Jump to content
SAU Community

Recommended Posts

Hi all, I’ll start by introducing myself I have been reading through your threads and even though I’m a member of another forum this one seems to be the most informative :wave: I have, as you can see from my aviator, a r33 gtst S2. I’m in the UK and have a slight problem maybe you could be kind enough to point me in the right direction.

The question is…. My mota has, since I bought it 2 months ago, “a crunch” changing from 1st to 2nd mainly at high revs and when cold, sometimes it’s a bit of a struggle to get it in.

I thought that the clutch maybe on its way out but it only does it from 1st > 2nd

Any advice would be appreciated

Shaun. :)

Link to comment
https://www.sau.com.au/forums/topic/142512-gearboxclutch-problem/
Share on other sites

I think it might be your syncros on 1st and 2nd gear, reason been they are the most gears been used, i dont think it matters that much, it depends how bad they are, try using redline oil might help it abit, or you could get them changed, it might cost you abit tho.

"high revs" and "cold" don't really go well together. The synchros are on the way out, and the more you combine "high revs" and "cold", the faster they will degenerate.

I have a similar problem going from 3rd to forth and 5th to forth at high speed and RPM.I think its my clutch? Also the take up point is really high.????

"high revs" and "cold" don't really go well together. The synchros are on the way out, and the more you combine "high revs" and "cold", the faster they will degenerate.

Hi this may help, and i tend not to rev her hard when cold ;-)

When Cold

Crunch at any rev range from 1>2

When Warm

Crunch at high revs 1>2

no crunch when at low revs

Edited by Spinky

Sounds like synchros to me from that clarification.

Remember that it is a often used gate AND it is the largest relative speed difference in the gearbox. (Largest rev difference from 1st to 2nd) so they work hard. Shift slow and feel the gate "open" when you change. No dragging from the lights for you anymore :laugh:

Throw some new oil in and check the clutch is releasing fully.

Edited by simpletool

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

    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
    • For race cars, this is one part where I find having the roll cage bar having gone through a hole in the floor better than the build it up on a ledge inside... The Merc I help on, the main hoop ends are marked on the car, and the jack is marked... Jack goes under a few inches and lifts one whole side of the car up... Removes that fight for long slim jacks for race car duties!   My biggest issue for the daily drivers I work on, is my jacks don't go high enough. The jacks start out on a few blocks, jack it up, then start a second jack under it on more blocks, and then I can get an axle stand under it. My axle stands are presently in use, and are nearly fully extended. The car is sitting with barely more than a cm of clearance to get the wheel off the studs! Sarah's Kluger is the same, as it has an ungodly amount of droop available in the suspension and a distinct lack of good jacking points!
    • Happy? Yep, my to do list is getting shorter and shorter. Either this light approaching is the end of the tunnel, or I'm about to be hit by a train... Ha ha ha   Also, Duncan isn't that far out of town that you need to make a multi day drive out of it. 😛
    • Sorry I meant that we are building the EH for a client.
    • LOL, when one "money pit" is never enough Noice, and excellent work mate
×
×
  • Create New...