z0stix

A very reputable shop installed an rxt clutch with steel flywheel, new gm pilot bearing and slave, it has 801 miles and has never been launched or abused since I'm still waiting on my weld drag pack, a couple of 3rd gear pulls but that's it...

Soo, I just starting getting this problem, when I take off in 1st gear, as I am slipping/releasing the clutch pedal there is a grinding noise coming from the shifter area.

It stops when i have fully released the clutch pedal and I'm in gear just driving

When I shift to any other gear, it will make the noise again upon releasing the clutch pedal

Also noticed if I am at a stop, with the car in 1st and the clutch pedal completely down, if I rev it up it will jump forward and make that grinding noise...

Sooooo, what do u think this is, pilot bearing? Master cylinder? Bad clutch??!!

NITRO UK

Hi
Might need bleeding , sounds like the clutch is not completely disengaging which might be why you hear the grinding .

And yeah shooting forward ,clutch in while reving is no good eh .

If it were me I would have a word with the shop that installed the clutch see what they say

If it does have to be taken apart again install a remote bleeder line if you don't have one already.

Just to add, did you change the master cylinder or is it original ? Might be worth looking at that first .

I'm sure it will get sorted , just a pita eh .

Update us when you have any info .

mate

z0stix

Original master cylinder, and it doed have a remote bleeder, I'll try bleeding it first

73Corvette

I'd say replace the Master... I'd also do some studying on the Tick brand.

Bill Curlee

CHANGE THAT MASTER CYLINDER and then bleed!!

Do it SOON as the longer you wait and drive the more damage that you are doing to the clutch and trans.

BC

z0stix

Quick update:

I flushed out the clutch fluid with the speed bleeder while refilling the little reservoir never letting it go empty...so I did that for a while...

It does not want to jump anymore while in 1st and reving it with the clutch pedal down

taking off in first still makes grinding upon releasing/slipping the clutch pedal

Once it gets going getting into other gears is normal....

After about 10 minutes of driving around my neighbor hood, the grinding noises have reduced greatly, but still not as smooth as before

I'm still going to replace the master though

racebum

is there a reason you never used an adjustable master with an aftermarket clutch

aftermarket parts don't fit like factory and don't have the same clearances. factory masters are made for factory clutches

RAM makes an adj factory master and tick makes one that flows much better but that larger piston can really increase effort

z0stix

I was told by others around this forum that the rxt was meant for stock master according to mcleod, anyways, already ordered a tick...hope it cures this

Chicago1

Mcleod does not recommend this. Their units are meant to be used on stock components and are built based on stock slave/master.to bearing, etc tec I love my RXT


OP I haven't looked through this just seen it..

https://www.mcleodracing.com/content...nter/tech-faq/

PEETYZ

OP,

How much power are you making and how long has it been since the torquq tube was checked or rebuilt? Do you have any vibration or high rpm shifting issues?

I hate to say it but i had a very similar problem about 3,000 miles after install then then the grinding went away. soon after that I had vibration at high rpm ( esp with clutch on the floor) and had difficulty shifting. I bleed it like crazy and changed the master cylinder still no luck.

Tore it all down and found my OEM 78k mile torque tube couplers had failed. They took out the pilot bearing and about $450 worth of rxt parts as well (front clutch disk and floater plate). The grinding noise was my clutch disk contacting the floater plate because of everything. My theory is the couplers got weak ( or drive shaft flexed) then it took out the pilot bear and clutch parts.

I hope this is not your case. PM me with your number if you want to chat via phone.

First question Mcleod asked me was what master cylinder do you have? They recommend OEM. You can run a tick however you must make sure it is adjusted perfect. If you are going to do a Tick the optional 3/4 Bore would be a better fit than standard 7/8 Bore.

