How Can You Tell If U Need To Change Trans Fluid?

[vroom8]

this has probably been discussed, but mine still looks and feels clean, but i haven't changed it in a year.

should i change it?

[1990LS400]

I can't remember if the recommended maintenance schedule regarding transmission fluid changes for my departed gen 1 LS400 was the same as for the 2000 LS400 I have now (I think it was), but my 00 LS maintenance manual recommends changing the transmission fluid only every four years or 60,000 miles and only if the car is operated under severe operating connections.

It's probably overkill, but I have always had the transmission fluid changed on cars with automatic transmissions every 30,000 miles.

Do you have the maintenance manual that originally came with your car?

[vroom8]

I can't remember if the recommended maintenance schedule regarding transmission fluid changes for my departed gen 1 LS400 was the same as for the 2000 LS400 I have now (I think it was), but my 00 LS maintenance manual recommends changing the transmission fluid only every four years or 60,000 miles and only if the car is operated under severe operating connections.

It's probably overkill, but I have always had the transmission fluid changed on cars with automatic transmissions every 30,000 miles.

Do you have the maintenance manual that originally came with your car?

i do and i will look. thnx.

[vroom8]

anyway....so i changed it and added lucas tranmission additive.

the guy at auto zone told me he had put it into his older infiniti, and it had worked great.

i notice a difference already....the trans slids easier....smoother.

i also have used the gas treatment, for quite a while, and notice a big difference in mpg and handling.

[amcdonal86]

anyway....so i changed it and added lucas tranmission additive.

the guy at auto zone told me he had put it into his older infiniti, and it had worked great.

i notice a difference already....the trans slids easier....smoother.

i also have used the gas treatment, for quite a while, and notice a big difference in mpg and handling.

So the gas additive improved your handling???? My BS meter is going off! :D

[billydpowell]

anyway....so i changed it and added lucas tranmission additive.

the guy at auto zone told me he had put it into his older infiniti, and it had worked great.

i notice a difference already....the trans slids easier....smoother.

i also have used the gas treatment, for quite a while, and notice a big difference in mpg and handling.

So the gas additive improved your handling???? My BS meter is going off! :D

RELAX, IT IS A MENTAL THING.....

[amcdonal86]

anyway....so i changed it and added lucas tranmission additive.

the guy at auto zone told me he had put it into his older infiniti, and it had worked great.

i notice a difference already....the trans slids easier....smoother.

i also have used the gas treatment, for quite a while, and notice a big difference in mpg and handling.

So the gas additive improved your handling???? My BS meter is going off! :D

RELAX, IT IS A MENTAL THING.....

Ahahahahaha :D :D :D

[AZ Mike]

I drained and replaced 2 quarts of tranny fluid when I did my 60K service last May. I replaced the timing belt, water pump, etc. last month, and did another drain and fill. Except this time, I let it drain overnight while the front wheels were up on ramps.......instead of a 2 quart drain, I drained 5-6! All that nice fresh tranny fluid.......it shifts "like butta". It wasn't necessarily shifting hard before, but there is a slight improvement. The old fluid was pretty dark, so in addition to a slight shifting improvement, it makes me feel better, too. :)

[azmalu]

I drained and replaced 2 quarts of tranny fluid when I did my 60K service last May. I replaced the timing belt, water pump, etc. last month, and did another drain and fill. Except this time, I let it drain overnight while the front wheels were up on ramps.......instead of a 2 quart drain, I drained 5-6! All that nice fresh tranny fluid.......it shifts "like butta". It wasn't necessarily shifting hard before, but there is a slight improvement. The old fluid was pretty dark, so in addition to a slight shifting improvement, it makes me feel better, too. :)

so for the non diy'ers like me that are considering a flush I have come across two options:

http://www.gadgetonline.com/TransFlush.htm

Cooler Line Flush

The first type of flush machine connects into the transmission cooler lines. BG makes this kind and here is how it works. The line going from the transmission to the transmission cooler is disconnected and connected to the machine line in. The line out from the machine carrying new fluid is connected to the line going to the cooler. There is a chamber on the machine that has a diaphragm in it. The top part of the chamber above the diaphragm is filed with new fluid. The engine is started which turns the torque converter and the input shaft on the transmission. The input shaft turns the transmission pump and it makes hydraulic pressure. This causes fluid to flow through the cooler line. As fluid leaves the cooler line it enters the chamber on the flush machine. As the old fluid side of the diaphragm fills it pushes the diaphragm up and forces new fresh fluid into the transmission. After a while the old fluid is collected in the machine and it is replaced by new fluid. Now the transmission has been flushed. Really pretty simple. As you can see the machine cause no pressure and all fluid transfer is done by the transmission�s own pump.

