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Omega Help Area => Omega General Help => Topic started by: Varche on 10 July 2008, 19:03:19

Title: Any difference btween 2.5 and 3.0 torque convertor
Post by: Varche on 10 July 2008, 19:03:19
Are there any differences between a 2.5 litre auto torque convertor and a 3.0 litre? I am after changing my gearbox and am looking to do so with an AR35.

My box lunched its thrust washer months ago and now is slipping under load in drive( quite scary really but then so is life). It had an oil and filter change recently. Would I be best using a secondhand torque convertor as well as the replacement gearbox. i.e. do they wear?

varche  
Title: Re: Any difference btween 2.5 and 3.0 torque convertor
Post by: tunnie on 10 July 2008, 20:41:36
not 100% sure but would imagine so, the 3.0's chuck a lot more torque than the 2.5's so suspects its beefed up.

But if your fitting a AR35 TC on, to a 2.5 its ok, but not the other way around.
Title: Re: Any difference btween 2.5 and 3.0 torque convertor
Post by: markey mark on 10 July 2008, 20:47:54
iirc they are the same ?? all they do is transfer drive to box torque is taken up in box ! :-/
Title: Re: Any difference btween 2.5 and 3.0 torque convertor
Post by: tunnie on 10 July 2008, 21:00:45
not sure  :-/

But what i do know is make sure its fitted propperly, heard of too many problems when they are not pushed fully back.

Push it right back, the lumps on the back of the TC should rub against the back of the bellhousing the the box, if it does not, then its not far enough back!

When its bolted in, the bolts pull it forward a bit so it does not rub.
Title: Re: Any difference btween 2.5 and 3.0 torque convertor
Post by: markey mark on 10 July 2008, 21:02:18
would think if you are fitting ar35 then fit the torque converter that is in it if it has been removed properly !! :y
Title: Re: Any difference btween 2.5 and 3.0 torque convertor
Post by: Kevin Wood on 10 July 2008, 21:08:33
The torque converter does need to be matched to the characteristics of the engine. Not so much in terms of strength but to give the right "gearing" at the right engine torque output. This makes me think they'd be different, although I don't actually know if they are.

Kevin

Title: Re: Any difference btween 2.5 and 3.0 torque convertor
Post by: Andy B on 10 July 2008, 22:52:02
Quote
The torque converter does need to be matched to the characteristics of the engine. Not so much in terms of strength but to give the right "gearing" at the right engine torque output. This makes me think they'd be different, although I don't actually know if they are.

Kevin


A different car but similar answer. My Dad requires another auto gear box for his MkII Granada (3 sp). While ringing round he discovered that although the torque converter for the 2.8 & 2.3 look the same  externally, they're different inside. Something to do with the curve & size of the vanes inside to compensate for the 2.3's reduced torque relative to its big brther. It might be the same for the 2.5 & 3.0.
Title: Re: Any difference btween 2.5 and 3.0 torque convertor
Post by: Kevin Wood on 10 July 2008, 23:06:45
Quote
Quote
The torque converter does need to be matched to the characteristics of the engine. Not so much in terms of strength but to give the right "gearing" at the right engine torque output. This makes me think they'd be different, although I don't actually know if they are.

Kevin


A different car but similar answer. My Dad requires another auto gear box for his MkII Granada (3 sp). While ringing round he discovered that although the torque converter for the 2.8 & 2.3 look the same  externally, they're different inside. Something to do with the curve & size of the vanes inside to compensate for the 2.3's reduced torque relative to its big brther. It might be the same for the 2.5 & 3.0.

Yep, that's exactly what I was thinking. The stall speed on the torque converter needs to get the engine into the bottom end of the torque band (2K-2.5K RPM) or it will take an age to pull away. Stall speed is proportional to engine torque output so it will be lower if you put a 3.0 TC on a 2.5 due to the lower torque output of the engine.

Here's an interesting article from across the sea where they talk about torque converters and racing in the same sentence. :o  

http://www.competitionplus.com/04_15_2004/converters_pt2.html

Kevin