Bill Dowd

As the guys suggested above change it out slowly I have 307,000 on my 91 LS and when I bought the car with 40,000 I put a trans cooler big enough for a motor home and change out 4 quarts from the cooler every 3-4 days until I changed out 12 quarts of mobile one synthetic fluid. I change it our every 30,000 miles along with the PS unit also using Mobile one fluid both are working perfect. You can also use Toyota type 4 trans fluid and still get great results. I also change the rear end 75-90 oil using Mobile one gear oil. My 1986 Toyota Cressida went over 500,000 miles using synthetic fluids and nothing wore out Toyota makes great cars.

LScowboyLS

Mobil is actually the manufacturer of T-IV, in fact Mobil 3309 is T-IV

and even further, all of the following are the same fluid, bottled in the same plant on the same assembly line using the same Mobil 3309 Aisin-spec recipe with base stock straight from the Baytown, Baton Rouge, and Beaumont refineries:

Mobil 3309
Toyota T-IV
Volvo JWS 3309
Mazda T-IV/3309
Saab JWS 3309
BMW/Mini JWS 3309

nostalgi

Thanks.

Greg5OH

there is no such thing as "shocking" teh system. In fact, the transmission will like ALL new fluid. People say you shouldnt do a flush because it might dislodge a piece of buildup in teh transmission and clog something. Listen, if you have buildup somewhere in the tranny IT IS ALREADY CLOGGED.
Fluid loses its lubricating properties with heat cycles. Drain and fill it a few times. Your transmission will thank you.

Aeok18109

I was wondering about this. When it was running it seemed like it might have been starting to slip from 2nd to 3rd. My bucket has 217k. virtually NO records after 50k.I was thinking of dropping pan and changing filter right off the bat.