auto box warmup time

[prelude]

It recently was some 30+c down here and I noticed that it took fairly long for the gearbox to lock up in 4th gear. To give you a bit of context:

Bloody hot car, hot outside, get in start car and drive of straight away. The climate control had to work hard of course to cool me down, but with that, it surely has heated the radiators behind the condensor extra fast since a condensor can get pretty hot (60c I recon) in no time when cooling the interior. Add to that the outside temp of over 30c and I should think that everything under that hood would surely be hot in the blink of an eye.

I live in what we call an outdoor area so when I leave my house I hardly ever dip below 60km/h. It's all long straights, no traffic lights nothing but then still it takes the gearbox up to 8km to lock up which I think is fairly long, especially since it seems fuel consumption is way worse in that period :)

Is this out of the ordinary?

-P

[Tins]

It recently was some 30+c down here and I noticed that it took fairly long for the gearbox to lock up in 4th gear. To give you a bit of context:

Bloody hot car, hot outside, get in start car and drive of straight away. The climate control had to work hard of course to cool me down, but with that, it surely has heated the radiators behind the condensor extra fast since a condensor can get pretty hot (60c I recon) in no time when cooling the interior. Add to that the outside temp of over 30c and I should think that everything under that hood would surely be hot in the blink of an eye.

I live in what we call an outdoor area so when I leave my house I hardly ever dip below 60km/h. It's all long straights, no traffic lights nothing but then still it takes the gearbox up to 8km to lock up which I think is fairly long, especially since it seems fuel consumption is way worse in that period :)

Is this out of the ordinary?

-P

Can't answer the lock up question, but I can say that 30° C is not hot. That's a mild Spring day here.

[Keithy P38]

Can't answer the lock up question, but I can say that 30° C is not hot. That's a mild Spring day here.

I agree wholeheartedly here! It's winter and still getting to 30 degrees

I do work on an old bloke's P38 here. It's a gems, on coils now sadly, but he also complained that the converter wasn't locking up in top for ages. The transmission fluid level wasn't low, but it also wasn't "full", so I topped it up and took him for a drive. Problem sorted.

Hope this helps!

Cheers
Keithy

[prelude]

I replaced all the oil back back when I went up north. It is nearly perfectly on the mark, however, I do beleive those ZF units are very picky about the fluid level indeed. iirc the fluid level needs to be measured on idle, in neutral and at a temperature of 20c :) Tall order to stay within that bandwith when first filling up the system... I'll check the fluid level again and see what's up.

And ok :) I get it, 30c is for pussies hahaha. Personally, I feel like rolling over and dying in those temperatures but then we hardly get "normal" heat here. If it get's hot in this otherwise wet country, we get pretty high humidity at the same time so it just feels... eh.

Thanks,
-P

[TheTree]

And ok :) I get it, 30c is for pussies hahaha. Personally, I feel like rolling over and dying in those temperatures but then we hardly get "normal" heat here. If it get's hot in this otherwise wet country, we get pretty high humidity at the same time so it just feels... eh.

Thanks,
-P

Mate

The people who live "Up North" in the tropics think that it's freezing down here in a temperate climate, they would have trouble even going outside where you live [bigsmile]

Steve

[TheTree]

This satire popped up this morning :Rolling:

Melbourne’s Coldest Morning Of The Year; 18 Queenslanders Found Dead – The Shovel (http://www.theshovel.com.au/2017/06/08/melbournes-coldest-morning-of-the-year-18-queenslanders-found-dead/)

Steve

[Chops]

Hummm,, 30 degs, nice 👍

As far as "lock up" etc goes, your box should work straight off the mark at any temp. Cold oil verses hot oil won't really make much of a difference to how the box works, other than "perhaps" being a whisker smoother. It's run on pressures not heat.
I would suggest at this point depending on how long it's been since you've done an oil change, perhaps swapping out the filter and fresh oil. Sounds more like you might have some crud in there slowing up things,, as in jamming valves etc. In a case like this, if your oils dirty, the warmer it gets, it'll work a bit better maybe, or as it gets hotter, it can flow better through various valves and orifice's.

[PhilipA]

The TD5 and probably V8 in a D2 will not lock up until the engine temperature has risen. By observation I think this is at about 70C engine temperature . This equates about to when the temp gauge moves to the centre on a D2 TD5.

AFAIK the 4HP22EH fitted to a 38A will be the same as in a D2.

If you have a low temperature or faulty thermostat in the 38A this could affect the lock up.
I am extrapolating here on the assumption that they work similarly. I am sure someone will come and flame me if I am wrong.
Regards Philip A

[Keithy P38]

The TD5 and probably V8 in a D2 will not lock up until the engine temperature has risen. By observation I think this is at about 70C engine temperature . This equates about to when the temp gauge moves to the centre on a D2 TD5.

AFAIK the 4HP22EH fitted to a 38A will be the same as in a D2.

If you have a low temperature or faulty thermostat in the 38A this could affect the lock up.
I am extrapolating here on the assumption that they work similarly. I am sure someone will come and flame me if I am wrong.
Regards Philip A

I'm not here to flame!! Promise!!

Only speaking from experience!

All P38's that I've driven, both GEMS and Thor, have the converter lock up (under the right throttle position and transmission pressure obviously) at around 60kmh. All 3 of my ones did, plus all of the ones I've worked on.

Cheers
Keithy

[gavinwibrow]

I'm not here to flame!! Promise!!

Only speaking from experience!

All P38's that I've driven, both GEMS and Thor, have the converter lock up (under the right throttle position and transmission pressure obviously) at around 60kmh. All 3 of my ones did, plus all of the ones I've worked on.

Cheers
Keithy

Yes, but that is the v8. The TD5 will never lock up in 4th below about 80 kmph on standard tyres etc, and as below, that is not until engine? temp gets to the right point and gives the electronics the all clear.
Funny how the two are so different in this respect, but I understand it is to do with still getting good torque from the smaller TD5 at lower speeds.

[prelude]

well, if the V8 is not supposed to do that, I did not know since it has always done that in my P38 :)

I can only asume that since I live in a colder climate I would notice it, since in a warm climate the engine temp would be up so fast that you would hardly ever notice?

Anyway, I checked the oil level and it's, bar a few mm, bang on. I replaced the oil, filter, gaskets, etc. only 10k ago so that should be good. What I have noticed is that sometimes the box "hunts" from 4th to 3rd when I get of the accelerator at around 50-70kph. Also, when braking and crossing the 60kph threshold the box shifts down from 4th to 3rd and this is not very smooth at times. I can hear and feel the entire drive train "clunk" when that happens. At first I thought I had a bad u-joint or something but when I checked underneath the car yesterday all is well.

So, does anything like this spell abnormal or can I just write this one down as expected behaviour?

Thanks!
-P

[TheTree]

Hi

If it's a GEMS check the throttle cable adjustment as per RAVE

Steve

[Keithy P38]

Yes, but that is the v8. The TD5 will never lock up in 4th below about 80 kmph on standard tyres etc, and as below, that is not until engine? temp gets to the right point and gives the electronics the all clear.
Funny how the two are so different in this respect, but I understand it is to do with still getting good torque from the smaller TD5 at lower speeds.

You're right, it is quite amazing how the two are different!

My post is relating to P38's only as well. TD5's and V8 D2's I haven't had much to do with.

Cheers
Keithy