UOA to ID ATF type

[SmoothFlyer]

Is there such a thing?

I have a 1993 Lexus SC400 that uses Toyota Type II ATF. I had the dealer flush the trans recently and now it shudders going uphill at light throttle. I'm beginning to suspect they may have put Dexron instead of the Toyota ATF. So if get a sample of the ATF to a lab, can they tell me definitively what type ATF it is? Perhaps 3 samples would be the way to do it:
1 sample virgin Dexron
1 sample virgin Toyota ATF
1 sample from my trans.
Then compare the results of all 3.

Any ideas, suggestions or comments?

 

[Ray H]

I'm not sure a UOA analysis would tell you. UOAs indicate what contaminants are present, not the actual formula assay. I would also be surprised to find a Toyota or Lexus dealer using a Dexron fluid where a proprietary ATF was indicated, but... Given the age of the car, I'm wondering whether that flush accelerated some problems that would eventually have appeared anyway. There've been a number of posts questioning the need or even the desirability of trannie flushes. Were you having any trannie shift or other drivability issues prior to the work?

 

[widman]

A standard analisis won't tell you much. If you had big bucks to spend you could probably find out that way, but there are lots of ways to get the performance required.
My guess is that it is cleaning up the mess inside unless it has been changed regularly. Get a 1,000 miles or so with it and change it out again with a new filter, since the one in there is probably clogging badly with what is being cleaned up. (Might even do an Auto RX treatment of the trans before changing out again)

 

[SmoothFlyer]

The car has 83,000 miles now, it had 80,000 when I bought it last month. I had the flush done about a week after I bought it because the fluid was brown, almost black and smelled a little burnt. The tech thought the flush was the right thing to do, and they did charge me for 16 quarts of Toyota ATF. It shudders when going uphill on a light throttle. And I added the AutoRX about 500 miles ago.

It hasn't been long enough to tell for sure, but it may actaully be getting better.

I am planning on another flush & filter change at the 1000 mile mark, at least I think that's the mileage recommended in the AutoRX instructions, I'll check. I'll see what the pan & filter look like then.

It had occured to me that the filter may be partially clogged with debri, thus restricting pressure on the clutches. Find out soon enough...

 

[SmoothFlyer]

The car has 83,000 miles now, it had 80,000 when I bought it last month. I had the flush done about a week after I bought it because the fluid was brown, almost black and smelled a little burnt. The tech thought the flush was the right thing to do, and they did charge me for 16 quarts of Toyota ATF. It shudders when going uphill on a light throttle. And I added the AutoRX about 500 miles ago.

It hasn't been long enough to tell for sure, but it may actaully be getting better.

I am planning on another flush & filter change at the 1000 mile mark, at least I think that's the mileage recommended in the AutoRX instructions, I'll check. I'll see what the pan & filter look like then.

It had occured to me that the filter may be partially clogged with debri, thus restricting pressure on the clutches. Find out soon enough...

 

[MolaKule]

Flyer,

Rather than a complete "forced fush" why not just drain through the filler tube and add fresh oil avery 1,000 miles? Keep doing this until the shifting smooths out. And use some Auto-RX each fluid replacement.

I suspect the forced flush may be partly the cause of your problems.

 

[unDummy]

Shudders on light throttle going uphill also sounds like an engine tuneup issue. Don't rule that out.
I would also guess that the newer T-IV would be more betterer at shudder control compared to T-II.
Definitely change that filter and reflush. Watch them add the fluid to the machine. Insist on bottled fluid or buy your own.

 

[SmoothFlyer]

quote:

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Originally posted by unDummy:
Shudders on light throttle going uphill also sounds like an engine tuneup issue. Don't rule that out.
I would also guess that the newer T-IV would be more betterer at shudder control compared to T-II.
Definitely change that filter and reflush. Watch them add the fluid to the machine. Insist on bottled fluid or buy your own.

---

I have considered tuneup issues, but it does have fresh plugs and I checked the distributor caps, rotors & wires. Timing is fixed. Throttle body is black but does not appear restricted. If the problems continue or get worse & a subsequent flush doesn't fix it I'll check the throttle body in more detail. I also tend to think it's not ignition related because the engine & trans are flawless at open throttle. It will pin my head to the seat from less than 10 to well over 120 with no hint of a miss. I've been really good at detecting even very small misses in other cars, but then again, this V8 is ultra smooth.

The dealer did suppossedly use the T-IV; T-II is not available. After considering Mole's suggestion I'm leaning toward DIY next time. Apparently the dealer's mechanic doesn't think pulling the pan for an inpsection is worthwhile. Egad.

Also, it usually DOESN'T shudder going uphill at part throttle. Only sometimes. I think the next time it happens I'm turning around and trying the hill again at the same speed and see if it repeats. If there's no repeatability I'd lean toward the throttle body.

Thanks for the suggestions!