Posts
554
Joined
7/16/2019
Location
Chattanooga, TN, USA
Edited Date/Time
10/9/2020 1:21pm
I recently replaced the clutch plates, steel and friction, in my 160 hour 2019 KTM 450 SX-F as it was slipping a bit due to wear. I replaced with the microfische called for OEM clutch pack KTM part number 79532010033 consisting of:
qty 8 lining disc part # 79532011000 1.95 mm
qty 7 intermediate disc part # 59032010200 1.4 mm
qty 1 intermediate disc part # 59032010100 1 mm
qty 1 intermediate disc part # 78932010000 1 mm
Problem I ran into is the newly installed clutch was not releasing/dragging when the bike was running. I was puzzled as the install went without issue.
Long story sort is the issue I discovered is the stipulated clutch pack does not provide what came with the bike from the factory. My son has an identical bike with the factory original/as delivered clutch still in it so I took his apart to have a look see. I discovered he only had one 1 mm intermediate steel disc, not the two called for in ALL documentation/parts fiches I've seen and read anywhere. I took his clutch pack out and put it in my bike and my observation was confirmed as my bike functioned flawlessly with my sons clutch installed. The clutch pack out of his bike as provided from the factory consisted of 8 - 1.4 mm steel plates and 1 - 1 mm plate. It DOES NOT have 2 - 1 mm steel plates, only one.
I'm totally baffled that I've not read of any other KTM owner having this same problem. ANYBODY changing a clutch pack in a current 450 would experience the same problem and have difficulty diagnosing if they didn't have an identical bike to use for comparative purposes. The wrong clutch pack is specified for a replacement. Only one 1 mm plate is required, not 2 as provided and stipulated in the parts catalogs.
As such my stack was 0.4 mm too short resulting in the clutch dragging. What really sucks is my "new" and incorrect $125 clutch pack was destroyed as I rode the bike with the clutch dragging while I was trying to figure out what was going on. It destroyed/burnt half the "new" friction and steel plates resulting in my having to buy another clutch pack. I'll have to reuse one of the "old" 1.4 mm steel plates in the second replacement clutch pack I'm now buying as it will also come with 2 - 1 mm steel plates.
Frustrating and puzzling. Any thoughts???
qty 8 lining disc part # 79532011000 1.95 mm
qty 7 intermediate disc part # 59032010200 1.4 mm
qty 1 intermediate disc part # 59032010100 1 mm
qty 1 intermediate disc part # 78932010000 1 mm
Problem I ran into is the newly installed clutch was not releasing/dragging when the bike was running. I was puzzled as the install went without issue.
Long story sort is the issue I discovered is the stipulated clutch pack does not provide what came with the bike from the factory. My son has an identical bike with the factory original/as delivered clutch still in it so I took his apart to have a look see. I discovered he only had one 1 mm intermediate steel disc, not the two called for in ALL documentation/parts fiches I've seen and read anywhere. I took his clutch pack out and put it in my bike and my observation was confirmed as my bike functioned flawlessly with my sons clutch installed. The clutch pack out of his bike as provided from the factory consisted of 8 - 1.4 mm steel plates and 1 - 1 mm plate. It DOES NOT have 2 - 1 mm steel plates, only one.
I'm totally baffled that I've not read of any other KTM owner having this same problem. ANYBODY changing a clutch pack in a current 450 would experience the same problem and have difficulty diagnosing if they didn't have an identical bike to use for comparative purposes. The wrong clutch pack is specified for a replacement. Only one 1 mm plate is required, not 2 as provided and stipulated in the parts catalogs.
As such my stack was 0.4 mm too short resulting in the clutch dragging. What really sucks is my "new" and incorrect $125 clutch pack was destroyed as I rode the bike with the clutch dragging while I was trying to figure out what was going on. It destroyed/burnt half the "new" friction and steel plates resulting in my having to buy another clutch pack. I'll have to reuse one of the "old" 1.4 mm steel plates in the second replacement clutch pack I'm now buying as it will also come with 2 - 1 mm steel plates.
