gearbox

[Stiggles]

Well two so far that we know of. Trups was an understandable driving situation (may have got a little "air" on a country road) and I drive mine very hard with all TCS/ESP off and kick-down full throttle gear changes from 2nd gear onwards which puts a lot of stress on a GB as there's too much grip to spin the wheels so that torque has to go somewhere, usually transferred to the road via a massive kick in the arse thump.

My guess would be that, if I drove differently, my box would still be perfectly fine - i.e. no kick-down, keep ESP/TSC switched On to chop power and reduce torque if I forget about the kickdown etc. The car would still be 95% as quick but that 40mph drop into 2nd full throttle change which hits so hard it actually flung my mates glasses off his head would would be missed!

So basically you drive it how it's supposed to be driven much like myself in that respect. However I'm still running stock power but am getting closer and closer to being ready to go to the next step.

It's all about getting that last percent of power and force from the acceleration lol

[don0301]

Well two so far that we know of. Trups was an understandable driving situation (may have got a little "air" on a country road) and I drive mine very hard with all TCS/ESP off and kick-down full throttle gear changes from 2nd gear onwards which puts a lot of stress on a GB as there's too much grip to spin the wheels so that torque has to go somewhere, usually transferred to the road via a massive kick in the arse thump.

My guess would be that, if I drove differently, my box would still be perfectly fine - i.e. no kick-down, keep ESP/TSC switched On to chop power and reduce torque if I forget about the kickdown etc. The car would still be 95% as quick but that 40mph drop into 2nd full throttle change which hits so hard it actually flung my mates glasses off his head would would be missed!

So basically you drive it how it's supposed to be driven much like myself in that respect. However I'm still running stock power but am getting closer and closer to being ready to go to the next step.

It's all about getting that last percent of power and force from the acceleration lol

Stage 2 makes it a completely different car to stock. I have very similar torque to Ian, but obv. down on hp.

I've been stage 2 (770 ps 1100+Nm) for 4 years or more with no problems.

Seems to be bad luck/driving style that kills them?

[ATinOf]

Interrogate error messages on VCDS; its likely failed to engage a gear and gone into limp mode?

It may not be as serious as a shaft shearing; it could be the pressure seal has gone at the interface to the valve block. Either totally via the pump supply interface (bridge seal) which can crack




or selectively at one or more of the pressure lines to clutch B, C, D


these are rubber tubes that compress to create a seal but get tired over time and heat cycles and lose their compressive force. If its either of these it can be done with box in situ

You rarely lose pressure at the direct interface between the block and the box for ports clutches A and E.

With the valve block out you can air test clutch engagement at these interfaces; The annotated image isnt quite the 6HP28 but the port layout is the same; D1 is the reaction piston of D; D2 is the apply piston of D

[welwynnick]

Hi Ian,

How are you getting on with your gearbox?

Do you know which gearbox you have - 6HP26 or 6HP28?

All the best,

Nick

[c3nturi0n]

Interrogate error messages on VCDS; its likely failed to engage a gear and gone into limp mode?

It may not be as serious as a shaft shearing; it could be the pressure seal has gone at the interface to the valve block. Either totally via the pump supply interface (bridge seal) which can crack




or selectively at one or more of the pressure lines to clutch B, C, D


these are rubber tubes that compress to create a seal but get tired over time and heat cycles and lose their compressive force. If its either of these it can be done with box in situ

You rarely lose pressure at the direct interface between the block and the box for ports clutches A and E.

With the valve block out you can air test clutch engagement at these interfaces; The annotated image isnt quite the 6HP28 but the port layout is the same; D1 is the reaction piston of D; D2 is the apply piston of D

I wonder how easy or difficult is it to replace these items?

And can it be DIY'ed as part of proactive / preventative maintenance?

[welwynnick]

I read about those seals elsewhere. Sounds like it's a common problem, and probably DIY capable. You would just get a lot of oil running up your arms.

http://transmissionfault.com/

Nick

[Jim Haseltine]

Looks DIYable to me as long as you've some spanner spinning experience and are sufficiently motivated - 'cos it looks like you'd be spending a considerable period of time under the car with fluid dripping on to you. If, like me, most of your work is done with the car on stands then you'll probably be laid in oil for most of that time too. For those reasons I think I'd treat it as 'fix on failure'.
Having said that, though the seal replacement looks like a DIY job, I was under the impression that changing the box oil isn't simply a case of draining the oil and then refilling - or am I off track?

Edit: Google is your friend. The refill procedure isn't as complex as I'd thought - that'll be a job for later in the summer then.

[c3nturi0n]

Agreed.

Just by looking at the link (and thanks Nick), it seems that valve sleeves / bridge parts are slightly different for 6HP26 vs 6HP26A. On the latter, which is compatible with C6 RS's, are tad challenging to source by simply google-ing etc. hence was wondering, do you guys have any preference or places where to get these parts from?

And re DIY... look fwd to it and will certainly have a look at it during / after summer.

I suppose there is no harm in addressing this as part of prev. maintenance !

[ATinOf]

Personally I use Automatic Choice and JPAT; the former are au fait with the 6HP28A nuances and the latter have historically been more successful in sourcing the not so commonly stocked parts for me (and mostly a tad cheaper)

Im not sure i would bother doing this as preventative maintenance, you can normally limp home from these faults.

[welwynnick]

Ditto JPAT. I used them when I rebuilt my Merc S600 gearbox. They're one of the few place anywhere that do torque convertor rebuilding. Can't recommend them high enough.

Nick

[welwynnick]

For anyone who is seriously interested in the 6HP26 gearbox, I found this Ford 6R80 service manual, which is Ford's version of the ZF.

Not EXACTLY the same transmission, but they're close, and it looks like a comprehensive manual.

https://www.scribd.com/document/2641253 ... ice-manual

Nick

[ATinOf]

There is a jaguar manual floating about the tinternet for the 6HP26 that I would recommend if you dont have the ELSA software (the RS6 gearbox teardown is covered in ELSA); but I wouldnt recommend the Ford unless you just want to appreciate the principles of operation, too many differences. Damn good find that link though.

pm me if you want the official ZF 6HP26A61 manual, I also have the ZF 6HP26 Official Parts List, I also have a ZF parts list for the 6HP28A albeit in Russian.
If I had time and knew a good sharing service Id share them directly

[welwynnick]

by IanH755 » 17 Apr 2019, 09:48

Well mine looks like it's just done the same as Trups and sheared the input shaft and mine has no unusual noises at all so, while I suppose it's possible it could be the shaft if its twisted before shearing, a whirring noise means something is still being turned within the GB and the input shaft alone (if sheared without twisting) wouldn't make that noise.

***OLD*** Daytona C5 RS6 Avant - MRC'd - 500HP & 820NM (PH Link).

***NEW*** Daytona C6 RS6 Avant - MRC'd - 907HP & 1130NM (PH Link)

How are you getting on with your gearbox Ian?

Nick

[IanH755]

Out in Saudi til Nov and left it with Unit20 until then but I've no idea right now what stage the rebuild is at.