Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB

Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB (https://www.ft86club.com/forums/index.php)
-   Engine, Exhaust, Transmission (https://www.ft86club.com/forums/forumdisplay.php?f=8)
-   -   Stiff to engage 1st/reverse from a stop after clutch install (https://www.ft86club.com/forums/showthread.php?t=74366)

mhiscott 09-17-2014 05:28 PM

Stiff to engage 1st/reverse from a stop after clutch install
 
I just recently installed an FX400 clutch/flywheel package in my FRS.

After doing so, I noticed it was more difficult to get into reverse/1st when stopped. It does this regardless of if its warm or cold. Trans fluid is Pentosin MTF2. Otherwise the trans setup is stock.

I have heard that insufficient lubing of the clutch disc spline can cause this. I did put some lube on, but mainly on the TOB/sleeve it slides on. I didn't put much on the splines as I didn't want it to fling off onto the clutch disc.

The pedal engagement point is fairly high currently. Could having excess pressure on the pressureplate's fingers when clutched in cause this? I'm not sure if its a clutch adjustment issue or if its the lack of sufficient spline grease.

The gears are also a bit difficult to engage near redline especially when flatfoot shifting. I figure the two issues are connected.

In one instance, at a stop in a parking lot (engine/trans warm), I wasn't able to shift into reverse at all from a stop. It was locked out. I had to engage a forward gear, then go back to shifting into reverse and it slid in. You can feel engaging 1st/reverse from a stop that there is resistance putting the shifter into the position you're trying to move it.

Any ideas or similar experiences?

Thanks!

murdoc 09-17-2014 05:37 PM

Sounds like a dragging clutch...that's all I got.

mhiscott 09-17-2014 05:42 PM

Back when I was into DSMs, dragging clutches often caused similar issues, but usually the cause was insufficient extension of the clutch slave. From the feel of where the engagement point is on mine, it seems like I'm overextending it if anything.

The trick on DSMs to check for this was to turn off launch control, start the car on a level surface, clutch in, shift into first, and rev to ~ redline. If the car creeps forward ever so slightly, the clutch is dragging.

I may turn off the launch limit (or just make it = to redline) and try this quickly to rule it out, but usually the clutch drag is caused by not pushing the slave far enough to full disengage the link between the gearbox and the flywheel.

Thanks for the suggestion!

wheelhaus 09-17-2014 06:12 PM

Yep both ideas sound 100% plausible. If your engagement point is high then I'd expect you're getting plenty of throw. I doubt the leaf springs are causing the drag even if flexed a bit to far, I'd be suspect of other noises if that were happening. Spline lube makes sense, but only if it were completely dry or catching on burs, even a super thin film will still provide lubrication.

I'd say test it with the near-redline rev with the clutch in to see if you detect any movement, and maybe slowly engage the clutch to see if it's slightly engaging earlier than you think. Also try shifting with partial clutch travel to rule out excessive movement.

It could be a screwy tolerance from manufacturing.
Side anecdote- A friend of mine bought a Spec clutch that had a pressure plate that was machined 1/4" too deep for his 2000-ish A4, leaving just barely enough clamping force for break-in. After a few days it slipped like crazy and Spec only offered to replace the clutch. My buddy had to pay for installation twice, thanks to terrible QA from the manufacturer.

mhiscott 09-18-2014 07:36 PM

Clutchmasters suggested I check the clutch adjustment. I did this today as per the video DIY here http://www.ft86club.com/forums/showthread.php?t=8040

At the suggested clutch pedal position of barely lower than the brake pedal in the video above, things seem to behave exactly the same as initially. This engagement point is considerably closer to the floor and while there is still the same blocked out feel of the gears from idle in N to 1st/reverse, being able to engage gears without grinding still seems to suggest the original problem wouldn't have been clutch drag from insufficient slave cyl travel.

I tried a bunch of adjustments ranging from the suggested one to the pedal WAY above the brake pedal. Nothing changed with any of this, as far as curing the difficulty putting it in gear.

What I did notice though (I did this in my garage where I could hear sounds reflecting off the walls easily) was when clutched in, when you'd go to put the shifter into any gear, you could actually feel the spot where the shifter hesitated to be pushed forward. When pushing up against this "hesitation point" you could hear a very very quiet faint whirling noise coming from the clutch area.

I'm thinking that maybe it could be the clutch disc binding on the spline after all (from not enough lube applied). Sucks I have to pull the gearbox to find out for sure lol.

I'm going to try the free rev thing here first. If it is the binding issue with the spline, it probably would creep forward while free reving, so stay tuned... lol

Calum 09-18-2014 08:15 PM

Bleed your slave cylinder.