Frustrating and puzzling. Any thoughts???
The Shop
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You might reread my post.
Edit: Finally read the entire post. You burnt up the new pack? That’s usually called slip, not drag. I see where the shorter pack could cause this, but it’s still odd because there should be room for 0.4 mm wear without slipping. Also, every KTM DDS I know of uses two 1mm plates, not one.
Are you on the OE slave cylinder? Flushed the fluid recently?
My issues were the clutch was dragging when stopped in gear. With clutch lever pulled all the way to the bars there was considerate drag/lack of disengagement.
Additionally, when under power on track it was slipping due to shorter stack not receiving "enough" pressure from the spring.
With my sons clutch pack I had zero drag and it didn't slip under power.
FWIW, I'm sharing this info so others might not have the same problem. I have no agenda...
Regarding your son’s bike: Either all the KTM literature and fiches are wrong, or his bike got 8 1.4mm plates by mistake.
FWIW, I have a ‘19 Husky 450 and it has two 1mm plates.
The KTM belleville resembles the force-adjusting variety at the bottom of this page:
https://bellevilleintl.com/engineering/load-vs-deflection/
I had a similar issue with my 300, comparing the two parts dia. they look the same.
I don't know if the 450 has an x,y,z adjustment on the spring ring, but if it does that's
probable the issue.
I had to readjust the spring tension from the stiffest setting ...where it was set which I think is X, to the Y setting.
Also the washer (ktm calls it) that sits under the belleville spring is directional....should have "top" stamped on it.
Too much spring tension will cause excessive drag.
I'm having similar issues, and would be keen to understand possible reasons.
Medium / Hard Enduro riding - Australia.
I'm on my 3rd clutch on a KTM 450 EXC-F 2021 - and in ~10hours - it's already burnt out.
Oil used - Motorex 10w50 & Castrol Power1 Ultimate 10w50 (Both are JASO MA2 compliant)
* Rebuilt Clutch Master / Slave cylinder.
* Replaced Clutch Slave piston
* Bleed clutch line a dozen times.
* Replaced Inner Hub dampers each time clutch plates replaced.
* Removed Clutch pack to remove clutch oil cooler nozzle - to check if it was blocked.
* Removed Clutch pack again to test clutch oil cooler nozzle was operational with engine running - to confirm oil pressure from nozzle.
* Checked clutch baskets for notches/grooves.
* Replaced outer 1.0mm steel plate to 1.4mm to get Bellevile Spring to be flat (after a ride it was no longer flat).
Next steps:
* Replace Belleville Spring with a stiffer one.
* Replace clutch pack with Hinson.
* Do a proper lubrication pressure test.
* Remove Oil pressure valve - and check spring length - if oil pressure isn't adequate.
* Through bike off a cliff :-)
I suspect the clutch is slipping under heavy load doing up hill climbs - resulting in clutch burning up and then resulting in excessive clutch drag.
I have no idea why I can't get the Belleville Spring flat using the tensioner when using 2x 1.0mm steel plates (standard) - when clutch pack is above min wear level (>26.4mm)
I think my first clutch was contaminated from a defective o-ring on the clutch slave piston, leaking brake fluid in to the crank-case.
Second clutch may have got burnt out from a incorrectly adjusted 'shorty' lever.
It's possible the third clutch may have got burnt out from not checking the Belleville spring being flat - on tensioner setting II
I've later found I can't get it to be flat without replacing 1x 1.0mm steel plate to a 1.4mm steel plate (Possible hub wear?!)
Any thoughts ?
Cheers,
Dave.
When I have adjusted the position to get the Belleville flat, I have burned clutch plates and it slips.
For some reason, following the manual doesn't work. Always run/mount it in position 2, always work.
Really weird.
So new OEM clutch package, set it to 2 and test.
The “incorrectly adjusted shorty lever” you speak of, if its from MME scrap it. I know of countless burnt up clutches from that piece of shit.
