ZF Auto, Can a service cause it to fail?

**blackrangie** · 15th December 2014, 09:33 PM

Ok picked my 89 Range Rover recently from a unnamed brookvale landrover mechanic.

My Rangie has an A & B Automatics auto with 24 internals and all the goodies, maybe 100k on it and serviced regularly.

Part of the major service they did which i didnt request (dont get me started) was a ZF filter and oil change.

Twice after this service i have experienced sticking in first until im guessing it warmed up, once after driving through lots of water in the road after storms and once in the morning starting from cold.

Now this got me thinking, strange this happening straight after a service with new oil and filter.

So I googled it and look what came up, a little shocking

Can a service be bad for your ZF? Solution?

http://www.ashcroft-transmissions.co...p22-faq-s.html

"I have a 4 speed ZF Auto and it sticks in first gear in the morning or when cold and is reluctant to change up from 1st gear. Once the gearbox has warmed up it shifts normally. Why?

The governor valve is sticking, which can be caused by contamination. i.e. clutch plates or other parts disintegrating. The fine debris finds its way past the filter and tends to accumulate in the governor, causing it to stick. A temporary solution is to remove and clean the governor. The problem will often recur as debris from damaged parts continues to build up in the governor. If the problem continues after cleaning the governor then it may be necessary it replace your Autobox.

We have noticed many customers reporting this fault starting a few days after an oil and filter change and after researching this using our experience and the expertise of others in the trade we have come to the conclusion that as ATF oil is a detergent type oil, when the oil is changed this will dislodge and stir up settled debris in the autobox which in turn jams the governor valve. In light of this although it sounds controversial it is debateable if changing the oil and filter is a good idea, some say if the box it going to fail it will fail if the oil is good or bad and their advice is leave it alone. I am still undecided but the truth is I get a lot of calls from customers thinking they are looking after the autobox by servicing it and a few days later this fault occurs."

**DiscoDB** · 15th December 2014, 10:13 PM

There is a view with auto's that you either flush and change the oil regularly to prevent sludge and contaminate build up in the first place, or you never change the oil for fear of dislodging that sludge and contaminate build up and run the auto to failure. It is this type of thinking that saw the introduction on sealed for life auto's.

When you say the auto only have 100k on it and has been serviced regularly, how often have you change the oil and filter prior to now?

**Blknight.aus** · 15th December 2014, 10:35 PM

yes it can, but tis not the fault of th service if it does, its usually all the previous neglect that causes the problem the service just eposeds it.

you can also wind up with th trans filter not installed appropriately and the box will be drawing areated fluid which plays merry hob with its operation

**blackrangie** · 16th December 2014, 08:17 AM

Originally Posted by DiscoDB

There is a view with auto's that you either flush and change the oil regularly to prevent sludge and contaminate build up in the first place, or you never change the oil for fear of dislodging that sludge and contaminate build up and run the auto to failure. It is this type of thinking that saw the introduction on sealed for life auto's.

When you say the auto only have 100k on it and has been serviced regularly, how often have you change the oil and filter prior to now?

Every 5-10k, always at landrover specialists.

**blackrangie** · 16th December 2014, 08:23 AM

Originally Posted by Blknight.aus

yes it can, but tis not the fault of th service if it does, its usually all the previous neglect that causes the problem the service just eposeds it.

you can also wind up with th trans filter not installed appropriately and the box will be drawing areated fluid which plays merry hob with its operation

Agreed, however my auto fluid and filter has been changed regularly during its life as per above comments. Good to know sbout the install issues, but im sure that would create more than just a single late change after the box being cool.

**blackrangie** · 16th December 2014, 08:34 AM

According to Dave ashcroft above, The problem seems to be with the new oil being like a detergent and "cleaning" the box out after new oil and or filter is instslled and contaminating the governor and or filter again after you pick it up and drive around for a bit or the next morning.

So should a mechanic when changing oil/filter flush the auto every time thoroughly to remove all contamination and sludge from box, then service the governer aswell?

I do also realize that it is the sign of parts wearing from age or being given a hard time, however if there are preventative measures to keep the ZF alive im all for it.

**PAT303** · 16th December 2014, 09:12 AM

I used to drop and flush every 12 months,about 300 bucks and never an issue after 275K. Pat

**Matt97** · 16th December 2014, 09:15 AM

Originally Posted by blackrangie

According to Dave ashcroft above, The problem seems to be with the new oil being like a detergent and "cleaning" the box out after new oil and or filter is instslled and contaminating the governor and or filter again after you pick it up and drive around for a bit or the next morning.

So should a mechanic when changing oil/filter flush the auto every time thoroughly to remove all contamination and sludge from box, then service the governer aswell?

I do also realize that it is the sign of parts wearing from age or being given a hard time, however if there are preventative measures to keep the ZF alive im all for it.

isn't the flush almost the cost of a second hand gearbox, I heard AUD2k once.

**PhilipA** · 16th December 2014, 11:05 AM

I have always done a half change ( 4litres+filter) each 30KK on my RRC and now D2.
Have never had much crap in the sump except first change at 80KK , and the RRC did 240KK when I sold it and still going strong AFAIK.

The D2 now at 165Kk after buying and changing at 135KK with Transmax Z. ( 2 changes in 1KK to increase Transmax to +- 80%)
Virtually NO crap in sump after 30KK of towing 1tonne for almost all of that 30Kk including up to Cabramurra and working perfectly.

I am a great believer in clean top quality ZF recommended ATF, and I wonder how many mechanics just use Dex 2 or 3 cheapest they can get.

BTW, Transmax Z apparently is of lower viscosity than most ATF so maybe that has something to do with it.

Regards Philip A

**blackrangie** · 16th December 2014, 12:03 PM

Originally Posted by Matt97

isn't the flush almost the cost of a second hand gearbox, I heard AUD2k once.

What

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