: gear grind issue redux



RADEoN
02-01-11, 11:16 PM
Well as some of you may have read in the past, I've been having a ton of trouble with my 04 CTS-V and grinding into 1st and 2nd, as evidenced in this video:


http://www.youtube.com/watch?v=RtNQEpZGjIc





Well, it started out occasionally grinding into 1st gear when rolling to a stop sign, I'd stop, and it would slide right into 1st gear, no problem. It later progressed and got worse and worse, and I eventually had to go from 4th into 1st.

People argued whether or not it was a dragging clutch, or the syncros. I finally settled on dragging clutch, and PISNUOFF/07CTS-V put an LS7 slave, clutch, pressure plate, flywheel, and bleeder extension in. After all this, the issue persisted. Oh well, time for synchronizers.

I drove the car and ground into gear as little as I could, after all it was getting harder to get it into 2nd gear.

A mechanic at a shop I deliver told me it sounds like I didn't get a good bleed on it, and that there's air somewhere in the system. I figured he wasn't sure what I was talking about, and it was still the syncros. Well, I held onto a shred of hope, and while researching new master cylinders, I saw how to bleed one with a mighty vac.

There was a ton of air coming out. I jammed the hose and needle into the fill port hole, put some fluid so it didn't suck air when I pulled it out, and this is what I saw:


http://www.youtube.com/watch?v=Tt438ek38z8


Wow, there's a lot of air to be had! I did that two days in a row, and there was a lot of air both times (but it seems to have been gone immediately after).

Well, my pedal was engaging halfway to the floor, which sucked, but it wasn't grinding nearly as much.

Tonight, I was driving, and I went to put it in 1st gear, and it wasn't working at all, no matter what I'd do I couldn't get it into gear. I'd push with the power of thor, but alas, nothing. Clutch in, clutch out, car on, or car off.

I figured my syncros were finally spent, and I drove the car to my garage to store it until I felt like pulling the trans. While I was there I decided to bleed it from the bleeder extension. I jacked the back half of the car up (is the fluid movement like this relevant?) Man, there was a lot of air to come out of it. I had a friend hold the pedal down, I'd open the bleeder, get a spray (is the spray normal? or should it drip and ooze?), and we did that a few times, and wow, my car not only can go into 1st sometimes now, but it doesn't grind into either 1st or 2nd, but it's a complete bitch to get it into 1st.

So after all this long winded bullshit that you probably didn't want to read, what do you think? Do I yank the transmission, or do I go with a master cylinder?

CadzillaTN
02-01-11, 11:48 PM
You have a few things on the radar, how are your mounts? Crapped out motor mounts will cause the same symptoms. Can you rev it a bit to make for smoother entry? Not necessarily rev matching, just enough to move the engine to it's proper position and allow it to slip into gear. Mine is acting like that now, and I too have bled my clutch twice recently.

I'll be putting new mounts in soon, and I'm going to enjooy that smooth shifting.

perfect
02-02-11, 01:58 AM
I'm definitely not a clutch expert and can't tell you the difference between a master cylinder or synchro issue...

but, I can attest to Cadzilla's post that motor mounts can cause some problems with our transmissions. I was having all kinds of difficulties with my transmission (grinding, inaccessible higher gears, and slipping out of gear). I thought for sure my gearbox or clutch was shot but KC Superior Cadillac accurately diagnosed the problem as busted motor mounts.

Good luck either way, that sucks.

WesH8398
02-02-11, 06:31 PM
Motor mounts may not solve your problem. My MM's were shot when I bought the car last year, and the shifting also wasn't that great. On cold mornings the first couple 1-2 shifts would give me a little grief (slight grinding), and I was also being "blocked out" of gears at seemingly random times. While coasting to stops or turns and trying to downshift, I would often find it difficult to get into 2nd (and sometimes other) gear(s). I found that a blip of the throttle would usually line things up and get me into gear quite easily, so I figured the MM's were causing these issues as well. Well, I'm now on my 2nd set of CS MM's and neither set has relieved the shifting issues. I'm currently still trying to figure it out. Thankfully, the car is still very driveable. It just bugs me.
What did help a lot was changing my fluid, which it sounds like you've done a number of times with all the bleeding you've done. I did my fluid change with a "Motive Power Bleeder" which was about $80 after proper adapters (for brakes and clutch) and so on, and I put Amsoil fluid in it. Made a good difference, but the issues are still there.

