Thread: Disco 3/4 Automatic Transmission FAQ - 6 Speed

Originally Posted by shanegtr

1. No idea what Dr.Tranny does in the box, but if you dont have any issues with it then why put it in? Everyone is always banging on about only using LG6 because no one else makes an approved oil for the 6HP26 - adding Dr.tranny IMHO you've just converted the LG6 to a non approved oil by the addition of whatever additives are in the Dr.Tranny.
2. I reckon as little as 100km would be enough to fully mix the old fluid with the new
3. Last time I did mine those front bolts where a pain - If I had a one piece torx 1/4" drive socket then it would have been easier rather that the one I had that kept falling apart
4. I personally sample my trans oil at regular intervals. You can get an idea of whats going on within the box, and get a good idea on the state of the oil as well. Im actually waiting on a sample from a few days ago so happy to show what sort of info you'll see if you want
5. You could get the trans close enough from the pan with an IR temp gun. But the IID tool has so much more uses so I think its a worthwhile purchase

Thanks Shane.

1. I know what you mean, I'm hopping around, sans an arm and a leg, having just bought 20 ltrs of liquid rocking horse **** and I'm going to put other stuff in it. Having said that, it does have a shudder of some description and anecdotal evidence is very favorable towards the DR Tranny.
2. Great, thanks. I didn't think it would need too much driving.
3. So, I've got a torx with a 1/4" drive. I'll give it a trial run over this weekend before doing it the following weekend.
4. I've seen some of the samples you've posted previously. But would be good to have a look and details about how to get it done. Also, does it give you within spec/out of spec information or is it just raw data?
5. Did think of using IR gun (have them at work) but it's a good justification to get the IID Tool. "Hey Honey, I can do the transmission service for about the same (I know if you add it all up it'll be more but that's just semantics in these sorts of conversations) as the shop and then have the tools to do it much cheaper in the future"

Originally Posted by Dagilmo

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1. I've seen some of the samples you've posted previously. But would be good to have a look and details about how to get it done. Also, does it give you within spec/out of spec information or is it just raw data

Heres my latest auto sample results, newest on the left working to oldest on the right. The first one is from the first change I did a little while after I brought stand the second in from the right was taken when the trans failed. I've added an inline filter into the cooler return line to help keep the contamination levels under control a little. My sample will flag up if levels are excessively high as you can see with the Al, Fe, Sn and Cu levels in the first couple of samples. The viscosity is flagged as ALS has no idea what the viscosity is of the oil they are testing (I've had a new sample tested and its still spot on). If the oil cleanliness levels (the ISO 4406 code at the bottom) increase ALS will flag them - you can see in my test from the 31 Oct 17 that it was flagged as Debris, most likely from me accidentally dropping some dirt into the sample at some point. Mostly its raw data and to be honest I dont really read into the diagnosis from ALS too much as its generic text to fit in with certain levels. You can get sample kits from ALS or westrac etc.. I buy mine in boxes of 10 from ALS - mainly because we deal with them at work. I get the back end of my disco up on ramps so no oil comes out of the trans sump when I undo the fill plug and suck the sample out with a vacuum pump (screws straight onto my sample bottles) and if you want reasonable accurate ISO cleanliness results you need to give the sample bottle and tubing a flush with the sampled oil and tip it out
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Originally Posted by shanegtr

Heres my latest auto sample results, newest on the left working to oldest on the right. The first one is from the first change I did a little while after I brought stand the second in from the right was taken when the trans failed. I've added an inline filter into the cooler return line to help keep the contamination levels under control a little. My sample will flag up if levels are excessively high as you can see with the Al, Fe, Sn and Cu levels in the first couple of samples. The viscosity is flagged as ALS has no idea what the viscosity is of the oil they are testing (I've had a new sample tested and its still spot on). If the oil cleanliness levels (the ISO 4406 code at the bottom) increase ALS will flag them - you can see in my test from the 31 Oct 17 that it was flagged as Debris, most likely from me accidentally dropping some dirt into the sample at some point. Mostly its raw data and to be honest I dont really read into the diagnosis from ALS too much as its generic text to fit in with certain levels. You can get sample kits from ALS or westrac etc.. I buy mine in boxes of 10 from ALS - mainly because we deal with them at work. I get the back end of my disco up on ramps so no oil comes out of the trans sump when I undo the fill plug and suck the sample out with a vacuum pump (screws straight onto my sample bottles) and if you want reasonable accurate ISO cleanliness results you need to give the sample bottle and tubing a flush with the sampled oil and tip it out

Thanks Shane.

