DTSFab.com (Desert, Trail and Sand)
Automotive Powered Off Road (AKA: Buggys, Jeeps, Trucks, Etc,Etc. ) => Motor and Drivetrain => Topic started by: dsrace on March 08, 2020, 03:22:46 PM
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does anyone have any experience with dual disc clutch's? i have been running one now for 3 years. stage 2 , 200mm flywheel dual disc from KEP. i just sent them an email. i took all this apart, (while the engine is out) because i have some oil seepage that i thought may be the rear main. these engines are know for that area or right behind it. i was looking at the clutch and it looks a little worse for the wear. it is supposed to be rated for 450 ft lbs tq as a stage 2 dual disc. i find it hard to believe i pushed that and i have never felt it slip while running but with out 1st i have had to slip it to take off. now on hard accel in the soft sand or in the trails i prob wouldn't have noticed it slipping a small amount.
any thoughts? does this look normal or like it's gotten hot?
(https://i.postimg.cc/zLcCnbTN/thumbnail-IMG-20200308-143023.jpg) (https://postimg.cc/zLcCnbTN)
(https://i.postimg.cc/gx4q2BJn/thumbnail-IMG-20200308-143735.jpg) (https://postimg.cc/gx4q2BJn)
(https://i.postimg.cc/mz1QVLSH/thumbnail-IMG-20200308-143743.jpg) (https://postimg.cc/mz1QVLSH)
(https://i.postimg.cc/94MPRtR1/thumbnail-IMG-20200308-143749.jpg) (https://postimg.cc/94MPRtR1)
(https://i.postimg.cc/k27v9d70/thumbnail-IMG-20200308-145202.jpg) (https://postimg.cc/k27v9d70)
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yes they look like faint ball peen hammer marks in person as well. the grooves in the friction discs is real also. could the rough ball peen looking marks be some sort of clutch chatter? they are not actual hammer marks just look like it. feel fairly smooth
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That is toasty for sure. Do you have to slip the clutch very much when loading the car into the trailer?
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Get it machined true and flat, get rid of the heat spots, the 6 pucks look ok from here. The new 1st gear will help a lot
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def have had to slip the clutch to load, take off, stay in 2nd climbing hills lol ;D i emailed kep for a call back on mon. i am going to order new friction disc's just because it's apart. i am taking the pressure plate and flywheel in for surfacing tomorrow. shop behind us does just that. sent those pics to the trans builder....he said maybe a floater clutch? i honestly have never heard of that before. anyone know what that is? the marks on the fly wheel and pressure plate can be felt but there pretty smooth.
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the new 3.44 1st gear will stop the slipping while loading and deeper 2nd thru 4th will stop 2nd gear slip lol alot of clutch dust in there as well. doesn't smell like a burnt clutch though.
so i just went look that floater term up. mine has a floater plate already as it is a twin disc. ya know i only have 3 years on this clutch , 6 trips to the dunes and a number of runs back here.
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took the flywheel and clutch to lincoln clutch and brake. so their first statement was how long as that been slipping lol so the pic of the flywheel only has those marks on the out ring or outter half of the surface. found out why....my pressure plate is smoked. it got hot enough that its surfaced warped, btw my flywheel weighs 14 lbs. for some reason i thought they were 11 lbs normally on the 200mm 091 trans??
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forgot to include the pic of the pressure plate. with just a stright edge you can see the warpage. 200mm stagw 2 kep pressure plate.
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so just for my info , i went and weighed the steel floater plate and second friction plate.......5 lbs! i will ask kep what a standard single disc clutch flywheel weighs 200mm. just curious how much weight that adds to the assembly on top of the extra 5 lbs from the twin disc.
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called KEP this morning and asked them to open the email and look at the pics. they say the pads barely look lapped in and that the spider web ball peen looking marks are normal wear marks for a dual disc clutch. pad thickness new is .200 and limit is .182. not a huge tolerence imo but apperantly they last quite a while. so thinnest pad on my clutch is .194, thickest is .198 and the floater plate is not warped, about .002 under new spec. pressure plate was the only part warped. no signs of bluing like extreme heat. this explain the weird wear pattern at the flywheel as well. they asked if there were signs of the disc center striking the flywheel bolt head.....no.....asked if i installed the pressure plate correctly......i said theres only one way to install that and a tq spec for the bolts. i then asked if it could've been shipped to me already warped, they said every one of there products are checked before shipping. thats amazing if its true. never would've guess that hammered look is normal wear pattern for a dual disc!
rated for 570 ft lbs tq
200mm stage 2 dual disc.......disc .200 new .185 limit
flolater plate .187 new and .182 limit
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How much heavier is a dual disc compared to a single?
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It's not just the weight. A small diameter dual disc will shift easier than a large diameter single disc of equal tq capacity. That is the main reason to use a dual disc other than the much smaller dual disc diameter allowing the engine to sit lower in the chassis.
Was this a new setup or a second hand one?
Te discs,floater and the flywheel look pretty good,IMO. The question is ,what caused the warped PP.
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How much heavier is a dual disc compared to a single?
the "lady" at kep claims after they machine the flyhweel for the dual disc its basically the same weight. so measuring the 2nd friction and floater.....those 2 alone weigh 5 lbs. i didnt ask how much a standard flywheel weighs but i know mine weighs 14 lbs.
