Thread: '99 TD5 Auto lockup

It hasn't lost ATF has it? One of the first indicators of low ATF levels is losing lockup in 4th.

O.K. 2 criteria need to be satisfied.

1...The auto will not lock up until the box senses the right temp.It is designed this way.

2...The auto will not lock up under 80Km/H.

You are saying 10-15Ks.that is too long so sure, check your ATF levels/condition.

You are also saying the revs drop,so maybe it is O.K.

Simple test.
90 Km/h pretty well equates to 2000RPM if it is working properly.If you are at 2500RPM it is still in 3rd.
As you gently accelerate up to 80-85 you should feel and see the revs drop off.

Trev.

Hi Trev,
Yes the revs drop however it doesn't fully lock. It is like you are in say, 4th below 80km/h and cruising with very little throttle. Put you foot down and the tacho rises quite fast. This same thing happens when you are cruising @ 85km/h and above the revs drop but no lock.

sorry not good with words.

Tony

Originally Posted by trev

O.K. 2 criteria need to be satisfied.

1...The auto will not lock up until the box senses the right temp.It is designed this way.

2...The auto will not lock up under 80Km/H.

You are saying 10-15Ks.that is too long so sure, check your ATF levels/condition.

You are also saying the revs drop,so maybe it is O.K.

Simple test.
90 Km/h pretty well equates to 2000RPM if it is working properly.If you are at 2500RPM it is still in 3rd.
As you gently accelerate up to 80-85 you should feel and see the revs drop off.

Trev.

Tony! I am not sure that you actually have a problem.Say you are cruising at 90Km/h at 2000RPM which is right on the peak torque band for a TD5,that is how it should be,however,if the load demand increases the auto will sense this and drop back to stop the motor labouring.
Lockup will drop in and out as load demand changes and if road speed goes under 80K.
the ZF electronic box is taking inputs from a number of sources all mapped to ensure min load on the driveline.
some people have thought it would be nice to have lockup under 80 but the auto is not designed that way.

Trev.

I know what you are getting at Trev., Still feel there is something not quite right as it still does it when you are cruising at 100km/h. The box used never used to do it. It is something that has started happening over the last six months. When it does lock you can feel it.
I ma begining to wonder if the lock-up relay is jamming somehow or, the clutch plates are starting to play up.

Tony

Originally Posted by trev

Tony! I am not sure that you actually have a problem.Say you are cruising at 90Km/h at 2000RPM which is right on the peak torque band for a TD5,that is how it should be,however,if the load demand increases the auto will sense this and drop back to stop the motor labouring.
Lockup will drop in and out as load demand changes and if road speed goes under 80K.
the ZF electronic box is taking inputs from a number of sources all mapped to ensure min load on the driveline.
some people have thought it would be nice to have lockup under 80 but the auto is not designed that way.

Trev.

O.K. Tony! if its changed from what it was then it sounds like a problem.
You could see if anything comes up on a Nanocom or T4 diagnostic before spending big bucks.And keeping in mind all the electrics in a D2 disconnecting cables to the gearbox and seeing if they are corroded or otherwise crappy is a good move. Spraying connections with CRC contact cleaner isn`t a bad idea either.
Oh and yes! maybe a check on your Throttle position sensor because that inputs to the auto.

Trev.

Had the vehicle into theauto specialists the past few days.
The problem was the torque converter clutch plates. They were worn and glazed. Problem caused by heave van and not forcing it to come out of lock up on steep hills. Now have h/duty plates out of the big V8 Holdens. Supposed to be a special material. Carbon fibre?
Hope to pick it up am tomorrow. Fingers crossed.
Also supposed to be a fairly common problem.

Tony

Originally Posted by trev

O.K. Tony! if its changed from what it was then it sounds like a problem.
You could see if anything comes up on a Nanocom or T4 diagnostic before spending big bucks.And keeping in mind all the electrics in a D2 disconnecting cables to the gearbox and seeing if they are corroded or otherwise crappy is a good move. Spraying connections with CRC contact cleaner isn`t a bad idea either.
Oh and yes! maybe a check on your Throttle position sensor because that inputs to the auto.

Trev.

Sorry tony! that sounds like a few bucks you`ve spent.
I don`t quite understand what they mean by forcing it out of lockup.
Do they mean manually changing it back to 3rd or whatever?
If so,that is strange,the ZF box should be good at doing that automaticaly
when it senses increased load demand.
I think you need to consider if the electronics is up to scratch.No harm in new clutch packs,but a check on the auto ECU may not be a bad idea.
Even if towing a heavy trailer,it should be up to it if working properly.

Trev.