ZF auto gearbox question

[JulesV8]

I wonder if anyone could answer the following questions relating to a ZF auto box in a 1996 V8 disco

1. When at stand still, in drive, should car with engine idling roll back - eg red light on an inline, car "creeps"? If not, any diagnostic?

2. Driving along in Drive and suddenly - temporarily - drive is lost. Engine runs normally but there is not forward motion as is a cluth is slipping and transferring forward motion to the wheels

3. What effect does going from D to R when the car is still moving forward at V low speeds eg 1 mph?

4. Has my wife successfully destroyed the auto gearbox on my car?

Thanks people

Jules

[discool]

O dear, sorry the hear that, sounds like a trip to Ashcrofts to get it looked at, but give them a call first i'm told they are very helpfull.

Answers
a no
b no
c don't know
d no she would not do that.... would she :)

[23skidoo]

Ouch , hope it all turns out tickety boo .

I wonder if anyone could answer the following questions relating to a ZF auto box in a 1996 V8 disco

3. What effect does going from D to R when the car is still moving forward at V low speeds eg 1 mph?
Jules

According to manuals I believe R will engage If speed is below 5 mph .. not sure if that is 5 mph + or - . I can see selecting reverse when moving 5 mph forward is going to be something of a strain on the mechanicals.

Accordingly however it reads that all the selection decision making process is not straight forward mechanical but there is a considerable EAT ECU and ECM chatter before all the changes take place . Now you would hope this stops anything fatal , but I bet the sophistication of that varies and in older vehicles is LESS than you would ideally want .

Certainly interested in following this thread to see what you have found and what expert opinion is here

Now I am definitely banning the missus from using the car on the basis of paranoia on selecting PARK on a similar basis .

[JulesV8]

Thanks for the answers, I'll speak to Ashcroft and see what they diagnose. I hope its not too bad. The car drives fine, it only sporadically loses drive which made me think it might be in need of an oil change and maybe also change the oil in the transfer box.

I take your point about the technology maybe not being quite as intelligent as newer vehicle saying this, from D to R at V low speed, there are not any clonks or nasty noises...Just the noise of me cringing when watching her arrive home...and each time I tell her:
"Please dear, wait until the car is stationary before changing"

Maybe I should get on her horse and start yanking its mouth left and right in very fast succession, while galloping, and tell her its not turning and must be broken :D

If anyone else can add to my questions that would be great.
Thanks
Jules

[JulesV8]

right, just spoken to Ashcroft who have told me that:

- Loss of drive when driving - ressembling the clutch been depressed, when driving with a manual: Not a known sympton of the ZF. If the the box was totally gone drive would be lost, permanently. I was advised to check ATF level and see what comes of it. I'm not sure whether the oil cooler I have on mine would make any difference...but the guy said, you will know when the auto box is dead as all drive would be lost - so mines is ok

- Creeping backwards on an incline when in drive: Depending on the gradient this is normal. All auto's creep forward, ie, level ground, the car in D, it will creep forwards...slight incline...stationary...severe incline, it would overcome forward creep and roll backwards.

- D to R at very slow speed. Is fine as long as it is a V low speeds.

the guy did say that you know when the box does not like something as you will hear the mechanicals telling you.

So it looks as if the car is ok, bar the sporadic, erratic loss of drive...so can now relax.

thanks for the advice gents

J

[thebiglad]

right, just spoken to Ashcroft who have told me that:

- Loss of drive when driving - ressembling the clutch been depressed, when driving with a manual: Not a known sympton of the ZF. If the the box was totally gone drive would be lost, permanently. I was advised to check ATF level and see what comes of it. I'm not sure whether the oil cooler I have on mine would make any difference...but the guy said, you will know when the auto box is dead as all drive would be lost - so mines is ok

- Creeping backwards on an incline when in drive: Depending on the gradient this is normal. All auto's creep forward, ie, level ground, the car in D, it will creep forwards...slight incline...stationary...severe incline, it would overcome forward creep and roll backwards.

- D to R at very slow speed. Is fine as long as it is a V low speeds.

the guy did say that you know when the box does not like something as you will hear the mechanicals telling you.

So it looks as if the car is ok, bar the sporadic, erratic loss of drive...so can now relax.

thanks for the advice gents

J

Hi J, check your oil and preferably replace it. It's easy and quick to do, so why wouldn't you??

It's much easier on a Disco 1 as you refill via the dipstick tube - I did a Disco 2 yesterday -drove onto blocks, lifted the rear air suspension (so that works then:D) and dragged my fat 'arris underneath.

What none of the instructions tell you is that on Disco 2, if you open the fill plug (set quite low on the side of the sump) without the engine running LOTS of oil will come out straight away !!!!!

This hole is only valid as a level plug with the engine running and the gearbox having taken up it's share of oil !!!!

[JulesV8]

HI there,

Yep, I'll change the transfer and G box oil and see if that makes a difference, as you say, its nice and easy so why not?

Cheers

J