Category: Clutch

Pedal box and master cylinders

Clutch, Pedal Box

Final set up of pedal set and master cylinders. Used aluminium spacers between the master cylinders and the bulkhead to achieve the correct free play in the clutch and brake pedal. The modification to the fulcrum point on the pedal set has worked well since I have not had to cut the push rods on the two brake cylinders (to the left) and end up with about 5mm of spacers to get the correct clearance. I ended up cutting about 12mm off the clutch cylinder pushrod otherwise i would have had more like 18mm of spacer. Used some laser cut aluminium spacers in 2mm and 0.8mm. the first 2mm spacer goes across all three cylinders then individual spacers to get the correct setting. Then finally connected the high pressure and low pressure lines. I’ll get a bracket made for the master cylinders, some jubilee clips and should get this plumbing finished next week.

In the first picture I have done a little bit tidying of the footwell pocket formed to the right of the accelerator pedal. It has ended up a reasonable silk finish gelcoat which I may just leave unfinished when i carpet or may end up putting some thin carpet in this pocket. Tried the pedal action with a mock seat setup and find the pocket really helps with the space – I remember feeling a little cramped when I tried this in the GD demonstrator but I’m pleased to say it now feels very “ordinary”….

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Engine Gearbox and Clutch

Clutch, Engine, Gearbox

The LS3 crate engine and Tremec Magnum gearbox has arrived.
Slight problems to resolve.
The yoke I had acquired was a 27 spline yoke from the tremec t56 unfortunately it does not fit the magnum gearbox.
The Yoke needed for a magnum transmission is 31 spline as detailed.

Dana Spicer 3-3-5961X
1350 Series Slip Yoke 31 Spline fits Tremec T56 MAGNUM and TKO 600 Transmission
Length to center of u-joint… Dimension #1 = 6 1/2 inches
Barrel Diameter… Dimension #2 = 1 11/16 inches
Barrel Length… Dimension #3 = 4 1/2 inches
U-joint cap diameter… Dimension #4 = 1 3/16 inches
U-joint width… Dimension #5 = 3 5/8 inches
Series… 1350
Spline count… 31

magnum yoke

Good news – called GD and sounds like they have one in stock. Ill order up a full propshaft from GD as soon as I do a trial fit of the engine.

Tried the engine and transmission in for size and works out the prop gap is about 366mm I guess the actual prop length will be something a little shorter than this with an allowance for a bit of clearance on the sliding spline.

Clutch Trial Fit

What on earth was I doing a clutch trial fit for you may well ask, well the truth is I wasn’t  meant to but after fitting the clutch and pressure plate housing I started to do a bit of reading up to find out what the odd looking connection was on the slave cylinder. Whilst searching for information on the slave cylinder fluid input fitting which turns out to be “Quick Disconnect Fitting” I also discovered that I had inserted the pilot bearing the wrong way around. It said nothing on the instructions I received with the installation kit about direction for the pilot bearing and although I did notice it had a slight difference I chose to put it in with the needle bearings visible and closest to the transmission. My logic was simply to get the needle bearings further along the shaft end.

Turns out my logic was wrong and the bearing goes in with the closed end towards the tranny, obvious when you realise that this is the grease seal end.  OK so the clutch has to come back off – no big deal but how the heck will I get the pilot bearing out that i just drifted in with a 3lb hammer?  My first thought was, OK its just going to get butchered out and buy a new pilot bearing but a quick google check and low and behold some genius on youtube had figured out a 3 minute solution. All I had to do was pack the centre of the bearing with grease and insert a close fit (15mm) drift through the centre of the bearing, strike it with a hammer a few times and low and behold the bearing jumps out. Extreme Hydraulic pressure pushes it out from behind – what a good trick –  and it works – youtube to my rescue!DSC_0302

Now on to the problem of that Quick Disconnect which got me searching in the first place. Apparently these fittings are used quite extensively in the USA and the idea is to enable disconnection of the slave cylinder for removal of transmission during clutch service etc. without introducing air into the system so alleviating the need to bleed.DSC_0298

The Quick Disconnect is the big orange part in the picture. The other opening is for the bleed nipple which is lengthy so it can just be bled from the bellhousing opening. I’m going to fit external bleed flexi pipes so I plan to modify both of these fittings. Pretty easy on the bleed side since its just an m10 fitting, so a standard male end of a flexi would work here but the quick disconnect is not so simple since its fitted into the slave cylinder aluminium casing with a flat o ring and groove, held in place with a roll pin. I think the simplest method here may be to cut this orange bit off and have the blank pipe end threaded to m10 with a taper. That way I could fit an m10 female/female extension fitting, effectively replacing the orange part with this.

m10 female

I’ll figure this out over the next couple of days and report my solution here.

Trial fit to get prop lengthDSC_0312

Things are starting to get heavy  LS3 and Tremec Magnum in place.

Engine back out to sort the clutch slave issue here’s a pic of the new fittings. The banjo fitting on top is for the remote bleed flexi this replaces the long brass bleed screw (above). The setup on the lower input shows the new fitting that replaces the ‘quick disconnect’ (orange plug above). It was easier to turn this fitting with a standard male metric brake end as shown, but since I already had my flexi pipe with a male end just adding a standard female/female coupling in between joins it all together.

clutch slave fitting

With this complete I can re-install the engine and gearbox in the chassis.