18 replies to this topic

[LukeFranky]

Hey guys,

 

Recently pulled the 5 speed gearbox out of my 3GEN Subaru Liberty B4 MY03 (EJ208) to do the clutch, but discovered a few issues with the gearbox. I need to replace a some bearings but while at it I'm considering the upgrade to a 6 speed.

 

Firstly, what 6 speed would be the easiest to swap or the best to go for?

Secondly, can I keep my new heavy duty clutch. I understand that the flywheel diameter is bigger on the 6 speed but being a HD clutch it should be fine with less surface area. Correct?

Thirdly, what's involved for my specific vehicle? Anyone know?

Lastly, is it worth it? I'm not going for massive amounts of power.

[Barbbachello]

Firstly, what 6 speed would be the easiest to swap or the best to go for?

Anything from a GD STi

 

Secondly, can I keep my new heavy duty clutch. I understand that the flywheel diameter is bigger on the 6 speed but being a HD clutch it should be fine with less surface area. Correct?
If its a pull (i think thats what the STi uses) you can. You have to use your current flywheel and starter motor as well

 

Thirdly, what's involved for my specific vehicle? Anyone know?

No more involved than any other gearbag swap but youll need an auto tail shaft as the 6 speed is the same length as an auto. Could possibly need a new rear diff and everything with goes with making that work too. Thats where it gets complicated and expensive

 

Lastly, is it worth it? I'm not going for massive amounts of power.
Based on your last statement here; no

[LukeFranky]

Thanks,

 

Anyone know what ratio the gearbox in ADM MY03 model B4 is? I know older ones are 4.11. Was there any change over the years? Might just buy a new 5 speed and be done with it.

[Robbks]

I'd also think you'd have issues with dump pipes and clearance with a 6speed stuffed in there too.

[Mosti]

Tailshaft needs to be changed aswell. From memory the gen3 auto tailshaft is whats generally used with maybe a little bit of custom work.

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[Poony_Tunes]

6 speed fits no problem with as mosti said, i know gen3 auto tailshaft fits

 

I am running mrt exhaust dumps no clearance issues, and theres a hanger for primary dump that fits but not the other will need bracket made up easy fix

 

as far as what else is needed, 6speed clutch/flywheel, master and slave cylinders, your 5speed speedo hookup and 6speed transmount can use your 5 speed cradle as well as GD shifter 

 

front drive shafts are the same as well as your 5speed starter works with 6speed, theres a slim plate under clutch assembly that is different to 6speed

 

 

 

 

I do have my old 5 speed sitting around if interested.

 

Sam

[Ben_20EJT]

Not sure on a b4 but I used a my07 gen4 specB 6speed in my converted gen3 heritge, by using the specb liberty gear it was r160 rear diff so no need to change hubs etc, just bolt out bolt in the rear diff with you shafts, box is a 8 bolt box so will bolt up with all the 6speed hydrolics etc. I used a new 6speed clutch kit etc but have herd you just use a 5speed starter and flywheel/clutch, I also just went to a wrecker and got auto tail shaft, went straight in. Only thing is front shafts, just need to make some hybrid ones as the specb rubs a male inner joint or buy some auto axle stubs and run you stock shafts, I've done both as I've run this set up in my old v3 sti converted gen3 and now its in my gc8. Also if you go a specb set up, you will need to get Am autos to mod the bell housing to suit a speedo drive and you will need to run a gd sti shifter as the specb one hits the floor.

Hope this info helps you.

[glenisanutter]

I have an 03 STI six speed in my B4! No machine work needed...plus DCCD goodness 

be careful using a 5 speed clutch... the throw on the fork itself is slightly different i think and after a while my clutch started to ride causing clutch slipage and My Engine Thrust Bearing to wear which would of caused major engine failure if i didnt pull it out before it happend! When i pulled it out the crank was floating forward and backwards and putting pressure on the oil pump casing and was about to F@#* things right up!

As above tailshaft needs to be done, matching diff for ratios plus front shafts need to have matching ends. Some six speeds have female outputs not male ones like the B4.

Six speed shifther fits no mods needed

5 Sped clutch needs 5 speed starter, or

6 speed clucth need 6 speed starter(recommended)

I used 6 speed slave and B4 master with adjustment to get pedal right.

R180 diffs and shafts will work in Gen 3s with some work to the hubs. ask me how if you get to that point! 

Six speed cross members and mounts

Speedo drive and reverse sensors are located differently but can be solved easily as plugs are same except for DCCD

I think thats everything!

 

6 Speeds aint cheap(3 to 4k easy) and the B4 Box($500 to 1k Give or take) has awesome ratios! Treat it right and it will last

[LukeFranky]

Thanks for all the info.

 

I decided to buy a low KM 5 speed I found to replace it. I just want to get it back on the road...

[Mmmbye]

Sorry to bring up an old thread but I'm considering this swap aswell. I'm not sure if it's the gear ratios in the B4s but it's annoying. As I come up to a t intersection on the road, the best speed to have a quick look for cars and turn the corner is too slow for 2nd but too fast for 1st. So I either have to take the corner too quick in 2nd, slow right down and change into 1st or go my prefered speed and bog the car right down. Just wondering if there was anything I can do other than change the gearbox to fix this?
Would a tune make my car run better off boost enough to avoid this?

[LukeFranky]

What do you mean it bogs down? Sounds like it isn't running right.

 

I do know first gear is very low and torque'y. Changing down from second to first does result in higher revvs than desired, and with my heavy duty clutch it occasionally is little rough, but it doesn't bog down.

 

First gear on Subarus are often more notchy and difficult to get into than other cars I've driven. Trying to get down into 1st on the track can be a challenge.

[Mmmbye]

By bog down, I mean the revs are too low and it's as slow as a wet weekend coming out of the corner if I keep it in 2nd. But yeah it is really hard to get it into 1st above 10ks or so. Do you know if a dyno tune improves off boost performance at all? Or have I just gotta really force it into 1st?

[LukeFranky]

Oh, you are bogging down in second. I misread that as you were bogging down after changing to first.

 

My tune really did help with the power down low, so coming into roundabouts I stay in 2nd, unless there is a car coming then I change to 1st to give way. On the flat above 2000rpm+ she pulls away nicely. Below that you need first.

 

I'll pay more attention on the way home, but I think when I come up to a give way sign at an intersection I tend to drop back to 1st.

 

As I said, 1st is the hardest of gears to change down into, but it shouldn't be that hard that you need to force it. Maybe somethings not right there.

 

Overall, I do like the gearing ratio on my B4. It is very quick to 100.

[LukeFranky]

I just drove home and realised I stay in second most of the time. Unless you are really trying to gun it, on the flat she has enough torque in second to pull away smoothly from 1500rpm. I only found myself changing down 15km or under. Keep in mind my car is not stock.

How is you car running in general?

[Mmmbye]

Yeah I was gonna say, Iv seen some of ur posts and it's not stock haha. I do find my car sluggish if left in 2nd but Iv only got a CAI and I suspect a catback. Generally good I think. Was coming on and off boost (like 1 second on, 1 second off, causing the car to jerk) but I think I mostly fixed that with a maf clean. Although my second turbo does seem absent sometimes. My mate that's a mechanic (doesn't know subarus well) said my hoses are no good and suspects a vacuum leak but other than that ok

[LukeFranky]

A vacuum leak would certainly make it run rough and sap a lot of power.

 

Once you fix your other issues the gearbox ratios might not be a problem anymore.

 

Good luck

[Mmmbye]

Thanks 👍🏼