auto got hot, is it now wrecked?

[muddymatt]

hi all,
I towed the horse trailer loaded today for the first long trip. 2 hours in after a long hill climb and I was giving it the jandal, the auto box temp light came on. I pulled over and waited a few mins and it went out. we drove on about 10 mins till destination and it came on again just as we got there.
the auto smelled hot and the transfer box leak I already knew about seems worse.
I had my nanocom plugged in for the drive but I was watching coolant temp! that peaked at 95/96 for the same hill.
it cooled for 4 hours and then we drove home more gently....
I'm not sure but the box may have shuddered coming out of tc lockup. ie at the end of a flat bit leading into a rise.
I was watching turbine speed, output speed etc on the way home but not really knowing what to look for....

I already have a trans filter kit here and I'm planning a flush/change but is it too late?

is the box stuffed?

[Slunnie]

My experiences are that you've done the right things but the damage has started and not long down the track it will increasingly fault as components break down.

I'd ensure the ATF cooler is absolutely clear so that it can cool the ATF and I would assume replacing the burnt ATF wouldn't be a bad thing either so that it can work properly.

That said, I would also keep driving it incase you got away with it!

[muddymatt]

My experiences are that you've done the right things but the damage has started and not long down the track it will increasingly fault as components break down.

I'd ensure the ATF cooler is absolutely clear so that it can cool the ATF and I would assume replacing the burnt ATF wouldn't be a bad thing either so that it can work properly.

That said, I would also keep driving it incase you got away with it!

i will be changing the burnt atf as soon as possible.
it has a discrete winch mounted, could this be blocking airflow to the trans cooler?

[Slunnie]

i will be changing the burnt atf as soon as possible.
it has a discrete winch mounted, could this be blocking airflow to the trans cooler?
Maybe, but if there is a gap between the winch and the radiator then the air should go around it. The big problem with the D2 ATF cooler is that it sits in between the Coolant radiator and the AC condenser, so it gets plugged up with mud and dirt and you cant clean it out or even see that it is still blocked despite cleaning it out the best you can. To make it worse, it sits right at the bottom underneath the intercooler, so its also the first to get blocked. The Torque converter also generates a lot of heat in these as a by product from making it drive so smoothly. I think they are undercooled from the factory.

[muddymatt]

Maybe, but if there is a gap between the winch and the radiator then the air should go around it. The big problem with the D2 ATF cooler is that it sits in between the Coolant radiator and the AC condenser, so it gets plugged up with mud and dirt and you cant clean it out or even see that it is still blocked despite cleaning it out the best you can. To make it worse, it sits right at the bottom underneath the intercooler, so its also the first to get blocked. The Torque converter also generates a lot of heat in these as a by product from making it drive so smoothly. I think they are undercooled from the factory.

on the to-do list is pull the intercooler and coolant rad and get both cleaned internally so I guess I'll attack the trans one then too.
this might now move up the list to the urgent section

[Slunnie]

Oh, I wouldn't disconnect the ATF cooler from it's lines or try to clean it internally. That'll quadruple the problem. The hose connectors are a problem and can blow apart and if you get any grit into the ATF cooler then it will also damage the transmission. I'd just clear all of the mud and dirt from within the fins. This is what they do - and I was always deliberate about cleaning the radiators externally after 4WDing.

https://www.aulro.com/afvb/images/imported/2017/03/309.jpg

[muddymatt]

Oh, I wouldn't disconnect the ATF cooler from it's lines or try to clean it internally. That'll quadruple the problem. The hose connectors are a problem and can blow apart and if you get any grit into the ATF cooler then it will also damage the transmission. I'd just clear all of the mud and dirt from within the fins. This is what they do - and I was always deliberate about cleaning the radiators externally after 4WDing.

https://www.aulro.com/afvb/images/imported/2017/03/309.jpg

no I just meant that I would have access when the intercooler and radiator were out.
thanks for the advice.

