Senator, Carlton, Omega autos

AFAIK there are indeed 'boxes with different degrees of electrickery. I think the more complicated boxes come in Senators and Clartons before around 1989/1990 or so. I'm fairly certain that the Omega boxes will be linked reasonably closely to engine management and will be less use to you.

I replaced the gubbed 'box in my '92 2.6 Carlton with one from a 2.6 senator of similar vintage and they had 4 or 5 multiplugs on them to get them to talk to the rest of the car.

There is/was a yahoo group for 24v Vauxhall enthusiasts - I think it was very senator oriented and someone at the

Autobahnstormers organisation will almost certainly have some info. I believe my 2.6 Carlton used the same autobox as the 2.0 versions. 3.0 versions got a gearbox rated for higher torque.

I hope what little I know is of some use.

the gm180 with lock up top is fitted to Bedford cf diesels (I own one)

But the 180 is a three speed?

I'm getting thoroughly confused.

The common GM four speeder is the 4L30E - used on many vehicles including USA spec BMWs, and it is made in the French Strausburg plant. But the 'E' part means electronic so it interfaces to some degree with the engine ECU. I was informed there was a non electronic earlier version, but I can't find any details although information on the 'E' series is easy to find. Although I've discovered it's possible to get aftermarket gearbox ECUs to interface with engines which weren't intended for this box. Haven't priced one up yet, though - they're made in the US and don't know if there's a UK distributor.

I've ascertained the Senator (or at least the early ones) use an Asian Warner four speed which would be ideal as it is a purely hydraulic box with the exception of electric lock out of the overdrive. But it won't fit the engine easily. I want one that will simply bolt on to the engine. All other mods I'm happy to do.

There are two versions of the 4L30E used on the Omega, the AR25 and the AR35 (Vauxhall designation). The AR25 is used on the 2.5v6 and early

2.5td and the AR35 on the 3.0v6 and later 2.5td. The AR35 can handle more torque so is the better choice. These boxes are sealed for life but the expected life is about 100k and seem to become a bit troublesome after that mileage. Quite often a filter and oil change fixes them provided it hasn't been left too long. The usual symptoms are taking a few seconds after startup before pulling away and/or clunking between gear changes. It seems that changing the oil and filter at this stage, before the ecu notices a problem, fixes them. You might be able to find one with an AR35 that's been scrapped due to gearbox failure and all it needs is a filter clean/change and new oil. If you do come across one of these and you get the chance it's worth taking off the front sump, the small one, just to see if there are bits of thrust washer in there. It's a circular plastic washer with three or four bumps on it and they have been known to break up very occasionally. It has been on older boxes but I don't know if it's due to the warning signs being ignored.

I know the first number in GMs designation is the number of gears, wouldn't a 6L30E be nicer :-)

I don't know what the 30 means, maybe that's the AR25 and there is a

4L40E which is the AR35.

As far as I'm aware the communication, at least on the earlier ones (pre 98/99?) was one way and just told the engine it was going to change and retard the ignition. The later ones have upgradable software and the latest upgrade reportedly gives much smoother gear changing.

None of this probably helps you because I can't be sure about the electronics and the engine but you might find a bit of it useful.

the box I have feels like a four speed, but the last 'change' is actually the torque converter locking.

It is Aisan, not Asian, BTW

Mrcheerful