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

Originally Posted by Disco-tastic

John, mine clunks from 1st to 2nd when cold. It also clunks when taking off after coasting (with the dreaded indecisive delay). Apart from that it drives just fine. It has 187k km.

I'd suggest driving it around in sport mode and see if that makes a difference, as it may just be the programming. I've heard if you drive it like you stole in sport mode for a day or two, then change back to normal mode, the gearbox kinda relearns your driving habits.

Give it a go and let us know how you go.

Cheers

Dan

The clunk is due to wear in the valve body and most commonly the small accumulators at the end of each valve line, leaking internal seals and clutch cylinder bypass. Sonnax ZIP kits have all the parts that you need to cure this. There is also wear on the clutch packs over time, 180,000 of constant load will do that. Dirty fluid also causes shift problems and partially blocked solenoids.

Sports mode increases the line pressure in the valve body, allowing the transmission to hold gear longer, plus the shift rpm point is set higher by the mechatronic unit (it’s programmed in).

The transmissions ecu is adaptive, in that it “learns” your driving style within set parameters.

So driving it “more proactively” (i.e like you stole it) will see shift points change within preset (non changeable) limits. It will also flush out the valve body, oil cooler and torque converter.

It’s also better for the engine, burning off build up etc.

Murder on the fuel economy though...

If you bought one of these with say 50,000k on the dial and then changed the fluids every say 40,000k would you be confident of getting say 250,000k before forking out the big dollars or is that just too optimistic?

Cheers

Originally Posted by ozscott

If you bought one of these with say 50,000k on the dial and then changed the fluids every say 40,000k would you be confident of getting say 250,000k before forking out the big dollars or is that just too optimistic?

Cheers

Ive heard of fully sealed transmissions reaching those km so i would expect longer out of a serviced transmission.

Ford also thinks it's 6 speed built under licence from ZF is "filled for life", although they do recommend a flush at 50 000miles/80 000k's if doing "severe duty".

Ford 6R transmission - Wikipedia

The 6R80 can be found behind the 3.7L V-6 all the way up to the 6.2L V-8. Ford has stated that while the transmission is used in multiple applications, each transmission is optimized and integrated differently depending on the engine it is mated to. The 6R80 features "Filled for Life" low viscosity synthetic transmission fluid (MERCON LV), though a fluid flush is recommended at 50,000 miles if your truck falls under the classification of "Severe Duty" operation. The transmission, as used in the Ford F-150, has a fluid capacity of 13.1 quarts and weighs 215 lbs
Applications:

• 2009–present Ford F-150
• 2009–present Ford Expedition
• 2009–present Lincoln Navigator
• 2009-2010 Mercury Mountaineer
• 2011–2016 Ford Territory (SZ TCDi)^[2]
• 2011-2017 Ford Mustang V6, GT, Ecoboost(15-17)
• 2011-present Ford Ranger 2.2L, 3.2L
• 2015-present Ford Transit

It seems there was an upgrade of the 6 spd ZF to a 6HP28 in 2006 not sure if this was ever installed in Disco's or if it would even fit. http://akpphelp.ru/images/contents/f...0manual(1).pdf

Originally Posted by RANDLOVER

It seems there was an upgrade of the 6 spd ZF to a 6HP28 in 2006 not sure if this was ever installed in Disco's or if it would even fit. http://akpphelp.ru/images/contents/f...0manual(1).pdf

Fitted to the 3.0 Discovery

Bought 20lt of LG6 from Repco for $625 today with RACQ discount.

Prob not cheapest, but was keen to get it.

Just done a full flush on my trans today. I used Penrite BMV - 20L for a $168 with discount at repco. New pan filter and I also run a magnafine filter on the cooler return line so thats new as well. Going to look at a bigger external filter as the magnafine is small and they are not the cheapest. Plus there was more metal "paste" on the internal pan magnets than whats in the filter magnet.