M5r1 extremely hard to shift

[camP95]

Hey guys. I rebuilt my m5r1 about 9 months ago due to 2nd gear grinding when downshifting and updhifting hard. I just recently went on a road trip and it is now super hard to shift. It was making a grinding noise when i pushed the clutch in but that is now gone. The clutch is fully disengaging im sure. It is very hard to get it into first gear from neutral and it will hesitantly go into second when upshifting. Reverse is easy to shift into but that is the only gear that isnt very stiff. Im thinking it has to be either the slave bearing or the input shaft bearing is worn out and wont allow the syncros to work properly. I also replaced the clutch with aluk clutch kit from rock auto. I have a habit of always putting it in neutral when at stoplights which should prevent wear of both those bearing as far as i can see. Any insight would be appreciated. Ps it wont downshift into second at all now even if i yank on the shifter hard. Thanks.

 

[RonD]

You are using ATF in the M5OD-R1 right?
Not gear oil

The transmission's gears are always spinning at the same speed as the Rear Wheels, no disconnect for that

So when you are stopped the transmission is spinning at..................0 RPMs

At idle engine is spinning at say 700RPMs
So you have to slow down the input shaft/clutch disc to 0 RPMs if you want to put transmission into ANY gear

The synchros are softer metal and are used to match input shaft RPMs to Transmission Gear RPMs, so as you push shifter into a Gear the synchro presses against that gear and speeds up or slows down the Input shaft/clutch disc to match RPM of that transmission gear.
Slowing input shaft/clutch disc to 0 RPMs is hardest thing to do.

Since Reverse slows down to 0 RPMs fine I would suspect a problem inside the transmission, not the clutch system

 

[camP95]

Actually all the helical gears are spinning at engine idle when in neutral. They are locked onto the splines of the output shaft when you shift the hub/slider via the stick shift. The transmission was shifting perfectly a few days ago. As i said it was rebuilt because second gear syncro was gone. I dont think the brand new syncros would fail instantly or the main bearings. It was making a grinding noise when the clutch was depressed. I think it has to be either the input shaft bearing or the shifting forks/ linkage inside. As far as i can see a worn input shaft bearing would make it very hard for the syncros to work properly. When downshifting the sychronizers have to speed up the input shaft and a bad bearing woukd make that very difficult. Correct me if im wrong. And yes im using mercon five of course. Also it is hard to shift even when the engine is off. Thanks for the reply.

 

[RonD]

Yes, the ratio(helical) gears are attached to input shaft so do turn at input shaft RPMs, just easier to convey the RPM matching needed

The shifter arm moves one Shift rail at a time, which moves the shift fork for one Gear Set, like 1st and 2nd, shift fork slides a Dog gear/clutch to engage one of those gears to the Output shaft(rear wheel RPMs), the synchros slow down or speed up the Helical gear/input shaft to match Dog gears RPM to connect the helical gear to output shaft.

Worn bearing would tend to slow a shaft down, so make it easier to shift into a gear when vehicle is stopped.
Stiff or hard shifting with engine off would tend to point at shift rod or shift fork/dog gear binding IMO

 

[camP95]

Well have just driven about 250 kms. The trans. seemed fine while in gear and is easier to shift now. However it started making a grinding noise while in gear but that quicky went away. When i back up and put the clutch in, the vehicle jumps and wants to stop. Doesnt do this forward. Im pretty stumped. I am now sure its not happy inside. Could the main bearings be gone? Anybody ever had problems like this with an m5r1?

 

[jtaborsky]

Any update on this? My transmission is giving me hell as of late. I have a donor on standby, but I would hate to replace a transmission and not have the problem solved.

- Joe

 

[RonD]

Any update on this? My transmission is giving me hell as of late. I have a donor on standby, but I would hate to replace a transmission and not have the problem solved.

- Joe

Is it easy to shift with engine off?
If so its a clutch issue

If it not then transmission issue

 

[Bill]

The input shaft may be binding on the pilot bearing (bad pilot bearing) I have this problem and I've replaced the pilot bearing three times. I read something on another forum about input shaft end-play ruining the pilot bearings. I plan on pulling my transmission out and getting the problem resolved. The problem here is I've only found one place locally that will rebuild manual transmissions, so the cost is steep, and around $850.00.

Anyway, you can put the rear axle on jack stands, start the engine and see if the rear wheels rotate with the clutch in all the way. If so, you have something rotating the input shaft. That could be clutch or bad pilot bearing.

 

[jtaborsky]

It's only 1st and 2nd, and only with the vehicle moving. I can shift 1st to 2nd easily if i do it quickly, but i cannot downshift into either. Sometimes cycling the clutch helps. Also, it grinds when i go into 4th; it gets louder as rpm's rise. Clutch was replaced within 2k miles.

Thanks for the help.
- Joe

Edit: installed entire clutch kit. Luk Repset.

 

[Shran]

That's weird, possible worn synchro(s) or the teeth on the slider ring maybe? Doesn't sound like a clutch issue to me since it happens when moving - usually clutch issues show up as a hard to shift into 1st or reverse when stopped. Pilot bearing suggestion makes sense too.