The Official LUK 07-225 SMF Clutch Kit & ZF S5-42/47 Rollover Noise Poll

I installed a LUK 07-225 Clutch Kit in my 6.9/7.3 IDI with a ZF S5-42/47 and..

  • I am experiencing a terrible racket...

    Votes: 1 7.1%
  • I have some additional noise, but nothing really concerning or unbearable.

    Votes: 10 71.4%
  • I can't tell any difference from before!

    Votes: 3 21.4%

  • Total voters
    14

HudsonvilleHornet

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When I was researching clutches, I had to dig around quite a bit to get to the bottom of things. One of the worst offenders was people taking about their experience, but only referring to "the SMF kit" they installed, and not brand and particular kit number. Or just referred to a Photobucket image that is no longer there, or "see my signature for details" but they no longer own the truck. Anyway, I thought I would attempt to put this together to try and centralize some data that might be helpful to others in the future faced with making the same decision.

I thought about making a lot of options to cover age of IP/injectors and other possible contributing factors, but I think I am just going to let people talk about details in the thread if they care to and not have 17 different possible responses. Never in my life have I created a poll on a discussion forum, so bear with me as there might be some bumps on this ride..

For the record, I am in the no noise camp, with an '87 6.9/S5-42, with 124k on the clock. I just bought the truck recently, and it came with no real known history or records, but I think the IP and injectors are getting tired - they're slated for replacement which I am doing as soon as parts get here. There are some signs of everything being original, but I can't say for sure. I refilled the transmission with 4 quarts/1 gallon of Redline D4.
 

Nero

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When I first got my '88 single cab 2x4, it had a dmf in it. Considerably quieter than my dad's' 89 4x4, but it was slowly falling apart. Put a SMF in it and I get gear rollover noise when I'm at low RPM's or taking off, but that's all. It's not too loud, and I'm used to it.

We sold the '89 to some kid who wanted a more reliable idi, and he was concerned that it was a release bearing, tried telling him it was just because it had a SMF in it... He pulled the trans and replaced it.. And lo and behold, no change haha
 

frankenwrench

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I installed the luck smf on my 91 back in 2016 and at low rpm I get some roll over noise, but that's it. Love the conversion, and only notice the extra noise when taking off in 2nd gear. Had the tranny out last year because of my rear main seal leaking and noticed no real wear or heat marks on pressure plate or flywheel and I tow regularly at 14-17k. I also have a bit more power than stock. Cdd stage 1 injectors, 110 ip, 3582 cdd turbo, intercooler, and I run 3.73 gear ratio(2003 SD rear end). Simply love the smf from Luk. My $.02
 

ih8minimumwage

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I had the same result (no noise) with my ZF5 swap out of a 97 with a dusted Powerstroke (I don't recall how many miles it had). Just drained and refilled with an added quart of Synchromesh and was expecting all kinds of rollover noise that never came (granted, I do have more soundproofing to do in the cab).

Had an intermittent loud squeak noise from the clutch area when first installed, but even that disappeared after I put some miles on it.
 

chillman88

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On the same subject, what range is everyone calling low rpm? Are we taking 700rpm or 1000rpm? I'm more asking in your experience what RPM does yours STOP making noise?
 

BrianX128

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Stops at higher rpm the lower the gear for me. 1500 rpm in first, at idle sounds like there are 12 extra gears bouncing. 1200 rpm in second but less exaggerated noise. 900 rpm in third lugging through a traffic light a little chatter but not super noticeable. Nothing in 4th or 5th.
 

The_Josh_Bear

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I installed the luck smf on my 91 back in 2016 and at low rpm I get some roll over noise, but that's it. Love the conversion, and only notice the extra noise when taking off in 2nd gear. Had the tranny out last year because of my rear main seal leaking and noticed no real wear or heat marks on pressure plate or flywheel and I tow regularly at 14-17k. I also have a bit more power than stock. Cdd stage 1 injectors, 110 ip, 3582 cdd turbo, intercooler, and I run 3.73 gear ratio(2003 SD rear end). Simply love the smf from Luk. My $.02
Lol "a bit more power than stock", like double. :fight: Nice setup!

I got the LuK for my 89 at least 7 years ago, and while I don't put a lot of miles on the ol girl, I do tow a 4.5k trailer and give the skinny pedal heck. It's held up great.

