I have a 92 Hiace 4wd auto - (transaxle A45DE G142)
It seems to take quite a while for the torque convertor to fully engage upon gear changes
I've had 3 autos before - a ford which never slipped, a peugot that never slipped, a nissan that only slipped for around 3 seconds when engaging top gear - Also a ford hire car with same characteristics as the nissan
The hiace however seems to slip on every gear change for several seconds. Is this a fault?
I love automatics but on this one I cant help wondering how much deisel is being wasted - as around town it barely gets the chance to fully engage at all
Things change for the better over 3000rpm though
There is no smell of burning from the dip tube when hot and deposits in the auto box oil are no more than I would expect for a vehicle of its age and mileage
Should I alter the kick down settings? - although on this vehicle there is no notchy feel through the pedal to identify it
Any diagnosis or reassurance would be appreciated - sorry if the question seems a bit basic but I am new to these vehicles
Teething problems and worries aside though 'what a bus'
I'm hooked
Thanks Chris
- (#7533) chris, 7 Mar 03
Chris. Have you changed the autobox fluid and cleaned the very fine filter,accessible after the drain pan has been removed? The symptoms indicate a low fluid level, ie, the internal pump is being starved and cannot deliver sufficient volume. For accuracy, the autobox fluid should be checking, while hot, with the engine running.
- (#7534) John Davis, 8 Mar 03
John's right, first thing to try is to change the fluid, however the traditional way to do this is to drop the sump off & clean out what you can, but the trouble is that most of the fluid sits in the torque convertor, so you only get out about 25-50% of the fluid, leaving the rest of the contaminated fluid to run around the box. The best thing to do is find a garage that has a 'Autobox Purge Machine' over here not many have them, but have a phone around & someone should be able to help. This machine goes in line with the oil cooler, so it pumps in new fluid whisl pumping out the oild fluid whilst the engine is running, thus removing 99% of the old fluid, gives a real difference to the gearbox. HTH Rob.
- (#7535) Rob Drinkwater, 8 Mar 03
Yup, a fluid change or two and filter check will improve the change, but be aware that the converter on the A45 locks up by road speed. On the townace it locks at around 40mph.
- (#7536) david miller, 8 Mar 03
Thanks for your responses guys
No I havent changed the fluid yet - so will make time over the next few days to do this and check the sump filter
However after checking the level today I am even more confused
The 2 low dipstick markings are for cold and 2 higher ones for hot checking
The hot check after a run (whilst running and after selecting all gears) was midway between the low and high hot check marks
6 hrs later when cold the level is on the high point for a hot check
I dont understand how these readings are possible
Does anyone else?
I was also told (2 professional and seperate sources)that in Japan the fluid is brown instead of red.
Can anyone confirm?
I'm begining to wonder whether I've landed an ex japanese taxi!
I will make some calls about auto box purging machines - sounds like the ultimate fluid change if available
Thanks once again for responding
Chris
- (#7537) chris, 8 Mar 03
When cold the fluid level will be lower, yes. BUT ONLY IF THE ENGINE'S RUNNING. It'll drain down to the sump while sitting. Only check the fluid level in N or P with the engine running... And be aware that the "hot" markings on the dipstick should actually be "normal"- the manual says to ensure that the 'box isn't HOT after a fast run before checking...
Re fluid specs, I was led to believe that ATF is of a slightly higher grade in Japan. Even if you have the system professionally flushed, the nice red fluid will rapidly brown! Nothing to worry about as long as it doesn't smell burnt tho.
- (#7538) david miller, 9 Mar 03
SILLY ME!
Yes, crack up the engine and the level drops.
I removed the bulb from a turkey baster - the remaining plastic tube makes an excellent dip tube extension for topping up!
Thanks Dave
Chris
- (#7539) chris, 9 Mar 03
Well
Firstly I replaced the ATF in the sump
Then 6 days later dropped the sump and removed the filter - cleaned whatever I could with kitchen roll
There was a thin layer of slimey black deposit in bottom of sump but the filter was clear
Problem remains in as much as it takes 4 or 5 secs for the torque converter to fully engage especially in 3rd and 4th
3rd is the worst - it feels as though there is an extra gear between 3 and 4 sometimes
The problem is masked a little when I use the ECT button which alows it to rev higher before engaging
The other option is 'clog to the floor' as it gets the slipping over with quicker - though I dont want to do this
I wondered RE
3rd if I keep the overdrive off and jab the accelerator on and off whilst driving if this would allow any crud on the bands etc to come off and restore normal operation
I tried it and a couple of times it 'seemed' to have an effect but I dont want to damge the unit
Is this a totally ridiculous idea (be honest!) or is there some logic in it?