[lewy]

Dought the light coming on automatically means oil is cooked,I would still change it and have a smell or get someone who knows what burnt oil smells like.Hopefully you only think you felt a shudder,good luck

[redrovertdi]

i would flush the tranny refilling with synthetic, bit dearer but a higher boiling temp etc....

[muddymatt]

Update,

So today I got the chance to change the atf and filter.
On the drive to the workshop unloaded not towing it still did the judder I felt before:censored:

I won't document the change process, it's been covered before but I have shared a few pics.

The oil was obviously brown, burnt and smelly but the sump magnet was not that furry:)

I fitted new filter and filled it up and went for a drive.

The judder appears to have gone yay! It shifts as before the overheat, normally.

I opened up the old filter and it was full of a plastically black melted looking stuff. The gauze seemed pretty well blocked with it too.

Drive home was uneventful too but the test will be tomorrow when my wife tows the horses again. I haven't had chance to strip the front and check the cooler for airflow but the tow tomorrow is only 25 miss so I'm picking it will be fine.

I will be dropping the atf again in a couple of weeks to get some more brown out.

Any comments on the filter debris?

[87County]

Sounds like you've got it under control.

One more, or even two more, fluid changes will reduce the remaining proportion of old fluid. I wouldn't wait too long to do this.

[muddymatt]

Sounds like you've got it under control.

One more, or even two more, fluid changes will reduce the remaining proportion of old fluid. I wouldn't wait too long to do this.

I think about a week should be OK before the next fluid change.

[Pippin]

Muddymatt,


Get the wife to tow the horses in 3rd and 3rd lockup. It will prevent excessive heat and less strain on the tranny.

[Marco Polo]

Good save hopefully! I just did my trans fluid and filter. Very dirty but no bits in the filter. The crud trapped in the gauze on yours would have alarmed me too...
I notice since the service my tc locks up faster and cleaner

[Roberto]

Pippin, how do you "lock up" third?

My interpretation of the story described, is that towing horses places excessive strain on the torque converter. Over a period of time there is excessive slippage which generates heat. Up to a point, a clean cooling system accommodates this extra heat. Eventually, overheating occurs, damaging the ATF and any other heat sensitive components. Provided the situation is promptly recognised, no other damage will occur, but the torque converter is still "kangaroo/edward". I'd stop giving the horses a lift (let'm walk) and use the gearbox more gently.

My understanding of this may be a total crock, and I'd appreciate hearing why.

Bob

[Pippin]

Hi Roberto,
With the trany in third the TC will lock up at 80Ks and stay locked right down to about 60. It's a great way to tow or drive up steep long hills. The engine revs at it's optimum of 2500 at 80Ks and you get all the advantages with engine breaking down to 60 and effortless response on gradients with no wear on the TC and no extra heat generated, you can also smoothly change to Drive if conditions warrant it. It is one of the least known features of the Auto that is ideal for towing horses and vans.

[PhilipA]

I agree with the idea of towing in locked 3rd and I do it all the time with my 1tonne camper.
Just a detail.
The trans locks in third at 70KMh and in 4th at 80 Kmh, so when you are coming to a big hill a quick shift back to 3rd at over 70Kmh will see it lock in a second or two, and you can see it on the tachometer.
You can also use it for engine braking and it will stay locked down to 60Kmh unless you floor it.
Unfortunately it looks to be pretty late in the day for your transmission.
Regards Philip A

[Pippin]

PhillipA,

Mine locks in third a little above 70Ks, but interestingly in the owners handbook there is no mention of TC lock up at all and thus no mention of how it can be used in third with only little mention of heat generation and driving techniques for towing.

[muddymatt]

Update.

Not good news :mad:
We did the same trip again today, 350k round trip and using third was better but there is still a judder on tc lock and unlock. It's magnified in 4th but still present in 3rd. Worse on tc unlock.

So it looks like it's stuffed.

My options are....

