Yes, the more expensive, the less repeats it takes me before the learning kicks in.

 

So what are you trying to say?
The 11" clutch with the stock SMF is a bad idea?
The 11" clutch kit from LMC is better than the one from CSK?
Convert to stock DMF?
Convert the stock DMF to SMF?
Buy the $600 kit with the new SMF & 12" clutch?

Proverbs about being burned by less expensive alternatives aren't the type of "answers" most of us are seeking, grasshopper!

 

Nope, it was stock from the factory. Later 'upgrade' kits took it to 12". The larger diameter allows the clutch assembly to handle increased torque loads without slipping. Kinda nice if you're planning a turbo install or other hp/torque mods.

Don't know; we'll see what others have to say. Don't mean to sound cynical, but they're both probably from the same manufacturer.

Uh-uh. Going from a SMF to a DMF adds complexity and cost, and accomplishes no real gains in terms of power reliability or smoothness.

[QUOTE]Convert the stock DMF to SMF?

A good ida. Lot of archived threads about the benefits of this. Usually, though, it seems to be most attractive when the flywheel needs to be replaced. Then the overall cost of the entire conversion kit is actrually much cheaper than the cost of a new DMF and matching clutch set.

Ahhhh... Now THAT'S the question. Next summer, I plan to install a turbo. Sooo... would it be better to spend an extra $300+ up front and have no clutch hassles for a LONG time, or try to get by with a cheaper solution. Basically, it's a $550 bet. This includes the driveline mods ($205) and 6 hours of my time ($18).

My gut feel here is to spend the money for a known high quality solution, and get on with things. I've tried twice now to be cheap - once with used oil as fuel and once with the piece-together clutch idea. Both times ended REAL badly.

 

As I said, I have been running the DMF on my 93 turbo and it has 225kkm on it and is doing fine. I towed a 27' fifth wheel up some pretty step hill and the DMF never complained about it. The tranny probably could have used a cooler thou as my Mercon was burnt and black when I changed it at 160kkm.


Seb.....

 

Please tell us more - specifically how you did a "piece-together clutch" AND how it ended "badly"....

BTW, the ZF-5 conversion is going to be done on is the second truck listed in my signture - the manual tranny with the Banks turbo....

Seb, sounds like you've had really good luck with your DMF. I would be really hesitant to install the one I have as-is withouth an (expensive) rebuild. I got it second hand and have heard too many horror stories about when they go bad.

 

I re-read your response and think there may be a bit of a miscommunication here. What I meant when listing this option is to use the stock DMF, but drill it and bolt the two (dual) pieces together to make your own SMF that is compatible with the 12" clutch and PP set - as opposed to buying the TRUE SMF that they sell with the conversion kits. Re-reading your reply I get the impression yoy are talking about replacing the DMF with a SMF - not converting a DMF into a SMF.....

 

I have a 6.9 smf drilled and taped for the 11" plate using the LUK revision clutch. It has been in my 88 450 7.3 zf for atleast 4 years. No strange noises and it works just fine.

 

Do you mean the 12" LUK clutch kit?

I thought that 11" is the standard size for the 6.9 SMF (as in the 11" kit for the '87 6.9 referenced above).

I'm confused....

 

CJ -

You're right, I misunderstood what you meant about 'converting' the DMF. Got it!

As far as how my clutch swap 'ended badly', the short answer is in post #7. I wasted $96 spent on a 12" pressure plate with a 1.25"/10spline hub, and almost $300 on driveline mods that had to be undone. Pretty expensive lesson. I started all this with a Rhino HD clutch set for an 85 6.9. I set aside the disk that came with the set and purchased the disk I mentioned above. (Sorry, I don't have part numbers in front of me. If you need them, I'll dig them up.) Problem was, although the disk was listed as 12", it was actually 12.125". Just enough to wedge itself into the PP. And not really do the job I purchased it for. Lessons learned:

1. Check all measurements. Then double check. Then check once more just to be sure. I wasted a staggering amount of money (for me) and two days of vacation because I didn't do this.

2. The more you know, the fewer mistakes you make.

3. Let someone else 'experiment'! I don't have the income stream to be a pioneer!

 

Yes, 12" clutch, my mistake.

 

Sounds mighty interesting! Do you have the part number for the 12" clutch kit that you used? Why did you have to have your flywheel drilled and tapped? Were the bolts physically larger, or were they in the wrong places? Also, where did you find your clutch kit? 'Preciate any info you can provide!

Dave

 

6.9 's use a smaller pressure plate than 7.3's. The clutch pack came from LUK clutch. It is the revision for a smf. You can buy the complete package from LUK including the flywheel. I found out a 6.9 flywheel will work providing you drill and tap for the larger plate. Sorry, cant find the the paper work on the part #.

 

One other difference is that the 11" pressure plate has 3 contact pads with bolts & alignment dowels, and the 12" has 4 contact pads with bolts & alignment dowels.

I would think that by the time you had the flywheel turned, drilled, and tapped, that it would be nearly as expensive as buying the custom SMF for the 12" disk.....

 

Well, I did a little calling around today and found what I think is going to be my best deal. An independantly owned local parts house called Big Wheel (CarQuest affilliate) has a new 11" clutch kit for the 6.9 & 5-speed combo for $164. Although that's 12 bucks more than the one from Schucks (CSK) its more than worth it.

The kit is sold under the brand name of "Rhino" but the guy at the parts counter said it was manufactured by LUK. On top of that, if I have the flywheel resurfaced then the clutch kit will be covered by a lifetime warranty - vs the 90 day warranty on the Schucks kit. Best of all, Big Wheel can resurface the flywheel for me for only $25 - a service Schucks doesn't even offer.

So, I can get the whole shebang, WITH a lifetime warranty AND a resurfaced flywheel for right at $200 after tax - and I'll be supporting an independant local shop instead of a big chain. That's a win-win all the way around in my book.

 

Do you have the part #?? My local clutch shop handles Rhino clutches. That's where I bought the one that started this mess!