I did notice 2 of the pipes inside the sump were restricted - One flattened a little about an inch long to bridge some component - the other seemed compressed 1/2 way through with a punch device for no obvious reason
The fluid was brown again a couple of miles up the road so obviously more dilution/flushing is required
Any words of wisdom greatfully recieved
Thanks
Chris
- (#7701) chris, 16 Mar 03
Chris, the gear you're sensing between 3rd and 4th is in fact 4th, but with the converter unlocked. Now as you are mentioning an ECT button, it sounds like you've an electronically controlled box, more like the Previa/ Lucida rather than the townie's hydraulic unit. Dunno, but they may lock the converter in 3rd at times also.
But if it's less apparent at higher engine speeds, I'm wondering if either one of the clutches is iffy, or if the line pressure is low for some reason.
- (#7702) david miller, 16 Mar 03
Cheers Dave
The gear box has overdrive switch and a ECT button (transaxle A45DE G142)
What do you think about the theory of driving up the road jabbing the gas pedal on and off in 3rd?
Historically - when I got it there was a vacuum tube disconected which came from some (solenoid?) device mounted on the other side of the rocker cover and went (or should have) to a vacuum device by the fuel pump which appears connected to a cable (kickdown?)with an orange shroud leading to the gearbox
I drove around for a week before I noticed (I put my thumb over the loose tube but could not feel any vacuum)- After a week it felt like it had a thousand different gears but improved to its current situation once reconnected
This vacuum device has an adjusting screw sticking out of the end which is not connected to any levers etc
Would you know what its purpose may be?
Thanks
Chris
- (#7703) chris turner, 16 Mar 03
the vacuum device you refer to is the "idle up" actuator- when aircon is on (or the dash switch where fitted is actuated), it raises the idle speed about 200rpm. not related to your problem.
don't know if your theory would do much good.
i've looked in my autobox manual (which covers the a43 and 46 de) and it looks like some diagnostics are possible from the electronics. first off, unplug the cable from the tranny to it's ecu, and go for a drive. this verifies the mechanical side of the box, and you should get manual changes according to these lever positions
l=1 2=3 d=od n=n r=r p=n.
reconnect the plug.
next hunt for the diagnostics socket (marked d.g) and put a voltmeter on it. on a test drive, you should see the voltage step from 0 to 7v as you go through the gears (here i note in the manual that lockup occurs in 2,3 and 4th...)
8v= solenoid fault
4v= speed sensor fault.
with engine stopped, slowly depress the accelerator. the voltage should slowly rise.
press brake pedal, 8v should be present.
later models can give blink codes on the o/d lamp, but the test procedure is the same, reading voltages at "t" in the diagnostic socket.
hth
- (#7704) david miller, 17 Mar 03
Dave
Thanks for taking time to research that
The vans at the supplying garage at the moment and they are taking it to the local autobox specialist tomorrow
I did pass the info on incase it would help and will try it myself if it comes back in the same state
I will post the 'final' (I hope!) diagnosis for reference
Thanks again
Chris
- (#7750) chris turner, 18 Mar 03
Well the garage took it to the local specialist - result? nothing wrong with it
Unconvinced I took it to the only other local specialist for 2nd opinion - result? nothing wrong with it!
1st garage said loosen the kickdown - 2nd said tighten the kickdown
Played about for a few weeks and currently have settled for taking all the tension out (full slack)
Have given 3 fresh sumpfuls of ATF and cleaned filter etc. and have enough ATF for one more change which I'll do in the summer
Havent tried taking off the electronics feeds etc. but may try at a future date when I have more time
As Dave highlighted the convertor locks at 40mph in 4th(sometimes locks in 3rd at 30)
Does seem wasteful of fuel though - but have changed my driving syle to accomodate (17.5-19.5 mpg best so far)
The second specialist said they are designed to operate this way as the transmission cannot cope with the stresses at lower speeds
So..there you go - its apparently fine - but I find it hard to believe it left the factory operating like this - or maybe it did?
Thanks for all responses to the posts - I've learnt alot from them
Chris
- (#8205) Chris turner, 22 Apr 03 17:29
Hi Chris
The following link will give you a general overview of how the torque converter works, and at times locks up.
http://auto.howstuffworks.com/torque-converter.htm
This link will give you a general overview of how the automatic transmission works
http://auto.howstuffworks.com/automatic-transmission.htm
I’m sorry it wont help you fix your problem, but you may gain more insight in to it.
regards for now
dave Bright
- (#8206) dave Bright, 23 Apr 03 1:38
Thanks Dave
That's a really good site and the 1st time I've seen any info like that on autoboxes
Nice to see things demystified - downloaded what I could and I'm sure it will improve my understanding alot - When I get time (ie. when I sort the other bus probs)I will hunt for the diagnostic socket Dave mentioned
Been on the lookout for autobox info (on and off) for years and you provided it 'just like that'
Thanks again
Chris
- (#8207) chris turner, 23 Apr 03 18:30