After 16 years of ownership, my 2001 LS430 with 169,000 miles has had a progression of morning sickness where the transmission likes to hesitate before making the first shift of the day. Once shifting its good to go for the balance of the day. There is no slipping. My trusty trans shop has already told me that this is quite common on Toyota/Lexus transmissions due to dry seals that will no longer hold proper pressure. My fluid is not dirty and still has a reddish color to it. I never changed the fluid and was told NOT TO. which I believe. When my transmission gets much worse I am planning on using some kind of additive and have heard about Lucas, TransX, Lubeguard shudder fix, AT-203 plus others. My trans does not slip and I know the fix will not last forever, however I'd like to keep the trans going as long as possible. Can anyone recommend an additive they have used for morning sickness that has helped them preserve the life of their trans and what was your experience? I know I will have to eventually either rebuild, replace, or sell my car. Any help would be greatly appreciated.

 

Just my opinion but I wouldn't use any additive product.
There's nothing wrong with changing the fluid.

 

Thanks for the suggestion, but as I see it, since I do have real "morning sickness" due to the hardened seals, a drain and fill theoretically should not be able to rejuvenate those seals and if anything the detergent in the new fluid may actually dislodge the varnish that has accumulated on the clutches that are keeping them from slipping....thus worsening the situation. I know this is a last resort, but I'm looking for something that will specifically swell the seals to get adequate pressure....at least for a while longer.

 

Drain and fill don't flush, your old fluid still has all the garbage and contaminates in it. Adding additives to it down the road won't help as your original fluid is still dirty. Adding water to your garbage can won't clean it if you don't empty it first. I changed in the fall, and even with this 14f temps we've had the car shifts butter smooth.

 

Using an additive rather than drain and fill is silly logic. Drain and fill. Repeat in your chosen interval.

 

As mentioned on an earlier post, drain and fill cannot rejuvenate hardened seals. It may help with other transmission issues.

 

At your age and mileage, three drain and fills over the next six to twelve months would be helpful. If no improvement after the first or second drain and fill, then try an additive.

Not sure if your first shift of the day is from reverse to drive, mine is. I just had the ECU repaired due to the downshift issue. It also solved the hesitation and roughness of that first shift from reverse to drive.

 

I have a strong suspicion that you own an 04-06 LS. The ECU fix does not apply to the 01-03 LS series. Thanks again for your feedback. PS. My first shift of the day is now in Drive. It used to be reverse to drive which was where the problem began. Now in drive as the first shift is starting to show a delay unless it is very warm out. Either way I’m sure my seals are hard and not holding pressure.

 

Never heard of whatever issue this shop is talking about with Toyota transmissions in my almost quarter of a century working on them.

A lot of transmission shifting issues can be solved by simply maintaining the fluid with spill and fills over the course of time. As an example, Honda 6 speed transmissions on the Pilots and Odysseys are notorious for apparent slipping issues, and doing several drain and fills to clean them out fixes the problem as they are very harsh on the fluid during their normal operation.

If the actual internal clutches or these "seals" the shop is talking about are bad, and trying a few fluid changes is out of the question, then it's probably time to start looking for a new transmission, as miracle fix fluids don't work at all with the testing I've seen.

 

My LS430 with 168,000 miles exhibits NO transmission slipping,or late, or abrupt, or erratic shifting......Just occasional delay going into gear when car sits overnight and when temps outside drop. All aspects of shifting are as they should be. From all the shops I've spoken to (many) the lip seals on the A650 get hard or sometimes even break, losing fluid pressure. After warming up, all is well. I've been told that the additives can expand the seals for some additional time, but basically for a limited time. I understand it is a temporary fix. I'm just trying to make it through the winter months, until the weather is warmer.My plan is that when the condition gets very servere, I will drop enough fluid to get the additive in without overfilling.