Muscle Mustangs & Fast FordsHow To Drivetrain
We Show How to Get More Power to Rear Wheels With Advanced Mcleod RXT Twin Disc Clutch
It doesn’t matter how much power your 1996-2004 SOHC Modular Mustang is making at the crank if most of it is lost in the driveline via clutch slippage and the dead weight of a heavy low-tech clutch. McLeod Racing and Modern Driveline understand your dilemma and answer the call with the RXT Twin Disc clutch—twice the grip, double the hookup for your SN95 or New Edge Mustang.
The McLeod RXT Twin Disc is an aggressive street clutch capable of taking 1,000 hp without breaking a sweat. Intended for the high-horsepower street/strip fan, the McLeod RXT Twin Disc clutch kit is an economically priced high-performance clutch kit that does not require a dedicated flywheel in most applications (you can use your existing flywheel, though it is suggested you opt for a new one). This clutch can handle almost any horsepower you can throw at it and remain streetable. Twin metallic lined clutch discs provide smooth engagement with minimal pedal effort, making this clutch ideal for street performance. The kit includes the pressure plate, two ceramic friction discs, a floater plate, an aluminum flywheel, and a pilot tool.
For today’s install, we are working with GTR High Performance in Rancho Cucamonga, California, a shop founded by Gonzalo & Ricardo Topete in 1997. Their approach to the performance business was fundamental: Create a positive and rewarding Mustang shop experience with a courteous, professional, and knowledgeable staff. GTR High Performance has emerged as one of the premiere Mustang performance shops in the country, and the locals are fortunate to have them close by.
That said, GTR decided to go all out in this clutch swap, opting for a Stifflers driveshaft safety loop and stronger transmission crossmember with urethane bushings. Both are easy bolt-on improvements that can be handled quickly.
Finally, when you install a new McLeod RXT Twin Disc clutch, change your transmission fluid and inspect the old fluid as it fills the pan. Torco ATF is a terrific synthetic automatic transmission, and we’ve seen this time and time again: Synthetic lubricants simply work better.
When you install your McLeod RXT Twin Disc clutch, be mindful of contact surfaces between clutches and plates and the flywheel. Surfaces need to be hospital clean. Use a thread locker on all fasteners, and torque them to McLeod’s specifications. While you’re in there, be sure to replace the clutch fork, release bearing, and ball stud.
Ricardo Topete of GTR wanted to know what could be gained from the McLeod RXT Twin Disc clutch. He was also interested in what could be lost. The stock Ford clutch, which was installed at Ford’s Dearborn, Michigan, assembly plant more than 15 years and nearly 60,000 miles ago, was ready for retirement. Topete put his Mustang on the dyno to get horsepower and torque numbers with the worn-out clutch. He got 366.37 hp and 366.58 lb-ft of torque with the factory clutch, which weighs 52 pounds including flywheel and hardware. The results with the McLeod RXT Twin Disc from Modern Driveline were 380.21 hp and 380.87 lb-ft of torque at 40 pounds. Topete gained 14.5 hp and 13.63 lb-ft of torque by eliminating slippage and 12 pounds.
|McLeod Power Snap Shot|
|Stock Clutch||366.87 HP||366.58 LB-FT||52 Pounds|
|McLeod RXT||380.21 HP||380.87 LB-FT||40 Pounds|
1. Ricardo Topete of GTR High Performance placed his own 2001 Mustang GT on his shop’s chassis dyno for a quick run and fact-finding mission. He wants to know how much power is lost through the Mustang’s factory’s original 11-inch clutch, which has never been replaced. Topete stresses how much power is lost through a slipping clutch.
2. This is the complete RXT Twin Disc clutch kit from Modern Driveline. The kit does not include cable clutch adjustment and underdash clutch quadrant, which are valuable options from McLeod that enable you to adjust pedal travel and engagement.
3. The transmission crossmember from Stifflers (PN TCB-M20) tightens up transmission support with real Made in America steel and urethane. It can be installed in minutes with simple handtools.
4. The driveshaft safety loop from Stifflers (PN DSL-M01) is a solid functional component. It contains the driveshaft should the shaft, universal joint, or slip yoke fail. This gem bolts on in minutes.
5. Clutch access begins with transmission removal. Topete removes the shifter handle and boot first.
6. The exhaust system is removed next to gain transmission access. Use WD-40 on the bolt and stud threads prior to disassembly—it is quick and easy and will help loosen up any stubborn bolts.
7. The cable clutch fork is wedged forward to disconnect the clutch cable.
8. The driveshaft is removed next by removing four fine-thread bolts with a 15mm socket.
9. With the transmission safely supported, Topete removes the crossmember. All 1994-2004 Mustangs have this stamped steel crossmember/mount combo.
10. The bellhousing bolts have been rattled out using a 19mm socket and long extension. Lower the transmission, and the bell bolts are easy to get to. Next, pull the transmission aft to clear the engine block and bring it down on the jack.
11. Topete bought the 2001 Mustang GT new and has run it hard for 15 years. It is remarkable how solid the original 11-inch factory clutch is.
12. The original Ford flywheel can be resurfaced and used again, but we opted for a new McLeod lightweight flywheel.
13. The factory clutch and flywheel, including bolts, weighs 52 pounds.
14. The McLeod RXT Twin Disc tips the scale at just 40 pounds.
15. The new McLeod aluminum flywheel is secured and torqued in one-third values to specifications using ARP bolts and a thread locker.
16. The first stage of the McLeod Twin Disc is secured to the flywheel. The provided clutch alignment tool is used to align the forward clutch. Note the black clutch reference mark on top. It is very important to recognize this mark and use it during installation.
17. When you’re installing the secondary clutch disc, it is very important to get friction pads in alignment. This gets tricky.
18. This close-up view shows proper clutch friction pad alignment.
19. The clutch plate straps are torque-checked before going further. Topete stresses never to trust parts right out of the box. They must be inspected and fastening torque checked; torque should be 25 lb-ft.
20. The RXT pressure plate is installed and checked for proper alignment.
21. The clutch pressure plate is checked for proper alignment with its bolts torqued to 35 lb-ft. Again, torque in one-third values.
22. Clutch replacement should always include a new fork, release bearing, and ball stud. Lube these items with transmission assembly lube.
23. Topete uses Torco synthetic automatic transmission fluid in all manual transmissions, especially the tight-tolerance late-model boxes.
24. The Tremec T45 is reinstalled and seated to the 4.6L engine. Because Topete has already meticulously checked clutch disc alignment and lubed the input shaft, installation is a snap.
25. The factory self-adjusting clutch cable doesn’t always perform as it was designed to. We are opting for the McLeod firewall click adjuster with bearing, which will get our clutch adjustment where it belongs. What’s more, we can adjust it to our liking.
26. Here are the original self-adjusting clutch quadrant (left) and the billet McLeod piece (right). We won’t kid you: The quadrant replacement is a bear. To make things a bit easier, start by removing the driver’s seat for better access.
27. Next is the Stifflers driveshaft safety loop. Even if you’re driving a dead stocker, install one of these in the interest of safety.
28. Finally, we installed the Stifflers transmission crossmember with urethane mounts for durability.