Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Tangerine on 04 September 2008, 08:47:10

Title: 2.5TD Autobox does not change up
Post by: Tangerine on 04 September 2008, 08:47:10
My facelift Omega (June 2000) is fitted with the BMW engine and Automatic Gearbox and has done 81k.
Just recently it has been failing to change up at the usual speed, mainly from 2nd and 3rd I think.  1st seems OK.
Very occasionally it has appeared to put itself in neutral and just allowed the engine to rev.  It has always recovered from this.  It has showed an 'Automatic Gearbox' warning.
Any ideas please and is it likely to be an electrical fault or a gearbox fault.
Title: Re: 2.5TD Autobox does not change up
Post by: Marks DTM Calib on 04 September 2008, 08:48:11
I suspect pending box failure......the AR25 fitted to the TD does not last long!
Title: Re: 2.5TD Autobox does not change up
Post by: Tangerine on 04 September 2008, 09:52:17
Sorry, but what is an AR25
Title: Re: 2.5TD Autobox does not change up
Post by: Entwood on 04 September 2008, 09:59:34
AR25 and AR35 are the two designations of autogearboxes on the Omega. They relate to the power that each is supposedly able to handle.

The AR25 is "weaker" than the AR35. As a diesel produces high torque at low RPM it tends to wreck the AR25 especially when driven hard over a long time.

After that info, back to your problem ... whilst I don't disagree with Mark - he knows way more than I ..... it is possible that you have low/old ATF fluid. For the sake of a few quid I'd do an ATF fluid/filter change and see what happened. It's not difficult .. just messy, and changes about 50% of the gearbox fluid. Has been known to bring new life to old gearboxes ...

HTH
Title: Re: 2.5TD Autobox does not change up
Post by: feeutfo on 04 September 2008, 10:06:47
its the type of gear box fitted to the td. It is not really strong enough for the power output of the engine. And, from what Mark is saying, its about to pack up, sorry. Standard reply from what i have read is to fit an Ar35 gear box, this is much stronger and will take more power and torque than your engine will put through it. You can then happily chip it to give more power and economy. There as a phew breakers on here. They may have one.
Dont panic, its not as bad as it sounds.
Title: Re: 2.5TD Autobox does not change up
Post by: Tangerine on 05 September 2008, 19:18:45
Thank you both for your responses.  I have owned the car since almost new and the last 60k miles.  I know it has not been driven hard   so I would like to try the ATF option first.  Is there any guidance anywhere regarding changing the fluid.  
Title: Re: 2.5TD Autobox does not change up
Post by: MutantCav on 05 September 2008, 19:35:36
There is a plug (13mm bolt on older boxes, has a hex key to remove on newer ones) which you can remove...its about half way up the box and towards the back of it...

Remove the plug (probably need car jacked up) then start the car and get it up to running temperature (after levelling the car back out)...put it through its various gears 1-2-3 and back (dont need to drive anywhere)

Then put some atf fluid (Dexron III) into the box through the plug hole until it comes back out, leave any excess to drain out...thats the right level...

Its tricky to get the fluid in without the car jacked up so a hose running into the hole with a funnel on the other end generally works for pouring in the atf fluid...

Then jack up the car and put the plug back in :)

Its really not hard at all...

And if the box has failed then I have a few of the stronger AR35 gearboxes (350nm torque versus 250nm on the AR25) from 3.0 elites...£100 if you can collect (not sure where you are)

Then jack up the car and
Title: Re: 2.5TD Autobox does not change up
Post by: feeutfo on 05 September 2008, 19:54:23
Quote
There is a plug (13mm bolt on older boxes, has a hex key to remove on newer ones) which you can remove...its about half way up the box and towards the back of it...

Remove the plug (probably need car jacked up) then start the car and get it up to running temperature (after levelling the car back out)...put it through its various gears 1-2-3 and back (dont need to drive anywhere)

Then put some atf fluid (Dexron III) into the box through the plug hole until it comes back out, leave any excess to drain out...thats the right level...

Its tricky to get the fluid in without the car jacked up so a hose running into the hole with a funnel on the other end generally works for pouring in the atf fluid...

Then jack up the car and put the plug back in :)

Its really not hard at all...

And if the box has failed then I have a few of the stronger AR35 gearboxes (350nm torque versus 250nm on the AR25) from 3.0 elites...£100 if you can collect (not sure where you are)

Then jack up the car and

See, £100, not to bad. And a better box. There is also i guide in maintenance section re atf level. Service at 60k. It is not a sealed for life unit and it takes Dexron 3,  dont let the dealer tell you any differant. Thier not the best place for atf anyway.
Title: Re: 2.5TD Autobox does not change up
Post by: MutantCav on 05 September 2008, 19:56:29
And so good it was worth mentioning 3 times! lol :D
Title: Re: 2.5TD Autobox does not change up
Post by: feeutfo on 05 September 2008, 20:17:19
Quote
And so good it was worth mentioning 3 times! lol :D
Yeah, i'm using a mobile and it keeps doing that. 3 is a record, usually it posts twice when i plays up. Sorry, now deleted. Only pressed the button once honest. Bloody gay Nokia.
Title: Re: 2.5TD Autobox does not change up
Post by: MutantCav on 05 September 2008, 20:37:29
You can delete posts?
Title: Re: 2.5TD Autobox does not change up
Post by: TheBoy on 07 September 2008, 18:31:29
try the atf change first, but I suspect the box is knackered, esp if you have revved it long and hard enough to get the wrning on the MID....