bentheswift

Hi all,

Just wondering if I can drum up any experience from the forum. I did some searching and saw a couple threads with the same symptoms, but no solutions.

Yesterday I was driving and put the car in 5th on the highway, let the clutch out, and it didn't engage 5th gear. It made a terrible grinding noise, kind of like when starter teeth don't engage on a flywheel. The other four gears and reverse still work, but gears 1 and 2 make a bit of noise, kind of like there are ball bearings rolling around in the bottom of the gearbox, but work fine. Gears 3 and 4 and reverse are silent and you'd never know there was anything wrong when using them. I was able to get the car home in 4th late last night. No leaks or other visible problems in the engine bay or under the car when I briefly looked it over.

Relevant background: this is a 2009 5MT car with just over 120,000 miles. I bought it new and it has been almost entirely trouble-free since I got it. However, about 5k miles ago I started getting a slight grind when shifting into 5th quickly. Shifting slower would not grind. Also, just in the past couple thousand miles, it feels like the engine mounts are worn out or torn. In fact, just this weekend I started hearing a very slight clank when going from zero throttle to full throttle in 5th gear when cruising. I was going to try to diagnose which mounts are bad this week, but hadn't got the chance yet. I am half expecting that these problems are related.

I am pretty disappointed to have serious transmission trouble at this mileage, especially since it's just a bone stock commuter and never gets raced or abused, but I also love this car and am determined to get it fixed. I've done some searching and am going to start by draining the transmission and looking for evidence of damage in the oil. Then I'll pop the 5th gear cover off. Best possible scenario is if the engine mounts have been allowing the engine to move enough to keep 5th gear from engaging, but the shift lever feels normal when shifting it to the 5th position. My next best hope is that the shift fork has broken or something along that line. If 5th gear itself is damaged, maybe I can replace it by itself. And worst case, transmission replacement.

Fortunately, I was literally on our way to the dealership to buy a new 2015 Mazda6. So now that I've got an additional car, this one can sit in the garage and wait for me to fix it. Also, I've previously thought about doing a Camry 5th gear swap to get a little taller gearing for cruising, and this may just be the perfect opportunity to do just that. So I'm keeping an open mind and being thankful for this awesome car, because it still rocks.

Anyways... please provide insight if you have any. I will update this thread as I find out more. Thanks in advance.

bbsciontc

That sucks dude. The cheapest option would be to swap with a used trans. I picked up an entire e351 Camry trans for only $200 bucks from a local junkyard. I'm in the middle of installing an LSD, and just yanked off the 5th gear clutch hub assembly on Tuesday. Rented a harmonic balancer puller from AutoZone. be careful if you try as the hub assembly loves to fall apart and is annoying to reassemble. The driven 5 gear is then yanked off with a gear puller.

minter66

iTrader: (2)

I have 152,000 miles and I have had the "5th gear grind" since 80,000. Not sure why yours decided to break. I have been shifting averagely into 5th for 70,000 miles and it has never become worst.

I have heard rumors here and there that 5th gear can be accessed by itself, supposedly.

I was going to replace my Syncro, but at this mileage I just don't care anymore. I'm old, I don't race anyone, and I'm getting an old fart car in the next couple of years.

bbsciontc

Yes, 5th gear can be accessed separately. In fact I believe it can even be done with the trans still on the car, but you will probably need to drop the subframe to access it. There should be a black cover bolted to the end of the trans (about 10 bolts or so). Once you take those off, you gently pry the cover off and 5th gear is right there. You'll need a harmonic balancer puller to pull the clutch hub assembly and a 3 jaw puller for the 5th driven gear on the output shaft. The gear on the input shaft slides right off once you pull the clutch hub.

I just removed both this past weekend.

bentheswift

I have been able to spend a little time under the car, but not enough to actually figure out the problem or a solution.

Drained trans fluid, no signs of damage. No metal flakes or specks whatsoever.

Pulled 5th gear cover off, same thing, no sign of damage. 5th gear shift fork appears to move correctly.

No visible problem with the engine mounts. No cracks that I can see in any of them.

Pulled off the intake and battery tray, but ran out of time last night to start messing around with the shifter and bellcrank. I think I should be able to visibly verify everything from the operation of the shift lever, shifter linkage, bellcrank, all the way to the 5th gear fork and the actual synchro itself. But just haven't had the time Will update after I spend the weekend working on it.

bentheswift

Got under it again briefly last night.

