6 hours ago, Zed Head said:

Redline MT90 has a dramatic effect on worn Nissan synchros.  It's not hype, it really works.  I had a 3rd gear grind on a 78 5 speed and Redline made it go away, over Valvoline 80W-90 gear oil.

It's a cheap fix attempt.  Pennzoil Synchromesh has a good reputation also.

 

Thanks for the suggestion, not heard that one before but will certainly try and give it a go! 

Sadly due to the slight wine it may be well worth removing and stripping the gearbox anyway.... 

Add me to the Red-Line fan base.  That stuff is like magic for the transmission and the differential.

Best price I've found on was amazon.com

9 hours ago, Woody928 said:

Sadly due to the slight wine it may be well worth removing and stripping the gearbox anyway.... 

I don't think you mentioned the whine before.  Might be that the whine and the vibration and the 4th gear synchro problem are related.  Maybe a bad bearing.

Thanks for the insight chaps. 

Hopefully it's mentioned above but there's a lot to take in, I'm suspecting a worn syncro and potential bad bearing. Due to the speed it comes on at and the way it transfers into the car I still think the prop is the likely cause of the vibration as it is very noticeable rather than more minor. I wouldn't have thought the gearbox would create that level of vibration at those specific speeds only.... 

Sadly I think the box will need to be ripped out and rebuilt assuming i can find spares! 

 I've experienced a transmission whine and a prop shaft vibration. Fortunately at different times. The trans. whine was audible and sounded like a bearing going bad but didn't transmit any vibration to the shifter or the chassis. It was a bearing as suspected. The prop. shaft vibration in mine occurred above 80 mph and was horrendous. Sounded and felt like there was a 600 lb. bumble bee in the back. I replaced the u-joints but there was no change. Took the prop shaft to our local drive line shop to check the balance. They discovered a tiny dent in one side that screwed up the balance. They re-tubed and balanced it. No more problems. I'm not suggesting your tube is bent but it is possible to bend them. Check the u-joints first. Especially the front one.

Just read about your aluminum flywheel.  That has to be the best "bang for the buck" for me.  The carbureted cars scream like a motorbike, just as you say. ?

4 hours ago, Woody928 said:

 assuming i can find spares! 

That seems to be the difficulty.  There are a few guys on the forum who have rebuilt theirs and know where the good parts are.  Some of the "kits" apparently are not of high quality.  Most say to use Nissan synchros, even though they can be expensive.  The bearings are common, it's the synchros that are hard to find, I think.

Great read!  I have a 71 in orange which looks identical to your( same bumper) although with Fenton slots on its way to me from Oregon. Should be here this coming Monday. I have a lot to learn about what to do, but no rush. Will be asking all sorts of questions as time goes by, but you have given me plenty of insights to get started on. Great job thus far. Keep at it and keep posting!

22 hours ago, Mark Maras said:

 I've experienced a transmission whine and a prop shaft vibration. Fortunately at different times. The trans. whine was audible and sounded like a bearing going bad but didn't transmit any vibration to the shifter or the chassis. It was a bearing as suspected. The prop. shaft vibration in mine occurred above 80 mph and was horrendous. Sounded and felt like there was a 600 lb. bumble bee in the back. I replaced the u-joints but there was no change. Took the prop shaft to our local drive line shop to check the balance. They discovered a tiny dent in one side that screwed up the balance. They re-tubed and balanced it. No more problems. I'm not suggesting your tube is bent but it is possible to bend them. Check the u-joints first. Especially the front one.

It sounds like I may be on the money with both bits of speculation from that! The prop was recently shortened and re-balanced for the conversion but I've been told these cars are really prone to balancing issues so still think it's the most probable cause. I'll investigate!  

21 hours ago, siteunseen said:

Just read about your aluminum flywheel.  That has to be the best "bang for the buck" for me.  The carbureted cars scream like a motorbike, just as you say. ?

There's a lot to take in ? I had no idea what big a difference it would make, originally I'd never even considered one. It only weighs 4.7kg so has really made the engine come alive! I think the rear anti roll bar really has to be up there for value for money personally.  