Pit Row
Old thread but I may be able to offer some assistance. I had a showroom new 2022 KTM 300 XC that had slight clutch drag from the factory. I called the dealer, "just ride it, it'll break in." Famous last words.
After a couple of woods trips and one stint on a moto track, the bike was unrideable. It would stall out with the clutch pulled all the way in, causing me to fall over if I didn't give it throttle. I tried all the usual:
Nothing fixed it. I got so desperate I called Hinson Racing, since clutches are their business, and they confirmed 1) they were seeing KTM's with clutch issues from talking to people at tradeshows etc. and 2) they had zero idea what was causing it.
I tried everything and I got so desperate I started looking into "Lemon Law" limitations for dirt bikes, then on a whim I decided to start gutting parts of the clutch and replacing it. In one go I replaced the following (with new OEM parts):
(6) driving sleeves
(1) pressure plate
(1) push rod
(1) pressure piece
...and the clutch was fixed. However, I strongly believe it was the pressure plate that fixed it. After a lot of digging around, I found the account of another KTM owner mentioning cheaper clutch parts can warp under heat/stress and cause issues: https://www.youtube.com/watch?v=y-X8HrDDvQE (skip the ~6:05, and warning, it's slightly wonky translated text-to-speech, but you can get the general idea).
This makes sense. A warped pressure plate will slip/drag out of tolerance and cause poor clutch engagement. (I called Hinson back and told them findings, and they gave me a free t-shirt - I haven't worn that and am keeping it as a trophy).
In general: I owned (notice the past tense) 2 brand new (2022, 2023) Austrian bikes with <0.1 hours on them that both had varying degrees of issues while brand new. In almost all cases, poor metallurgy/part quality was the culprit (the rest of the time it was electronics issues, like the infamous crankcase pressure sensor). Therefore, if something isn't right on yo
ur Austrian bike, assume that potentially a factory part is poorly-made and may need replacement.
tl;dr - My clutch issues on a brand new bike were solved by replacing the clutch pressure plate (see pic below). Later Austrian bikes suffer from inconsistent/poorly made part quality.
I have had about 10 new KTM 450 since 2013. Only time I had issues with the clutch was when I tried lighter Belleville washer, and also when I tried to follow the manual to set it completely flat.
It's very strange, but putting it in mode 2 as they all come from factory fixed it, even though it wasn't flat.
Yes! The Midwest Mountain levers are absolute dogshit. On one instance with MME levers, we sold a brand new Husky 350. Customer installed lever. He immediately started having clutch issues. We had him bring bike in. We did a oil change and told him it felt like the lever wasn't engaging properly. He didn't agree with assessment, so he kept riding it with MME lever. Fast forward a week, the clutch is now fried and the bike is overheating. We tell customer that since the MME lever is installed, Husky isn't going to warranty anything. Customer gets wife involved. To make customer happy, we trade him for a new KTM 350. He doesn't install MME lever on KTM. No clutch issues since.
Also, the pressure plates are susceptible to hairline cracks, especially on certain models. There can be a fine crack that is essentially imperceptible to the naked eye but will cause plenty of slippage and/or dragging issues when it distorts under pressure.
Two clutches were set using Belleville Spring tensioner at mark II.
I am using Castrol Power1 Ultimate 10w50 JASO MA2, which I wonder might not handle high temps as well as Motorex oil. Spec sheet doesn't show max oil temp - though I'm going to try some Motorex 10w60 oil and replace the coolant with some fresh - to help keep temps down.
I've replaced the Belleville spring with a higher rating (KTM EXC-F 500) - which should help reduce clutch slip if that's the problem.
Was hoping to do an oil pressure test - but the oil filter replacement cap I received from Ali-Express (Needed to drill/tap a threat for a pressure gauge) was the wrong size.
And yeah - shortly lever incorrectly set - caused clutch slip - so I haven't touched it since.
That's good info.
I might try to rotate the pressure plate in a drill or similar and see if I can use a run-out gauge to see if it might be warped.
That would definitely cause issues if its not right.
D.
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