R34 Gtt 5Th Gear Resistance / Very Slight Crunch Sound - Redline Shockproof Help?

[iwanta34gtr]

Hello every1,

I have been researching redline shockproof because my R34 GTT 5th gear gives a bit of resistance when under any load and also gives a very slight crunch when shifting in to it.

When driving around town (50 - 60km/h and get in to 5th) its okay, when driving on highway (70 - 90km/h and get in to 5th) it will resist / slightly crunch.

Ive noticed that it only happens after around 15 mins of driving and the car is warmed up. Im thinking that it may be because oil thins when it warms up. It has 2.5 year old royal purple synchro max in it at the moment.

People on the forum have advised that redline shockproof will help with this.

I am going to buy some, have noticed that there are two types. What do I need for my car / problem - lightweight or heavy? Whats the difference?

And how much of it do u need for a R34 GTT box?

Or any other ideas to fix (apart from ripping the box out and replacing the synchro) would also be appreciated.

Thanx heaps in advance for the direction with this.

Edited October 17, 2011 by iwanta34gtr

[Little]

hey dude;

One Galleon bottle will do it for the redline oil. I found i had a small amount left after.

Most people use the lightweight; including myself. Not sure about the differences between light & heavy though

With your box... Most likely it's the fifth gear syncro.

I myself am in the same boat; i will need a gearbox recondition soon.

No way around it. It costs money.

Lots of it.

The other thing i've been told by people is the longer you keep driving with worn syncros the more damage you do to the gears and then the repair job becomes

exponentially more expensive.

Out of curiosity; how many km's have you done?

I'm at 125,000 and Pretty much all my syncros need replacing.

[iwanta34gtr]

Hi mate, Thanx for the info.

My car has 93,000 on the clock. Its been tracked quite a bit though.

Im pretty sure that the heavy shockproof is for boxes which are already crunching. But need confirmation on this.

Id like to give shockproof a go because the resistance / crunch is not really that bad and only happens when the cars been running and heats up.

Edited October 17, 2011 by iwanta34gtr

[Moodles2]

Heavyweight is for gearboxes that are f**ked already, lightweight to fix existing crunching

[iwanta34gtr]

Hi Moodles2, thanks for the post. Please define f*cked. I did some research and was actually going to go heavy as it i thought it was for problematic boxes (like mine is?)

[10 4]

Stick to lightweight.

[Moodles2]

Heavy IMO is for gearboxes that crunch every gear no matter what.. the type of gearbox that needs replacing or a rebuild ASAP but you want to mask the problems (ie. don't want to hear the crunching anymore). Heavy will mask the crunch, light will prevent it happening (did in my case)

[iwanta34gtr]

Thanx guys,

Im pretty sure 5th synchro is rooted and box needs a rebuild / new synchro to fix it. Was only wanting to go heavy mainly because I dont want 2 hear the crunch or get the resistance (which hopefully guranteed to stop it with heavy).

Just didnt want to go putting in lightweight and then having no improvement and needing to get heavy anyway.

What threw me off is that when I read about the lightweight it says "It has excellent low-temperature flow which allows easier shifting when cold." and my box is fine when its cold its when it warms up a little bit and you see the fault.

I wonder if there is anything wrong with skipping lightweight and jumping straight in to heavy when all other synchros are fine?

Will take ur guys advice and go lightweight though.

Edited October 17, 2011 by iwanta34gtr

[iwanta34gtr]

And was also thinking, when i do put the lightweight shockproof in.

After draining the existing oil, would u guys recommend completely cleaning / flushing the box out or is this not really necessary?

[Little]

Hmmm... I'm not sure... Look i don't think its neccesary; when you take that bottom bolt out it's at the lowest point and it all comes flooding out. I don't think you need to do much more than let it

drain for a while. Just don't get the shit on your clothes the smell will NEVER come out.

[iwanta34gtr]

Hi every1,

I got redline lightweight shockproof today and put it in my box. Since then the resistance, crunch, vibration in to 5th has stopped (touch wood) and every gear seems so much smoother.

Just wanted 2 say thank u 2 Little, moodles2 and 10 4. I really appreciate your advice and help with this thanks so much.

[Hanaldo]

Just warning you now, it will come back.

It's not exactly a big problem though, you need to keep in mind that 5th is your cruising gear, it's the smallest gear in the set and doesn't like going into gear quickly. So when changing to 5th, just do it smooth and slow. The majority of RB25 gearboxes will all do this, they are just big heavy boxes.

[iwanta34gtr]

Yeah I understand mate, its not a permanent fix.

I've heard from some people that it can last years before it does come back (if it does) though.

What time frame would you put on it?

Edited October 19, 2011 by iwanta34gtr

[KiwiRS4T]

Just double declutch in and out of 5th and it will last forever.