18 hours ago, Zed Head said:

That seems to be the difficulty.  There are a few guys on the forum who have rebuilt theirs and know where the good parts are.  Some of the "kits" apparently are not of high quality.  Most say to use Nissan synchros, even though they can be expensive.  The bearings are common, it's the synchros that are hard to find, I think.

Ahhh now that's disappointing to hear the only rebuild kits I've really seen are the Kenjutsu ones... It sounds like I need to speak to Nissan and try and work out some part numbers. 

16 hours ago, Sunline said:

Great read!  I have a 71 in orange which looks identical to your( same bumper) although with Fenton slots on its way to me from Oregon. Should be here this coming Monday. I have a lot to learn about what to do, but no rush. Will be asking all sorts of questions as time goes by, but you have given me plenty of insights to get started on. Great job thus far. Keep at it and keep posting!

Awesome, congratulations on the purchase! I'll try and keep an eye out for a project thread, don't worry I knew almost nothing a couple of years ago and its turned out ok so far! Thank you, she's getting there slowly. 

On ‎7‎/‎25‎/‎2018 at 3:54 AM, Zed Head said:

Redline MT90 has a dramatic effect on worn Nissan synchros.  It's not hype, it really works.  I had a 3rd gear grind on a 78 5 speed and Redline made it go away, over Valvoline 80W-90 gear oil.

It's a cheap fix attempt.  Pennzoil Synchromesh has a good reputation also.

 

Exactly. It depends on where you are though. We can't get redline MT90 here in Europe. But I'm using the classic line from Kroon Oils here, and that's about the same stuff I think. It's formulated for the old post war cars. Never had problems, and my 4 speed hasn't been open since new. There's a slight difficulty going in 2nd gear when cold, but when it's warmed up everythings fine.

I'm only using everything from the classic oils line, for my mustang to. I won't put modern oil in these old birds...

Edited July 28, 20186 yr by bartsscooterservice

Well I thought I'd put together a little update, the car is getting lots of use at the moment getting to various meets and going out on runs and drives just for the fun of it. I'm not sure exactly, but the car has definitely done well over 600 miles since the recent overhaul. There are still points to address however I'm too busy enjoying the beautiful weather to worry for now. 

 

I'm still finding the attention the car gets comical, I feel like some sort of celebrity driving it around half the time, the engine bay is now also getting lots of ooohhh's and aaahhhh's and wowing people. Lots of comments that its got a proper engine fitted, it was pretty swamped at most times during its recent visit to the Goodwood Breakfast meet. Even when I've just dropped into Waitrose several people have stopped to take photos, compliment the car and chat before I've got near the store. I even met an Audi Motorsport heritage engineer in a traffic queue at Goodwood who has a German market 260Z +2 and has worked on several of the winning LMP1 Le Mans cars over the years that I've watched. It really is incredible who you meet...

 

I'm pleased to report that it's running very well, the engine in particular. The fuel economy is now where we'd expect it to be now with it being about 23-24 mpg with my enthusiastic driving and over 30mpg possible on motorway cruises now which has really impressed me. The engine is super rev happy, albeit stops really performing around 5.5k rpm and in reality is getting used to between 4-5k for spirited use. Handling wise now the car is very impressive, it needs the uprated front roll bar to dial out some under steer however on a recent drive out with the MR2OC it had no problems keeping up with cars with over double the power in several cases. It certainly surprised a friend in a Noble M12 at its ability to corner and get around roundabouts. It handles incredibly well for a car that is almost 48 years old now. As you can imagine it's no straight line monster and was left slightly lacking in that regard, however I've been too busy smiling and listening to the soundtrack to care! 

 

The car has just been accepted into the show and shine competition at JAE this year so I'll actually have to give it a proper clean and see how I get on, not something I've ever contemplated before however she looks so nice at the moment I thought what the hell. I've got a few show weekends coming up so more time to show her off to people and enjoy.       

 

DSC_0071 by Mark Woodrow, on Flickr

 

DSC_0081 by Mark Woodrow, on Flickr

That is a quick collection of cars! What is the first car in line, the dark blue one, next to the Noble?