PDA

View Full Version : Pending Transmission problem?



PaulP38a
16th April 2009, 01:18 AM
Last couple of weeks have noticed that my '99 4.0 is getting a bit rough on gear changes. Mostly noticable in the morning when the engine is cold and it is reluctant to upshift to 4th gear, and/or shifts back to 3rd and then up to 4th again under normal acceleration.

Had a service done on the car a few weeks back, cleared some faults (SRS, height sensors etc) and the transmission fluid was topped up and checked out ok according to Canberra Motor Works.

Around the same time I swapped over the 33" muddies on 16" rims to a set of 265/60R18 Cooper HT's on 18" HSE rims for better on-road handling. Could this have an effect on transmission changes?

I understand that the transmission in the '99 4.0 is the ZF4HP22 and not easily serviced by a willing amatuer such as I.

A search on RangeRovers.net reveals opinions on similar shift problems relating to filter and fluid change, TPS or MAF sensor.

Appreciate your advice on this.

Cheers, Paul.

willem
16th April 2009, 04:52 AM
G'day Paul,

About the only advice I can offer on this is that with previous auto trans on Rangies and Kombis, when I have had problems like you're describing, is to take it to an auto trans specialist and get it serviced by someone who knows. It has always sorted out the little irritating things. But having said that, none of those were electronically controlled transmissions, like I understand the ZF in the P38 is.

But it seems to me that a good service is worth it for your car, especially given the nature of the work that Hardy put it to. It could well be a few hundred buck well spent.

Willem

PaulP38a
17th April 2009, 12:02 AM
Thanks Willem.

Can anyone suggest a transmission specialist in the Canberra region that knows P38A's please?

Cheers, Paul.

andrew e
17th April 2009, 12:09 AM
You can still service them yourself, you just need to devise a way to fill it with oil, as there is no fill tube, only a plug hole.

The best way that i saw someone do this, was a sealed container with the measured amount of oil, there was a tube coming out the bottom which had a fitting that screwed into the plug hole in the gearbox pan. In the top of the container was an air fitting with a tap. When the container was slowly preasurised, the gearbox filled with oil. Then replace the plug without spilling too much.


Andy

PaulP38a
19th April 2009, 10:43 PM
Tried cleaning the MAF sensor yesterday to see if it made a difference - it didn't.

Carefully pried off the front mesh on the MAF, sprayed the "hot wires" liberally with isopropyl alcohol, let sit for a few miutes and then gently dried it with indirect compressed air. Reassembled MAF and went for a drive.

Still jerking between gears and relucant to engage reverse at times. Went for a run in the dirt and mud to give low range a work out and noticed that 1-Low wouldn't engage on a couple of ocassions. Seems the shifter just couldn't get to the notch if that makes sense.

Wondering if the shifter has moved or the cable is worn/stretched. Probably not the main problem but a possible side-effect?

Guess I'd better add this to my ever-growing list of stuff to get checked.

Just as well I love my Rangie more than paying off my credit cards... ;)

cheers
Paul.

andrew e
20th April 2009, 09:52 PM
hi and low is changed by a motor (and a controller under the pas seat) so no cables to stretch. It has a switch in the gear shifter.


Andy

andrew e
22nd April 2009, 11:12 PM
this bloke has similar problems.

RangeRovers.net • View topic - Slight jolting when shifts to 3rd gear (http://rangerovers.net/forum/viewtopic.php?f=3&t=30810)


Andy

p38arover
22nd April 2009, 11:17 PM
Still jerking between gears and relucant to engage reverse at times. Went for a run in the dirt and mud to give low range a work out and noticed that 1-Low wouldn't engage on a couple of ocassions. Seems the shifter just couldn't get to the notch if that makes sense.

Wondering if the shifter has moved or the cable is worn/stretched. Probably not the main problem but a possible side-effect?

Quite possible. I had the same problem and had to adjust the cable into the switch. In theory, one needs the right tools but I found I could adjust it (under the car). I slackened off the nuts and moved the arm, adjusted the nuts, and retightened them.

