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2.5 RS Transmission & diff

Posted: Tue Oct 12, 2010 10:05 pm
by SubyFusion
I just bought This http://bbs.legacycentral.org/viewtopic.php?f=15&t=44711 Legacy SS as a doner car for my TURBO and AWD swap! Now the fun begins :-D this car has a 2.5 rs drive train in it, are these any good, can they handle a turbo engine if so about how much HP/Boost? Also I'm trying to compile the information and what its going to take to do the swap. My car has a cable clutch so I know I'm going to have to swap the hydrolics. I was also wondering is the 2.5 rs trans have a push or pull fork and can I leave the hill holder in and use it with this transmission? These are just some of the questions I have, but I appreciate any help :D

Thanks, Brian

Re: 2.5 RS Transmission & diff

Posted: Wed Oct 13, 2010 3:53 am
by Legacy777
The 2.5rs drive train should be alright. What kind of power are you planning to run? Either way, it should be fine unless you're shooting for crazy power.

The 2.5rs clutch is of the push design. You should be able to retain the hill holder if it has it. What year RS did it come out of? I heard the hydraulic hill holder was a little finicky when Subaru first released in hydraulic form.

I did both of the swaps you're planning. My awd write up has good info, and I've got a thread on here about the mods I've done for the turbo swap.

Re: 2.5 RS Transmission & diff

Posted: Wed Oct 13, 2010 6:59 am
by AWD_addict
pro tip: the 2.5RS master cylinder reservoir is short enough that you can fit a slanty-style TMIC. If you get a larger TMIC, the reservoir from a MY02+ WRX or STi can be used on the 2.5RS master cylinder for more clearance.

Re: 2.5 RS Transmission & diff

Posted: Wed Oct 13, 2010 7:20 pm
by SubyFusion
Legacy777 wrote:The 2.5rs drive train should be alright. What kind of power are you planning to run? Either way, it should be fine unless you're shooting for crazy power.

The 2.5rs clutch is of the push design. You should be able to retain the hill holder if it has it. What year RS did it come out of? I heard the hydraulic hill holder was a little finicky when Subaru first released in hydraulic form.

I did both of the swaps you're planning. My awd write up has good info, and I've got a thread on here about the mods I've done for the turbo swap.
Well I wanted to just start out with an EJ22T, but these engines are hard to find in California! So I'm not sure what to do just yet, guess all keep looking.

So the doner car has no hill holder on it, and from what you said I take it that I wont be able to adapt the hill holder from my cable clutch set up thats on my car right now!

As far as I know, I think its a late 90's like 99 or so RS drive train.

And what about a short throw shifter? Do they make after market or STI ones that fit like you have? It feels a lot better and the throw is shorter then my stock legacy trans but Idk much about what a short throw actually feels like since I have never had one lol.

Thanks, Brian

Re: 2.5 RS Transmission & diff

Posted: Wed Oct 13, 2010 7:23 pm
by SubyFusion
AWD_addict wrote:pro tip: the 2.5RS master cylinder reservoir is short enough that you can fit a slanty-style TMIC. If you get a larger TMIC, the reservoir from a MY02+ WRX or STi can be used on the 2.5RS master cylinder for more clearance.
Thanks "AWD_addict" thats always good to know, I think it just has the stock reservoir on it right now, but I will be sure to pick one up if I have any clearance issues.

Re: 2.5 RS Transmission & diff

Posted: Thu Oct 14, 2010 5:55 pm
by SubyFusion
Also what flywheel and clutch set up should I go with? I have the original one that was on there but its well used, mine is new but it wont work because my car has a cable clutch any ideas? what are people using?

Re: 2.5 RS Transmission & diff

Posted: Mon Oct 18, 2010 1:45 am
by Legacy777
You can pretty much use any 5spd shifter linkage/short shifter. Typically what I suggest is to get a stock WRX linkage setup and replace the u-joint on the tranny if it's of the old design. You can then put in a kartboy short shifter or any other kind. I didn't like the notchiness of the short shifters and kept the WRX shifter. I'd highly suggest replacing the shifter stay mount with the kartboy front and rear urethane mounts.

As for flywheel, just use one for a 2.5 RS trans and Go with a stock exedy clutch & pp setup.

Re: 2.5 RS Transmission & diff

Posted: Mon Oct 18, 2010 2:02 am
by SubyFusion
I read that the kartboy short shifters ruin transmissions is that true? the shifter linkage on there feels way better then my stock legacy shifter. I think all just go with the shifter thats on there or stock WRX shifter linkage like you :-D Now if I only knew exactly what year the transmission is! will it say on it anywhere?

Thanks, Brian

Re: 2.5 RS Transmission & diff

Posted: Mon Oct 18, 2010 3:00 am
by Legacy777
What happens is the kartboy and other short shifters shift faster than the stock transmission is designed for and the syncros can't match speeds fast enough and you end up wearing out the syncros even faster.

There should be an identification number on the trans up near the top of the bell housing where the starter is. It'll start with a T something.

Re: 2.5 RS Transmission & diff

Posted: Mon Oct 18, 2010 3:14 am
by SubyFusion
O well that makes sense lol how much better is the WRX shifter linkage then the 2.5 RS? If its almost the same I guess all just leave it. Great thanks that would help a lot if I know the year so when I go to get a flywheel I know what year 2.5 RS it is for instead of looking like dumb ass hahahah

Re: 2.5 RS Transmission & diff

Posted: Mon Oct 18, 2010 3:18 am
by Legacy777
There's a subtle difference in the dimension width at the pivot point of the shifters, but functionally, they're the same.

Re: 2.5 RS Transmission & diff

Posted: Mon Oct 18, 2010 3:22 am
by SubyFusion
Well thats good news :-D Thanks for all your help Josh, hopefully all have the swap done before the snow comes so I can have some AWD fun!! hahah

Re: 2.5 RS Transmission & diff

Posted: Tue Oct 19, 2010 5:50 pm
by SubyFusion
Okay I found the Numbers On the transmission, but I don't know what the hell they mean there was one above the starter hole its 515375 and then there was one on the side of the starter hole and its 67-TY754VCAAB I have no idea what these mean are there any other numbers in the transmission that could tell me the year? or do theses some how say what year it is?
Thanks, Brian

Re: 2.5 RS Transmission & diff

Posted: Sat Oct 23, 2010 3:27 am
by AWD_addict
Like Josh pointed out, it's the T-something number.

http://spda-online.ca/modules/tinyconte ... tc_28.html

Re: 2.5 RS Transmission & diff

Posted: Sat Oct 23, 2010 7:20 am
by SubyFusion
Dang there isn't very many LSD's on that list they must be hard to come by

Re: 2.5 RS Transmission & diff

Posted: Sat Oct 23, 2010 7:20 am
by SubyFusion
Thanks lol that helps a lot