Hope that helps a bit, although it doesn't provide any answers.

CadzillaTN
02-02-11, 08:51 PM
I'm going from fubared cs mounts to stock mounts very soon. I'm expecting it to shift perfect afterward! I'll let you know.

Even when everything is right, I still expect 'tougher' shifting on cold days until tranny warms up. I think it's a characteristic of the drivetrain. For example, it was 70 this weekend. I could start the car, leave right away, and shift gears on my street. When it's 25 degrees ill warm her up for 10 minutes and still can't get into 2nd or 4th for a half mile after I leave.

WesH8398
02-02-11, 10:32 PM
Neither of the 2 sets of perfectly good CS mounts changed much/anything for me in terms of shifting issues, so don't get your hopes up.

CadzillaTN
02-03-11, 12:17 AM
Oh they're up!.. I've been through this a few times before and it's been the mounts or the clutch fluid. I'm also fairly sure my diff bushing is shot although the diff is only 2.5 months old. They must go bad almost immediately.

darkman
02-03-11, 07:05 AM
Motor mounts may not solve your problem. My MM's were shot when I bought the car last year, and the shifting also wasn't that great. On cold mornings the first couple 1-2 shifts would give me a little grief (slight grinding), and I was also being "blocked out" of gears at seemingly random times. While coasting to stops or turns and trying to downshift, I would often find it difficult to get into 2nd (and sometimes other) gear(s). I found that a blip of the throttle would usually line things up and get me into gear quite easily, so I figured the MM's were causing these issues as well. Well, I'm now on my 2nd set of CS MM's and neither set has relieved the shifting issues. I'm currently still trying to figure it out. Thankfully, the car is still very driveable. It just bugs me.
What did help a lot was changing my fluid, which it sounds like you've done a number of times with all the bleeding you've done. I did my fluid change with a "Motive Power Bleeder" which was about $80 after proper adapters (for brakes and clutch) and so on, and I put Amsoil fluid in it. Made a good difference, but the issues are still there.

Hope that helps a bit, although it doesn't provide any answers.

I agree this problem is most likely a clutch hydraulics problem - either the bleeding is not done yet or a there is perhaps a master cylinder problem. If the synchros are a not problem yet they will be if the hydraulics aren't fixed.

I can't quite get to the motor mount theory since the transmission is bolted to the engine - with bad motor mounts the two still move in tandem. The motor mounts can cause shifting problems under heavy throttle if the motor/transmission rotational forces cause the shift linkage to bind, but from the decription I do not think that is what is going on here.

PISNUOFF
02-03-11, 09:11 AM
^^^^Agreed. I've driven it and there wasn't a bind in the linkage when first gear was grinding.

WesH8398
02-03-11, 10:14 AM
I can't quite get to the motor mount theory since the transmission is bolted to the engine - with bad motor mounts the two still move in tandem. The motor mounts can cause shifting problems under heavy throttle if the motor/transmission rotational forces cause the shift linkage to bind, but from the decription I do not think that is what is going on here.

Dito.

Cadzilla - I had the same hopes, believe me. You're setting yourself up for a big let down, unfortunately. If your new mounts make fools out of all 3 of us, make sure you post back!!

CadzillaTN
02-21-11, 12:58 AM
Dito.

Cadzilla - I had the same hopes, believe me. You're setting yourself up for a big let down, unfortunately. If your new mounts make fools out of all 3 of us, make sure you post back!!

no let down... I got major success with my mount swap this weekend, 85% improvement. I didnt even have time to bleed the clutch again (I assume the last 15% of my issue) before I test drove it 30 min ago...

one pic to support my opinion..consider engine ride height and security (no up and down or side to side motion), and how it plays into a successful shifting operation...then look at these mounts. What you see is a used but still working stock mount on the left, one of my removed cs mounts in the middle, and one of my new stock mounts on the right.

http://i1027.photobucket.com/albums/y332/memphisctsv/IMG_3564.jpg

kevm14
02-21-11, 08:12 AM
I know this isn't a MM thread but has anyone tried these?

http://www.rockauto.com/catalog/moreinfo.php?pk=2744588

$120/ea. Not any cheaper than stock, right?