Inspected the 5th synchro up close and couldn't find any evidence of damage...

Put it in 5th gear from the cabin... then went over and turned the crank pulley with a big ratchet... watched both front axles and they didn't turn at any point while I was turning the motor...

That got me thinking, so I started poking around more and noticed the big 30mm nut on the 5th driven gear ... that nut is LOOSE. I'm pretty sure it should not be loose. I stole a picture from j3st3r's extremely helpful transmission threads:

It is keyed into the shaft so it can't turn more than a little bit, but it's definitely loose. I looked it up and that 5th driven gear is splined to the output shaft, so it's not like that gear can turn... but maybe the fact that it's loose is causing the problem somehow.
I ran out of time after noticing this.

Also found this on the internet, but of course no solution.

DoinItWright

Yes the nut being lose can allow the gear to move out of place on the spline shift and therefore not engage. That sounds like your problem.

bentheswift

That's my hope and gut feeling, though I can't quite justify it in my brain yet. I talked with my Nissan master tech brother and we agreed that even though we're not 100% sure, our guts both say that it's probably causing the problem. Too unlikely that a loose nut on the output shaft would be not causing any problems... and that something else was causing this problem.

I am going to replace the fluid, put everything back together, and drive it. If it doesn't fix it, at least I learn that that wasn't the problem. And if it does fix it, then I just got bailed out of a $2,500 transmission replacement with a $0 fix and a total of maybe 3 hours in the garage.

I did some googling and found 3 other posts on this board and others that describe exactly the same problem... plus the youtube video (which is not mine, btw) ... but none of them have a solution to the problem.

bbsciontc

Well, all that nut really does is retain 5th gear. What you want to make sure of is that the gear didn't back off the spline of the output shaft. If it did, then press it back down before tightening the nut. When I took mine apart, that nut was tight as hell. Had to lock the trans and hit it with the impact for a while. 5th gear was tight on the shaft too. Needed a 2 ton puller and cranked on it with a 3/8 wrench just to break it free.

bentheswift

Wow... torqued that nut down (90 ft-lbf), resealed the end cover, put everything back together, and wow it did it!!! 5th gear is back!

2 weeks ago I thought I was out a few thousand bucks for a new transmission... today I have my car running again for a total cost of $44: 2 quarts of Redline MT90, one new trans drain plug and gasket, and one 24mm end wrench that I had to buy to get the drain plug off after I almost rounded it with the croissant wrench. And to be fair, I had 90k on the old transmission fluid and it was time to change it anyways.

Since I've seen other people on the internet with this same problem... hopefully it can come in handy for others in the future!! I will update it in a week or so or if anything changes. Thanks all for your insights (plus j3st3r for making those wonderful transmission threads).

bbsciontc

That's great to hear man! Huge thanks to j3st3r for his write up. So far it's been a huge help on my project as well.

minter66

iTrader: (2)

Thanks for letting us know the solution!

I halfway wonder if this is the reason I grind going into 5th too fast. I can shift slow (like you) and have no problems. Although, i've been doing it forever, and I have no clunking and I still have 5th (lol)

Was the syncro serviceable when you had it all apart?

bentheswift

You can access the synchro by removing the end cover, but I did not disassemble any of it. I've heard you can get it as well as the 5th gearset without cracking the transmission case, but have not verified that myself. I am still hoping to find a Camry or xB2 5th gearset and swap it on in place of the super short tC 5th gear some day, but that project is still a ways out.

My car never crunched or ground anything until maybe the last 5k miles. It started to crunch a little going into 5th but only if you shifted quickly. If nothing has changed, I wouldn't worry.

Also, my car has had a fair amount of gear whine since it was brand new, and this did nothing to change that.

bbsciontc

Yup, the 5th gear synchro set (clutch hub assembly) and 5th driven gear are accessible from popping open that same cover without having to open the transmission case.

For the clutch hub assembly, remove the retaining ring from the shaft, then use a harmonic balancer puller to pull it off the input shaft. The 5th "driving" gear slides right off below it. The 'driven' 5th gear needs to be pulled off the splined output shaft with a 3-jaw puller. This should be all you need to replace to use taller gears from a Camry.

