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Third(and Last) McLeod RXT vs. T56 Magnum input shaft
I realize this is a LONG post, but Its summed up of everything thats happened over the course of the past 18 months or so…
I’ll try to keep this thread PG rated on my opinion of McLeod’s customer service and the quality control of their clutches. I’ve unfortunately had been on the receiving end of multiple short comings on 3 different McLeod clutches that ALL had issues.
each time I contact McLeod to figure out the reason for the failure, they don’t stand by their product. Always an excuse as to why they assume the failure of the clutch. I’ve been working on cars my whole life and come from a family with plenty of successful racing experience and plenty of hardware to back it up at the highest levels.
As a business owner, I’m always reluctant to post negatively on another business, but when I’ve exhausted all my efforts with trying to reach a resolve and hope they step up and do the right(and obvious) thing, they’ve left me between a rock and a hard place and out of other options…
First clutch RXT: had chatter and hot spots that they said would go away after break-in. The symptoms only got worse. They eventually told me it was due to improper setup. But I disagree.
2nd clutch RST: The individual in the tech department at McLeod recommended at my HP level and the light weight of the vehicle(toyota pickup) that the RST might be a better choice. Smoother engagement and no chatter. I confirmed that the clutch would hold up to my Setup prior to purchase. Went ahead a got the RST. After install, I broke the clutch in properly and from the first drive the clutch worked like butter. Very smooth for about 5-6k miles. Then the clutch started slipping bad in 4th, 5th and 6th gear. Pulled the clutch to find out that it was done. There are more specifics as to the reason why it failed. I explained and proved to the individual that their dual disk clutches need slightly more release of the TOB than their recommendation says. my setup did not release the disks exactly at the same point with the shims they provided and when I installed a set of new disks(tested on the bench & shop press) the same result. So even though the clutch was Already toast, I kept this in mind to make sure to bench test before installing any other clutch...
after going back and forth with McLeod tech department and the same person that suggested the RST finally responds after about a week, he tells me that my setup exceeded the HP rating of the clutch and I should have installed the RXT instead! I didn’t bother responding to my findings about the releasing of the clutch plates, since I was lost for words at the point, knowing it was just another excuse to re-direct the blame. I replied to the email and suggested he take the time to re-read the previous conversation attached to the email, with our conversation from months ago and then get back to me… needless to say, He never responded after that.
Third clutch RXT - at this point I was in a pinch and needed to get the truck back together asap. I was beyond fed up with McLeod. But I got a deal on a new RXT clutch from a seller online that I went ahead and bit the bullet on so I could get the truck back together. I tested the setup on the bench for release, measured for air gap and bearing clearances 3 times to be certain. The clutch worked fine with some light chatter during break-in period. About 1500 to 2000 miles later, i notice some strange noises from the bellhousing area. The noises seemed to potentially be related To the TOB because they seemed louder with the clutch disengaged. Although just speculative, I ended up pulling the motor and transmission due to an oil leak on the back of the motor and the noise continuing to get worse with other issues felt through the clutch pedal.
when I separated the trans from the engine, this is what I found….
the input shaft is completely destroyed from the splines on the clutch hubs. After doing further research, I have found others have recently had experienced this same exact issue with destroyed input shafts and RXT clutches. All of them seem to have had similar issues with the customer service with McLeod too… what gives here?!
So all in all, my suggestion is to NOT consider buying one of their dual disk clutches until they can prove they have got their act together and their product quality control in line. The chatter from the first RXT was likely due to the tolerance of the splines on the RXT clutch hubs, which is also why the last RXT clutch destroyed the input shaft after experiencing the same symptoms. The RST disks fit the input shaft much better than the RXT’s did. So its apparent that their manufacturing inconsistencies are inadequate for a product that they speak so highly of, based on the parts I received from them and from other’s experiences on their cars. Without getting too deep into the emails that were exchanged back and forth between this company and myself over the past year and a half(there were many) and seeing their lack of willingness to stand by their own words and their products, the best Grade I could give them, from my experience, is a D-(and I think that’s pretty generous, all things considered).
