landyrow
Member Since: 16 Jul 2024
Location: Klagenfurt
Posts: 7
  
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| Automatic Transmission 3-4 shifting desparation |
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Hello,
Disco 3, Year 2005, TDV6, 140kW
After a crank break complete engine new overhaul I drove out of the garage did a full vehicle reset also a tranny adaptation value reset and there started the big problem.
Driving the first couple of miles Skipped 2-3 and 3-4 with algorithmic errors and the tranny goes to F all the time.
My thought was that the broken crank did wear bushings on the 6HP26 and did somehow harm the Tranny bearings after all.
#So I removed the Tranny 1st time to fix all bushings 12 incl. stator bushing and a friction kit for god sake. The mechanical part of the tranny felt like new-> I was confident and put it back in.
Drove it and shifting from 1-3 and thought it was fixed, but oh no -> now refusing and trying the 3-4 a couple of times sends the tranny in to F.
#So I removed the Tranny 2nd time to see whats wrong and oh my... the E-clutch slightly burned. so I put in new solenoids for the heck of it.
Drove it and and now I had much more problems than ever before. Long delay on inserting 1 and reverse. shuttering right before shifting and changing gears with a hammer, if shifting at all. Tranny goes to F...limp mode vehicle was unusable
# So I removed the Tranny 3rd time and overhauled the entire mechatronic body with separator plate and zip kit. The accumulator pistons where flat and the separator plate was so worn and and the silicon pieces where everywhere. Flushed it cleaned it and thought all fixed and good. Reset all tranny adaptations again and drove with recommended procedure in the hope but hope is still hope if you do no know what the problem is.
The car did shift when cold and it seem that it was fixed. As soon as we had temperature the shift 5-4 was rough as hell and upshift from 3-4 if at all was a rpm up and down then a rough if at all 4-5 and 5-6 was luck
# So I removed the Tranny a 4th time. In the meanwhile speaking to experts did not bring me any further, since nobody knows, respectively nobody wants to help/tell -everybody wants to get the business. Anyways I did everything... so I decided to buy a "new" tranny from a used disco3. I took all the parts from the "new" tranny and put it in my old housing (because I had it painted and it looks like new from the outside). I also changed all bushings and put in the new friction kit. The guy I talked to who sold me the transmission said that it shifted perfectly and no issues at all 150tkm. The oil looked really good an nothing was burned just worn down.
The mechatronic body felt much tighter than mine and even so I put in the new m-body a zipKit and was glad since the accumulator pistons were down anyways. Separaor plate as well.
I drove about 50m to know that no upshift from 3-4 was possible.... desperation comes in my life.
# So I removed the tranny a 5th time and now it sits on the table fully disassembled and I do not find any mechanical problems. All bushings are tight and have almost no play.
A new friction kit is in, no burned clutches
All new bushings are in. Run tight and feels like new
Mechatronic was rebuild with new separator plate and zip kit to seal ends
With all that components changed and done.... the car if cold shifts 1-3 like butter.... hesitates and tries a couple of times on 3-4 but does it, then 4-5 and 5-6 soft like butter.
If warm condition the car shakes like a discofox when requesting torque on lower rpms right before shifting on the 4-5 and 5-6. the warmer it gets it also shakes on 2-3 if you step on the pedal. Temperature is about 75°C on 18°C outside temperatur.
The only 2/3 things left which I did not change/refurbish/rebuild are
1 Torque converter
2 Electronics because of the reset with the GAP tool under android
and if so I did not vaccuum test the mechatronic valve body.
Why do I say so. I had a conversation with GAP where they interchanged rail pressure with fuel pressure and this costed me 3weeks and endless hours to pinpoint the problem. After the debakel they meant that I supposed to use the IOS version which is the standard? I still use android.
And I read a comment on another post that it all started with a reset in adaptation values.... there might be not a conicidence. Since I have non reset electronics from the used tranny I bought I will try to do so in my next attempt.
Anyways feel free to comment and assist me in my 3-4 upshift challenge
I don't know if you can imagine removing a tranny for 6 times on the same vehicle within 3 weeks. In the meantime I made a documentation on that which I will put online to give everybody the chance to do it with least effort under 120minutes  I optimized the process like in a WRC team but this was not the intention
all the best
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 10th Oct 2024 10:35 am |
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loanrangie
Member Since: 18 Jun 2017
Location: Melbourne
Posts: 703
 
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I cant think what the problem is but i had similar shifting issues from 2-3 then when under load it would go to limp mode and lock in 3rd gear with F on the dash.
I rebuilt the valve body with zip kit,solenoids and separator plate in April last year and no issues since then.
I reset the adaptions and didn't bother with the learning process just drove as normal.
What fluid are you using , i would have thought it impossible to have the same issue with 2 different transmissions and all that work you have done.
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| 11th Oct 2024 2:48 am |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10729
 
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Have you fitted a new E clutch? These are a failure point.
I see no mention of fault codes in this post. Will all those F's on the dash, their must have been some
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| 11th Oct 2024 9:25 am |
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landyrow
Member Since: 16 Jul 2024
Location: Klagenfurt
Posts: 7
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| One more time - this time the last time |
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As I mentioned I had the tranny on the table and disassembled the whole mechanical part once again and did remeasure all clutch packs as in the technical specifiations. also did test the mechatronic part with vaccum as recommended in the zip kit.
I put everything back together and used other electronics and a different torque converter. !!! I did not reset adaptation values.
Voila it drives like a new car. super smooth shifting and then I was courious and read all the faults from all ecus. Here it comes. The guy who sold me the used tranny told me that the car had like 190k km on it. So I used the lower milage torque converter first. But the fault codes where something like 452342km shifting algorithm errors... lots of them.
So the mistery solved... the torque converter was the mechanical issue.
The real problem was the dishonesty of the seller. If I would have known I would have never used the Torque converter and would have saved me uncountable hours.
Conclusion:
New bearings
New bushings
Rebuild mechatronics with ZIP Kit Endcaps and Middle Plate
Electronix without adaptation reset
I will send in the torque converter for rebuild since this piece was the point of failure and mine is probably next. so I will keep one in spare.
All the best and you guys were great in thinking with me.
I upload a few photos so you can imagine what I'm up to 
All the best
Landy Row
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| 11th Oct 2024 11:06 am |
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