Recommendations for Mustang (10.5"/10 spline) clutches?

[cgrey8]

When I 1st started this V8 Ranger venture, I got a lot of used parts off eBay. Standard kinds of parts, I got from AutoZone just because it was convenient, and wasn't likely to be enough different to matter (e.g. hoses, gaskets, etc). For more specialty stuff (e.g. Universal spark plug wire kit, clutch, electric pusher-fans, high flow fuel pump, etc), I went to Summit Racing.

Back then, Summit sold the FMS King Cobra Clutch kit. It promised better than OE performance with a stock pedal feel. I think it was somewhere around $180 and was actually made by Valeo. It even had the Valeo emblem stamped right on the plate and clutch disc. When I swapped in with the 331, I used some kit I got off eBay sold by some performance shop that promised it'd be just as good as the FMS/Valeo kit for $140ish IIRC. It's worked, but I don't feel it had quite the holding power the original King Cobra had. Although that could've had more to do with it being bolted to an engine with objectively more torque than the stock Explorer 302 the King Cobra was clutching for. Overall it's been fine and is still working 10 years later.

The problem right now is the throw out bearing is starting to squeal. It doesn't happen all the time, but it's happening with increasing frequency which can only mean it's trying to let me know to do something about it before it makes that decision for me. If I'm going to take the time to drop the trans, I might as well replace the clutch & rear main seal while I'm in there.

So that brings me to the question of what clutch should I go with? Even with the added torque of the 331, I just don't drive the truck hard the VAST MAJORITY of the time. Thus stock-like pedal pressure, smooth engagement, and reliability are far more valuable to me than "Stage" clamping performance. Hell, an OE replacement clutch kit from Autozone ($115ish) would probably be just fine. But if I can find something better for a reasonable difference in price, why not? So I went looking in the typical places.

Looking on eBay, I see a LOT of suspiciously counterfeit Valeo clutches. The listings have Valeo claimed, but the images, I don't think are. And then there's are lots of clutch brands I just don't recognize, like McLeod and Luk. And even if those are good brands, I don't know enough about them to know what I'm looking for on the images (or once delivered) to pick out the counterfeits from genuine ones. I found similar frustrations when looking on Amazon.

So I went back to Summit Racing. The FMS clutch I find there is no longer called the King Cobra AND has a MUCH heftier price tag (over $300) and doesn't even include a replacement pilot bearing (the King Cobra kit of yesteryear didn't either). But I did see the McLeod and Luk brands there too along with some others I'd also never heard of before.

The Summit Racing branded clutch looks fine and is probably perfectly acceptable. It's certainly got an affordable $125ish price tag and includes the throw out as well as a new pilot. My only observation of concern is the plate only has 4 springs vs most plates for these engines (including AutoZone's Duralast) having 5 springs. I have NO CLUE if that's even a valid concern. I do believe Summit uses quality manufacturers for their Summit Racing branded products. I have a Summit-branded ignition box that, based on its construction, I'm pretty sure was made by MSD. Their box has lasted longer than the MSD 6A it replaced. So unless someone has a compelling reason not to use their clutch, I'm perfectly fine picking one of these up.

But before I bought something, I thought, maybe there's others more familiar with this area that could offer some insights I might want to consider before making a purchase.

[MalcolmV8]

Unless you know exactly what you're looking for I'd stay off Amazon and eBay for the very reasons you sited. A good source of Mustang parts is LMR. They're not always cheapest but somewhat reasonable but the huge upside is no counterfeit parts and their customer service is fantastic. Might add that to your search choices.
FYI McLeod is a solid clutch company. I've run lots of their various clutches, twin disks etc. in various projects over the years with great success. I have no clue if they have anything that fits your requirements but if they do it's a legit clutch company.

[cgrey8]

You weren't kidding about them not being the best priced. Even their Stock/OE replacement clutch kits are double the AutoZone Duralast or Summit Racing branded clutch kits. I can understand being 10-20% more, but it begs the question what justifies that hefty of a price tag for something like a clutch kit? I get it if the part is a rare or completely out of manufacture part. But a clutch kit used on a very popular vehicle and across a very wide number of years? I'm just having a hard time understanding what the justification is.

Thanks for the response and the confirmation that my suspicions about what I was seeing on eBay were justified.

[MalcolmV8]

Ah that's too bad on their clutch pricing. They sell a lot of reproduction parts you cannot get anywhere else which I think is what made them popular and well known but you have to know your prices as some of their stuff is decent and some items they just gouge you.

[cgrey8]

Well one thing I didn't notice is the price for the Summit Racing clutch was a Thanksgiving sale price. When I looked at the clutch again later this week, the price went up to $138. While that's not a massive increase in price, it puts it above the price of other aftermarket brands, like the Zoom (MU48-1 for $127) & Luk (07-042 for $117) both of which are also sold by Summit. Although both of those offerings are advertised as OE Replacement, which begs the question, how much better are they than any other OE Replacement clutch kit you'd get at a local parts store? Probably none...

