Member Since: 17 Jul 2013
Location: North Yorkshire
Posts: 141
anyone upgraded d4 from a 6 speed to 8 speed
After recently uprgeding my sump on discovery 4 2011 gearbox i noted the magnests had swarfe on them, i dont really recall any on my old 2.7 when did that.
looking around there are literally loads of the 8 speed boxes around and due to age are mostly much lower mileages,
obviously you would need gearbox loom and ecu but what else, on the basis its the same engine and literally a few months later came with the 8 speed box wheat esle could have changed.
ive heard issues with canbus speeds but if so can this be tested as its not fact just speculative, i currently have a 2013 commercial aswell with the new box so testing should be fairly straight forward assuming i know what i need to compare.
Last edited by Sloppy on 17th Jan 2018 11:31 pm. Edited 1 time in total
28th Nov 2017 8:04 pm
Sloppy
Member Since: 17 Jul 2013
Location: North Yorkshire
Posts: 141
had a look at looms they look like the main connectors are same, has anyone a link or idea where i can check part numbers of main engine looms to see if they vary
While the looms look the same, the important information sent on the CAN bus is different enough to not do it. We didn’t just swap gearboxes in work during development. It was everything on the power train.1972 Range Rover Classic 2 door V8
2013 Land Rover Discovery 4 HSE - SCRAPPED
2016 Land Rover Discovery 4 Landmark
2022 Volvo XC40 T5 PHEV 282HP FWD 3 cylinder!
1st Dec 2017 9:19 pm
Sloppy
Member Since: 17 Jul 2013
Location: North Yorkshire
Posts: 141
am i to understand you have tried this conversion then without success? and from what you say canbus issues.
i have noticed that my diff is a 3;54 ratio and most from the 8 speed are 3;21
2nd Dec 2017 8:18 pm
markate
Member Since: 17 Sep 2011
Location: England
Posts: 702
I think you'll find he hasn't actually tried it but was involved in the transition from 6 speed to 8 speed through his day job.
2nd Dec 2017 8:27 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
I think he is try to articulate the complications and that even during the development stage this was not tried.
The engine ECU and gearbox ECU are tied at the hip, the CANBUS structure is different, the running gear ratios are different with additional changes in a variety of other systems.
It is a case of forgetting this idea and moving on.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 17 Jul 2013
Location: North Yorkshire
Posts: 141
yea when i spotted the diff ratios i began to think this would be much bigger, real shame as there literally tons of 8 speed boxes around and if your doing a box swap it would be nice to have an upgrade
although i do like a challenge swapping the full loom and both ecu,s is not really economical
Yes, sorry, I've been in hospital the last few days.
I work for JLR in powertrain controls looking after gearbox electronics and diagnostics for the Disco Sport/Evoque and previously FL2. I have also worked closely with the engineers on the 6HP and 8HP programmes.
It's not a case of just changing the looms and ECUS, there are software changes in about 7 or 8 modules which would not necessarily work with an earlier model year vehicle. For example, if the gearbox ECU is told the vehicle isn't the same model year or engine power as the gearbox software is expecting then it will not allow the transmission to come out of Park, no matter what you do. Also the other modules may have had changes to them which would not be backward compatible.
When we 'plan' a change, we make sure that all modules are changed at the same time and sometimes they are compatible with earlier vehicles, sometimes not. You could fit everything and get it all updated and find that one simple module that costs £50 isn't working and can't be updated then the £1000's you'd spent would be worthless.
Hope this makes some sense.1972 Range Rover Classic 2 door V8
2013 Land Rover Discovery 4 HSE - SCRAPPED
2016 Land Rover Discovery 4 Landmark
2022 Volvo XC40 T5 PHEV 282HP FWD 3 cylinder!
2nd Dec 2017 10:22 pm
Sloppy
Member Since: 17 Jul 2013
Location: North Yorkshire
Posts: 141
where were the days when stuff was plug and play, i one converted a blown 306 gti6 to diesel, the engine loom just used the same plugs so the derv loom plugged straight in. this and a new binicale away it went everything worked!
also fit a gti6 engine to a 405 mi16 some soldering to match wire numbers on looms but again pretty much just fit and it worked.
thanks for the input tiger, much appreciated as you say it is possible but im not that invested to get it working, if i had a breaker to go at i would give it a go but i dont!
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