transmission drain & fill, 3qts??

[Cool_J30]

Hi, been lurking here for awhile and have gotten loads of good info. -- great site!

I just did a drain and fill on my new-to-me 1995 J30's trans. It's been shifting just fine prior to change and a service was done about 10k miles ago. I just wanted to freshen the fluid is why I did it, and please let's not get into the right way to do a trans service, etc.

Car was level other than slight block under tires for a slight front and passenger side raised level (drain plug is rear driver's side, so I wanted to get all I could out).

On to my Q: I only got a little less than 3 qts. out, so I put back in 3qts... After driving and levelling car, the dip stick shows over full? I tried again with the car cold the next morning (following owners manual procedure). The dip stick still shows well over full?

I've read here that a normal drain and fill should be about 4qts., so I'm well under that. What gives?? Can someone help me please?

Thanks in advance...

[yodawill2000]

Welcome to NICO !!
If you put in the same amount that drained out it must have been overfilled to start with ?
Its not a good idea to run a transmission thats overfull of fluid.
You might try draining a half quart or so and check the level again.

[Cool_J30]

thanks, yodawill2000

I know on other automatics, the biggest risk is you puke fluid if it's too full -- some autos have pressure vents just for this. Do you know if the J30 has a pressure vent? Have you done a drain and fill on yours?

Thanks again...

[yodawill2000]

yes.
But I dropped the pan and replaced the filter and gasket.
Then did about 16 quarts of drain and refills.

used two identical sized tupperware containers so I could match the amount I drained to the amount I poured back in.
Ran the transmission though all the gears between drains as well.
Basically kept going till what came out was the same color as what I was pouring in.

[Cool_J30]

So when you did your major fluid change-out, did you drain from the sump drain or did you disconnect the trans cooler line and do it that way?

I have two ford trucks and that's a procedure the ford guys have for a complete change out by pushing the new fluid through the system and catching the old fluid coming back from the cooler. It's a bit easier when you have sumps that are 6-10 qts each tho.

I think I'd drop the pan and check to see if the filter has ever been changed before I'd do either. I bought a case of trans oil on sale and was planning on doing some dump-n-fills every couple of thousand miles in the meantime.

I just still have a hard time believing there's less than 3 qts held in a J30 sump tho. Since I just got the car, I wonder if there's any possibility the dip stick is the wrong one... hummmm... The trans shifts perfectly -- bought it from a one owner little-old-lady friend and she put 93k pretty easy miles, plus everything has been done ahead of schedule on it always. I'm just AR, so I'm going thru everything myself so I know where the lil' guy is at maintenance-wise...

Thanks again -- learned (and fixed) and am learning a lot here...

[goody90q45]

Only 3.5 qts. comes out of my Q45 transmission when I do the drain and fill at every engine oil change so 3 qts. in the J transmission may not be too far off. For comparison the Q45 transmission is 11 qt. capacity and my dip stick does the same. I can never get a true reading.

What is the correct procedure for checking transmission fluid level?

[Cool_J30]

There's two procedures in my manual: one for a barely warmed trans and one for a driven but not hot trans (like 175 deg F). It'd be tough to do the latter one perfectly, imho.

Both have you park on a level surface and run the trans thru each gear, put it in Park and then pull the dipstick, wipe it off and seat it fully, then check the level. I don't believe mine -- I think I'll try it with the engine off -- how could it hurt??

I still think a trans isn't like an engine that's too full: where the crank can whip the oil into a foam if it's too full. Then again if you burp the trans fluid, maybe a fire would be worse... :-(

I'm going to do some more checking on the J30's sump capacity. The total for the J30 is 8.75 qts, btw... I'm thinking an external cooler or going to syn fluid might not be a bad idea...

[1994 infiniti j30 190+]

What is the correct procedure for checking transmission fluid level?

what i did when i replaced my transmission was warm up the car in the driveway if you dont want to drive it and risk messing something up or drive it around the block then back at your house or wherever your at, and with it still running put it through each gear for like 5-10 sec then put it in park and check the fluid with the car still running then add any if needed or even opposite if you added too much. i did this and it drives great better than before. i have done this with all my parents cars and friends and families and works great and easy to do. so thats what i use.

oh and do it with it running if you turn off the car, the level in the pan will go up because of fruid from parts draining back down and giving you a false reading and make it very wrong.

[colincliff2]

I've done several drain and fills on mine. It drains 2 quarts every time. I do it when the trans is warm (say 30-45 mins after driving). When I re-fill it, the fluid level is right in between the low and high marks on the dipstick.

[Cool_J30]

I've done several drain and fills on mine. It drains 2 quarts every time. I do it when the trans is warm (say 30-45 mins after driving). When I re-fill it, the fluid level is right in between the low and high marks on the dipstick.

Thank you very much sir! I will take some fluid out tomorrow morning

[Cool_J30]

For those of you still following this thread...

I went back and did a little bit of checking of what volume I took out/put in -- thanks to colincliff2 for his info. Here's what I found:

When I drained the old trans fluid, which had been in there for 9k miles w/o any aparent issues (trans service done at an ASE independent mechanic), I actually got out about 2 3/4 Qts fluid. So if it was ok but high, 3qts was definately high.

I checked with a friend who, besides being a gearhead, owns a '95 300zx TT. He says the transmissions are virtually the same and close to the same fills. My friend says our transmissions are in fact vented at the top rear drivers side. If it's overfilled, that's where the extra fluid will go...

So based on that I'm not really worried about ruining the trans with a bit of an overfill. However, I drained some out anyway...

I drained 1/4 qt out and then did the "cold" level check procedure (see above). It shows at the top of the hot range now, so I know my dipstick isn't screwy...

I'm going to leave it there for now and do another drain and fill in a thousand miles or maybe less. I think I'll try closer to 2 qts and add if I need to (easier to do for-sure!).

Thanks again to colincliff2 -- you are the only one anywhere I searched on the internet that had a quantity to go with...

Also thanks to yodawill2000 -- you were 100% correct in the trans being overfilled to start. I guess I had to re-learn the old "a**-u-me" rule...

[yodawill2000]

next time your near one of those Dollar stores go in and buy two identical Tupperware type containers.
That way you can match exactly.

[driverdriver]

The same era Nissan Pathfinder and J30 have identical JATCO transmission units.