Suspecting Gearbox Problems

[Sage222]

So i seem to have a wierd issue with my m35.. just doesnt feel right under accelaration and numerous times the speed is going up though the revs are not.. (yes i know slipping is the other way round!) i must admit i am new to automatic gearboxes and this is the first i have ever owned and i might be simple paranoid though at approx 2800rpm and above some wierd shit is going on...

car pulls great up to then..though once it hits approx 2800rpm then the engine noise changes to what sounds like air blowing (yes thats very vague) and despite is still accelarates it doesnt accelarate well like it should..

just checked the transmission oil and its running way too much (about 1 cm above the full line when hot).. the oil itself doesnt look too old though it is not the red stuff i was expecting..

so how hard is to change the gearbox oil and filter? i have read Nulon or Matic S is the way to go.. how much work am i looking at and where do i get a filter? (350z is the same i presume?)

once again appreicate all your help.

Edited August 12, 2011 by Sage222

[ironpaw]

I had a similar issue when my car was worked on by the gas conversion mob.

It would rev up but then when it hits boost all I get is a crap load of hissing sound.

Scott looked at it and found some pipe was loose. Can't remember which one...

[Sage222]

ooo that sounds very a lot more inexpensive than a gearbox! Scott please tell me you remember which one!

[scotty nm35]

I cant remember yesterday. Have a look in your engine bay, but i'm thinking your'e just in 5th gear. lol.

[zei20l]

So i seem to have a wierd issue with my m35.. just doesnt feel right under accelaration and numerous times the speed is going up though the revs are not.. (yes i know slipping is the other way round!) i must admit i am new to automatic gearboxes and this is the first i have ever owned and i might be simple paranoid though at approx 2800rpm and above some wierd shit is going on...

car pulls great up to then..though once it hits approx 2800rpm then the engine noise changes to what sounds like air blowing (yes thats very vague) and despite is still accelarates it doesnt accelarate well like it should..

just checked the transmission oil and its running way too much (about 1 cm above the full line when hot).. the oil itself doesnt look too old though it is not the red stuff i was expecting..

so how hard is to change the gearbox oil and filter? i have read Nulon or Matic S is the way to go.. how much work am i looking at and where do i get a filter? (350z is the same i presume?)

once again appreicate all your help.

no its matic J, DONT put matic S in it!!!! it will destroy your transmission.

mine sometimes does that too, doesnt accellerate as hard as it should, i just kick it back a gear. its entirely possible youre not pushing the throttle enough to force the torque converter to unlock.

[ironpaw]

no its matic J, DONT put matic S in it!!!! it will destroy your transmission.

mine sometimes does that too, doesnt accellerate as hard as it should, i just kick it back a gear. its entirely possible youre not pushing the throttle enough to force the torque converter to unlock.

REally? Matic S will ruin the box? I thought S is better then J?

Isn't it Matic D that's bad for the tranny?

[zei20l]

read the stick, it will tell you

the nulon stuff is matic J and D or S or whatever it is compatible...........

[Sage222]

nah its not 5th i have confirmed it happens in every gear by driving round in manual.. ironpaw sounds like he had the exact same issue.. come on scotty you must remember what pipe!

its almost as the engine isnt seeing the boost..

Edited August 12, 2011 by Sage222

[bigkevracer]

I dont think manual mode always actually displays the gear its in...

[Sunkist]

its probably a leak in the piping after your turbo. boost leak.

check all of your IC piping... a loose clamp will do it

[Sage222]

yes i know bigkev though it does hold the gear until you manually change up and i can count

will have a look tomorrow at the core pipes i really hope its that easy!

[Sage222]

nice one ironpaw! was intercooler piping much better now. thanks again!

[Sage222]

anyone want to tell me about the gearbox filter and oil though? best way to take some oil out and how hard is it to change?

[Ross]

The box is suppose to be service free, unsure if there is a filter to change.

The fluid is simple to change, just warm the car up, drain the box via the lower plug.

Then drain the transcooler.

Replace the same volume of fluid as you drew out of the box and cooler(around 4-5 L) via the transmission fluid inspection pipe located next to the fire wall.

A full flush involves more work and uses a fair amount more fluid (8-10ish L?).

There are youtube videos for G35s/350z that can be of some assistance if you get stuck.

[zei20l]

there is no filter, but there is a strainer in the valve body. its worth probably cleaning any metal bits out of that. but youll need to remove the pan.

just remember to check the fluid level after you have filled it. go for a short drive and check it again after.

[Sage222]

much appreciate the info ill give it a shot

[iamhe77]

What colour is it if is isn't red???

What was used in it and whom did the service?

I'd drop a little out of it (unhook one of the trans cooler hoses) and make sure it is on or just below the "FULL" line when hot.

I know if you have too much or too little in there it can do what you are describing.

no its matic J, DONT put matic S in it!!!! it will destroy your transmission.

Nup, Matic S is the synthetic replacement for Matic J (which is a semi-synth) and will be fine for our transmissions.

It's Matic D (or Dextron III) you can't put in there

[zei20l]

ahhh ok thanks dude, sorry for the misinformation. ill remember matic S when i change my transmission

[Sunkist]

What colour is it if is isn't red???

What was used in it and whom did the service?

I'd drop a little out of it (unhook one of the trans cooler hoses) and make sure it is on or just below the "FULL" line when hot.

I know if you have too much or too little in there it can do what you are describing.

Nup, Matic S is the synthetic replacement for Matic J (which is a semi-synth) and will be fine for our transmissions.

It's Matic D (or Dextron III) you can't put in there

not going against what your saying, but ive been tod by ALOT of trans auto joints that its not bad to overfill by a little, and that a lot of trans joints actually overfill

[bigkevracer]

not going against what your saying, but ive been tod by ALOT of trans auto joints that its not bad to overfill by a little, and that a lot of trans joints actually overfill

Isnt that when cold though? And just below the line when hot = just above the line cold?