Not posting this because I have nothing better to do nor as an ego trip or as a reason to take the 'iss out of anybody, but this week I've had my first opportunity to take a decent look at and become a little educated on the ZF auto in these cars.
It has always been said that the ZF auto was considered "bomb proof" in the CX yet in the lighter BX it has had all kinds on things said against it; granted not the same box, but rarely does a manufacturer go from a quality product to a crappy one and then persist with the crappy one and it gets used on further models still bearing the crappy reputation.
I have heard it said on many an occasion that a BX auto "might" last 120,000 klms, so you have to ask, why?
I'll go back to the start.
Friend of the family is looking for a car and has a soft spot for my BX. We search high and low looking at cars everywhere but most were neglected, abused or sold, so in desperation I spot a car in Sydney but it's an auto. It has low klms, she's not that happy with an auto but she decides to give it a go, so buys it.
Happy for a while, but is sceptical of getting anybody to service it near where she lives (with good reason I might ad) and seems nervous about driving it even thiough it only had 80 K klms on it.
Eventually she brings it up here to me to take for a run and do whatever needs doing to it.
When I drive it, I'm firstly somewhat impressed at how it gets off the mark; none of the slipping and roaring I am used to with autos. Changes are fair, if anything a bit jumpy in the lower gears but when it goes into 4th, it seems to fall back momentarily in speed, almost as if something is half seizing. This can't be right.
I check the ATF; it's black. To drain, I find there's two drain plugs both that take an allen key about 5mm. One is set higher in the sump than the other and a look at the ZF manual shows the tp one holds about 1 litre that is splash fed to it. I check the service records and see it had 1 litre of Dexron3 put in it when it was serviced in Sydney prior to her taking delivery. I also note that the insides of the drain plug are partially stripped and vice grips or stilsons have been applied to the lower plug but can't determine if it was removed or not. I remember that Dexron3 came out long after the BX was on the market, so I decide to play it safe and ring a friend who owns a small oil & lubricants company and ask the question as to what it should have in it. He comes back with a different fluid. "Not Dexron3 then" I comment to which he gasps in horror and tells me under no circumstances should Dexron 3 be used in these transmissions. When I ask why, he tells me that the Dexron3 contains additives and extra friction enhancers that makes this fluid incompatable to the set up in these ZF boxes and they should be run on ATF type D2 fluid which is not an expensive ATF.
Further reading of the ZF manual tells me that the transmission should run at 100 degrees, yet this car had an opened thermostat that only allows the gauge to reach around the 60/65 mark, the original one specifies opening at 82 degrees, so I also replaced that too.
The result has been, that by removing both drain plugs, I managed to get 2.7 litres of the old ATF out and replaced by the proper stuff and the increase in temp due to replacing the thermostat has the box working at around its optimum operating temp, so now all changes are smooth, there is no drag back on changes and overall the car is much more responsive and pleasant to drive.
The point is that this car was serviced by a well known repairer who obviously is of the opinion (as I've heard expressed by other repairers in the past) that Dexron3 is the latest of the Dexron fluids and supercedes the others; this is incorrect and according to the iol guy can destroy the internals. Couple this to a box operating below optimum temperature making it think that it's driving the first few miles of the day all day, and little wonder the autos have been blowing up.
In the past, we have seen on a number of occasions, Dexron 3 being put into C-matics which then causes them to not change cleanly and to also get slow in the synchros and even had some use it in manual gearboxes as they used to back when Total Fluide T was readily available. It is obvious that these guys aren't checking the technical specs before blindly dumping this stuff into them; I wonder how many transmissions these problems and actions have killed?
Perhaps we had a bomb proof auto all along. It just couldn't stand being poisoned. :crazy:
Alan S
It has always been said that the ZF auto was considered "bomb proof" in the CX yet in the lighter BX it has had all kinds on things said against it; granted not the same box, but rarely does a manufacturer go from a quality product to a crappy one and then persist with the crappy one and it gets used on further models still bearing the crappy reputation.
I have heard it said on many an occasion that a BX auto "might" last 120,000 klms, so you have to ask, why?
I'll go back to the start.
Friend of the family is looking for a car and has a soft spot for my BX. We search high and low looking at cars everywhere but most were neglected, abused or sold, so in desperation I spot a car in Sydney but it's an auto. It has low klms, she's not that happy with an auto but she decides to give it a go, so buys it.
Happy for a while, but is sceptical of getting anybody to service it near where she lives (with good reason I might ad) and seems nervous about driving it even thiough it only had 80 K klms on it.
Eventually she brings it up here to me to take for a run and do whatever needs doing to it.
When I drive it, I'm firstly somewhat impressed at how it gets off the mark; none of the slipping and roaring I am used to with autos. Changes are fair, if anything a bit jumpy in the lower gears but when it goes into 4th, it seems to fall back momentarily in speed, almost as if something is half seizing. This can't be right.
I check the ATF; it's black. To drain, I find there's two drain plugs both that take an allen key about 5mm. One is set higher in the sump than the other and a look at the ZF manual shows the tp one holds about 1 litre that is splash fed to it. I check the service records and see it had 1 litre of Dexron3 put in it when it was serviced in Sydney prior to her taking delivery. I also note that the insides of the drain plug are partially stripped and vice grips or stilsons have been applied to the lower plug but can't determine if it was removed or not. I remember that Dexron3 came out long after the BX was on the market, so I decide to play it safe and ring a friend who owns a small oil & lubricants company and ask the question as to what it should have in it. He comes back with a different fluid. "Not Dexron3 then" I comment to which he gasps in horror and tells me under no circumstances should Dexron 3 be used in these transmissions. When I ask why, he tells me that the Dexron3 contains additives and extra friction enhancers that makes this fluid incompatable to the set up in these ZF boxes and they should be run on ATF type D2 fluid which is not an expensive ATF.
Further reading of the ZF manual tells me that the transmission should run at 100 degrees, yet this car had an opened thermostat that only allows the gauge to reach around the 60/65 mark, the original one specifies opening at 82 degrees, so I also replaced that too.
The result has been, that by removing both drain plugs, I managed to get 2.7 litres of the old ATF out and replaced by the proper stuff and the increase in temp due to replacing the thermostat has the box working at around its optimum operating temp, so now all changes are smooth, there is no drag back on changes and overall the car is much more responsive and pleasant to drive.
The point is that this car was serviced by a well known repairer who obviously is of the opinion (as I've heard expressed by other repairers in the past) that Dexron3 is the latest of the Dexron fluids and supercedes the others; this is incorrect and according to the iol guy can destroy the internals. Couple this to a box operating below optimum temperature making it think that it's driving the first few miles of the day all day, and little wonder the autos have been blowing up.
In the past, we have seen on a number of occasions, Dexron 3 being put into C-matics which then causes them to not change cleanly and to also get slow in the synchros and even had some use it in manual gearboxes as they used to back when Total Fluide T was readily available. It is obvious that these guys aren't checking the technical specs before blindly dumping this stuff into them; I wonder how many transmissions these problems and actions have killed?
Perhaps we had a bomb proof auto all along. It just couldn't stand being poisoned. :crazy:
Alan S
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