Almost exact same thing happened to Ben before me. Thread here with pics https://www.corvetteforum.com/forums...rivelines.html

z0stix

I have 811 miles on the rxt clutch right now, nwver launched, just a couple 3rd gears pulls, not even going into 4th

Cars makes 648hp/530tq

Im getting into contact with the shop that did the install...of course they probably can't help me out

racebum

so basically they recommend the ram over the tick

still doesn't address pedal travel if the OP hasn't measured

aftermarket parts in general are off a LOT, would really never trust any brand without verifying

CTD

I re read your original post a few times, it sounds like a mechanical issue. Will throw this out there just as another idea, I had a clutch installed by a professional shop as you did. Some strange noises started happening, not bad noises but related to clutch pedal positioning.

Not going to get into a bunch of detail of symptom's, in the end flywheel bolts were not tightened & torqued. They backed out into the disc ............

I've had a rough go with clutches, my current McLeod RST works exactly as advertised. I do run their adjustable MC only because the previous clutch did not work as advertised. I'm not quite the power level you are at, just over 600/500.

PEETYZ

I honestly think your pilot bearing is toast. Not trying to blame the shop but if installed incorrect or it failed it will live for a bit but then symptoms will develop.

Best course of action would be to try bleeding, then pull inspection cover on the bell housing and look really carefully and check the torque on the pressure plate bolts. Mine appears to be fine with no leaks etc however upon closer inspection you could see the disk was contacting the floater plate straps just like the pics in bens thread I shared. I pulled it down and the news got worse. I hope yours turns out better. If your clutch pedal feels fine and clutch appears to operate fine with inspection cover off chances are your problem is deeper than just the hydrolics. Keep us updated and let me know if you have any questions.

-Pete

73Corvette

THIS and this...

racebum

agree with 73

haven't you ever installed a new clutch in a car with an adj master? this is exactly what happens when you don't have enough travel dialed in

aftermarket parts often require adjustment regardless of what they have in print

SaberD

It's obvious they didn't measure the pressure plate fingers to bellhousing distance to see if they needed to shim the slave. That's why the clutch isn't fully disengaging. Common mistake for a lot of shops even "very reputable" ones installing aftermarket clutches. Take it back and tell them to measure and add the proper shims.


From the Tick Performance website:

How to determine if a shim is needed for your setup:

During each and every clutch install you perform on a newer GM vehicle, you must measure to see if a shim is necessary for proper installation. This is done by taking two simple measurements (see worksheet):

1) Measurement "A" is the distance between the surface of the bellhousing that meets the transmission to the tip of the pressure plate fingers. To get an accurate measurement, the clutch must be torqued properly.

2) Measurement "B" is the distance between the throwout bearing surface to the transmission surface that meets the bellhousing. To get an accurate measurement, the slave spring must be removed and the bearing must be fully seated at the bottom of it's travel; resting on the slave's base.

Once you've got your two measurements, make sure that measurement "B" is ~3/16" to 1/8" LESS than measurement "A". If you come up with more than 1/8", add an appropriately sized shim between the slave cylinder and the transmission in order to get the measurements where they need to be.

Your “A minus B” measurement should be 0.125 to 0.200 for adequate bearing travel and to allow for clutch wear. If there is no difference between the two measurements, or if "B" is greater than "A", there could be a problem with clutch engagement which could result in premature clutch slip and eventually a total failure. Contact your clutch manufacturer before proceeding with the install.

73Corvette

While your there I'd ask if the match balanced your flywheel also...

PEETYZ

Wouldnt he have had this issue from the start if a shim was needed? Sucks but only sure way is to tear it down and see whats wrong.

McLeod has been very helpful to me. Yea I had to spend over $400 to get parts to rebuild mine but it wasnt the clutch's fault the pilot bearing and torque tube bushings failed.

SaberD

not necessarily would it be there from the start. the pressure plate adjusts as it wears and breaks in. there is also the unthinkable... if the clutch is dragging between shifts it puts major wear on the synchros since they aren't strong enough to control the rpms on the engine. Then they are shot in a very short time. Let's hope this isn't what happened. If it did cause transmission damage the shop may be liable.