Gen 2 Transmission in a Gen 1 Car

[Breadman]

Originally Posted by Irace86.2.0

My power goals are less than what people have done with the FA20 on the gen 1 transmission, so if it holds on the dyno, that won’t be saying much empirically.

Are you an auto? I don't think a lot of people are saying the manual can hold that power. If it can that's cool because i don't need to trans swap.

[Irace86.2.0]

Originally Posted by Breadman

Are you an auto? I don't think a lot of people are saying the manual can hold that power. If it can that's cool because i don't need to trans swap.

I think when people start tracking their car then all bets go out the window. It is possible the trans gets too hot, things expand, stuff breaks from pressure, stuff becomes dislodged from lateral g’s or heat cycles break things down. People have broken manual transmissions at stock power. I don’t know if this is money shifting, hard downshifts or what. I’ve seen bearings stuck to oil drain plugs. I’ve seen conversations about 4th gear being weak and others about the synchro being a bad design.

All I know is that the FA20 and transmission seems to hold up to top end power/torque, as one would expect from adding a larger turbo, because multiple people have reached 500whp on stock internals and with the stock transmission. It could be the case that low end torque, track driving, harsh launches, time and fate are the main culprits, outside of absolute torque. We will see what happened and how long the transmission lasts. While I tend to drive fast and hard, I won’t be doing drag races from a dig or tracking the car. The amount of time the car might see north of 350wtq won’t be a lot.

[NoHaveMSG]

Originally Posted by Irace86.2.0

I think when people start tracking their car then all bets go out the window. It is possible the trans gets too hot, things expand, stuff breaks from pressure, stuff becomes dislodged from lateral g’s or heat cycles break things down. People have broken manual transmissions at stock power. I don’t know if this is money shifting, hard downshifts or what. I’ve seen bearings stuck to oil drain plugs. I’ve seen conversations about 4th gear being weak and others about the synchro being a bad design.

Jack's details these issues in their build information. The bearings that people find are shift detents. I am still beating on the same transmission with sticky tires and aero, but it is starting to feel, gritty.

https://www.jackstransmissions.com/t...ervice-brz-frs

The 4th gear thrust issue is a major concern for those who are making above stock torque levels. The added torque puts excessive force into the 4th gear clip, causing it to rub against, and chip, the teeth on the shaft. As the gear floats across the countershaft, they become misaligned resulting in a major gear failure.

When the 3-4 Shift Fork / Gear Slider overextends on the gear hub, there is a chance that the small synchro spring and detent ball can pop out, causing additional issues.

[RedReplicant]

His (Jack's) 4th gear collar can still loosen up, wear against the teeth, develop play, and allow movement.



Eventually you get the overtravel



I was making 180ftlb when my Jack's broke

Happy to see someone testing the second gen box, I'll also buy one when I pop the stock transmission in the car now.

[Irace86.2.0]

The other factors that are worth mentioning could be sintered/ceramic 4-6 puck-style clutches that grab abruptly/harshly and things like a supercharger versus a turbo. In the former case, I have a kevlar clutch, which should be smoother in engagement than a ceramic disc, and in the latter case, while the turbo transfers more torque, there is always some lag at lower rpms that may be easier on the transmission than the immediate torque of a positive displacement supercharger.

[Irace86.2.0]

Originally Posted by Sasquachulator

So does it actually feel different in any way?

Would that just be due to the upgraded/tweaked components inside?

So my gen 2 tranny had a few hundred miles I was told, and it looked brand new. It is paired with MTEC springs, Whiteline trans bushing, Kpower linkage, South Bend Endurance clutch, Verus forged fork and billet pivot.

A few things to note for me:

--In general, the transmission feels like it needs to be worn in like there are burs and sharp surfaces that make engagement more notchy than my higher mileage engine. I don't know if that is unique to the gen 2, but as I suggested, I think it is low mileage versus high mileage difference. It feels notchy and tighter.

--5th gear-- My used car with 40k miles had 5th gear grind from the previous owner that required me to carefully place the gear or rev match. If I didn't rev match then I often went from 6th to 4th and back up to 5th. Even going slow or careful versus normal or faster didn't help. A slow rev match was it, typically. I was surprised that the new transmission also has difficulty with 4th to 5th. It isn't as bad because the gear isn't worn, so I don't get gear grind or miss shifts. I can actually downshift to 5th without rev matching, but I do that anyway because I am use to it. And it isn't because it is off to the side or the MTEC springs, IMO. I think it is just a tolerance issue or something. The point is that it is also probably a new transmission thing, but I don't know. Regardless, it is nice to have a more usable and freer engaging 5th gear, even if it is especially notchy.