Not sure how much of an improvement the taller 5th gear will be, as the final drive is really the biggest difference between the tC and Camry. I think changing 5th alone will be a pretty subtle difference. It would however let you retain the shorter gearing in 1-4, which is pretty nice. I'm sure it will feel down on power when I'm done, but that's what the turbo is for!

bentheswift

Well, very odd. It drove great this past week, but yesterday when coming home from work, it started doing something odd. I had it in fifth, and when I gave it full throttle at about 55mph, the transmission slipped. At first it felt like I had one wheel spin just for a moment, and it was almost freezing out so that's what I thought had happened, but then I realized that it would do it once every couple of seconds at WOT in fifth, but not in any other gear. It makes a funny noise that I could have confused with a tire spinning on pavement. But it's clearly not a traction issue.

If I didn't have a 5th gear problem two weeks ago, I would have said it was a funny clutch slipping problem, because those usually only happen in fifth too. But it doesn't feel like any slipping clutch I've felt before, it happens for a moment and then not again, whereas slipping clutches usually just let the revs creep up at WOT in fifth.

I haven't done anything to the car since putting it back together except for drive it, so I'm gonna take it into the dealership and ask them to spend an hour on diag. The local Toyota dealer has helped me once before when I had a really odd problem that I couldn't figure out.

Will update... Bummer...

bentheswift

Well after 3 more days of commuting, I can't duplicate the problem. My only guess is that there was some black ice on the ground as it was about freezing and there was a freezing rain advisory. Plus, I can't figure out in my head how a manual transmission could possibly slip like that. So even though it seems all wrong in my head, until I experience the problem again, I'm not gonna worry about it.

Taintstick

I have the same problem with shifting into 5th. It scares me because I had a zx2 that grinded similarly into 3rd and that tranny lasted me 2 months. I have mixed results some of the time which confuses me even more. It happens every time I go to 5th normal shifts or quick shift above 80mph, i have to go real slow and let the RPM drop almost to idle. Anything under 80 doesn't grind unless i throw the shift absurdly fast. It didn't start until 70ish thousand miles, I'm up to 92K now but i have been cautious slamming 5th. Its parked for the winter, if you guys find a solution plz update.

bentheswift

Based on my experience, my car developed the crunch when shifting quickly into 5th, and then within 5k, maybe 7k miles at the most, 5th gear died. So I would guess if you've had the problem for 22k miles that it most likely isn't related.

Like I said, I've done a lot of googling and have found only 3 other instances of people with the same symptoms as I did on the internet... so it's obviously a very uncommon problem. If you have the problem I had, then it's an easy fix... and if you don't, there's no reason to suspect that your transmission is going to break on you. Serious manual transmission problems aren't exactly commonplace on these cars.

06ScionTc5sp1

Wow, seems like we all having the same issue with older models. I just bought an 2006 Scion Tc about a month ago and it does have 158k, yes I should had bought something newer or brand new but, can't afford higher payments at the moment. At first, I thought it was just me tried shifting at an higher speed like 60 mph but, then finding out 5th gear works best at 58-59mph without a grind. It is odd too, even tried shifting in 5th at 55 but, it grinds. So, guess we know now, what the problem is. Thanks for the pic and youtube info, it will certainly help when I get the chance to fix the 5th gear hub, if can be able to get to sooner. However, with my work schedule is, kinda doubt it, til' Spring.

bbsciontc

Wow, my car just did this last night too. I was a little hasty and grinded third a little, so I double clutched and shifted back in. When trying to accelerate, the engine revved but the car didn't really move, like the clutch was slipping. I instinctively switched into 4th and it continued to slip on me, so I was thinking my clutch went, but shortly after it resolved on its own. I gave full throttle in 3rd through 5th afterwards and the clutch held just fine.

When I came to a stop, there was a definitive burning smell, likely from the clutch. Took a few minutes of driving to clear the smell out. I'm gonna keep an eye on it to make sure it's gone. This is with the original trans and clutch, so I guess I'll take care of it when I get around to installing my LSD trans and clutch/flywheel in the spring. It felt very weird though. I've owned this car new since 2005, and this is the first time it's ever happened.

My theory is that maybe grinding third somehow caused the clutch disk to temporarily bind to the input shaft of the trans, and the pressure plate was unable to properly seat it against the flywheel. After a few attempted shifting cycles, it may have worked its way back into place and resolved itself.