WBT56

Clutch/flywheel imbalance will not generate a speed related vibration, it will be engine rpm related. Ben.

The whine is from incorrect contact path set up, and no additive will fix the problem, it may just quieten it down to get it out of warranty and cut to pieces later. Ben.

We can supply suitable clutches, but look at the problem first. The first thing to do is to diagnose the problem, and then go back to ford and prove to them what the problem is. I would look at the back end first, and go from there. Ben.

Take it to someone who knows what they are doing, and do not assume such a place will have a big blue oval on the front of the shed. Your clunk is almost certainly a combination of clutch hub damage and backlash in half shaft CV joints.

As you have been told Frank, the noise is transmitted noise from the engine. This is in part caused by the solid centre clutch plates that were fitted to the clutch to make it bulletproof under its' original buyers usage, and in part caused by the tune. Your kit was purchased second hand, before we developed our new 11" clutch kit. We have PM'd you and left you phone messages, we had one of our prototype 11" units set aside for you to try, but you never returned our calls.....Ben.

The contact patch is the area on the teeth that actually pushes agaist the next tooth on the other gear. When the area gets damaged for whatever reason, The gearbox will start to get excessively noisy. Eventually it will grenade. Third gear is usually the first to go, or the input shaft/ cluster drive gear set. A certain amount of noise may be present in first gear in a new box, but not elsewhere. Ben.

Consider yourself corrected. The T5 will start to whine once contact patch damage has occurred to third gear or the input drive. Ben.

Assuming fluid was at the correct level at some time, the two obvious choices are leaky master or leaky slave. The master is under the dash, and will leak into the carpet and not be obvious. The CSC may leak and not drip on the floor, as clutch dust will soak up quite a bit of fluid first. I have seen one each of these in BA, and both still had a perfectly operating clutch. Ben.

Ben, would you please expand on that a little, I would like to know more as to how these things work? Also, could you give us some idea of how these systems behave so that we have a better idea of how to use them?. <{POST_SNAPBACK}> Wet clutch = limiting device runs in oil bath of primary lube fluid.((as opposed to a sealed ,typically viscous (silicone drive) unit, eg subaru system). Basically means that lube fluid is important for effective operation of LSD. Metal plate = metal clutch plates, as opposed to friction linings. Non ramping= Cross pin is fixed, so torque does not ramp up the unit as in KAAZ style diffs, eg Rodeo. Both axle = runs a small clutch on both axles, as opposed to a large clutch on one. Basically friction tries to tie each axle to the housing individually. Work great when they are working, but one wheeling can fry them very quickly. If it does one wheel often, find out why and rectify. Ben.

LSD is a wet clutch, metal plate, non ramping, both axle design, as used in many 4wd vehicles. Ben.

Checking timing on boat motors can be difficult. Many have no harmonic balancer, and the cam is generally advanced to buggery. Sounds like a fuel supply issue.

Brian, I would move the reservoir, not replace with alloy. The heat soak from the alloy will boil the fluid and kill the plastic master cylinder above your feet. Ben.

Anyone care to consider why the ratios that are "such horrible crap" in an SS commodore, are now "so beautifully spaced", with a blue oval on the front? (2.66, 1.78, 1.3, 1.0@ 3.46 diff?)

It wasn't the rpm that killed it, it would have let go after failure through heat cracks from running/riding/slipping a too harsh clutch, ie metallic or carbon button. (The old rule of thumb of go steel above 6000rpm still sounds good to me though.)

The clutch is rated at over1200ftlbs. I guarantee that there are no clutch issues. There might have been issues with the apprentice who fitted it incorrectly last time and damaged it, (as can happen when anything mechanical is incorrectly fitted). As the unit in question had an unconditional warranty, I am sure we would have heard if there was a problem. Ben.

Thanks for your input Mal. What power levels are your gearboxes currently working to at maximum? Also, when have you noticed, in terms of rwkw, do the CV joints fail? <{POST_SNAPBACK}> We dont really know what our T56 boxes are really capable of holding, as we have never had a failure to date. We have 12 or 15 running over 800rwhp, (800+ftlbs), and many more running in the 300-400rwkw class. CV joint failures at this stage seem to be more related to wear or poor build quality than outright output. If you have a back end clunk, it will almost certainly not be the diff, check your CV's. Ben.

Fuel economy at low rpm is in most cases a myth. The extra throttle position required generally results in higher fuel usage. This is true under acceleration, as well as at highway speeds. This is of course when considered sensibly, comparing off idle out into the midrange. Sitting around the limiter with obviously result in higher fuel usage. Ben.

No problem. For those that do not understand the low rpm bit, it is simple. Torque kills gearboxes, and at the same load conditions, (car speed, rate of acceleration) the higher the rpm the power is being transmitted at, the less torque the box is copping. Ben.

Can't speak for the factory one, but I would not be worried about our std box out into the 500-550rwhp bracket. Ben.

Nothing. The T5 "Z" in the "T" is the best T5 you can get. Basically do not abuse it, do not drive at below 2000rpm in any gear, do not let it get into axle tramp, etc. Nailing it at low rpm in third gear is much harder on the box than revving it out more in second. Ben.

has that come down from 300rwkw with some more research Ben? What can we do to strengthen the T5? <{POST_SNAPBACK}> This has been the pattern that is emerging. We have had "Z" spec boxes follow the same pattern in other cars at the same power levels, which is a helpful cross check. (People who buy a box and then supercharge the car later against our recommendation.) Ben.

We have customers running in the 10's with our T56 in other cars. If you can drive, it will do it. Ben.

Our experience has been: (assuming you actually have it, and use it) 330rwkw-irreparable damage before it comes off the dyno. 270rwkw-irreparable damage in about 2000km. Ben.

No problem Robin, and no offence intended. JB can confirm that I have listed EVERY POSSIBLE cause of backlash from the crank to the rubber. I just find it necessary to jump onto clearly incorrect information in the interests of clarity. As what you have described is not possible, perhaps the flywheels shown to you were not factory turbo flywheels? I have seen some abused ones also, blued right through to the back and warped 60thou. Ben.

I have got to say that this is absolute rubbish. The ford flywheel is really just a flex plate with a cast iron running surface on it. Although poor quality, prone to warping, and giving a tttzzz noise as the starter engages, it will not give the symptoms you describe, as there is no backlash or give in it. It is not a "mass dampening" type wheel. It is an auto flexplate with the cast iron BOLTED to it using the converter bolts. The flywheel bolts go through both parts into the crank. Ben.