Hi: 2002 RX300; second owner; currently 250K miles. Reasonably well maintained by previous owner. Transmission works flawlessly in forward gear, and in reverse until there is a noticeable slope at which point it shudders and slips. What is the likely explanation? Possible to repair in place? Had a 1999 RX300 in which the transmission failed at 120K; not interested in replacing the transmission in a 22 year old car with 250K. Thanks.

 

Don't expect much help from the internet. Realistically, you would get the proper advice/option from a transmission shop.

Salim

 

Assuming up mean you are driving up a "noticeable slope" in reverse then it is under increased load and maybe that causes a slip.
But another effect of the slope is on the fluid, it would pool towards the front of the pan and maybe the flow is affected.
Is the level right, quality good, filter ok?

 

MaxSteel: Yes to all your questions.

 

The transmission itself is pretty complex component. As an owner one can typically do level checks and condition of fluid + filter. Inside there are hydraulic paths which are operated by the ECU and drive gear selector. Any issue with the solenoid(s) and or passage(s) + condition of the bands + clutches is best determined by transmission expert.
My concern is with that much milage on the clock is it worth paying an expert for evaluation? But then again they change a solenoid to put you back on the road.

Salim

 

Do a drain change filter and refill with new fluid. Add some more magnets if you got them and see if you can notice improvement. I would service before anything as you have a first sign so don't ignore it or drive it till it stops like everyone else. Not many take first signs seriously enough you might fix it with maintenance rather than rebuild.