Cadzilla, have you tried the CS black mounts?

CadzillaTN
02-21-11, 02:42 PM
I know this isn't a MM thread but has anyone tried these?

http://www.rockauto.com/catalog/moreinfo.php?pk=2744588

$120/ea. Not any cheaper than stock, right?

Cadzilla, have you tried the CS black mounts?

Never tried them, I was about to buy a (discounted) black set to replace my greys when I learned of the design and felt it wasnt the best choice despite price or positive reviews..

Those you posted look well thought out but I'm not sure anyone is running them.

I've seen stock mounts for sale btw 90 and 180 each, online.. Never checked the dealer cost..

RADEoN
02-21-11, 03:50 PM
Cadzilla, you're gonna need a tranny soon I bet.

Got my tranny rebuilt this week, still waiting on the replacement reluctor wheel, then I will have my very own smooth shifting CTS-V again.

CadzillaTN
02-21-11, 04:25 PM
Well, that's bad news. Not for me, for the boys at gmpp!

CancerJCC
02-21-11, 04:53 PM
I would say if Brian helped you out and drove the car then take his opinion. He can offer you way more than we can on here from actually knowing how the car feels and comparing it to his and his experience.

Also you should be able to personally feel whether it is the hydraulics (clutch not letting go completely) or an actual blockage of syncros etc internal to the transmission. And of course I just realized this thread is getting a bit older....did you figure anything out?

PISNUOFF
02-21-11, 05:16 PM
It never really felt like a hydraulic issue to me, but it was worth the effort to swap the master and slave just to be sure before spending money on rebuilding the trans. First and second gear synchros were completely broken. In case anyone is interested, the blocker rings were paper.

RADEoN
02-21-11, 05:20 PM
yeah my blocker rings were all paper, but now they're carbon fiber.

i should also note that the LS7 slave we installed was actually leaking too, hence why all that air was coming in through the lines and I was leaking fluid. I replace the master thinking it was the issue.

Luke really took care of me when I needed that part replaced. Sent me a new one out that day, and I got it sent back to him the next day.

Yet another reason to buy parts from him.

CancerJCC
02-21-11, 05:26 PM
Well glad you got it taken care of anyhow!

RADEoN
02-21-11, 05:49 PM
hehe i'm not out of the woods yet.

transmission is sitting on my garage floor with the tailshaft and shifter off of it while I wait for the parts to come in.

CadzillaTN
02-21-11, 06:03 PM
Pisnuoff has some nice brass bushings for sale that go in the shifter mints on the tranny. Definitely part of the overall effort to tighten up shifting.. You may want to get a set since it's out of the car..

RADEoN
02-21-11, 06:11 PM
Brian is PISNUOFF.

I was his guinea pig on those bushings. Glad I signed up for the experiment.

PISNUOFF
02-21-11, 06:54 PM
LOL. He already has all the latest goodies. Besides the grinding, it shifts very tightly and precise. I guess that's one plus about having me live an hour away.

RADEoN
02-21-11, 07:09 PM
LOL. He already has all the latest goodies. Besides the grinding, it shifts very tightly and precise. I guess that's one plus about having me live an hour away.

<3

see you Saturday.

CancerJCC
02-21-11, 07:54 PM
hehe i'm not out of the woods yet.

transmission is sitting on my garage floor with the tailshaft and shifter off of it while I wait for the parts to come in.

Ah gotcha. Well good luck getting her back together!

CadzillaTN
02-21-11, 11:09 PM
Brian is PISNUOFF.

I was his guinea pig on those bushings. Glad I signed up for the experiment.

Yeah I failed nicely on that one lol.

On a lighter note I was just throwing some bones and im told my tranny is o-k.