Transmission lessons learned: (McLeod & FA24 transmission upgrade) - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

GrandSport · 06-12-2023, 02:09 PM

(this is a track only car)

So I kept eating syncros.
First one went... okay, it happens.
Second one- maybe it was a bad one. Got it off ebay.
Had the dealership rebuilding my engine and swapping in a 300 mile takeoff in check everything. Check alignments, bushings, shifter, etc. Looks fine.
Third one goes real quick. WTF.
I keep driving it, just till I can get a new trans in there and then it gets real ugly.
Clutch won't disengage, towed off track.

Turns out the McLeod wasn't fully disengaging causing the grinding gears, and then eventually it gave out. I guess this all that uncommon. Given I'm near stock power level, no reason to even deviate from OEM.

I replaced it with a trans from 21+ (22+?) and HOLY CRAP. What a difference. It's damn good. It's hard to miss a gear and about as smooth as you could ask for. If you're building a track car, just add this trans to your list.
Had I known, I would have got one a while ago. From what I hear, they are supposed to last longer anyway, but it's worth the cost of admission just for how much easier it shifts. No worrying about missing a gear.

CounterSpace Garage · 06-12-2023, 07:23 PM

Quote:

Originally Posted by GrandSport

(this is a track only car)

So I kept eating syncros.
First one went... okay, it happens.
Second one- maybe it was a bad one. Got it off ebay.
Had the dealership rebuilding my engine and swapping in a 300 mile takeoff in check everything. Check alignments, bushings, shifter, etc. Looks fine.
Third one goes real quick. WTF.
I keep driving it, just till I can get a new trans in there and then it gets real ugly.
Clutch won't disengage, towed off track.

Turns out the McLeod wasn't fully disengaging causing the grinding gears, and then eventually it gave out. I guess this all that uncommon. Given I'm near stock power level, no reason to even deviate from OEM.

I replaced it with a trans from 21+ (22+?) and HOLY CRAP. What a difference. It's damn good. It's hard to miss a gear and about as smooth as you could ask for. If you're building a track car, just add this trans to your list.
Had I known, I would have got one a while ago. From what I hear, they are supposed to last longer anyway, but it's worth the cost of admission just for how much easier it shifts. No worrying about missing a gear.

The 2nd gen transmission isn't completely immune to implosion to negligence either, but it is a definitely a step up in engagement. Highly suggest replacing gear oils consistently as a means of keeping it fresh!

GrandSport · 06-12-2023, 08:13 PM

Quote:

Originally Posted by CounterSpace Garage

The 2nd gen transmission isn't completely immune to implosion to negligence either, but it is a definitely a step up in engagement. Highly suggest replacing gear oils consistently as a means of keeping it fresh!

No trans is immune to negligence, but the Gen I was just weak in general. I am glad the Gen II is an easy swap as it will be hard to find them sooner or later.
Durability aside, the Gen II is just so much better.

ROADRACER · 07-13-2023, 03:33 PM

Quote:

Originally Posted by GrandSport

No trans is immune to negligence, but the Gen I was just weak in general. I am glad the Gen II is an easy swap as it will be hard to find them sooner or later.
Durability aside, the Gen II is just so much better.

Are the gear ratios the same in gen 1 and gen 2?

DocWalt · 07-13-2023, 04:50 PM

Quote:

Originally Posted by ROADRACER

Are the gear ratios the same in gen 1 and gen 2?

Yes

rice_classic · 07-13-2023, 05:06 PM

Three of us have been racing these cars hard for 4 years without synchro issues so I’m surprised to see this assessment. One of us has ejected the 4th gear retention balls that ultimately led to a gear becoming unuseable. Over the winter I replaced my synchros out of boredom and preventative prep but found the outgoing synchros to look good as new and they were performing that way before being taken out.

