dual mass??? single mass???

[RLDSL]

My DMF is a love hate thing.

Love it in the Utah rocks at very low speeds crawling around bouncing back and forth. It smooths out the clutch work enormously compared to diesel trucks that don't have that feature.

Hate it because it rattles, clanks, creaks and all around sounds like its going to explode when I'm idling in neutral and judging by my records its only a few years old

That said I will probably buy the best SMF that money can buy when my engine blows or the clutch lets loose which could be any day now

Unfortunately, if it's making those kinds of noises already , chances are it's already received enough wear to be a danger to itself ( and your chances of getting home everytime you leave the house ) It's probably already been overtorqued real good a time or two and is running on borrowed time.

When the time comes and you ditch the thing, you will find one of those 12 1/4 " setups with the 2 rows of springs in the hub to be just as smooth if not more smooth but without the drawbacks of worrying about having your flywheel self destruct

 

[fuzzydog]

.... So a SMF on a ZF sounds like an orbital floor sander on a hollow body guitar. ...[/URL]

aha! that explains it - my truck must have a SMF. I occasionally pull pretty heavy loads - a couple of years ago I did about 2000kms with 15,800 lbs (camper and a car hauler with jeep cherokee on it), regularly haul a very heavy camper and pull a 17.5 fiberglass boat (=heavy) in the summer, a week ago I did about 800kms with the car hauler to pick up a car, then a week later did another 500kms to get another car.
At low rpm - ay caramba! it sounds like..well...like an orbital floor sander on a hollow body guitar....! But never had any problems, no slippage so I am guessing it was converted to SMF a while back. I should know soon as I'm pretty sure I'll be changing the clutch sometime this summer.

 

[dave186]

Looks like I am going to convert to a SMF next week. My DMF is slipping, it just cant hold the power im making now. The clutch is only a year old so I think its the flywheel itself thats slipping. I know its my only option, but im not excited about my tranny rattling!

 

[RLDSL]

Looks like I am going to convert to a SMF next week. My DMF is slipping, it just cant hold the power im making now. The clutch is only a year old so I think its the flywheel itself thats slipping. I know its my only option, but im not excited about my tranny rattling!

If you go with the 12 1/4" setup it really doesn't make any noise to speak of My dmf made more noise. I'm running a 30wt synthetic ATFwhich helps a bit I imagine. I had it in there before I swapped the flywheel so Idon't know if it made a difference in noise or not, I'll have to ask a friend who I put some of that in to see, but the 30 wt shifts better and it's a better match than motor oil which has compatibility issues with synchros. I use the Amsoil CTJ , 30 wt synthetic atfs are pretty common and easy to source as they are a standard fill for most big truck manual trannys

If you have a fairly fresh clutch and it's not holding that sounds like what mine did when the flywheel folded. You don't want to be driving that thing very far from the house right now, it's on borrowed time. When I yanked my clutch it measured out like new and was still in perfect condition, but the flywheel was toast where it had slipped internally

 

[franklin2]

I did the lucky mod to my DMF, and have been complaining about the noise ever since. But I am learning a little bit more about it.

The noise is generated by the engine. I am finding out the amount of noise is directly related on how smooth your engine runs, especially at idle. Now the weather is warming up, my truck is idling a little better sometimes, and the noise is greatly reduced. I am finding out if I just barely touch the accel pedal and raise the engine idle about 100rpm, the noise almost goes away.

Besides the different clutch setups, I think different state of tune of each person's engine, is why you will get so many different opinions on the noise level.

 

[dave186]

If you go with the 12 1/4" setup it really doesn't make any noise to speak of My dmf made more noise. I'm running a 30wt synthetic ATFwhich helps a bit I imagine. I had it in there before I swapped the flywheel so Idon't know if it made a difference in noise or not, I'll have to ask a friend who I put some of that in to see, but the 30 wt shifts better and it's a better match than motor oil which has compatibility issues with synchros. I use the Amsoil CTJ , 30 wt synthetic atfs are pretty common and easy to source as they are a standard fill for most big truck manual trannys

If you have a fairly fresh clutch and it's not holding that sounds like what mine did when the flywheel folded. You don't want to be driving that thing very far from the house right now, it's on borrowed time. When I yanked my clutch it measured out like new and was still in perfect condition, but the flywheel was toast where it had slipped internally

Im planning another trip up to Seattle and I will be loaded to about 10,000 or close to it so I ordered a clutch set today.