My rollover noise issue is in the rearview mirror for me-- once I put it in she had some bad noise at idle and low RPM.
So I drove around a week and realized the noise went away very quickly with RPM so I just turned up the RPMs to 850ish and bam, no more noise.
:peelout
 

cozinsky

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Some noise but not unbearable. I run Redline synthetic ATF.
 

Jesus Freak

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I'm not sure what flywheel is in my truck, but I've reconciled myself to the rollover noise. I kinda like it. At red lights if I decide I'm tired of hearing it, I just hold the clutch down. And when I'm going slow in a neighborhood or parking lot, I like the "truckyness" factor of all the racket. I'll tell you this, when I first put it in and I heard all that I thought something was wrong.
 

IDIBRONCO

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On the same subject, what range is everyone calling low rpm? Are we taking 700rpm or 1000rpm? I'm more asking in your experience what RPM does yours STOP making noise?
I've had the same exact SMF setup in three different vehicles now (2 85 F250s and the Bronco). I have no idea how many miles are on it now. I don't do much towing and most of what I do is relatively light, in the 2k-3k range at a guess. I'm running Valvoline synthetic ATF it the trans. Like most of the answers, I have some noise at low RPM. Since I haven't had a tach in any of the three vehicles, I can only guess at the RPM. I would have to guess that most of my noise is gone by 1000 RPM and it's probably all gone by 1200. Since it had been several years since I had much to do with ZF5s and I installed the SMF at the same time as the ZF5 in my first F250, back in early 2006 or so, I had forgotten that the noise wasn't normal so it never did bother me.
 

renjaminfrankln

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If I could get a DMF at a reasonable price I would have. Seeing that one was not available, the SMF worked just fine for me. The noise is annoying but you get used to it quickly.
 

03wr250f

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@nerIs spot on!

Never ran a luk, but 1 autozone smf and clutch which held up amazing to what I put it through, and am now running a south bend 13" flywheel And clutch.

The autozone clutch went through 3 or 4 trans fluid changes, (fluid changes not related to noise,) no change.
Rebuilt motor balanced rotating assembly and new south bend clutch. No change
Rebuilt trans, no change, developed a leak at front imput seal, so i swapped trans, no change

As everyone else has said, low rpm noise stops somewhere around 1200rpm
Nothing to be concerned with.

The one we need to hear from is @IDIoit
He had a nasty bout with rollover and what he did to get rid of it. But it went far above 1200 rpm and was quite loud
 

lotzagoodstuff

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I had both versions in my red and white truck. Rollover noise was definitely present at lower RPMs. Turning up the idle slightly dramatically reduced the noise for me.

The other question you have to ask is regarding the value of a quiet flywheel versus the longer term potential of the DMF coming apart and potentially damaging the trans. Lastly: There’s “making” a SMF out of a DMF via the Lucky Mod, which I haven’t seen anybody talk about in many moons.

Good luck to all you manual shifters out there.
 

IDIBRONCO

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The other question you have to ask is regarding the value of a quiet flywheel versus the longer term potential of the DMF coming apart and potentially damaging the trans. Lastly: There’s “making” a SMF out of a DMF via the Lucky Mod, which I haven’t seen anybody talk about in many moons.
The noise and vibrations that a bad DMF flywheel makes throws a whole new light on the minor noise that comes from a SMF flywheel. That Lucky Mod sounds interesting enough for me to want to hear more about it. Not that I'm going to give up my SMF any time soon.
 

Nero

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I am @nerls now Y'all see it!
To put it into perspective, my truck I bought from the original owners back in 2011, and they used it to tow a 5th wheel solely through California and to Washington and back. By the time I got it, it had 72k on it, and I had to swap out the dmf in 2013 due to slow down rattle. I looked into doing the lucky mod, but I decided almost $600 (at the time) was worth it to just do it right. I was out of state for school and wanted to make sure I made my 1200 mile trip home, plus my remaining 6 months of school. I would never go back to a dmf in my rig.

If I remember right, the Lucky mod was a mod by a user that went by Lucky, all you do is drill out the dmf and put bolts in to "lock it in place"
Odd our trucks use dmf's, they don't really exist in the heavy duty field. Solid flywheels with twin friction discs.
 
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