Osg 5 Speed Issue

[Piggaz]

^^^

Is that fork a aftermarket one or was it just a new OEM one?

[BK]

That is for the last Nissan revision fork on 3rd/4th. Shouldn't need aftermarket ones though. If you do, Pfitzner sell billet forks to suit the late synchros. Pretty dear though.

[Piggaz]

^^ Hmm. In my case all the internal stuff was out of a almost brand new Series 3 box which had 11,000 KMS on it. It was purchased in may/ june 2006 from Just Jap. You would think that I would have the lastest revision in my box at the moment. and I cant see it being worn that much after so little work to require a new one.

[BK]

Your right mate, you should have the latest synchro setup. You gotta ask yourself, is it really that bad you want to pull the box down ? Maybe your a harsh shifter ? has it been like this since day one with the OS ?

[Piggaz]

Since the first time i drove it. It doesnt matter if i shift hard or not as it is there under power in 3rd gear only. After smashing a box im the biggest fairy with shifting!

I got a call from a bloke in England who has exactly the same issue at exactly the same speed. He has done 12,000 kms on his box and has run a high 10 @ 135 ish MPH, so making a fraction more grunt then me. He hasnt broken it yet, so i might just put up with it. Only time will tell.

[Marko R1]

hi paul,

i just came across this thread - 4yr thread bump

how is your box holding up & that 3rd gear vibration?

is anyone else still having 3rd gear vibration symptoms & any subsequent updates since?

[Piggaz]

  On 30/03/2013 at 11:19 PM, Marko R1 said:

hi paul,

i just came across this thread - 4yr thread bump

how is your box holding up & that 3rd gear vibration?

is anyone else still having 3rd gear vibration symptoms & any subsequent updates since?

Well while the car was apart I had it pulled down and rebuilt. The vibration is still there, but no where near as bad as what it was. When the new rear diff goes in illl be putting in solid alloy bushes. See is that has any effect on it.

[Marko R1]

Did u end up changing any parts during the rebuild or balance any of shafts?

This intrigues me and I'll explain why. My mechanic changed my clutch and as soon as this was done, 3rd gear vibration became apparent under load and boost. With the old clutch, it was perfect.

I called Terry @ Award Diff and explained the symptoms my car was having and he bluntly said "its your spigot bush" which makes perfect sense to me as it was obviously damaged during the r&r (before I changed my clutch, there was no vibration). He explained it is something to do with 3rd gear running on the same shaft / input shaft. I can't remember the exact explanation BUT he was adamant and this is why the issue is there only in 3rd gear...under load 3rd gear vibrates due to loose tolerance between input shaft and spigot.

Have u replaced your spigot?

[Piggaz]

Yeah man. Terry gave me a needle bearing spigot to use and that went in.

[Marko R1]

OK. Did that take out most of the vibration?

What explanation did Terry give you for your car?

[Piggaz]

He said there probably weren't any dowels between the block and box... There were though. When it goes out there to put the new diff in, I'll take him for a drive and see what he says.

[Marko R1]

Terry also suggested I check for dowels. U can use 8mm drill if u cut it in the right length as dowels.

[Piggaz]

Well mine were in and it still did its thing... As I said, it is a lot better.

[Marko R1]

Why is it better though? What did u change to make it better, spigot?

[Marko R1]

I also heard it is hard to put the box in with a bearing spigot off the ground. Did u install your box?

[Piggaz]

Spigot was changed. Apart from that, nothing. The only reason I had it pulled down was because two out of the three 'locator pads' were on my plug when we dropped the gearbox oil.