Transmission Only Works Normally When Fluid Level Is Low

[sonicz]

I've been struggling with automatic clutch transmission slippage for a while now. Dexron 6 definitely works better than dex 3 compatible oils for slippage issues. Shifts are a bit harder but there is less slip.However, after about 1/4 acceleration the clutch is no longer fully engaged and it begins to slip under the power of the engine and thus increasing acceleration is halted.

notcied the problem is less pronounced when the car is cold, leading me to believe rising fluid due to temperate causes more and more slip.

I changed the auto trans fluid and this time left about 1 litre of oil missing from the auto transmission.

The transmission doesn't slip at all. Shifts are rougher but thats a result of less slip which I want.

I drove for 2 days no problem. I topped it up to the normal recommended about and the slip is back.

Can anybody comment on this?

I'm considering running low amount of oil permanently.

The oil level is about the point of little kink on the dipstick, just showing up barely at all.

Yes I check the level with the car running in P when warmed up.

S1 R33 GTS-T

[Drorysoyday]

Hi! Welcome to our website.

Look on this

astomishing

acné

[scotty nm35]

I've been struggling with automatic clutch transmission slippage for a while now. Dexron 6 definitely works better than dex 3 compatible oils for slippage issues. Shifts are a bit harder but there is less slip.However, after about 1/4 acceleration the clutch is no longer fully engaged and it begins to slip under the power of the engine and thus increasing acceleration is halted.

notcied the problem is less pronounced when the car is cold, leading me to believe rising fluid due to temperate causes more and more slip.

I changed the auto trans fluid and this time left about 1 litre of oil missing from the auto transmission.

The transmission doesn't slip at all. Shifts are rougher but thats a result of less slip which I want.

I drove for 2 days no problem. I topped it up to the normal recommended about and the slip is back.

Can anybody comment on this?

I'm considering running low amount of oil permanently.

The oil level is about the point of little kink on the dipstick, just showing up barely at all.

Yes I check the level with the car running in P when warmed up.

S1 R33 GTS-T

You don't think Nissan trans fluid may have been a better choice? Mine did the same thing after I suspect Dex3 was added.

Time for a rebuild or replacement trans. Which box is it you have?

[sonicz]

You mean matic s? Felt like dex 6 Is thinner thus would get me less slip.

Rebuild costs 1000s. May as well do manual conversion. New auto box can be had for almost nothing. I just not confident the other AT will be any better than mine.

A transmission specialist had a drice in mine and said the box works perrectly which is hilarious since its slipping like in snow mode under boost. It works perfectly under light load though.

Do ypu really think matic s is worth a shot...?

[scotty nm35]

If you put the wrong fluid in, then yes. Hopefully you haven't cooked the clutches, they don't like slipping.

Matic J, or Nulon Synthetic trans fluid should be fine from my experience. Matic S is hard to come by.

Look at getting a shift kit at a minimum if you plan to wind some power in. It might be a good idea to clean the filter in the sump before you drop the new fluid in too.

[sonicz]

Well I don't know if fully synthetic dex 6 is bad for it? My reasoning is since it seems to have the lowest viscosity so its the most likely not to slip?

The clutches are definitely cooked. It never used to do this a year ago. Too many downshift from WOTs and it seems the clutches coudlnt hold on and they started to wear out. The transmission can still hold on fine at stock boost, i.e zero slip, but it starts to slip at higher than 10psi. Is there any way just to change the clutch plates?

I actually tried Nulon Synth S a few days ago. Just a drain and top up, so not all of it is changed. It seems a bit thicker than Dex 6?

My impression so far is the slip has reduced and the shifts are nicer. hmm. That said it could be just the fact the fluid has been refreshed.

I have dropped the Pan and put a new filter kit and gasket on there. There was minimal debris on the magnet, next to negligent.

So it looks like I have no choice but to try a new auto box, or convert to manual. Unless somoene can replace the clutches for me for something reasonable under $500.

The rest of the tranny does not need a rebuild.

Also I feel like the mounts on the car and tranny are a bit sloppy, could this cause the transmission to tilt under load at a bad angle and cause slip? I was looking at getting all poly bushes for engine and transmission. I'm ok with increased cabin vibration.

Edited September 30, 2013 by sonicz

[steve200b]

If you don't upgrade your auto ie shift kit you will have the same issue in your next one. I suggest you call mv automatics in Adelaide for a solution. Be prepared autos are expensive compared to manuals.

[sonicz]

I'm in sydney. How much will as shift kit cost me?

I don't think their is a point fitting a shift kit to this box. Does anyone sell an auto box with a shift kit already installed, and if so, how can I be guaranteed of the condition?

When I got the car the auto box already had a ton of KM, and it was VERY low on oil because of a leaking auto fluid cooler. I feeel like If I had the car from new it would have lasted me 20+ years as I regualry change oil, and try to go easy on it If I feel a problem. Kind of like Im the guy that was in the room when the light bulb blew when i hit the switch for the 10000s time. I only run up to 13 psi max anyway with minor mods. I was always told the nissan boxes are very tough..Dont get me wrong it still shifts beautifully it just cant get a grip on itself under higher loads.

By the way for someone who asked, its a s1 rb25det auto box so most likely a re4ro1a

Edited October 1, 2013 by sonicz

[scotty nm35]

I meant 4 speed or 5 speed, as I have a 5 speed here...

If the clutches are slipping then the box is now in need of an expensive rebuild. You don't open an auto and not change the bearings and seals, it is usually a full build that is required and it will set you back in the region of $3k or more.

You best bet of getting out of it on the cheap is to drop a replacement box in there, and shift kit it.

[sonicz]

If thats the case then what reason do I have not to run low fluid in current box? This was the main point of the thread really. It solves my problem and if It breaks as a result, well I needed a new AT anyway. Do you follow?

Also which way should the dipstick should be facing when inserted to check the oil level?

The is a kink on the top of the dipstick, if you face if left when looking at the front of the car the fluid level is MUCH higher than if you face it right. Try it out if you dont beleive me. I am checking the level with the car fully warmed up on a level surface with the engine running and the car in P gear.

Dipshit facing left, higher fluid reading.

Dipshit facing right - lower fluid reading

Edited October 1, 2013 by sonicz