Transmission fluid

2000 5.3, 232K miles on original engine and transmission, at 118K I installed a TransGo shift kit to fix the famous hard shifting issue. That was also the last and only time I changed the filter and fluid. I've read some people saying to never change it others say every 40-50K. If I want to replace the fluid now, would it make sense to use synthetic or wouldn't it matter at this point?

2000 5.3, 232K miles on original engine and transmission, at 118K I installed a TransGo shift kit to fix the famous hard shifting issue. That was also the last and only time I changed the filter and fluid. I've read some people saying to never change it others say every 40-50K. If I want to replace the fluid now, would it make sense to use synthetic or wouldn't it matter at this point?

dexron III is no longer the recommended fluid for your vehicle. gm did this in 2006. dexron VI is now the fluid to use. ya its synthetic !

I use mobil synthetic TRANSMISSION FLUID ON MY 2000 SIL 4X4. no famous shifting problems or repairs/leaks good stuff ..this was done in 2001 . about 140,ooomi on it now.

also GM no longer licenses dexron III. defective fluid !

j cAT, what is the best way to do a flush so I get everything out?

Bert

On another note: over the past couple of years I've had the issue that it wouldn't take of in D or 3rd but will in 1st or 2nd, probably happened a total of eight times or so, in D it would go, but very very slowly, a little better in 3rd and fine in 1st and 2nd, I just take of in 2nd and then manually shift up. Every time this happened it would do it for the rest of the day but the next day it would be fine and then it wouldn't happen for months. It happened again last Friday but this time it didn't go away until Wednesday when I left work, now it shifts fine again?? Any ideas? Changing the fluid and filter is probably not the solution to this problem but it's been too long anyway so it can't hurt. Truck is long paid for and like to keep it for another while, it's my daily driver for my business and I love it even though it's outdated.

j cAT, what is the best way to do a flush so I get everything out?

Bert

you remove the radiator top tranny cooler line . place a fitting with a hose attached and aim into a container when the engine is started the fluid will flow out . as 1qt comes out add one qt to transmission . with filter /pan removal and filling then do this proceedure for about 10 qts.

cost of fluid is about $8-10.oo / qt.


Its the fluid exchange method not power flush as some manufacturers can use because on those transmissions there is no clutch material.

slow/ non initial engagement means low pressures when cold. I would say worn components . as time passes this will get worse. the reason dexron III was banned in 2006 is because when it gets hot after 10,ooomi the fluid turns too acidic . this over time eats at the metal this is why the red fluid turns darker over time . the etched particles also act like sand blasting causing more damage and restricted passaways and torque converter failure.