Just looking at the clutch discs, the construction is IDENTICAL between them. And I'm pretty sure I can see the Raybestos emblem stamped on the Luk. The pressure plates are similar, but not identical.

And while I'm talking similar products with common origins, the AutoZone Duralast NU31175 ($114) on AutoZone's website is THE SAME PICTURE as Summit's website uses for the Zoom MU48-1...so literally no difference other than the price IF the pictures are actually representative of what you'd receive.

But then I got to thinking maybe other local parts suppliers other than AutoZone have options worth considering. Napa did have Valeo-branded kits which are priced up where I'd expect them, in the $200+ range.

Then I found O'Reillys has a Power Torque Clutch Kit for $125 (K0048-01). It seems Power Torque is an O'Reillys brand, like Duralast is for Autozone. What's interesting about this kit is it explicitly advertises having 10% higher clamping force than OE Spec which is about the same all the other "Stage 1" aftermarket pressure plates. Any more than that, the pedal effort increases noticeably above OE. And for my purposes, I don't want a heavy clutch pedal effort. Neither my driving habits nor the engine's capabilities can justify it.

Purely based on the similarity in part numbers, I thought maybe this kit was similar or the same as the Zoom kit mentioned above. Using the picture on the O'Reillys website and the 360 viewer, I tried to find any other offering that had similar disc and plate construction. I found some similar constructions, but I couldn't find anything obviously identical. Googling around to find out, I discover there's a company called Power Torque, but their website looks like they sell industrial equipment. Then there's a Power Torque Transmissions, which looks like a stand-alone company, but when you click Shop Now, you get taken to the O'Reillys website. Then I stumble across a page that indicates PowerTorque friction material was developed by Raybestos. But then I realize the page was from the Raybestos website explaining that PowerTorque is their trademarked branding for the friction material in lock-up torque converters, not manual trans clutches. So I'm no more informed than I was before. I have no clue who actually makes this clutch.

But what I didn't find is anybody claiming the Power Torque clutches as unreliable from 1st hand experience. Maybe that's because few people are using them? I'm sure there are examples of bad experiences, but I suspect ANY product offering is going to have an unsatisfied customer somewhere. The only negative comment I found was some anonymous poster on an off-roading forum that claimed to be an O'Reillys employee and referred to their products as "junk parts." But that was a generic reference to all of their products, not specific to the Power Torque clutches as the post was asking about. And being the person was literally making the post as "Guest", I don't exactly put a lot of value behind his contributions.

So I've got choices in the sub $150 range...Zoom/Duralast, Luk, Summit, or this O'Reillys Power Torque kit.

[MalcolmV8]

They likely all come from the same place as you suspect. One large corporation makes them and just sells them under various brands at various locations. Very painful to figure out what you're getting.

[cgrey8]

I don't doubt that there are only a few companies that make these, I also understand that just because the same company makes them, there can be quality differences between the various products they make based on the purchaser's specs. So differences in material, differences in construction, etc. Point is, made in the same facility does not mean the products are functionally equal.

I remember back when I learned that most of the off-brand (and some name brand) motor oils actually come from the same plant. Walmart's SuperTech, Costco's Kirkland oil, and most all of the auto parts branded oils (Autozone, Napa, etc) are all blended by Warren Oil. But that doesn't mean that all those brands are the same oil for the same advertised weight (e.g. 5w30). The base stock combinations, detergent packages, anti-foaming agents, and last-line-of-defense lubricity ingredients (i.e. zinc) are all different. Each brand, from what I understand, specs their own formula, not because they think that combination is better, but in some cases, there might be legal requirements that they be some amount different than a competitor so they don't get hit with lawsuits. Even if the suit can't be won, it is still a cost to defend, and some larger companies will weaponize the legal system to cripple their opponents, even if they have NO actual legal standing what-so-ever for the suit they are making. But this is effective.

Here's another example you may have never thought about. Do you remember the smell of Crayola Crayons and how the off-brand crayons never smelled the same? Crayola actually trademarked that smell (yes a smell can be trademarked) so no other crayon company can, legally, make their crayons smell that way.

While that's a huge tangent from the topic, it's one of the reasons I've felt Tort Reform is so needed here in the US to prevent people from filing frivolous lawsuits with the expressed purpose of harassment. Tort reform would give defendants in civil suits the ability to counter-sue for legal damages if they are NOT found liable for a suit brought against them, thus discouraging the filing of suits unless the plaintiff believes they have a real case they can win. In the extreme, this has its own set of negative consequences if taken too far. The fear of losing could discourage people from using the legal system for legitimate issues, triggering them to turn to less-than-legal options to solve their issues (think intimidation tactics of mobs and cartels).

So like so many things, the devil is in the details. Unfortunately too many lawyers benefit from that system, and what profession makes up the most of law-making politicians in government? Lawyers. So will that ever get fixed? Probably not.

