Thread: D4 Gearbox rebuild

Originally Posted by rar110

Graeme, how often should the lead free stator bush plagued transmissions be flushed?

Someone here, IIRC BobD, has his MY10's oil changed frequently, possibly around 60K kms, and has avoided any problems with quite high kms travelled.

Originally Posted by Graeme

Someone here, IIRC BobD, has his MY10's oil changed frequently, possibly around 60K kms, and has avoided any problems with quite high kms travelled.

Mine was first fluid changed at 210k km (when I took ownership) and has had annual part flushes each year since (four now). My box is happy other than the shifts can be a little harsh in the morning. My vehicle has done next to no towing in its life and spend a lot of its time travelling between Perth and Northam each day (country driving) and so has had a pretty easy life, unlike those that have towed 3T trailers a lot. I think that’s why it’s now 265k km and not showing any issues unlike some that don’t make half that. Off to touch some wood.

My MY10 3.0 D4 had its first oil and filter change after 120K of oil and clutch nursing usage then 5K kms later spat the dummy, requiring a rebuild due to stator shaft bushes not holding pressure. Within 2K kms of the first failure the vehicle became almost undriveable above 80 kph.

Originally Posted by Graeme

My MY10 3.0 D4 had its first oil and filter change after 120K of oil and clutch nursing usage then 5K kms later spat the dummy, requiring a rebuild due to stator shaft bushes not holding pressure. Within 2K kms of the first failure the vehicle became almost undriveable above 80 kph.

How much towing had it done in that 120k km?

Very little towing of a 1200kg older van and occasional box trailer towing.

I shunned TC slip, regularly up-shifting to stop TC slip of lower gears and generally gave the gearbox a very gentle time. At the fluid and filter change the old oil was absolutely clear, as I had hoped.

I dropped 3L from the pan of my 8-speed yesterday. It was quite dark for 90K kms although no burnt smell. The gearing in my L322 is very high and its programmed to slip the TC holding 2000 rpm just to get rolling and at many other times too. At least the rebuilt 6-speed with its updated TC was lovely to drive, much better than this 8-speed.

Just had my 6 speed oil and pan done at 65K,and the oil looked only slightly darker than the new.

Minimal towing,but around 7 yrs old.

Originally Posted by Matty_P

$4,500 for my ZF rebuild a few months ago but that included removal / fitting rebuilt valve body etc.. happy with the results

Hi Matty,

who did your rebuild in Brisbane, if you don’t mind me asking. My D3 auto needs a rebuild and prices I’m getting quoted down here on the Gold Coast are scary.

Originally Posted by Graeme

Someone here, IIRC BobD, has his MY10's oil changed frequently, possibly around 60K kms, and has avoided any problems with quite high kms travelled.

As Graeme said my 2010 transmission has had no issues at all and is now over 285,000km. I have changed the transmission oil about once every 18 months after the first change at around 60,000km. My car does a lot of long distance touring on rough roads towing a 2.2t Kimberley Karavan most of the time in the last few years. The transmission was running quite hot so I reckoned frequent oil changes were essential. I have just had a new radiator fitted so the temps should be a bit lower now but the transmission still runs pretty hot when towing.

The trans runs much hotter in the D4 than the 8 speed in my RRV, doing the same job. The electric fans on the RRV TDV6 cut in earlier and stronger than the D4 viscous fan which doesn't fully lock until about 109 degrees, at which time the coolant is all hot and the transmission is not getting enough cooling. This is easy to achieve when towing up hill. The temperature gauge doesn't start moving from the mid point until around 112 degrees so you haven't got any warning that the trans oil is pretty hot, thus reducing long term reliability of the transmission, even though the transmission does not need to protect itself at these temperatures.

The negative is that I could probably have rebuilt the gear box with the amount I have spent on services over the years. The D4 has now been relegated to light work and the harder core off road driving without the van while the RRV does the touring and towing. Hopefully that will mean that I won't need to rebuild the D4 trans for some time, especially since it still works like new.