I wonder if some of this is a function of using full synthetic transmission fluid which doesn’t let synchros do their job and causes them clash more and fail faster. I can only speculate but we just aren’t seeing these transmissions to be weak with the abuse we give them. We also use Pennzoil synchromesh as well and we wrap our exhaust to keep unnecessary heat out of the transmission (heat kills). So that could be something.

strat61caster · 07-13-2023, 09:31 PM

@rice_classic seems like op had a bad clutch, not a bad transmission

rice_classic · 07-16-2023, 12:09 AM

Quote:

Originally Posted by strat61caster

@rice_classic seems like op had a bad clutch, not a bad transmission

Yup. Sometimes I like to address topics that aren’t applicable. Character flaw, or perk.. still not sure.

Speaking of clutches.. Racing this weekend and a couple of us have learned the importance of bleeding the clutch fluid. They do not like dirty fluid.

06-12-2023, 02:09 PM	#1
GrandSport Senior Member Join Date: Sep 2018 Drives: 13 Viper; 14 BRZ; 90 Miata; 18 AMG Location: TX Posts: 382 Thanks: 82 Thanked 230 Times in 128 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	Transmission lessons learned: (McLeod & FA24 transmission upgrade) (this is a track only car) So I kept eating syncros. First one went... okay, it happens. Second one- maybe it was a bad one. Got it off ebay. Had the dealership rebuilding my engine and swapping in a 300 mile takeoff in check everything. Check alignments, bushings, shifter, etc. Looks fine. Third one goes real quick. WTF. I keep driving it, just till I can get a new trans in there and then it gets real ugly. Clutch won't disengage, towed off track. Turns out the McLeod wasn't fully disengaging causing the grinding gears, and then eventually it gave out. I guess this all that uncommon. Given I'm near stock power level, no reason to even deviate from OEM. I replaced it with a trans from 21+ (22+?) and HOLY CRAP. What a difference. It's damn good. It's hard to miss a gear and about as smooth as you could ask for. If you're building a track car, just add this trans to your list. Had I known, I would have got one a while ago. From what I hear, they are supposed to last longer anyway, but it's worth the cost of admission just for how much easier it shifts. No worrying about missing a gear. __________________ 2014 BRZ: WRL Build (GP2) Gutted, caged, coilovers, AP enduro, etc- 2014 FRS: Similar WRL Build. Back up / parts / practice race car. 2013 Viper GTS : Tractive Coilovers, ACR sway bars, aero, carbon, exhaust, etc. 1992 NA Spec Miata: 1.6 + 1999 NB Spec Miata: 1.8 w/ all the goodies. 2022 CT5 Blackwing: Stock.

07-13-2023, 05:06 PM	#6
rice_classic Senior Member Join Date: Jun 2012 Drives: Nevermorange FRS Location: Seattle, WA Posts: 4,171 Thanks: 757 Thanked 4,206 Times in 1,807 Posts Mentioned: 78 Post(s) Tagged: 1 Thread(s)	Three of us have been racing these cars hard for 4 years without synchro issues so I’m surprised to see this assessment. One of us has ejected the 4th gear retention balls that ultimately led to a gear becoming unuseable. Over the winter I replaced my synchros out of boredom and preventative prep but found the outgoing synchros to look good as new and they were performing that way before being taken out. I wonder if some of this is a function of using full synthetic transmission fluid which doesn’t let synchros do their job and causes them clash more and fail faster. I can only speculate but we just aren’t seeing these transmissions to be weak with the abuse we give them. We also use Pennzoil synchromesh as well and we wrap our exhaust to keep unnecessary heat out of the transmission (heat kills). So that could be something. __________________ SCCA T4 - FRS

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Automatic Transmission (AT) Information and Upgrade Thread	wlfpck	Engine, Exhaust, Transmission	95	06-01-2021 11:40 PM
Transmission upgrade options for stock power and track only use?	GrandSport	Tracking / Autocross / HPDE / Drifting	46	02-24-2021 06:57 PM
Transmission upgrade	GsxrMe	Engine, Exhaust, Transmission	15	04-27-2016 09:18 PM
How to upgrade an AT FRS transmission?	CodyFRS	Engine, Exhaust, Transmission	13	12-06-2013 12:56 PM
topspeed difference between manual transmission and automatic transmission	torquemada	BRZ First-Gen (2012+) — General Topics	51	05-04-2012 08:54 PM

User Name		Remember Me?
Password