R33 Gtr Gearbox 4Th To 5Th Crunch

[Ishman]

Hi there, bought an R33 GTR a while back but never checked gear changes at high speed. There is a crunch when changing from 4th to 5th above around 130kmh, especially under load. Apparently this is a common problem to check with these cars What I'm wondering is- what does this mean for the health of the gearbox? Otherwise it seems fine.

[lachlanw]

means 5th gear synchro is worn out .

have you tried putting some decent oil in it ?

learn how to rev match

[Ten Four]

Redline lightweight shockproof gearbox oil.

Get some off Harold from PerformanceHub on eBay.

Mate had exact same problem, the above fixed his.

Not cheap, approx 120ish?? for the oil, but definitely worth it, don't skimp on cheap shit.

[Birds]

Redline lightweight shockproof gearbox oil.

Get some off Harold from PerformanceHub on eBay.

Mate had exact same problem, the above masked his.

Not cheap, approx 120ish?? for the oil, but definitely worth it, don't skimp on cheap shit.

FYP

[Ten Four]

I wouldn't say masked.

It could have never been changed and its low on fluid etc causing it to crunch.

Edited March 11, 2011 by Ten Four

[R31Nismoid]

You'll find just about all boxes will if you try too fast of a gear change. Same with my RB25 box in my 31 and the GTR.

4th to 5th demands you be a little slower I've found for whatever reason. It is the smallest gear too remember.

Doesn't do it if you just give it that half second longer.

[Ziller]

Its a bit late to put good oil in now, had the same problem, need new syncro's

[Ishman]

Thanks for the feedback guys; hadn't logged on since I posted sorry. Sounds like I should just take it a bit easy on the 4th to 5th- it's not like it doesn't go fast enough in 4th. I'll try and get my hands on some of this high quality gear oil in the mean time. Are you saying that even with the right oil and a lack of abuse it may still crunch a little if changed too fast, in which case there may be nothing wrong?

[Ten Four]

Thanks for the feedback guys; hadn't logged on since I posted sorry. Sounds like I should just take it a bit easy on the 4th to 5th- it's not like it doesn't go fast enough in 4th. I'll try and get my hands on some of this high quality gear oil in the mean time. Are you saying that even with the right oil and a lack of abuse it may still crunch a little if changed too fast, in which case there may be nothing wrong?

Redline! Do it and report back.

[pharlap]

yeh mechanic said syncro for mine too, he said u gota drop gearbox to replace ><

[webber]

rear end of box is easy job once housings off. check clearances on 5th snchro with dial gauge. If in spec replace spring shifter insert.

i have some details here

I will have the synchro page up this week.

Cheers

[Ten Four]

OP, did you ever order the redline?

I've discovered mine has a crunch at only 5th to 4th between 4-6k RPM. Will update..

[Brandon]

Sorry if I'm hijacking the topic. I experience crunching from 3rd to 4th on high rev (e.g. 7000rpm). It does go in but you can hear the crunching noise. However, this only happens on load and never when I shift below 6000rpm. <BR><BR>Another problem which happened ages ago and only once was grinding noise when engaged in reverse gear after a drag day. A quick summary of what happened that day was 3x 6000-7000rpm launches and grinding starts. Drove the car nicely and after that day, the sound went away. Might be something loose from heat expansion? <BR><BR>I know its a million dollar question but if it was you, would you rebuild the gearbox or would you just try using redline? I am planning to change the clutch if that helps making the decision. Rebuild by my mechanic was quoted around 1.5k - 1.8k (everything included except for buying the clutch)

[Ten Four]

Redline is costing me $120 delivered from Harold @ performance hub.

Give it a go first. If it fails to fix it (I doubt it from what you're describing..), then rebuild/buy another, fill with redline from get go.

With the reverse thing, it could be the clutch cable stretching, making the friction point move to the floor and beyond? This happened with my M3 after a hard day out. New cable, $20 and it was sorted.

Edited April 5, 2011 by Ten Four

[KiwiRS4T]

Clutch cable??

[turboedsloth]

arent skylines hydraulic?

[PIG747]

I have the same problem but with 3rd sometime's and 4th more often. I tried the redline oil and it still has the problem.

I'm planing on replacing the synchro's so does anybody know of a good place to get these or someone that sells rebuild kits?

[smithy85]

Redline is costing me $120 delivered from Harold @ performance hub.

Give it a go first. If it fails to fix it (I doubt it from what you're describing..), then rebuild/buy another, fill with redline from get go.

With the reverse thing, it could be the clutch cable stretching, making the friction point move to the floor and beyond? This happened with my M3 after a hard day out. New cable, $20 and it was sorted.

clutch cable - ummm, no

[10 4]

M3 = diff to Skyline... Just saying what problem was for the M3.

Anyway, redline went in today, changes are now sooooooo smooth.

Edited April 28, 2011 by 10 4

[Fantm1]

I had an occasional crunch into 5th even when changing at a casual rate also the odd crunch on fast changes into other gears. I put in Redline Shockproof Light and it pretty much all went away. It crunched once into 5th soon after putting it in but not again for the last 3-4,000kM. Occasionally I feel a slight grab into one of the other gears, but not a crunch. For my g/box and hip pocket Redline Shockproof Light was the answer.