I've been suffering from gearbox problems since I got the car! even an exchange box only worked for a while until a ham-fisted mechanic interfered with it.
Anyway, I had the fluid changed using instructions from this forum and, although I had a bit of juddering, I got by.
Now have a new problem. Over the last few days, I have had trouble pulling away! Ok, when I start up in the mornings. Can pull away on tick over which works until I get to the main road but, after a mile or so, can be problematic. Doesn't always pull away which is a bit dodgy on roundabouts. Found a workaround! If I go into semi-automatic and select third or fourth gear, it pulls away smoothly!
Any ideas?
C8 Gearbox problems
Moderator: RichardW
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Re: C8 Gearbox problems
Are there any warning lamps on / messages / Service Indicator? Without a diagnostic or if the are no diagnostic codes or warning lamps / messages, my first thoughts would be that some of the clutch packs have had it, causing the slipping or non / slow moving.
This is the AL4 box you have on this from the VIN.
This is the AL4 box you have on this from the VIN.
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Re: C8 Gearbox problems
There are no warning lights or messages! On occasions, I have had a gearbox fault show up but this has cleared within seconds without leaving any fault codes! Are the clutch packs replaceable if they are the cause?
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Re: C8 Gearbox problems
Hi John. I'm not an expert on these - they can be rebuilt by specialists, but they do have a bit of a reputation for recurring problems - see this chap:
His ultimate solution to cure the problem with his AL4 was to remove the bloody thing and fit a manual!
I only ever had the earlier BVA4 (4HP18) boxes on my XMs and had one of these rebuilt for slipping at a gearbox specialist. The trouble with fitting used boxes as I think you mentioned, is that you don't know the history of it and what if anything has been done on it.
There are gearbox specialists - but as per the chap in the video - he had loads of repairs done on it to no avail.
His ultimate solution to cure the problem with his AL4 was to remove the bloody thing and fit a manual!

I only ever had the earlier BVA4 (4HP18) boxes on my XMs and had one of these rebuilt for slipping at a gearbox specialist. The trouble with fitting used boxes as I think you mentioned, is that you don't know the history of it and what if anything has been done on it.
There are gearbox specialists - but as per the chap in the video - he had loads of repairs done on it to no avail.
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Re: C8 Gearbox problems
Could it just be low on oil? A common symptom if the oil is slopping away from the pick up.
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Re: C8 Gearbox problems
I didn't mention the oil Eric, seeing as John already replaced it in the first pos, along with the absence of any fault codes gets me leaning towards the internals....