3.0 CRD Auto gearbox 'slipping' on steep hills

[Bacho86]

Hey guys

Recently got back from a trip in the high country out the back of Dargo and had a few issues with the auto gear box on some steep hils.

It would be climbing up nicely in low range, revs sitting around 2300 - 2400rpm doing about 30km/h, then all of a sudden it would loose power drop down under 2000rmp and slow down to 10-20km/h, it would not hanger down gears automatically and appeared to be 'slipping'. In one case I even had to stop the patrol on the hill, physically changed it down into 1st gear and off we went again.

Admittedly, some of these hills were very steep and long, and it was a hot as day - but I thought this was pretty average?

More concerning was driving along in 2H on main dirt access tracks doing about 60km/h, going up steep long hills again it would slow down to 20-30km/h and struggle to kick down a gear.

Has anyone experienced this type of issue before or have any suggestions?

The patrol was not loaded heavy nor was it towing a trailer.

Cheers

image.jpgimage.jpg

[Hodge]

Might be a silly thought but... Do those automatics have some sort of a overload / overheat protection, where they down-step them selves, in certain scenarios ??
Just a scenario my uncle had with his bmw where it was low on autobox oil, and because of it it wouldnt let him go above certain speed / gears once it reached a certain temperature ?
As I said, might be a silly notion, but just throwing it out there.

On a other note love those photos mate great pics of the HC! I'm jealous.

[threedogs]

you weren't losing boost were you.
I had a similar thing happen , I tried to drive my Patrol when I first brought it like my 350 chev troopy
Select low 2 hit 1200 rpm and away we go, Not to be it would build boost then lose it build boost then lose it
I thought what a shite box these Patrols are. Noticed you had your revs up though, other than that I'd think maybe a sensor was telling you something
Do you have a SCAN Gauge fitted so you can pull up any errors

[jack]

Hi Bacho86,
Doesn't sound like the automatic is slipping as you were also loosing revs, I'd expect the revs to stay high or increase and speed to decrease for it to be slipping.
Not sure if you have VDC (traction control) on your model but that was my problem. First time I took it up a gnarly track the system tried to take over and I lost power, not at all impressed.
Now I turn in off when I go into 4WD and never had the issue again and I've done some very steep climbs both with and without a camper on the back.

[Bacho86]

Might be a silly thought but... Do those automatics have some sort of a overload / overheat protection, where they down-step them selves, in certain scenarios ??
Just a scenario my uncle had with his bmw where it was low on autobox oil, and because of it it wouldnt let him go above certain speed / gears once it reached a certain temperature ?
As I said, might be a silly notion, but just throwing it out there.

On a other note love those photos mate great pics of the HC! I'm jealous.

Hey Hodge, I honestly don't know - all the oil levels were checked before the trip and were in good condition, however possible that due to the heat and work load the oil was over heating? I'm not sure, but wouldn't have thought so - not like I was doing beach work with lots of changing and stress on the auto?

Cheers mate - Yeh ive got a bunch more photos I'll put up later when I get around to it, it's a great area to visit!

[threedogs]

might need a trans cooler, I know I'll be fitting one when funds allow

[Bacho86]

you weren't losing boost were you.
I had a similar thing happen , I tried to drive my Patrol when I first brought it like my 350 chev troopy
Select low 2 hit 1200 rpm and away we go, Not to be it would build boost then lose it build boost then lose it
I thought what a shite box these Patrols are. Noticed you had your revs up though, other than that I'd think maybe a sensor was telling you something
Do you have a SCAN Gauge fitted so you can pull up any errors

Hey 3D - you may have a point there, may actually be more boost related.... Not sure

Originally I was driving it similar to you, as I had driven my dads LC105 with the 4.2 turbo diesel, and that thing just pulls from real low with no issues but the patrol I definitely had to have it further up in the rev range - I recall reading somewhere the peak torque is developed around 2000 rpm so that was always my goal to try and have it sit there.... But when it started suffering I tried to keep the revs up further to compensate but without much luck

No scanguage or boost gauge at this stage - so couldn't tell excatly what was happening, just trying to piece it together...

[Bacho86]

Hi Bacho86,
Doesn't sound like the automatic is slipping as you were also loosing revs, I'd expect the revs to stay high or increase and speed to decrease for it to be slipping.
Not sure if you have VDC (traction control) on your model but that was my problem. First time I took it up a gnarly track the system tried to take over and I lost power, not at all impressed.
Now I turn in off when I go into 4WD and never had the issue again and I've done some very steep climbs both with and without a camper on the back.

Hey Apollo - yeh perhaps more a boost issue. Only an ST model so no traction control I believe - how to you go with the camera trailer and the auto - have you fitted reduction gears or done any modifications to the auto box?

[Bacho86]

might need a trans cooler, I know I'll be fitting one when funds allow

I was of the understanding they already had a trans cooler fitted?

[jack]

Hey Apollo - yeh perhaps more a boost issue. Only an ST model so no traction control I believe - how to you go with the camera trailer and the auto - have you fitted reduction gears or done any modifications to the auto box?

No modifications to the auto at all, stock standard mechanically but may put in a torque converter locker when the warranty runs out. So far I've done about 16,000km towing over various conditions including the Cape and some sand, never missed a beat. Camper is a Jayco Eagle and fully loaded would come in close to 1400kg, must weigh it some time. Handled the Bloomfield Track and a pretty good climb up to Atherton with ease.