GU1 Auto Trans not engaging

[twisty]

G'day all,

Well, the auto (r03) scared the willies out of me yesterday! 80km/h on cruise and the auto disengaged. Engine revved to 3k and climbing before I turned the cruise off. Give it some revs with the right foot and away we go again. wtf? Then, 5km later coasting down a hill at 70kmh (3rd gear, OD off) and engine revs drop to idle, huh, apply right foot and ... nothing. Hazard lights on and find a safe place to stop. No gear is engaging, not even park, engine idles happily with new fuel pump. Turn it off and contemplate my situation while I roll a smoke. Restart and we have gears again. hhmmm ... Another couple of k's down the road coasting and same again ...

Now I was intending getting dirty in the local mountains but I've changed my mind and I'm heading home. Climbing back up the valley and same problem again but this time under load. Nurse it home and get every green light

So this morning I go for a test drive. No problems.

Yes, I've checked the ATF before and after the problem. It's a honey colour and hard to see on the dip stick. I checked it in "P" and "R". It looks over full to me? Put 500ml of castrol transmax multi (red) in anyway and check again. It still looks overfull but seems to drive better (it may be my wishful thinking). Got me buggered

Last professional check and top up was 3k ago. We're going back to the mechanic this week for a better look.

Any ideas, suggestions or words of wisdom greatly appreciated.

edit. AT eventually dies and is now replaced with Wholesale Auto Extreme.

[Sir Roofy]

cant realy help here but could be a dirty filter
youll know more after you drop the oil check the plug
oil could be streched wrong oil

[Chaz]

They don’t have a filter as such, just a fine gauze mesh that can be cleaned.
It sounds like you’re losing line pressure, which can be very difficult to find without recreating the symptom with a pressure gauge fitted. It could be a number of things, either forward clutch seals or one or more of the valves in the valve body. Even a loose or leaking transfer tube, but one of the more common causes of this would be the solenoid valves, which are normally replaced during an overhaul.

[twisty]

Update ... drained the oil and dropped the pan. Not bad, a bit of sludge but no metal although the oil was a bit smelly (burnt). Service kit from repco included mesh filter in housing and pan gasket $50. 8 litres of castrol transmax z (did the transfer while we were at it) $120 from castrol (and they sell it in 20l drums @ $299.50). Transmax z is a honey colour (not green or red) so I suspect that was used by a previous owner who probably did a bit of towing.

Chaz, I recall you saying Tz was green (in one of the many posts I read), is that still your experience?.

Seems to shift better now and also seems quieter (time will tell). Also discovered that a genuine (?) atf cooler had already been fitted (we suspect as part of a tow pack). What really annoys me is the uncertainty ... will it happen again, but, this time, in the mountains, on that sharp pinch with the blind hairpin ... bugga.

2012-01-18 14.39.021638.jpg 2012-01-18 14254.39.40.jpg

2012-01-18354 14.39.21.jpg DSC00545606.JPG

The plan is to do it all again in a month. See, the transmax z comes in a pack of 3x4 litres so, I still have almost 6 litres left :-) I've also decided that after the lift and snorkel the auto gets a "Wholesale" overhaul ... if not before ...

Thanks for looking.

[gq4200]

Yes Castrol Tz used to be a really dark green color...

[Chaz]

Hi Twisty,
The original Nissan DMatic is a clear hydraulic fluid which usually turns a honey colour after a while. If it smells burnt, it’s a good indication that the fluid has reached the end of its life and can also be the cause of it losing it’s hydraulic properties. This is often the result of too much city driving in O/D where excess heat it generated through the torque converter.

Yes, TransmaxZ is dyed green.

Reference: http://www.castrol.com/liveassets/bp...Transmax_Z.pdf

[twisty]

The original Nissan DMatic is a clear hydraulic fluid

Sh!t ... I hope it wasn't the original oil I drained yesterday ... naaahhhh ... I guess someone might have used DMatic in a previous service.

Yes, TransmaxZ is dyed green.

Reference: http://www.castrol.com/liveassets/bp...Transmax_Z.pdf

or "amber" ... http://www.msds.castrol.com.au/msds....no=450358-AU07 ... item 9. I wonder why they didn't put the green dye in mine? Must be an optional extra :-)

[Chaz]

Sh!t ... I hope it wasn't the original oil I drained yesterday ... naaahhhh ... I guess someone might have used DMatic in a previous service.



or "amber" ... http://www.msds.castrol.com.au/msds....no=450358-AU07 ... item 9. I wonder why they didn't put the green dye in mine? Must be an optional extra :-)

Interesting! I can’t imagine why they would change the colour, but it looks like they have. Sorry for the bum steer.

[twisty]

Interesting! I can’t imagine why they would change the colour, but it looks like they have. Sorry for the bum steer.

I was looking forward to having green oil, easier to see. They must have changed it recently.

[twisty]

update. 2 weeks later and the AT hasn't missed a beat. Better changes, kickdown and less flaring although, a whine has developed in 2nd once properly up to temp (2-3k rpm) under load. Manual gear changes and no O/D around town.