Here's a video to see exactly how bad these hubs are. This is basically a new clutch hub on a Brand new input shaft!
I wonder if quality control went down , or bad materials, ive had my rxt in my car for 5 yrs and its been great , have 2 others local to me with it no issues. They did theirs around the same time. My rxt was broke in correctly and never chattered. You have a t56 magnum same as me . What bell housing are you using ? also i needed to shim my clutch , i measured and used 1 of the tick shims when i installed.
I have always been sus about the McLeod input shaft interface. Just not enough spline engagement for my liking. I think I even mentioned it in a post not too long ago. Sorry this happened. I moved to a monster twin which has >2" spline engagement which protects the splines. Only downside to the monster twin is the 4th gear noise.
Had the same situation with a beat up input shaft using their twin disc. I moved on to a Monster triple and like the design much better (load is spread over a wider area).
It's all about surface area and the ability to handle the load. When you run a narrow surface area, the ability to disperse the load goes down significantly and accelerates the rock between the surfaces and thus the tolerances between them (wear).
I 100% agree that McLeod is absolutely not worth the money. I had an original Street Twin that was great until McLeod rebuilt it. Long story short, I had to remove/replace the clutch twice because they installed the wrong parts. After they finally said it was right, the clutch started slipping after less than 5000 miles. By 6000 miles, it was toast. And that was ZERO track time. I will never use another McLeod product.
I 100% agree that McLeod is absolutely not worth the money. I had an original Street Twin that was great until McLeod rebuilt it. Long story short, I had to remove/replace the clutch twice because they installed the wrong parts. After they finally said it was right, the clutch started slipping after less than 5000 miles. By 6000 miles, it was toast. And that was ZERO track time. I will never use another McLeod product.
I have had 2 original street twins(aluminum and steel flywheel). Both gave me issues from day one. The customer service at that time was awful at best. I just bought an RXT 1200.....my fingers are crossed. The monster LT1-SC I had gave up the ghost soon as I turned the nitrous on. It was a great clutch up until that point. A buddy had a new monster RR twin sitting around. I tossed in for a few runs. It worked well but it is basically an on/off switch as far as engagement. A couple friends have had great luck with the RXT 1200 and say it drives close to stock. Hopefully it works out
You're saying the LT1-SC gave way due to the NOS? Were you doing hard launches on the bottle? How much NOS? Just curios as I have an LT1-SC and you're stating the clutch was the issue.
You're saying the LT1-SC gave way due to the NOS? Were you doing hard launches on the bottle? How much NOS? Just curios as I have an LT1-SC and you're stating the clutch was the issue.
It gave up on literally the FIRST nitrous pass(200 hit). I have no idea as to why it gave out. Monster couldn't really give me an answer either...other than I should've been running an RR twin instead of the SC. The SC was a great clutch all motor. I'd cut a bunch of 1.32-1.36 60 foots and went 9.99 all motor..... and my car is heavy.(3500lbs)
couple years back I posted up about McLeod too. Bad clutch (RXT). Sent it in 3 times, Had to R&R the trans 7 times in 8 weeks trying to figure out the problem. Finally got it to a point where it would work. Turns out it also bent my input shaft. The trans was fresh from Tick. After installing a Monster triple disc and having shifting issues, I sent the trans back to Tick and they found the input was bent.
Also, McLeod customer service fought with me the entire time.
I even posted on here about the initial issue and service and got blasted a few times on how great they were. Yea, well this just reinforces my dealings as well.
Even my Monster triple had an initial problem with the pressure plate. They asked 3 questions, sent me a label. 5 days later had it back in the car, broke it in for a few miles and hooked so hard, broke the Trutrac carrier in the Moser 12 bolt.
No Nitrous on this. All N/A.
It gave up on literally the FIRST nitrous pass(200 hit). I have no idea as to why it gave out. Monster couldn't really give me an answer either...other than I should've been running an RR twin instead of the SC. The SC was a great clutch all motor. I'd cut a bunch of 1.32-1.36 60 foots and went 9.99 all motor..... and my car is heavy.(3500lbs)
Thanks for the heads up! I'm was planning to go NOS becasue that's what the engine was built for but it's mainly been just an NA street car. It may be best to use the NOS once I grab third gear in a racing situation.