What truck trans uses ATF? I asked my Kenworth salesman today and he said they didnt stock any ATF for trannys. I have a bucket of 50wt synthetic trans fluid, maybe I will try that. I just put a tranny in a Mack that called for 75-140 synth gear oil.

 

[franklin2]

...What truck trans uses ATF?..

The zf 5 speeds use ATF. If you want a smooth effortless shift in all temperatures, use the ATF. I tried 6 quarts of straight 30w motor oil in mine, and I could not shift it at all in cold weather. I took that out and am now running 6 quarts of 10w-30 motor oil, and I have to double clutch the tranny the first few miles when the tranny is cold. Maybe my synchros are worn more than other people's, but I could not run the heavy oil. Someday when I get the time and the money I am going to try the synthetic oil.

 

[dave186]

sorry, I meant real truck trans not pickup truck. I know the ZF uses ATF but im looking for this 30wt version.

 

[RLDSL]

I
What truck trans uses ATF? I asked my Kenworth salesman today and he said they didnt stock any ATF for trannys. I have a bucket of 50wt synthetic trans fluid, maybe I will try that. I just put a tranny in a Mack that called for 75-140 synth gear oil.

All the old spicer boxes used to spec mineral oil that has been changed to where most are running synthetic 30 or 50 wt atf so they don't have to change out the oil every 15k 3o in cooler temps and 50 year round. I had some 30 wt synthetic atf for my brownie and so I filled my zf with it and it loves the stuff. I really need to switch the brownie to 5o wt though, the 30 is a bit light for that box and I do get some gear rollover noise from it. I don't know how the 50 wt synthetic atf would act in a zf but if you have some , it wouldn't hurt to try it. the 30 makes it shift WAY better than the dino 20 wt even when ice cold

 

[dave186]

The stuff I have I wouldnt call ATF. Its Delo Synthetic Transmission Fluid SAE 50. We use it in all of the Eaton trannys.

 

[RLDSL]

The stuff I have I wouldnt call ATF. Its Delo Synthetic Transmission Fluid SAE 50. We use it in all of the Eaton trannys.

IT still is ATF, just a heavier atf. The standard ATF that most cars run is a 20 wt, the dexron etc and now they even have new low vis 10wt atf, in the slushbox the stuff does less lubricating and more cooling and wet clutch function and fluid coupling function. That stuff you have is very similar to what I'm running. it wouldn't hurt to give it a shot in the zf. there's a few guys running 50wt dino oils in their zf boxes, , that 50wt synthetic atf will shift a dang sight better than any dino oil in that range

 

[82F100SWB]

My PSD has a SMF conversion in front of a ZF from a 94 factory turbo IDI, I was expecting nasty gear rattle et al, but, it's really no louder than what I'm used to hearing out of a DMF setup, maybe a little, but, my Cummins and my old Super Duty with the 6 speed were louder.

 

[dave186]

So heres another question, whats up with the factory turbo trucks clutch setup? There was confusion when I ordered mine because they just asked me if it had a turbo, which it does just not from the factory. I got them straightened out, but there are two different part numbers and he said the factory turbo is balanced different, pressure plate and disc are the same but the flywheel is balanced different. I was unaware of this difference.

 

[Rot Box]

That old dual mass contraption was only hanging on by a spring or 2 and ready to fly apart, anytime....

Ughhh..

Unfortunately, if it's making those kinds of noises already , chances are it's already received enough wear to be a danger to itself ( and your chances of getting home everytime you leave the house ) It's probably already been overtorqued real good a time or two and is running on borrowed time.

Ughhh..


It's a clank-clank-clank...........clank.................clank-clank.......... Is there anyway to inspect it without removing it? Assuming not Its only in neutral with the clutch released.

 

[Pino2234]

Everyone says to convert a ZF to a single mass flywheel but no one talks about price. The cheapest I've seen was $550 for a LUK kit from a company online. Thats pretty expensive. I found out that you can use a Single mass flywheel from a T-19 and 6.9L instead.

I have a 6.9L diesel that I recently converted from a C6 to a T-19 and I have an 85' 7.3L F350 that I am doing the same thing by taking the C6 out except putting a ZF5 behind it. I am going to try the single mass flywheel from the 6.9L first hand.

Also with the noise complaint about the SMF it is no different from a T-19. Infact I think the T-19 is louder than a ZF with a SMF.

If anyone's ever done this let me know.