Take it to auto box shop for pull and rebuild. $$$$$
Buy s/h replacement unit from wrecker and fit. Less $$$$
Buy s/h replacement unit, strip and overhaul and then fit. Middle $$$$

If I go the last route, what mods do you recommend? Bigger t/c? Thicker flex plate?

I will be stage 2 Jose chipping it eventually and I have read about lower stall speed converters. Has anyone got first hand experience of them? It will be primarily a tow wagon until we get a horse truck then it will be my off road truck. :D

Lastly, if I'm going to all this bother I may as well swap out my non cdl lt230 for a cdl equipped unit and give that a birthday too!

Ashcroft has all the bits to overhaul both units, is a strip and rebuild of a ZF4HP22 a job only for a auto box specialist or can it be done at home?

[simonmelb]

Have a look at what's involved here then you decide:

Transmission Videos (http://www.manuelautomatics.com.au/mobile/Transmission_Videos)

I went option 1.

[clubagreenie]

MAY just be the lock up clutch in the TC.

[fredd63]

Talked to a motor mechanic friend with a lot of experience. His opinion is that the black sludge in the trans filter was a product of the oil breakdown when it got hot. Recommends that you have a filter change and transmission flush, ie, a trans fluid change where all the fluid, including the torque converter is changed. Might need a trans shop to do that.
Main thing is fitting a larger trans cooler, as it seems that the original cooler is not big enough to cope with the amount of heat from the trans.
Or consider a manual transmission; as a heavy vehicle towing a lot of weight, might be too much for that auto trans.

[muddymatt]

Hi All,
After literally heaps of research i have located a factory rebuilt zf4hp24. it's a 065 suffix box which I believe is identical length to my knackered hp22.
Before I push the go button and hand over my cash, can anyone answer my last couple of questions...
Will my early D2 cdl equipped transfer box fit the output housing and shaft of this auto?
Will my standard 2004 td5 auto trans ECU connect and run this box?
This box comes with a medium size 2400 rpm stall speed torque converter modified to suit the td5 motor. Will this be OK?
lastly, I have another standard trans cooler that I plan to add in series with the original to protect my investment.
I was thinking of up behind the front grill, this will be higher than the standard one, should I plumb it in before or after? Will the trans pump fluid thru both happily?
I plan on using the new coolers temp sender location to add in a trans cooler gauge. probably a madman or similar. Eventually I will monitor engine coolant temp, trans temp and egt.
Any thoughts or ideas I have missed?
cheers matt

[Pedro_The_Swift]

lots of posts on extra trans coolers,, I doubt it matters which way you plumb it,, yes they seem to pump through both happily,
more important to check all the trans line connections for movement/leakage:ohyes:.
temps should be taken as close to the box as possible.

[Slunnie]

I was thinking of up behind the front grill, this will be higher than the standard one, should I plumb it in before or after? Will the trans pump fluid thru both happily?
I plan on using the new coolers temp sender location to add in a trans cooler gauge. probably a madman or similar. Eventually I will monitor engine coolant temp, trans temp and egt.
Any thoughts or ideas I have missed?
cheers matt
The additional ATF cooler is a very good move! I've had no transmission problems since going to this setup in 2008, but you must use proper multibarb pirtek type fittings and coolers, not push on and hose clamp fittings as they will burst off every time. One of the ATF lines has just been interupted by the cooler, so the ATF goes through both coolers.

https://www.aulro.com/afvb/images/imported/2017/03/326.jpg

[muddymatt]

Thanks heaps for the cooler answers.
Any ideas on the other questions?
cheers matt

[Pedro_The_Swift]

Any ideas on the other questions?
cheers matt

yea,,
where did you get the 24 box?:angel:

[muddymatt]

yea,,
where did you get the 24 box?:angel:

hahaha I'll tell you that AFTER I get it fitted and working....

I know it has been done before by roarin8 amongst others and the 24 was factory fitted to NAS 4.6 d2a but what I really need to know before I have over the cash is will my trans ECU connect and operate it?