Interesting to see the 'metal' levels high (Rio might be upset to see some Fe not going to China) when it failed and now steadily increasing with time. Demonstrates why changing the fluid is important. My wife works for a heavy mobile plant maintenance company (competition to the one mentioned above), so I'll see if they can get a sample done for me. Comparing mine to yours when it failed might give an indication of its health.

Just in regards to the failed sample - an important point to note is the PQ index - thats a total count of all the ferrous material in the sample. The elemental anaylsis can only use particles upto around 10micron in size, so the jump in PQ with minimal change to the Fe levels in the elemental analysis is a good indication of larger wear particles and IMHO its not a good thing to see at all. You kinda need to look a the data and correlate the elemenatal levels vs the PQ to gauge particle size - which is easier if you have historical data

I keep waiting for transmission to play up. My 2010 Discovery 4 has now 208,000Km, of which 80,000 would be towing a 2.5 tonne caravan and no hint of a problem. Would I have a different transmission.

Gday...

I am very reluctant to provide this information as I firmly believe that a hidden member on forums is Mr Murphy and he jest loves to exercise his law.

But - wot the heck - here goes. Rossco I have 2006 TDV6 Auto SE which now has 245,000Km on the clock.
I bought this little beaudy in 2009 when it had 72,000Km under its belt. I travel full-time and have been towing my 23ft 2,600Kg van for about 120,000Km of that 170,000Km.

Transmission had steel pan, full flush and new filter at 80,000Km and has flush and filter change every 50,000Km since. Now this is the bit we need to say very quietly so Mr Murphy doesn't get aroused - it has performed faultlessly all this time and changes are still silky smooth and no shudder when dragging the van up hill and dale.

I tow in Drive - never cruise control - change to manual when going up, or down, any long/steepish hills. I do not have an additional transmission oil cooler fitted.

Personally, I don't think you are lucky - although if the box hasn't had 'good preventative maintenance' praps ya are lucky.

Luv me Disco 3

Cheers - John

Just doing the steel sump change now - done 147,000km light towing from time to time and the fluid has never been changed - colour is that of strong tea but clear so looks Ok.

I am at the stage of having just removed all the bolts and letting the old sump hang there to drain the remaining oil.

My experience so far is typical - I had to cut down a torx bit (a loose bit not the type with the drive attached) to the minimum length so when in its socket and 1/4" drive it would fit between the old bolts and the cross members. The rear x member has the tighter fit. At the front I could undo and unscrew the bolt a far way before the tool hit the x member but then with fingers or a screw driver at an angle finished the job - thankfully none were corroded. The rear is tighter and all I was able to do was loosen the bolts as any further then the 1/4" rachet hit the x member - again there were not corroded and could be undone with fingers or an angled screw driver.

Now at the design stage of the car - why didn't they take this into account when designing the cross members - either holes through them in line with the sump bolts or indentations to allow tools to actually fit. I would hate to have a UK car and trying to get corroded bolts out. We all love our cars but some admire them though rose coloured glasses - but then all makes have similar stupid design aspects.

So I am about to go out side and break off the filter housing - any tricks for getting the new sump on and getting the bolts above the x members started?

Thanks

Garry

So two hours later - the metal sump is on. As expected the front bolts are the issue - if the roll bar was not there it would be a lot easier.

The front outer bolts were Ok to get started and the front center bolt is OK because you can go through the big drain hole in the front x member - however the other two bolts were extremely difficult to get started. No problems getting the bolts to the holes but hard to get the threads to get started and easy to cross thread them due to the angle of the bolt. The 1/4" rachet was no much use to start the threads as on the return the bolt would just undo. I considered drilling two small access holes either side of the drain hole in the x member (as LR should have done) but after a million goes I managed to get the bolts in - so all is good.

The other issue I found is that the new filter would no stay in position and kept on falling down as I manoeuvred the sump into place. I assume that as the sump bolted up OK it stayed in position in the end.

Again - poor design on ZFs part - why not design the sump so the filter could be changed without having to remove the sump to change it - too easy.

Any way job done and just gotta put the oil in - as I am doing this completely cold, I am just putting in the same amount of oil back in (through the oil cooler) as I took out (+200mm for oil loss in the change) and when I do the next drain and fill I will do it hot as per the manual.

Garry