Crunching gears - Synchro Questions

[kraiye]

Hi all,
My EM1 box has just started crunching when changing from 2nd to 3rd. It's fine when I double clutch or am shifting down from 4th.
Just wanted to know how hard is this to fix and what's involved? Do I have to pull the whole box apart? :o

[mr180sx]

try changing gearbox fluid first

[I heart the SSS]

As above, try a lightweight box oil

VMX80 works well in tired nissan/toyota Boxes.

You could also add a tube or two of Nulon G70 to your box with fresh fluid.

[90LAN]

As above, try a lightweight box oil

VMX80 works well in tired nissan/toyota Boxes.

You could also add a tube or two of Nulon G70 to your box with fresh fluid.


probraly diff weight justin
hondas rev a bit more so they need a bit more protection
check out my eg6 thread
i had to change my gears
shows you whats involved

[Benson]

We used VMX80 in all our gearbox's, even for racing! Very good quality oil

Heaps better than OEM

[kraiye]

thnx but no thnx guys.
box fluid was changed not long ago and i'm not after a temp fix.
maybe if it was a gradual thing i could stretch it out but it came on suddenly, like one day the box was flawless and the next day 3rd is fked on up-shifts.

[delsol9000rpms]

*Change your gearbox oil (Castrol VMX80 is good.. its cheap too)
*bleed your clutch...

Expensive but propper fix would be to pull the gearbox out and apart and rebuild it...

[Benson]

Go to Castrol Syntrax

Doesnt hurt trying! Can always reuse the fluid later on

[MRK20CRX]

none of the suggestions will work, it will only be a band-aid fix, until it screws up again, my advice is rebuild the box

[kraiye]

thanks everyone
i'll do the fluid for now anyway and see if that helps until i can rebuild the box

2 more questions:
any idea what parts would be required? or would that need to be worked out when the box is apart?
and is there anything i should upgrade while the box is out? (possibly looking to boost it in the future)

[fatboyz39]

changing @ low rev or high revs?

Most likely worn synros. I would replace bearings and seals. Upgrade to a 4.7 or 4.9FD.

[Lukezen27]

I've tried all the diff oils and even automatic oil

Nothing works that well but half OEM and automatic oil seems to be OK.

Only really crunches down from fourth to third but not to bad going up gears..

One thing though

At the Creek last week hit'n it hard not one crunch changing at high RPMs \

What's with that?

[Mikecivic78]

Sounds like the 'box is on its way out. Ur symptoms sound like classic 'box wear symptoms. It's been driven hard (or badly) and it's time for an overhaul in the near future. Start savin' beans.

[kraiye]

probraly diff weight justin
hondas rev a bit more so they need a bit more protection
check out my eg6 thread
i had to change my gears
shows you whats involved

started researching gearbox rebuilding :thumbsup: lol

ta lan. hey did you guys use a press to get the gears apart? if not, how'd u do it?

anyone know if kits are avialable?

btw: fluid change fixed crunching 2nd to 3rd but 2nd gear synchros or shot!
now have grinding from 1st to 2nd and 3rd to 2nd (3rd to 2nd sometimes won't go in at all :thumbdwn: )


oh yeah... where do you buy and how much is a 4.7fd ?

[Lukezen27]

I just got my box done

Bloody love being able to change smoothly through all gears :thumbsup:

[kraiye]

how much was your box luke?

priced parts... holly crap! 1&2 synchro $6xx, 3&4 synchro $4xx.
over a grand just for synchros alone! then there's bearings at approx $25 each!!



or DIY kit from the US... bearings, seals, synchros... $600 landed :thumbsup:

[Lukezen27]

how much was your box luke?

priced parts... holly crap! 1&2 synchro $6xx, 3&4 synchro $4xx.
over a grand just for synchros alone! then there's bearings at approx $25 each!!



or DIY kit from the US... bearings, seals, synchros... $600 landed :thumbsup:

scored a good nick second hand B18 box set for $150 plus $650 installed :thumbsup:

[dougie_504]

I also used Castrol VMX80. Great for shifts, and also for cold-shifts :)

[lookingforboost]

dam.... box parts a dear :(

[kraiye]

dam.... box parts a dear :(

only if you buy OEM from Honda! found a good site in the states though...
http://shop.synchrotech-transmissions.com/

[kraiye]

Anyone know what size gear puller/s to get?

[paps02]

instead of starting a new thread.... bringing this one back to life.

got problems 2->3, 4->5... about to try an additive(aparently helps the synchros) with a g/box oil flush... will report back with results