Jump to content
SAU Community

Recommended Posts

hey all well we just finished a rb26 conversion in the ceffy and when it came time to put the car on the dyno the car would not disengage with the pedal all the way to the floor.

the clutch is bled fine, we are running a rb25 gearbox and a direct clutch services solid centre twin plate clutch + flywheel with the standard rb25 thrust bearing(new of course) + fork pivot(not spaced).

now we wound the adjustment at the clutch pedal to its maximum and this fixed the problem but the clutch pedal HAS to be touching the floor hard to disengage the clutch and over time obviously when the clutch wears slightly the same problem will occur so what can we do. also i am not going to risk things in regards to hard gear changes while the car is like this want it fixed before i start giving it a load.

to fix this problem i'm thinking maybe a spacer and upgraded fork pivot ??? or i have read about the use of different thrust bearings and carriers being used with all the jap brand clutches has anyone had experience with these particular clutches ???

also im thinking whilst this is going on mabey a braided line and by passing the jointing block would help things slightly ???

any help would be great

Hate to say it but I'd say its a gearbox out job. If the car still wants to "drive" with the pedal pushed in the clearances arent right. Was it a custom clutch? what pressure plate was used?

A mate of mine had some super duper custom twin plate for his XR6T and it took us forever to get it right. It took 3 different places to setup the clutch before the clearances were correct. Thats why i just go the jap stuff now :P

to fix this problem i'm thinking maybe a spacer and upgraded fork pivot ??? or i have read about the use of different thrust bearings and carriers being used with all the jap brand clutches has anyone had experience with these particular clutches ???

I haven't used this particular clutch but my exedy hyper twin i bought gives you the recommended sleeve length on the bearing carrier. The recommended length is 14-16mm, i don't know if that will be the case with your clutch. Here are all the nissan part numbers for different sleeve length bearing carriers. Hope that helps.

30501-A3800 12mm, 30501-N1601 14mm, 30501-U0200 16mm, 30501-S0200 18mm, 30501-B6000 20mm, 30501-S0160 22mm, 30501-K0404 24mm, 30501-K0510 26mm, 30501-N1600 28mm, 30501-N8400 30mm

no your money is mine i spoke too direct clutch and they designed the clutch to be used with the standard gear he said the only times they have run into trouble the solution is to re sleave the slave 1 size smaller to get more stroke

if they say OEM everything works and you've 100% checked everything between your foot and the slave (easiest and cheapest to do), and you installed a brand new clutch kit correctly (can't really go wrong much if you've got the box in and car running), then there's not much else it can be: fork/pivot/carrier/bearing :(

same thing happened to my gtr, bled it up and the clutch pedal was hard, and it would still be in gear when the pedal was pressed.. :P

had it towed to all brake and clutch and they removed and re-fitted the gear box and fixed the problem, $780 including the tow.. :P

turned out that my mate who had "worked in a gearbox workshop before", installed the twin plates wrong, they were facing each other instead of the oppposing each other.... :)

who installed ur clutch, because if u don't do it ur'self you never know??? :D

that's my 2 cents

I'd also be checking you haven't snapped the mounting brackets off the firewall for the clutch pedal...

I snapped the top one off with my setup, and could only JUST get the thing to disengage.

  • 1 year later...

Strange im having the same issues with the same clutch hmmmmm..... so bearing carrier lengthened will fix this hmm DSC told me bearing would be fine standard...which it isnt apparently

tried

replacing nismo slave with standard slave

replace braided line with solid

replace clutch master with another that worked in our track car.

spaced pivot ball out

removed dust plate from engine/box to get it closer.

was looking at cut and shutting the pivot ball to make it longer (got it spaced out 10mm atm to compensate for the 10mm thick adaptor plate (gearbox/engine)

bearing carrier will be a better idea by the sounds of it making it sit closer than the standard one im using atm...

OP what was your resolution to this problem??

Edited by xris
  • 3 months later...

As above ive got the same clutch and had the same problem with it as the OP. Now ive had my slave resleaved and it worked. BUT...it was super heavy and still at the bottom (about 15mm off the floor). short story engines bearings died and its apart again.

Now.....if i change the bearing carrier over. to a thicker unit will this increase the height of the release point? im looking at trying to make this more user friendly (hopefully i can change the bearing over and swap slaves back to normal and have not so much a 10kg spring to push.

will that fix my issue? and what is the standard sized bearing 12mm?

  • 2 weeks later...
  • 2 months later...

Sorry for the resurrection but it hasn't been dead for that long.. :P

Anyone know where I can source one of these smaller diameter release bearings/carriers? or have a part number?

Cheers!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...