertech ATF
2) pan drop & clean magnets
3) 9qt cooler line exchange w/ Amsoil ATF

Blackstone Comments:
We have seen nearly 40 samples from this type of transmission, and their average wear is listed in the universal averages column. On average, the oil in this type of transmission has been run about 13,000 miles. We'd guess this oil was run a lot longer than that. The only source we know of for lead is marking compound used at the factory -- is this factory original oil? We doubt it, but it's entirely possible this oil has only been changed once. Insolubles were high -- a sign the oil was run long. This oil should be changed & the system flushed.

Code:

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OCI 88,717 _____ Universal

Veh Mi 104,598 Averages

Type Toyota T-IV ATF

Date 3/22/2007



Al 143 16

Cr 0 0

Fe 53 34

Cu 50 72

Pb 120 14

Sn 1 2

Mo 0 1

Ni 0 0

Mn 1 1

Ag 0 0

Ti 0 0

K 0 7

B 43 54

Si 54 20

Na 2 3

Ca 127 128

Mg 2 28

P 274 278

Zn 17 84

Ba 4 3



Visc 44.8 43-51

Flsh Pt 385 >335

Fuel 0 0

Coolant 0 0

H2O 0 0

Insol 0.2

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oil blotter from this ATF...

 

[unDummy]

Yuck, get rid of the fluid.

1) Make sure you use supertech HM ATF or a fluid converter
2) While you're there since you're over 100k, why not toss in an ATF filter kit?
3) Good choice!

 

[sky jumper]

Quote:

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2) While you're there since you're over 100k, why not toss in an ATF filter kit?

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hey unDummy, do these things have a screen or an actual filter media? I guess I thought they had a wire mesh screen that didn't need servicing. if they do have a filter media, then absolutely I'll change it.

(the owner's manual mentions nothing about ATF filter, and only reccomends ATF changes for "severe" service).

 

[Pablo]

I don't think there is any filter media in this one - but I could be wrong.

sky jump - your plan sounds excellent.

I'll just comment on Toyota T-IV ATF - pffffffft! But the viscosity held - or rather, maybe, just maybe, it made an excursion.

 

[unDummy]

Visc calculator show ~5.68cst@100 and its ~7.2 new.
I also wonder if ATF, after shearing completely, might start oxidation thickening back up.

When you pull the pan, you'll be able to see the media. AW's typically have fine mesh screens and not real filters. You can visit the parts store/dealer and take a look at some filter kits to answer the question. Some aftermarket filters add media even if OEM uses only a screen.

 

[benjamming]

Does it really only get out 2 qts in a drain/refill? That's not much.

 

[unDummy]

Yeah, common issue with AW boxes is that they hide ATF everywhere but in the pan.

 

[Tempest]

Where does Aluminum wear come from, both auto and manual? I'm not intamently familiar with tranny innards, but aren't most bearing surfaces steel with some Cu bushings?

 

[unDummy]

Bushings, apply solenoids, valve body, transmission case ...... there is plenty of aluminum that could be wear or simply sloughing off the transmission case.

 

[dkryan]

Yeah, remind me to leave the T-IV in my wife's Highlander for another 80k miles. It just turned 19k and I'll dump the original fluid no later than 25k for Amsoil ATF.

sky jumper: why'd you leave the T-IV in that long? Also, why perform #1 (4 Supertech evolutions) if you're gonna perform #3?

 

[sky jumper]

Quote:

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Yeah, remind me to leave the T-IV in my wife's Highlander for another 80k miles. It just turned 19k and I'll dump the original fluid no later than 25k for Amsoil ATF.

sky jumper: why'd you leave the T-IV in that long? Also, why perform #1 (4 Supertech evolutions) if you're gonna perform #3?

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it's a family member's car. were it my own I never would've let it go so long.

reason for the 4x drain/fills is this -- even with the cooler line xchange there still is some old/new fluid mixing. it is not a straight shot from pan-->trans-->TC-->cooler. some fluid comes back to the pan without going out to the cooler, where it mixes with whatever your adding to the pan. so -- I really don't like the idea of mixing fresh expensive Amsoil with old dirty/nasty T-IV. instead, I'd rather get a higher concentration of clean ATF in there first to minimize the contamination to the Amsoil. so, I'll start with cheap ST high mileage, and use that to dilute away most of the dirty fluid. then switch to Amsoil and finish the job with a cooler xchange (and in the process waste most of the ST I put in to begin with).