Quick ZF5HP24 question..

[upallnight]

Originally Posted by turquise1

I tried to follow the procedure I have been reading everywhere..


- Fill up when cold until slight drip of oil
- Start car, switch gears to circulate oil and fill up more as the car runs until slight drip again.
- Make sure the transmission temperature stays in between 30c to 50c.


The transmission temp maybe slightly higher at the end because I was doing the whole thing by myself and I was transferring fluid from the big bottle to the small one to be able to use the pump.


Should I try to add more fluid when the transmission is around 30c?


Thanks,


Ozzie

I would let the engine sit over night so you know that you are dealing with a trans at ambient temperature (Hopefully the ambient temp in your location is below 30C).

Start the engine up and run through all the gears. With the engine still running open the fill plug to the trans and fill it till the fluid starts coming out.

The ATF temp should be around 30C or below. If you have it fill up you don't need to add any more ATF at this point.

Now monitor the ATF temp and observe the ATF dripping out of the fill port.

Once the ATF reach 35C put the fill plug in. The trans should be at the correct level.

[turquise1]

Originally Posted by upallnight

I would let the engine sit over night so you know that you are dealing with a trans at ambient temperature (Hopefully the ambient temp in your location is below 30C).

Start the engine up and run through all the gears. With the engine still running open the fill plug to the trans and fill it till the fluid starts coming out.

The ATF temp should be around 30C or below. If you have it fill up you don't need to add any more ATF at this point.

Now monitor the ATF temp and observe the ATF dripping out of the fill port.

Once the ATF reach 35C put the fill plug in. The trans should be at the correct level.

I will definitely try this but do you think it would make a difference? I am reading the expansion of transmission oil with heat is around 0.07% increase in volume per degree C for atf oil. That means if you have 10qts of oil at 30C, you will have appx 10.49qts at 100C. Would that really create such delay?


Thanks,


Ozzie

[upallnight]

Originally Posted by turquise1

I will definitely try this but do you think it would make a difference? I am reading the expansion of transmission oil with heat is around 0.07% increase in volume per degree C for atf oil. That means if you have 10qts of oil at 30C, you will have appx 10.49qts at 100C. Would that really create such delay?


Thanks,


Ozzie

Do the math in reverse. You have 10 quarts of ATF at 50C (assuming the ATF is flowing out of the fill hole) what will you have at 20C or 0C in the winter.

Google symptoms of low ATF in a ZF trans and you should find the answer to your question.