[Pedro_The_Swift]

Do we have a trans ECU?


and if we do,,,
it does ****all telling us stuff!!

[Disco Muppet]

Yes the auto ecu is under the passenger seat.
Will work fine methinks. Ask ashtrans

Sent from my HTC One using AULRO mobile app

[muddymatt]

Yes the auto ecu is under the passenger seat.
Will work fine methinks. Ask ashtrans

Sent from my HTC One using AULRO mobile app

hmmmm i emailed Dave Ashcroft and got this reply..

.No good, that's for a P38, back end is wrong,

Different transfer case,

but from here....

ZF4HP22 swap with ZF4HP24 (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/42895-zf4hp22-swap-zf4hp24.html#/forumsite/20563/topics/42895?page=2)

I get different info.

I'm bloody confused now. I think I will take my diesel bellhousing and my cdl transfer to the place with the new 065 hp24 and physically see if they match up.

[PhilipA]

I think he was pretty clear.
If the 4HP24 that you have is from a P38, then the transfer case on a P38 is different, as the outputs on a P38 are on the left side not the right side as in a D2.
So the mounting points for the transfer are wrong/flipped.
AFAIK the discussion UK is about P38 to P38 where the transfer mountings are the same.
Regards Philip A

[Disco Muppet]

If that were the case Phillip, then you couldn't fit a 24 to a d2 unless you got one from a NAS d2. Roarin8 got his from a p38a.
Perhaps the OP should send Roarin8 a PM


Sent from my HTC One using AULRO mobile app

[muddymatt]

If that were the case Phillip, then you couldn't fit a 24 to a d2 unless you got one from a NAS d2. Roarin8 got his from a p38a.
Perhaps the OP should send Roarin8 a PM


Sent from my HTC One using AULRO mobile app
i did send roarin8 a pm. he didn't reply.:(

[Slunnie]

To clarify, wont an LT230 go on to the back of the 4HP24?

[Lotz-A-Landies]

Sorry for coming onto this thread so late.

I find that one of the problems with the D2 cooler is that there is basically only convection drawing air through the element. This is because the lack of a direct connection requiring airflow caused by engine fan shroud which pulls air through the engine radiator, the resistance of the element itself and its position reduce the airflow through it from the forward motion of the vehicle.

In relation to the transmission cooler, an additional capacity cooler is a good idea, however placing it in front of the radiator will decrease the efficiency of the engine cooling. You may also want to install an engine oil cooler to compensate. Having an electric fan on the cooler can be a significant benefit, particularly if thermostatically controlled.

You may also want to consider installing a transmission temp guage. I advocate this because by the time the indicator lamp comes on, the damage may already be present. By monitoring the guage you can adjust your driving style to achieve the best transmission temps. e.g. I have engine and transmission coolers plus engine oil and transmission temp guages on my RRc with ZF-4HP22 transmission. On a journey with a tri-axle 4 tonne plant trailer loaded with an SIIB forward control and spare transmissions. I had to drive up Mt Victoria west of Sydney. Monitoring the transmission temp I was achieving the best temp Vs speed in 3rd but engine oil and transmission were in high normal range. As I started clumbing the mountain both transmission and engine oil temps were in the high-extreme range so I decided to pull over and run the engine in park and watch the transmission temp fall before moving. Just as I was pulling up the warning lamp came on.

Had I only had the warning lamp I wouldn't have been planning to pull over and may have done transmission in only a few more metres.

As it was I had to stop twice more on the climb but got to the top of the mountain without ruining the transmission, I did get the burning smell near the top of the mountain so changed the oil on my return to Sydney and am still running on the same transmission 5 years later.

[muddymatt]

Another update.
I took a knackered and stripped but complete hp22 to the trans specialist with the Hp24. He is fitting the td5 bellhousing and tail housing to allow my cdl transfer to fit.
he is also supplying a medium size torque converter with 2400 rpm stall with plate to suit my td5.

I should get it all back in a few days and I'll post some pics then.

cheers matt