Loyale Transmission MT5 FWD

[rickyhils]

I have a salvage yard MT5 FWD tranny that I am accessing to have as a backup. My 1991 Loyale runs ok. But 13 years and 150k miles ago, I saw "Gloyale" post how to split the tranny case halves. In 2008 I had exactly ZERO experience with any Subaru, but I was forced into it. With leaking (very messy) front mainshaft oil seal and vibrating mainshaft, it was either fix it myself or junk the car. I put in SUBARU (NOK) seal and two new mainshaft bearings.

So, I sort of know a bit about that tranny. Pics here of the synchros. I think they look ok. And ANYONE, what is that "lockout" device opposite the shift arm? (See pic) Edit: I'm guessing it is a reverse lockout when car is moving forward.

Farthest out (larger of the two) bearing has enough play to feel by hand. Just the tiniest bit of play, but it would be STUPID to not change both bearings along with the front and rear seals. And the two output shafts have seals.

The smaller bearing is a IKO G TR224220E03. Subaru parts dept is iffy for me, as when the Loyale came out, there were more than one supplier for the trannys. I can't see the larger bearing number, as It needs to be pressed off first.

The output shafts have the slightest play at the pinion gear. At least I know enough NOT to mess with them! Better to have a bit of play then to muck things up trying to turn that outer plate and burning it out by being too tight. HOWEVER, I admit that in 2008 I brought them in by one cog (and one cog step only) which is about 5 or 10 degrees worth of inward mov't. But no problems so far  after 150k miles.

And, back in 2008 I had enough "beginners luck" to remember to put sealant on the case halves before putting it back in the car! And I knew about the dowel pin at the smaller bearing. Point being that with some experience can cause one to become overconfident and that can be where stupid mistakes happen.

Edited January 15, 2021 by rickyhils
Add Loyale to title. Add "reverse lockout"

[el_freddo]

Yes that is a reverse lockout device so you can’t slip into reverse when shifting down from 5th. 

To properly look at synchros you need to pull them out as the real action happens on the friction cones. What you’re looking at is just the tabs that align for the gear selector ring to slip over and lock the gear in for use. 

Cheers 

Bennie

[rickyhils]

I can lift out the mainshaft easy enough. If I slide the gears can I then see the friction cones? I guess that I am looking for smooth surfaces that are not "chewed" up?

And I now see how that reverse lockout forces you to go from 5th to neutral before going into reverse. That is so clever. And that is exactly why I would sometimes think that I had meshing problems when going into reverse.

Thanks a bunch.

Ricky

[el_freddo]

1 hour ago, rickyhils said:

I can lift out the mainshaft easy enough. If I slide the gears can I then see the friction cones? I guess that I am looking for smooth surfaces that are not "chewed" up?

You can’t see the friction surfaces without disassembling the shafts and gearsets. Not an easy task I reckon (I’ve not done this). 

With synchros you’re looking for some roughage on the friction surfaces. They stop working when they’re smooth and don’t create friction to slow or speed up the gear that the driver is trying to select. That’s when the crunch happens same as when changing gear without the clutch and you don’t rev match properly. 

You could pull the synchros and have them lightly bead blasted - I’ve heard this is a good method to bring them back to life. But the effort (or f’-it) to get the synchros out usually isn’t worth it. 

Cheers 

Bennie

[rickyhils]

All good info there. Thanks.

[rickyhils]

I have been learning more about synchros. Do I have this right? They are individual clutches that freely spin at engine speed before being pushed over to mesh and then the clutch surfaces make contact, all within a split second. On the Subaru, are the synchro clutch surfaces "tapered mating surfaces" or are they "flat" and just butt up against each other? I think they might have a tapered "inner and outer" clutch surface, and that would explain why they cannot be viewed unless removed. A smooth clutch surface would not push away enough of the oil and grip well enough.

[GeneralDisorder]

You need a hydraulic press and bearing splitters to disassemble the shaft for inspection. You can't determine anything with it together. 

GD

 

[rickyhils]

Thanks GD .   I can get the large rear bearing pressed off sure enough. Both bearings will be replaced anyway. (middle bearing just slides off the front of the shaft) . Then it's a matter of keeping my wits in getting the gears off and back on ok. Need to first research availability and price of any needed synchros. Very likely that synchros are still good , as currently running 1991 Loyale is at 326k and MT5 tranny is good.

Edited January 17, 2021 by rickyhils
spelling

[el_freddo]

Subaru’s have cone shaped synchros  

Cheers 

Bennie

[rickyhils]

So, do synchros wear out faster with heavy acceleration?

[idosubaru]

9 hours ago, rickyhils said:

So, do synchros wear out faster with heavy acceleration?

Don’t think so. Terrible shifting and lack of fluid changes. 

During non-shifting driving the synchros aren’t doing anything are they?

A couple 200k+ subarus that never had the trans fluid changes, had crunchy popping out synchros. Maybe it wasn’t fluid but seems suspicious.

 

[1 Lucky Texan]

just pointing out also, that due to MTs sharing lube with front diffs, fluid choice can matter in 'feel'/smooth-shifting. many folks experience clashing when using synthetic fluids. NON-synth, name brand lubes seem best. There is a Walmart semi-synth blend that some folks claim is a good value.

 

[rickyhils]

My running 1991 Loyale has 326k on it . It has never been driven rough. It will always have 90w gear oil in the trans.

Edited January 18, 2021 by rickyhils

[GeneralDisorder]

The best bet for fluid is the Subaru HPGO. It's about $12 a quart. Shifts excellent. Motul Gear 300 is better but at $25 per liter - it's fairly expensive and unless you are throwing your STI around a track you are unlikely to notice the difference. 

GD

[el_freddo]

On 1/18/2021 at 2:22 PM, rickyhils said:

So, do synchros wear out faster with heavy acceleration?

No. Only when changing gears if the clutch isn’t used properly. 

Thus a low mileage gearbox could have a crunchy gear or two if it lived in a city driven vehicle - lots of gear changes for that amount of distance. 

A country driven gearbox with high kms could have very good synchros due to few gear changes for the distance driven - many kms at cruise speed in top gear. 

At the end of the day it all comes down to the driver and it can be a gamble. 

Certainly the choice of oil, it’s condition/age (what’s already in there) have an impact on what the gearbox feels like to change gears. 

Cheers 

Bennie

[rickyhils]

Then I am easy on the drive train due to my habits. I'll check the 90w gear oil in the currently running car. It was fresh 12 years and 150k miles ago. I could drain the gear oil and inspect it for debris. FWIW- If I were an STI owner [with MT5?] and wanted to invest in new synchros, [for max performance] I wonder how much four new synchros would be, if available. That would be just the parts only.

And - I also drive a 1997 Honda Accord w/ 5spd man trans, and the 2nd gear synchro has been out for a long time now. I usually accelerate more in 1st and then go directly to 3rd. It uses 30w motor oil. Hondas are known for weak synchros.