But as it relates to this topic, I decided to go with the O'Reillys clutch. I've got it here in the garage waiting on me to get time to replace it. Replacing the clutch will require the flywheel be surfaced. So one thing I'll likely do is really look at the existing clutch and see if there are any obvious signs of wear or eminent failure. And if everything looks good, I may just reuse the existing clutch, only replacing the rear main seal and TOB. But if the wear material is cracking, is anywhere near the rivets, or there are obvious hot-spots on the flywheel & plate, I'll take the time to get it resurfaced. When I was younger, it wasn't a HUGE deal dropping the trans. But nowadays, the most annoying part of the whole endeavor is muscling that T5 back up without a transmission jack. That aspect will weigh heavily on whether I take the flywheel to be resurfaced & go with the new equipment...likely biasing me more towards doing it even if all looks perfectly reusable. Add to that, the damn TOB hasn't squealed in days. But I've got vacation time coming that I have to burn before the end of the year, so the trans is getting dropped and that TOB replaced.

[cgrey8]

Well, I've got an update. I TRIED to go with the O'Reillys Power Torque (K0048-01) and boy what a mistake that was. Despite this being the model number listed for an 89 Ford Mustang 5.0L, the pressure plate is for a much older clutch fork and bell. Those pressure plates require double the amount of throw out motion to fully engage and disengage. Had I known about there being 2 different 10.5" pressure plate specs, I might would've noticed that this plate's fingers stick out way further. But not being aware of there being incompatible plates, that didn't tip me off.

But what did capture my attention was just how far I had to preload the fork before it would completely disengage. Then when I went to try to drive it, I discovered it slipped like CRAZY. So I backed off on the preload and I could barely get it into gear, but when in gear, the parking brakes were strong enough to make it slip. This indicated to me that the throw required to completely engage and disengage was just way MORE than my previous clutches.

Searching around, I find this video where another guy ran into just this:
Youtube > Don't make this T5 transmission swap mistake on your Mustang!

And you can see a similar thing here with my old (working) clutch right next to the newer one:

Notice how much further out the fingers of the clutch protrude compared to the older one. I did notice that, but at the time, I just didn't think anything of it.

But what I find surprising is just how little info there is out there. I would think incompatible pressure plate setups for the same flywheel would be something more well known and more talked about. But I'm just having a hard time finding info on this so I'm thinking there's something I need to know to get hits on this info. What would that be?

The good news is the old clutch was still in GREAT shape. For 10 years of daily driving wear (a bit less since 2020), I thought it was quite impressive. BOTH the flywheel and pressure plate wear surfaces still had their original machining marks in their surface. There were only a few places on them that had smooth spots.

As for the clutch itself, roughly 1/2 the block thickness was still in tact. And once they are worn smooth, there's still at least their thickness worth of more wear material before you hit rivets. Although I suspect if the material ever wore that much, the clutch wouldn't have enough clamping force anymore to be really useful. But being that's the only working clutch I had, I tore it all back down and reinstalled everything with the original clutch. The good news is if I had to do this yet again a 3rd time, I could do it in just a few hours. Although at this point, I'm hoping to get another 10 years out of it particularly now that I work from home full time and the truck doesn't see nearly the daily driving miles it used to.

The other interesting thing I did note is I recognized the clutch disc as the same construction and design as the Zoom/AutoZone clutch disc. The metal between the center and the friction material even has that same blue tint.

In this picture, the blocks and rivets look shallower than they actually are because they are covered in dust material. When I used my finger nail to feel the real depth, there's still substantial thickness left...but not as much as the new plate had.

But back to the issue with that O'Reillys clutch, I don't understand why that kit shows as the OEM replacement for an 89 Mustang 5.0L. I considered that maybe my kit just got packaged with the wrong pressure plate. But even the picture on their website (and store) shows the more-elevated fingers. Does anybody know what's going on here and why this era of 5.0L Mustang would legitimately use one of these older-style plates?

As for what setup that plate is made for, I'm GUESSING it's for this fork-n-bell or one very similar to what's seen here:
Click for image
For some reason, the forum won't display the image, so I had to include it as a link instead of an embedded picture.

Notice how the TOB is roughly 1/2 way between the pivot and the push-point. Being located here would give the TOB WAY more travel distance, which that style plate requires.
Also notice, that's not a stock 10-spline T5 input shaft either making me wonder if this is a T5 application at all. But the pic still shows the point...

Compare that to the T5 clutch fork used with 79-93(ish?) Windsor blocks (maybe other applications too???):

Notice how much closer the TOB is to the pivot point and how much further away the pull-point is. Locating the TOB so close to the pivot point significantly reduces the travel-distance of the TOB, and thus would require a different pressure plate designed for this dis-engagement distance.

What's interesting is I suspect the newer plates would work on the older setups, albeit with noticeably heavier petal force but not requiring near the same distance of travel to disengage the clutch. I guess there's also the possibility the older setups would over-travel the fingers and possibly damage the plate.

There's also pictures out there of center-pivot forks for older Mustangs, like this one:

But that bell is huge and doesn't look like it bolts to a 302 Windsor block at all. This looks more like a bell for some big block.