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-   -   Clutch/Transmission issue (https://www.rx8club.com/series-i-tech-garage-22/clutch-transmission-issue-239207/)

wrightcomputing 10-14-2012 05:25 PM

Clutch/Transmission issue
 
I am having some issues with my clutch/transmission.
Symptoms
  • Car lunges forward about an inches when engaging 1st gear from a stand still - Happens every time and also happens with other gears
  • Grinds and goes into gear when down shifting to 2nd (rev matching) - about 1 in 5 times
  • Grinds and locks out when shifting to 2nd from 1st at high speed (autocross launch) when you shift too quickly - usually co-drivers but occasionally it happens to me also
  • Grinds when shifting into 5th occasionally.
  • The car seems to move forward in neutral - I had the car on jack stands and in neutral the wheel turn forwards. I can stop the movement by touching the wheels with my hands but they definitely move.
Steps takes to resolve
  • Stainless steel clutch line installed and bled clutch system
  • changed transmission oil (I used mobil, based on research I will switch to Redline or Eneos)
  • Adjusted clutch pedal up and down (no real change to the grinding)
Other possible solutions :-(
  • new transmission
  • better oil


I think changing the Oil may help with some of the grinding but would that make any difference to the car lunging forward.


As always any help is greatly appreciated.

wrightcomputing 10-14-2012 08:10 PM


Originally Posted by Charles R. Hill (Post 4366796)
What is meant by this? Did you adjust the pedal height or the pedal free-play?

I adjusted the free play to virtually zero and the added about 4 turns to increase the free play. It did not seem to effect the grinding either way.

It is feel like the Clutch is not full disengaging when the pedal is pressed.

I forgot to mention that I have the Exedy Stage 1 Clutch (Same as OE with more pressure) which is about a year old maybe 15K.

Sugarfree135 10-14-2012 09:20 PM

I wonder if your clutch fork may be bent not allowing full disengagement. Regardless the fact is the clutch is not disengaging fully. If you put it in nuetral and rev it does it move forward? The only thing I could suggest is replacing the cmc and slave. It should be done when you replace the clutch anyway most people dont realize this. It especially holds true when upgrading to a stiffer pressure plate because the system is stressed more upon installation of the new clutch and pressure plate.
I've seen this happen on one of my old dsm's and on a close friends civic si. It's not that expensive or difficult to fix don't worry ;-)

wrightcomputing 10-14-2012 10:03 PM


Originally Posted by Sugarfree135 (Post 4366846)
I wonder if your clutch fork may be bent not allowing full disengagement. Regardless the fact is the clutch is not disengaging fully. If you put it in nuetral and rev it does it move forward? The only thing I could suggest is replacing the cmc and slave. It should be done when you replace the clutch anyway most people dont realize this. It especially holds true when upgrading to a stiffer pressure plate because the system is stressed more upon installation of the new clutch and pressure plate.
I've seen this happen on one of my old dsm's and on a close friends civic si. It's not that expensive or difficult to fix don't worry ;-)

Thanks for the advice. I will replace the Master and slave, can you get in to the slave without lowering the Transmission its a bit tight up there?

Sugarfree135 10-14-2012 10:24 PM

I've had my 8 for a little over a month so I'm not sure on this car lol From what I saw before you should be able to get to it as I could see it but that doesn't mean anything :-P lol

Sugarfree135 10-16-2012 07:23 AM

Good point Charles I had forgotten about that issue on these cars.

04Green 10-16-2012 12:56 PM

Also, that clutch will require you to raise the pedal. I think free-play is the adjustment farthest from the firewall, pedal height is the one closest. I have that clutch and had to mess with both.

Just be happy the damn thing does not release itself at 8,000 rpm... I had to take mine back out and shim it.

The move in neutral thing is interesting though... Maybe really dirty or sticky oil?

wrightcomputing 10-16-2012 05:58 PM


Originally Posted by 04Green (Post 4367758)
Also, that clutch will require you to raise the pedal. I think free-play is the adjustment farthest from the firewall, pedal height is the one closest. I have that clutch and had to mess with both.