Pump Inlet Flush

This kind attaches to the pump intake after the pan and filter is removed. This machine only supplies fresh new fluid to the pump intake and as the fluid passes through the transmission it dumps out to a collection tray and never goes back through for a second pass. All of the old fluid and crud is GONE and replace with fresh new fluid. After the service a new filter is installed, the pan replaced and then it is topped off with new fluid to the proper level on the dipstick.

This process takes a total of 20 quarts of fluid to flush out 15 quarts of old fluid, replaces the fluid, and gives the mechanic the opportunity to look in the pan for anything unusual that would indicate a pending failure.

Most local shops aamco brake masters midas etc use the cheaper cooler line flush option but always say they replace 99% of fluid. That sounds great but if they are not removing pan how do they get rid of metal sediments gunk etc.? Any thoughts? My car is at 100k . I think previous driver was very gently but I have had it for about 10k with constant stop and go traffic that is why I am concerned. I know doing flush can sometimes make things worse so maybe the less intense may be the better option. Please advise.

[azmalu]

I drained and replaced 2 quarts of tranny fluid when I did my 60K service last May. I replaced the timing belt, water pump, etc. last month, and did another drain and fill. Except this time, I let it drain overnight while the front wheels were up on ramps.......instead of a 2 quart drain, I drained 5-6! All that nice fresh tranny fluid.......it shifts "like butta". It wasn't necessarily shifting hard before, but there is a slight improvement. The old fluid was pretty dark, so in addition to a slight shifting improvement, it makes me feel better, too. :)

so for the non diy'ers like me that are considering a flush I have come across two options:

http://www.gadgetonline.com/TransFlush.htm

Cooler Line Flush

The first type of flush machine connects into the transmission cooler lines. BG makes this kind and here is how it works. The line going from the transmission to the transmission cooler is disconnected and connected to the machine line in. The line out from the machine carrying new fluid is connected to the line going to the cooler. There is a chamber on the machine that has a diaphragm in it. The top part of the chamber above the diaphragm is filed with new fluid. The engine is started which turns the torque converter and the input shaft on the transmission. The input shaft turns the transmission pump and it makes hydraulic pressure. This causes fluid to flow through the cooler line. As fluid leaves the cooler line it enters the chamber on the flush machine. As the old fluid side of the diaphragm fills it pushes the diaphragm up and forces new fresh fluid into the transmission. After a while the old fluid is collected in the machine and it is replaced by new fluid. Now the transmission has been flushed. Really pretty simple. As you can see the machine cause no pressure and all fluid transfer is done by the transmission�s own pump.

Pump Inlet Flush

This kind attaches to the pump intake after the pan and filter is removed. This machine only supplies fresh new fluid to the pump intake and as the fluid passes through the transmission it dumps out to a collection tray and never goes back through for a second pass. All of the old fluid and crud is GONE and replace with fresh new fluid. After the service a new filter is installed, the pan replaced and then it is topped off with new fluid to the proper level on the dipstick.

This process takes a total of 20 quarts of fluid to flush out 15 quarts of old fluid, replaces the fluid, and gives the mechanic the opportunity to look in the pan for anything unusual that would indicate a pending failure.

Most local shops aamco brake masters midas etc use the cheaper cooler line flush option but always say they replace 99% of fluid. That sounds great but if they are not removing pan how do they get rid of metal sediments gunk etc.? Any thoughts? My car is at 100k . I think previous driver was very gently but I have had it for about 10k with constant stop and go traffic that is why I am concerned. I know doing flush can sometimes make things worse so maybe the less intense may be the better option. Please advise.

Update: went to aamco.....

Said they wont flush it. suppossedly has some internal problems. same issue we all describe about jerking between 1st and 2nd. told him not worried went on my way. still would like to find a shop to flush it. He said it was a quart low so debating on whether to fluid and some lucas...any thoughts?