F1point4 09-18-2014 09:48 PM

I'm not going to lie, I'm currently experiencing the same thing. I have an ACT clutch. Didn't do it immediately. For me started 5000 miles after installing the clutch.

I tried bleeding it the old fashioned way, adjusting hte clutch pedal, messing with the reverse lockout plate and it still does it.

I may use a vacuum pump this time to bleed the clutch. After that I may have to pull the gearbox out to check :(

qtwre 09-19-2014 01:20 PM

I've been having the same problem with an Exedy stage 2 for a couple months. It was initially fine after install then it got to a point where it's definitely dragging. On a flat surface with no brake, putting it into first gear makes car push forward a tiny bit. It often requires a couple tries to get it into any gear from stop.

In my case, my mechanic has already taken it out once to regrease things. The pedal has been adjusted and the fluid has been bled. What else is there?

mhiscott 09-19-2014 02:04 PM

Here's what mine looked like before reinstalling the trans. Looks like it was a bit on the dry side of things.

I'm pulling the trans tonight.

http://i60.tinypic.com/mmeov9.jpg

wheelhaus 09-19-2014 03:25 PM

Quote:

Originally Posted by mhiscott (Post 1952446)
What I did notice though (I did this in my garage where I could hear sounds reflecting off the walls easily) was when clutched in, when you'd go to put the shifter into any gear, you could actually feel the spot where the shifter hesitated to be pushed forward. When pushing up against this "hesitation point" you could hear a very very quiet faint whirling noise coming from the clutch area.

That's your proof the disc is still dragging. The whirring sound is most likely gear noise from the input shaft spinning down to a stop when you engage a gear; it stops because the output shaft is stopped. I can't remember exactly how the 86 tranny is designed, but it may be the gears between the input and intermediate shafts that will spin with the engine when the clutch is engaged in neutral.

Ive been doing some searching, and seems like lubing the input shaft splines is debated. yes, no, sometimes, never...

Sportsguy83 09-19-2014 04:09 PM

Quote:

Originally Posted by qtwre (Post 1953272)
I've been having the same problem with an Exedy stage 2 for a couple months. It was initially fine after install then it got to a point where it's definitely dragging. On a flat surface with no brake, putting it into first gear makes car push forward a tiny bit. It often requires a couple tries to get it into any gear from stop.

In my case, my mechanic has already taken it out once to regrease things. The pedal has been adjusted and the fluid has been bled. What else is there?

That sucks...

@alpine @marcoaferrer......

It's a weird problem and it sucks more it seems its not brand related, since ACT/Exedy/CM are having the issues

wheelhaus 09-19-2014 05:23 PM

Quote:

Originally Posted by Sportsguy83 (Post 1953540)
That sucks...

@alpine @marcoaferrer......

It's a weird problem and it sucks more it seems its not brand related, since ACT/Exedy/CM are having the issues

Seeing how it's so widespread, I wonder if manufacturers are just resourcing and renumbering clutches from other cars, and the issues may be arising from slightly different hydraulic systems... For instance, if the car(s) these clutches are originally designed for use a system that provides X throw at the slave, but the 86 system produces Y throw, it may just be too little throw... Just a thought.

mhiscott 09-20-2014 06:27 PM

Ok, so I dropped the gearbox, and cleaned the input shaft spline with a wire brush, as well as the clutch spline. I cleaned it then with brake cleaner, and lubed with white grease.

Since driving the car a bit, it seems the shifting is a bit better into 1st from a stop. It feels pretty smooth now. That said, I raised the launch limiter to redline, and with the car in first gear, clutched in, when holding the revs at redline for a couple seconds, the car would start to creep forward.

Can someone else try this and tell me if theirs creeps? On past cars I've owned this would indicate an unacceptable amount of clutch drag, but I'm not sure with the subaru setups.

If no one else is getting creep, I figure the Clutchmasters flywheel's step height must be a bit too tight. Is that even possible on a single stepped flywheel like the FRS uses?

Ugh...

mhiscott 09-20-2014 10:39 PM

I drove the car a bit more, it seems to shift well now. The car only creeps forward at 7k rpm+ in first clutched in after about ~ 3-4 seconds. Seems like it has a very very small amount of drag still. I bled the clutch and adjusted in a bit more throw on the slave.

Going to the track tomorrow so I'll get a chance to see if it requires any more tweaking.


All times are GMT -4. The time now is 06:40 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2025 DragonByte Technologies Ltd.


Garage vBulletin Plugins by Drive Thru Online, Inc.