--6th gear-- My previous 6th gear wasn't any more notchy at all compared to the rest of the gears, but this one is almost as difficult to get it into 6th, as it is to get it into 5th. I mean, I do it, but I almost had a few incidents where I nearly missed the gear or had some grind where I wasn't expecting resistance, so my timing got off. Maybe 6th gear is a little tighter on the gen 2, or maybe it too needs to be worn in, and this is all par for the course.

I don't know if that information is helpful. Just a few surprises I had after the swap based on my expectations versus reality.

[fableluke]

Originally Posted by Irace86.2.0

So my gen 2 tranny had a few hundred miles I was told, and it looked brand new. It is paired with MTEC springs, Whiteline trans bushing, Kpower linkage, South Bend Endurance clutch, Verus forged fork and billet pivot.

A few things to note for me:

--In general, the transmission feels like it needs to be worn in like there are burs and sharp surfaces that make engagement more notchy than my higher mileage engine. I don't know if that is unique to the gen 2, but as I suggested, I think it is low mileage versus high mileage difference. It feels notchy and tighter.

--5th gear-- My used car with 40k miles had 5th gear grind from the previous owner that required me to carefully place the gear or rev match. If I didn't rev match then I often went from 6th to 4th and back up to 5th. Even going slow or careful versus normal or faster didn't help. A slow rev match was it, typically. I was surprised that the new transmission also has difficulty with 4th to 5th. It isn't as bad because the gear isn't worn, so I don't get gear grind or miss shifts. I can actually downshift to 5th without rev matching, but I do that anyway because I am use to it. And it isn't because it is off to the side or the MTEC springs, IMO. I think it is just a tolerance issue or something. The point is that it is also probably a new transmission thing, but I don't know. Regardless, it is nice to have a more usable and freer engaging 5th gear, even if it is especially notchy.

--6th gear-- My previous 6th gear wasn't any more notchy at all compared to the rest of the gears, but this one is almost as difficult to get it into 6th, as it is to get it into 5th. I mean, I do it, but I almost had a few incidents where I nearly missed the gear or had some grind where I wasn't expecting resistance, so my timing got off. Maybe 6th gear is a little tighter on the gen 2, or maybe it too needs to be worn in, and this is all par for the course.

I don't know if that information is helpful. Just a few surprises I had after the swap based on my expectations versus reality.

how difficult was the swap? was it a plug n play swap? any sensors you swapped?

edit: read the post about it being a easy swap but i think the info is helpful.

[Irace86.2.0]

Originally Posted by fableluke

how difficult was the swap? was it a plug n play swap? any sensors you swapped?

edit: read the post about it being a easy swap but i think the info is helpful.

No difference. Plug n play. Should take an hour or two to pull and put back.

[churchx]

BTW, was shifter detent 1:1 as old one? Wonder if something "outside" gearbox may make some gears shift bad ..

[dragoontwo]

Originally Posted by churchx

BTW, was shifter detent 1:1 as old one? Wonder if something "outside" gearbox may make some gears shift bad ..

You're welcome to check the Subaru parts website.

[Irace86.2.0]

Originally Posted by churchx

BTW, was shifter detent 1:1 as old one? Wonder if something "outside" gearbox may make some gears shift bad ..

Which piece exactly are you referring to? When I swapped the MTEC springs to the new unit, everything there seemed the same.

The shifter assembly is a little different. The most obvious thing is the rear lockout bracket has a plastic cover and the interface on the shifter is plastic versus all metal. There are slots in the plastic of the boot retaining part of the reverse lockout, which I assume helps with removal of the boot--less surface area for material to grab--and maybe lighter and cheaper.

I removed everything having to do with the shifter assembly and attached the new transmission to the car and just hooked up the Kpower linkage, so none of the shifter cradle or assembly from the gen 2 was moved over, which shouldn't matter

The car before seemed to be notchy and once the transmission was warmed up, it was smooth, while still moving like a bolt action rifle. Now it is more notchy and gets less notchy once warmed, but it still feels less smooth than my old transmission. Gear engagement takes more effort, but it also doesn't have any grind issues on 5th. Overall, the transmission is basically new at a few hundred miles, so I feel like it needs to be worn in before I really commit to it being different, and I honestly would need to drive another GR86 and a low mileage previous gen back to back to really say it was different. There is really nothing to complain about. I'm sure most people won't tell the difference in any meaningful way.

OLD style eBay pics




NEW style eBay pics

[Irace86.2.0]

This shows the difference too.

[gpvecchi]

Do you think the new lever can be fitted to the old mechanism? How does the lever height compare? Thank you!

[dragoontwo]

Originally Posted by gpvecchi

Do you think the new lever can be fitted to the old mechanism? How does the lever height compare? Thank you!

I don't see why not. I don't believe there would be any reason to. You can't carry over the first gen shift knob if you do it.