Just be happy the damn thing does not release itself at 8,000 rpm... I had to take mine back out and shim it.

The move in neutral thing is interesting though... Maybe really dirty or sticky oil?

It is really slight hardly noticeable but it is there and it does not increase if I rev the engine. I think I need to adjust the clutch some more and I believe there is still some air in the line so I will bleed it again at the weekend once it has settled.

I have ordered a new CMC so I will install that and see if makes a difference.

wrightcomputing 10-20-2012 11:38 AM

Well I have changed the Clutch Master Cylinder and bled the system. heT car is still rolling forward in Neutral, its really weird because if I rev the engine it does not affect the speed at which the car rolls forward which is very slowly.

I have checked the brake pedal assembly and there are no signs of cracks or bending or anything else that would affect the the clutch operating correctly.

The car still grinds in 2nd gear when shifting down from a higher gear.

dannobre 10-20-2012 12:03 PM

The only things that would allow forward movement in neutral are friction from the oil transferiing power to the final gears.....or something in the transmission rubbing/bent that is allowing the transfer across the gear train.

The grinding going into gear, and on shifts could be a syncro or a problem or a problem with the clutch dissengaging completely as long as the driver imput is correct ;)


With the gear oil that I run...on a lift with the tranny cold...the rear wheels will turn slowly until the oil warms up considerably....

wrightcomputing 10-20-2012 12:13 PM

Good to know about the transfer to the higher gears with the cold oil, that makes sense. I will get some redline MT90 and try to put that in after that my only other option is the slave cylinder, then I have to crack open the tranny to check for a bent fork or forked transmission.

dannobre 10-20-2012 12:19 PM

It sounds to me like your second gear syncro is done as well ;)

NO_PSTNS 10-20-2012 05:26 PM

What is the best way to tell if you need to have the clutch shimmed if you’re installing a new clutch at the moment? Or do you find out when you drive it?

wrightcomputing 10-20-2012 05:39 PM


Originally Posted by dannobre (Post 4370412)
It sounds to me like your second gear syncro is done as well ;)

If the syncro is done I need a new transmission correct?

Sugarfree135 10-22-2012 12:39 AM


Originally Posted by wrightcomputing (Post 4370501)
If the syncro is done I need a new transmission correct?

No sir not at all lol just a tear down and replacement. Might as well do them all at the same time and freshen up bearings and etc. but it all depends on how much money you want to spend ya know. Syncro is an easy fix though, more labor intensive than anything else :-P

wrightcomputing 10-22-2012 06:50 AM


Originally Posted by Sugarfree135 (Post 4370953)
No sir not at all lol just a tear down and replacement. Might as well do them all at the same time and freshen up bearings and etc. but it all depends on how much money you want to spend ya know. Syncro is an easy fix though, more labor intensive than anything else :-P

Do you know how much the parts will be to for the synchro and bearings. I found a kit for $1300 and $950 which seems very expensive. I can get a replacement series 1 transmission for about $800 or preferable a series 2 for about $1200 and then I don't have to worry about making any mistakes.

I also think this is a job I need to do myself as taking of the tranny is lots of hours labor before any work is even done to it, I have taken it off before so it is no big deal. I would also change the clutch and flywheel too if I had it open so that's an additional $400+ dollars

04Green 10-22-2012 07:15 AM

@ No_Pstns... On stack height....

When you take it apart, observe the slight dome formed by the fingers in the center of the pressure plate before you remove it from the flywheel. If you can measure it at the center most part of the finger, and at the edge to get the profile, great, if not, take a picture from an angle. You want about the same level of doming (crowning?) with the new one. If they are flatter, that is where the issue can come in. Mine were pretty flat, with the washers / spacers the dome came back. I have an Exedy Stage 1.

FWIW, In hind sight, I would rather have put in the OEM style for a tad lighter pedal, but it is what it is. I did not consult the group before the purchase. I am incredibly happy with the light flywheel thought.

dannobre 10-22-2012 03:28 PM

The syncros aren't that expensive to replace if you can do it yourself...but the labor to have someone else do it is where it gets pricey.

I think that the parts to do the bearings and syncros is only a couple of hundred $ if the gears are all OK


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