You're saying the LT1-SC gave way due to the NOS? Were you doing hard launches on the bottle? How much NOS? Just curios as I have an LT1-SC and you're stating the clutch was the issue.
How you launch and apply the nitrous will greatly affect the amount of torque the clutch will see. Here's a graph showing calculated torque applied to the clutch disc during an actual NA launch...
Add around 200ftlbs of nitrous on top of any of those NA torque spikes, now its far easier to blow thru a clutch. Then after you've blown thru a clutch, that clutch is going to slip until vehicle speed catches up with engine rpm. Clutch now slips too much to pull engine rpm down, so clutch will be toast if you stay on the nitrous long enough for vehicle speed to catch up with engine rpm.
If you want to add nitrous to the above graph, first order of business should be to fix those nasty NA spikes after the gear changes. Those spikes are the result of installing too much clutch, which in-turn increases wear/tear on the drivetrain. Those spikes also make it easier to break the tires loose, a big problem if you plan to keep a set of radials hooked up. Couple of ways to deal with excessive spikes after the shifts. Best way is to reduce clutch clamp pressure, either by shimming your existing clutch or by installing a clutch with less capacity. If you want to keep the clutch you already have and don't want to shim it, a device like my ClutchTamer of Hitmaster can be installed to soften the clutch's hit.
Here's the calculated effect of softening the clutch hit just enough to roughly double clutch slip time after the shifts...
Now instead of knocking the radials loose with an intense spike after the shifts, you now get a hit they can tolerate that lasts roughly twice as long. Here's what those spikes look like at the driveshaft, multiplied by the transmission ratios...
The best approach to adding nitrous to the above graph is to delay the nitrous until after the NA torque spikes. If you do this, the clutch will be worked no harder than during an NA pass as the nitrous doesn't come on until after the engine speed has been pulled down enough to match vehicle speed. A big advantage to doing that is that you can fit a much larger nitrous shot in between the torque spikes without blowing thru the clutch. But why stop at a 200 shot? Here's an example showing a calculated 400hp shot being applied between those NA spikes. Note that the total torque applied to the driveshaft, including the 400hp nitrous shots, does not exceed the torque applied during the NA launch...
Far smoother radial friendly way to get down the track with nitrous, also far easier on the clutch. Same clutch that works for NA passes now works for nitrous passes.
Thanks for the heads up! I'm was planning to go NOS becasue that's what the engine was built for but it's mainly been just an NA street car. It may be best to use the NOS once I grab third gear in a racing situation.
From what Monster told me, they didn't recommend the SC for hard N2O launching. They said I should've gotten the RR....which has 2 sintered iron discs. It's noisy and engagement is an on/off switch.
IMO if you're concerned about the clutch, delay the nitrous on the launch or turn it on soon as you hit 2nd gear. I don't know the details of your set up so I'm assuming alot. A good buddy of mine(long time member here) blew through an SC the first time out with it. 500+ break in miles as well. His old RXT had hundreds of passes on it and wanted to toss in another one. He saw the luck I had with the SC so he tried one. Literally the same night we both killed our SC Clutches. He tried a Tilton but wasn't happy with that. Right now he has an RXT 1200 in his car....has yet to be back to the track to test it out.
Hello, there are several factors at play here. It is possible by reducing the overall thickness of the (2) discs to cover the spline area of (1), the discs can fight each other and punish the shaft. You also have typically now four friction surfaces instead of two friction surfaces typically with higher coefficients of friction. This is a delicate balance and the dimensional tolerance of the splines and heat treatment of the hubs can play a significant problem, either to hard, or too soft. We have not seen the issue with our clutch nor the clutch we've based ours on. Rest assured, if there are any issues in the future, we will treat it with high priority and take care of the customer as we always do.
05-15-2022, 07:27 PM
Third(and Last) McLeod RXT vs. T56 Magnum input shaft 
