[Mpovas]

I have an OMEGA B 2.5 L automatic gearbox (AR25) is it possible (and easy) to instal a 3 L (AR35) automatic gearbox.

Because I believe my gearbox is on the verge of braking down

And to my mind a 3 L gearbox is stronger thant the 2.5 L .

Or am I wrong and there is more to it ?

 

[Auto Addict]

I have an OMEGA B 2.5 L automatic gearbox (AR25) is it possible (and easy) to instal a 3 L (AR35) automatic gearbox.

Because I believe my gearbox is on the verge of braking down

And to my mind a 3 L gearbox is stronger thant the 2.5 L .

Or am I wrong and there is more to it ?

I think this has been covered before, do a search.

 

[fastcarmaniac]

the gearbox will fit physically as the 3.0 engine is just a bored out version of the 2.5

 

[Mpovas]

the gearbox will fit physically as the 3.0 engine is just a bored out version of the 2.5

thnx, but what about all the screws...will it fit in the AR25 place...or will I have a hard time fiting it in ?

P.s. sorry but I didn't find the post about it :mmmm

 

[Vectrolosys]

Hello,

It can be done, but the torque of the 3.0 will rip the AR25 apart. A common mod is to fit the AR35 to lesser engined models, all you need to do is swap the bellhousing and torque convertor over.

What symptoms are you experiencing? usually a change of fluid and filter is enough to fix these units for good, occasionally the selector switch can play up also.

If you do go the gearbox route, get an AR35 replacement, as the AR25 will die when attached to the 3.0 .

James

 

[Steve W]

Thats what he wants to do. He has a faulty AR25 and wants to fit an AR35.

 

[Mpovas]

Thats what he wants to do. He has a faulty AR25 and wants to fit an AR35.

and I was starting to think that i wrote something wrong...

so what you are saying i will still have to ripp apart both boxes and change
your mentioned "bellhousing and torque convertor".

How the bellhousing looks like I know but what about the torque converter...

I recently had an opportunity to help a friend ripp apart his Sentaro 3L 24 V automatick gearbox...so i'm thinking i just might be able to do this


And what about the effects on speed, timings, performance with a different gearbox ?

 

[Vectrolosys]

Thats what he wants to do. He has a faulty AR25 and wants to fit an AR35.

DOH!!!

Mustn't post a reply when half asleep!!

James .

 

[Vectrolosys]

and I was starting to think that i wrote something wrong...

so what you are saying i will still have to ripp apart both boxes and change
your mentioned "bellhousing and torque convertor".

How the bellhousing looks like I know but what about the torque converter...

I recently had an opportunity to help a friend ripp apart his Sentaro 3L 24 V automatick gearbox...so i'm thinking i just might be able to do this


And what about the effects on speed, timings, performance with a different gearbox ?

Hello,

You'll need the torque convertor and bell housing from the AR25, remove and discard the ones from the AR35 and fit the AR25 items.

It's worthwhile having the torque convertor cleaned, someone please correct me if I am wrong, but parrafin is a good item to use to clean the convertor out with.

You need to be a bit careful when changing the bellhousing, also be meticulously clean about carrying out the procedure as you don't want to get anything trapped in there .

James

 

[Mpovas]

Thanx...I talked about it to my friend and we came to a decision that basicly it will be easy to to change the parts...the f***n hard thing will be getting the gearbox out, and trying not to spill the oil everywhere

any tips on that

 

[chrisravo]

I managed to change a box on a 3ltr on my own. the biggest problem was jacking it up and getting it back in. the main spillage of fluid was from the pipes on the drivers side. if you take these off and seal with bag, this will stop a lot of spillage. also take the converter out with box, this will stop a lot of fluid pouring out when you puul the gearbox away from the flywheel. It is also ann easier way to drop the box, but make sure it is well supported. you will find 1 locating pin on the passenger side top of the bellhousing, which gives a bit of support when you have removed all the bolts. one final thing, is make sure that the locating pin is either in the bellhousing or on the engine, especially when changing box as you are, as you could end up, as I did, with 2 pins in the same place and you have to drop the box again to remove it.

Good luck and hope all goes well.

Chris

 

[awoodier]

It's not that bad changing a 'box, i've recently changed mine. The old one was leaking at the seal where it goes into the Torque Converter. If you're interested i've got the old box, either i can fix or you can. Whatever you think it's worth really!

Oh, it's the AR35, ran perfect apart from the leak at the front.

 

[Mpovas]

well the cost of a used gearbo in Lithuania, is about 200 pounds so it's not that big of a cost.
The cost of me flying in for a gearbox and returning, then fixing it might be a little more

 

[lorrliew]

Found this from a GM US site, providing procedures of changing gearbox.

http://www.gmgoodwrench.com/_res/pdf/TransmissionPdf/Transmission Replacement.pdf

Please note that it is quite a big file.