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It's not just the weight. A small diameter dual disc will shift easier than a large diameter single disc of equal tq capacity. That is the main reason to use a dual disc other than the much smaller dual disc diameter allowing the engine to sit lower in the chassis.
Was this a new setup or a second hand one?
Te discs,floater and the flywheel look pretty good,IMO. The question is ,what caused the warped PP.
i agree.
this was purchsed new with adaptor and starter from kep. she said maybe i put it together wrong.....i then asked if they sent me a warped pressure plate LMAO she didnt like that question as i didnt like hers! it was assembled correctly. i think it may have warped dues to having to slip it so much on take off and loading. several times i had to slip it climbing a dune to stay in 3rd and get it to rev. had to take so much off to surface the press plate it is now at its min thickness. i'm running it anyway! my frictions are at 75% so i put them back in and floater is damn near new on thickness too. i have never ran a dual disc and those wear marks arent like that of a single .....now i know lol
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OK,makes sense now. The heat from slippage and the perimeter loading of the diaphragm would tend to cup the PP. In all honesty,they should have told you so.Those metallic frictions make some serious heat when slipping yet are able to mostly take the abuse.
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not only did they not tell me that but instead asked if i installed the pressure plate wrong! now when i say this i should also explain that i spoke with 2 different techs. 1st on was female and second a male. " she " asked me if i installed it correctly........of course my comment was sure did which is why i now ask if you (kep) sent me a warped one?? struck a nerve with that question LMAO now i know thats a normal wear pattern and i have the max and min spec on the friction pads for a dual disc. good to know i have 75% left. yes i had the flywheel and pressure plate surfaced and re used my friction pads. if i got 3 years slipping them that much......should get even longer now that 1st gear is a 3.44 rather than a 2.23 and the other 3 are deeper as well.
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not only did they not tell me that but instead asked if i installed the pressure plate wrong! now when i say this i should also explain that i spoke with 2 different techs. 1st on was female and second a male. " she " asked me if i installed it correctly........of course my comment was sure did which is why i now ask if you (kep) sent me a warped one?? struck a nerve with that question LMAO now i know thats a normal wear pattern and i have the max and min spec on the friction pads for a dual disc. good to know i have 75% left. yes i had the flywheel and pressure plate surfaced and re used my friction pads. if i got 3 years slipping them that much......should get even longer now that 1st gear is a 3.44 rather than a 2.23 and the other 3 are deeper as well.
Ya gotta admit they likely deal with a lot of mechanical morons.
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Ok, I'm a mechanical moron. Not really but I do have questions about the dual disc that I hope don't sound dumb. I have considered one to have less pedal pressure. How does it make the shifting easier? And some said that they do not feather or slip well; more on or off. I did a quick search with conflicting answers. thanks
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Ok, I'm a mechanical moron. Not really but I do have questions about the dual disc that I hope don't sound dumb. I have considered one to have less pedal pressure. How does it make the shifting easier? And some said that they do not feather or slip well; more on or off. I did a quick search with conflicting answers. thanks
so to answer what i can........i have a stage 2 pressure plate with the dual disc. the stage 2 pp gives me a very light pedal ( with appropriate mc and slave size) full circle friction plates, yet still rated to 570 ft lbs tq on a 200mm ( 8") clutch. a stage 4 pressure plate on a 6 puck isnt even rated that high! the puck clutch offers the least amount of slippage and ease of engagement. these are the reasons i went with a dual disc stage 2. i had a stage 4 puck clutch on the v6. it was a very grabby clutch and the stage 4 pp on a 9" clutch was hell on my knee. i tried every combo of mc and slave i could buy as well as pedal ratio and taller throw out lever arm. it all made it better but my knee would ache for 3 days after a dune trip. waaay to stif and dont just take my word on it, ask enemy, he remembers too lol carl should remember as well. the dual disc with full circle ( organic/ceramic) friction plates is the most forgiving to slipping the clutch as well as ease of engagement short of a clutch with a spring loaded center puck. this is my opinnion based on my experience. you can see for yourself from the pics and the info i included from kep. after 3 years of having to slipp the shit out of it just to take off cause my 1st gear was a 2.23 on a 4.43 r&p let along loading in the toyhauler or slipping it to rev the engine to build boost in 2nd gear so as not to have to downshift to pull the dunes and not back up the line. all that for 3 years and according to kep and fabr those marks are normal wear marks and according to kep my friction pads are still 75%. that unto itself is a testament imo plus my knee doesnt hurt from pushing the clutch lol
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as far as shifting easier.....i cannot say i noticed but i have nothing to make a personal comparison. with fabrs racing background, i bet he does!
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forgot to meantion that the 2nd friction and floater plate weigh 5 lbs even. flywheel weighs 14 lbs. so kep says by the time they machine the flywheel for the twin disc that the weight gain is minimal but it does weigh a little more. they did not give specific weights so if someone knows what a standard single 200mm disc flywheel weighs then we could compare.
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as far as shifting easier.....i cannot say i noticed but i have nothing to make a personal comparison. with fabrs racing background, i bet he does!
The inertia os much less with the smaller diameter dual disc compared to a large diameter single disc even if the same weight total so the synchro rings are able to more easily/quickly match the gear and slider speeds to enable the shift easier/faster. The higher the rpm of the shift,the more pronounced this will be.