Uprated primary shaft.

[andyblackman777]

What are peoples thoughts on the GTO upgraded Primary shaft. I think this is the only one currently available. The thing that puts me off, apart from the cost is the changed gear ratios of 1st and 2nd. 
I must say that after stripping the gearbox and looking at the shaft it does look somewhat weak. I was planning to run an LSD which would I assume put more strain on the shaft. 

Cheers 

 

Andy 

[Erikl]

In to hear others thoughts. 

I am considering one for a rebuild iw/LSD install n next couple years.  I did see a pic posted by GTO of a GT40 replica doing extended burn outs uing an upgraded UN1...not that that is much help.  Thinking the gear ratios would not be too big an issue with the torque of the V8?

I have seen several folks installing them over the last few years and asked for a driving review but none of them have made it onto the road yet.

Probably overkill for my S4.

 

[mike_sekinger]

I ran a GTO Engineering upgrade kit and LSD in both my 510bhp V8 project.  1st gear is straight-cut and of course whines,  but I did not have any other issues.   It was great and handled the extra torque without any issues.  I did not spent alot of time in 1st or second gear.

The only reason that I moved completely away from the UN1, was that I wanted a sequential gearbox with dog engagement that could handle a much higher torque rating.

[andyblackman777]

Mine is stock apart from a chip from Marcus, but I need a second gear and maybe a primary shaft, (a bit of scoring around the front seal contact area). so why not just put in the gto shaft. There was another shaft kit about a while ago that had better gear ratios. Holloway or Emco. I wonder if anyone has one laying around...

[cweeden]

I have the GTO with the Quaife ATB diff and can fully recommend it. I don't find first too leggy and I find the subtle whine quite special, a little bit race car but not in your face.

I opted for the tougher 1" Ford input spline that the clutch slides on rather than the original Renault but I am not sure if its still an option, you'd have to source specific clutch plates to match though but this isn't difficult.

cheers

-Chris

[andyblackman777]

So I've gone ahead and completed rebuilding my spare gearbox with the GTO uprated primary shaft and Quaife LSD.

I've fitted it to the car and it works perfectly. The gear change is perfect, I was quite surprised at how the gearshift is. Before both gearboxes were somewhat stiff/sticky/vague when shifting. Adjusting the linkage recently did improve this. The rebuilt box I refitted and just quickly reconnected the linkage and cross shaft to test it out and the shifts are spot on. I did spend some time during the rebuild matching the synchro sleeves and selecting the best gears out of the spares I have?? The first gear whine is ok sound pretty cool.

The only issue I have is that the driveshaft seals are leaking a fair bit. I installed them by hand  maybe this distorts them and they leak. I'm going to get the proper tool and refit some more new seals and see if that sorts it. Any tips on making the seal work would be appreciated. 

 

 

 

[Erikl]

Thanks for the feedback!  Keeping the GTO upgrade on the short list!

[mike_sekinger]

1 hour ago, andyblackman777 said:

Any tips on making the seal work would be appreciated. 

Hi Andy,

Glad that you have had success.

The Quaife ATB diff does not have the o-ring seal at the base of the output shafts.  When I fitted this arrangement to Simon Francis`s V8, I had a leak and then used a pair of thinner driveshaft flange seals.  The outer one without the lip seal spring fitted.  These sorted the leak out.

They can be ordered here:

TC42X58X7 TTO Oil seals • 247industries • Order directly online

[andyblackman777]

cheers mike,

I knew it had no o ring. I'll do as you say. double seal

cheers

 

 

 

[andyblackman777]

Did a messy sealing job on the end of the pins to see if it was the seals or pins leaking, and its not leaking so far, so I'm hoping its just the pins.... time will tell

[andyblackman777]

Quick update. I've done around 150 miles on the gearbox now. One thing is I have way more confidence in it, happy to give it full throttle through the gears from a standing start. The Quaife lsd is awesome, hardly Any wheel spin in a straight line. Before it would spin in 1st and second, now it just grips. very happy.

As for the driveshaft oil leaks, its leaking from the roll pins. One side I cut the pin down so that it sits below the surface of the drive shaft, that way a really good seal can be made with the silicon, no leaks, bone dry. The other side I just tried re sealing as it was, still leaks. I'll do the same to this side and hopefully no more leaks. This does require draining of the oil to facilitate a really good clean of the roll pin holes. Otherwise more oil would just run down the splines. I did also take care to line up the groove in the larger outer pin with one of the splines on the shaft, just making the gaps for the oil to pass through smaller hopefully making a better seal with the silicon.

 

[jonwat]

22 minutes ago, andyblackman777 said:

This does require draining of the oil to facilitate a really good clean of the roll pin holes

A thorough degreasing so that the silicon attaches to the roll pin ends & drive shaft holes should be sufficient. Without the O ring the oil is going to seep along the splines & into the roll pins anyway so as long as the silicone seals properly the oil should stay within. Even if you do decide to drain the oil you only need to let some out so the level has dropped below the level of the output shafts & then you can save it & put it back in. 

[andyblackman777]

Yes John. I cleaned thoroughly with acetone, I found with the roll pin cut down and just below the surface I could more easily force in the sealant for a better seal. I drained the oil into a new clean container and reused.

 

[Steve V8]

Great work Andy, shortening the roll pins slightly to improve the seal is a great idea, one I hope you don't mind if I copy.

[LotuStuart]

>This does require draining of the oil to facilitate a really good clean of the roll pin holes. Otherwise more oil would just run down the splines

 

What is the oil level in the gearbox? Can you just park on a slope instead?

[andyblackman777]

Jacking up the effected side would probably be enough but not difficult to drain some out and refill.

 

[andyblackman777]

I was trying to find a diagram I had of the oil level, can't find it . However the oil level is inline with the fill plug so approximately inline with  the drive shafts. I don't think a fore/aft slope would help