I understand what Andy is saying but mine must have been right on the verge of the correct position.

PaulP38a
22nd April 2009, 11:36 PM
this bloke has similar problems.

RangeRovers.net • View topic - Slight jolting when shifts to 3rd gear (http://rangerovers.net/forum/viewtopic.php?f=3&t=30810)


Andy

Thanks Andy - think that was the thread I got the idea to clean the MAF from. That bit was easy 'coz I know where the MAF is. NFI where the TPS is though.

The previous owner told me that the tranny was rebuilt about 35,000Km ago so the new/renewed components are probably a good place to start checking.

I'm biting the bullet (and probably a significant bite in to the bank balance) and sending it off to a workshop next week.

Hoping they can change the fluid, filter and adjust the cable and all will be good again.

cheers
Paul.

p38arover
22nd April 2009, 11:38 PM
The previous owner told me that the tranny was rebuilt about 35,000Km ago so the new/renewed components are probably a good place to start checking.


Ahh! Check the cable setting. Mine had been replaced by the PO as well.

PaulP38a
22nd April 2009, 11:45 PM
Ahh! Check the cable setting. Mine had been replaced by the PO as well.

Yeah, will do for sure. He also told me that 1-Low was sometimes a problem for him and that a quick shift from D-Low -> 2-Low -> 1-Low would sort it... and it did so I reckon it's a safe bet that it is just the cable.

Funny though, my previous P38A started doing exactly the same thing not shifting in to 1-Low just before I drowned it. Ooh spooky :eek:

PaulP38a
6th May 2009, 10:42 PM
Maybe this is the calm before the storm.

Went out 4WD'ing on the weekend and the transmission was fine off road, probably 'coz most of the time it was in Low-1,2,3. Driving home from the Brindabellas (approx 40Km) it seemed ok until the last 10Km where I don't think it upshifted to 4th at all.

This morning the transmission was it's usual obnoxious self and wouldn't shift up to 4th until the engine warmed up (approx 3-5mins), although I could feel it trying to shift up.

Went out a couple of times during the day and although it was a bit hesitant to shift at times, there was no jerking when it did shift.

Is this sounding more like a programming problem than a mechanical one? There are still no faults reported on the dash.

Also changed over the TPS tonight so will see if this has any effect tomorrow.

Cheers, Paul.

PhilipA
7th May 2009, 08:09 AM
I have been following this thread without comment as I do not know much about the later electronic transmission.

However , as the trans is electronically controlled by the ECU, the FIRST thing I would be doing is dismantling and cleaning the connectors between the trans and the ECU. It is pretty well known that there is a possibility for water to get into the connector nearest the trans.

AFAIK the main causes of poor shifting is a problem with electronic control, either the connections or the solonoids themselves. I also think you would know about a bad MAF from very poor economy, and a TPS would usually show as a "tip in" miss IE on take off or at the bottom of a hill.

When was the trans last serviced?
If the fluid is filthy and the filter screen full of crap, then this could affect the shifts, but if it is that bad you will be up for some big money.
Regards Philip A

PaulP38a
7th May 2009, 10:43 PM
Thanks for the suggestions PhilipA - I'll check and clean the ECU connectors. My car does get pretty dirty, muddy and a bit wet sometimes - just as the maker intended :)

After changing the TPS over last night, no real noticable difference to how the car behaved today. Still reluctant to shift up to 4th when cold, but pretty good once it warms up.

The transmission had a service last week - new filter and 5L of Dexron ATF, no faults found by the AutoLogic. The mechanic reckoned there was more metal filings in there than "normal" and that the filter was pretty bad.

Cheers, Paul.

adm333
15th May 2009, 08:47 AM
I did some research and discovered a Penrite semi synthetic ATF that is specially formulated for ZF transmissions.

It is Penrite ATF-BMV

It specifically lists Rover / Range Rover 4HP22 and 4HP24 as ZF models suitable for use.

I did a full empty /fill /drive /empty / fill of this stuff about 8000 kms ago and its running very smoothly.

Dave