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2009 DRZ400S Clutch Slipping

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DM164450

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It’s cool to have some folks I can ask DRZ questions of. I only know one person in real life near me that has one. Guess I have an average amount of mechanical ability and I worked as a commercial electrician for 20+ years...but I only have about 10 years motorcycle experience.

2009 DRZ400S, purchased by me at 19K+ miles, was never ridden off road until I did it, and it was stupid clean…cleaner than my dirt bike.

Clutch fibers and plates were worn so I replaced them. Changed the oil and filter and put in Rotella T and an OEM filter.

Took it to Big Bend. Rode pavement out of Cottonwood west to Santa Elena Overlook, than back east over to Ross Maxwell to 118 east and turned south on that road into Chisos Basin. There’s some hills on that route.

Twice on that route, after a hill, the thing free-wheeled. I’m assuming the clutch over heated and just slipped/spun. FWIW it seemed Ok on flat ground.

Ate lunch in the basin, checked free play at the lever and had more than the manual calls for, and the only thing I could think to do was loosen the clutch cable as much as possible and still disengage the clutch. I rode another 100 miles or so that day…maybe 50 on dirt. The last run was all pavement from Rio Grande Village to Cottonwood…so I hit all those hills again. And had zero problems.

I mic’d the old fibers and steels but didn’t mic the springs…I should have. I have new springs and a new clutch cable in the mail. I’d bet the farm I put the clutch pack together correctly, but when I take it apart I’ll verify that. Guess also verify I didn’t burn/tear any of the fibers off or warp steels.

I’m thinking either the springs are shot and/or the clutch cable is binding. I’d say just the springs are bad but loosening the cable and fixing the issue is throwing me off here because I’d bet the farm there was free play in the cable. Friend also checked it when we were in Chisos Basin and he said it felt like his DRZ.

Changed the oil and filter when I got home. Oil was a little dark…kind of like it was just old…but didn’t smell burnt.

Am I missing anything?
 
Just a thought, are you sure the oil is not the 'energy saving' 'friction modifier' oil that should not be used for wet clutches?
 
I just re-read and saw Rotella T. I used Rotella dino oil for years with no problem, that's probably not the issue.
 
Thanks JT. Yeah it's the original Rotella T. When I heard it was being discontinued I stocked up. Think I have about 6gal left. Been using it in my 250 YZ250FX Rekluse for 7 years with zero probs.
 
I know a lot of folks swear by the Rotella T and I've used it before quite a bit as well. I had issues though with my FJR (with the auto clutch) throwing error codes about the clutch. It was always worse right after an oil change with fresh Rotella T. It got worse and worse and became unrideable. I ended up replacing the plates and changing the oil I used. Haven't had a problem since. I just found it odd that the code throwing was always when it had fresh Rotella T in there, once it aged a bit most of the time it'd go away, until it got awful. Coincidence? Perhaps, and many will swear by it, but it is possible it's not the best in certain bikes.
 
Funny you mention that. Bought a new 2013 YZ250, put RT in it on that first oil change, put a Rekluse in there soon thereafter, and the Rekluse just wouldn't work right. Long long frustrating story. Spoke with Rekluse many times and they finally steered me to a Maxima oil...I forget which one. Used that for the 2 years I had the bike, but the Rekluse in that bike just didn't work exactly right. It was either too tight and almost stalled or too loose and freewheeled. Rekluse actually told me they heard reports of some YZs/Rekluse not working exactly right.

In 2015 bought a YZ250FX, put that Maxima in there on the first oil change and it stuck the entire clutch pack together...I mean stuck. I put the bike on the stand, put it in gear and revved it a bit trying to unstick it. Maybe riding it would've helped but I didn't want any part of that. Drained that Maxima out, took the clutch pack apart and washed it with RT, put it back together and have been using RT ever since. I put a Rekluse in at about 5-10 hours...I forget exactly when.

I'll replace the clutch cable and springs and if that doesn't fix it guess I'll hunt for a new oil.
 
Diesel engine oil is made to run in powershift transmissions on heavy equipment , that is an automatic clutch pack positive action transmission . From one gear to the next , one clutch pack will disengage while the other engages . No internal slippage like an auto trans .in a auto trans one pack will engage and stay in till you slow down and it disingages , there is a sprague gear on the shaft of every clutch pack allowing the output shaft to turn higher rpm’s and creating huge amounts of heat that’s gotta go somewhere and into the oil and to the cooler is it .
 
Clutch basket slots might be worn.
 
Rydah said:
Clutch basket slots might be worn.
Click to expand...
Thanks.

I don't remember seeing a spec for that in the manual but I'll check again. When I put new fibers and steels in recently, the basket had faint lines, but even with a pick I wouldn't feel them.

FWIW I'm not new to tools, but fairly new to motorcycles.

Apparently my parts just hit the mailbox, so maybe I'll know what's wrong soon.

Edit: Anyone ever measure DRZ clutch springs? Talked to my friend and he's never measured his.

New springs = 53.4mm
Old springs = 1.9 to 2mm shorter than new
Service limit = 49.9mm

Which puts the old springs about 1.5mm from the service limit.
 
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Super simple test to see if your clutch is slipping: Go ride your bike on pavement in its highest gear, and from the meat of the power curve roll on full throttle and hold it. If the clutch is worn or the springs are weak, it will start to slip then. If the clutch holds, then it isn't slipping in lower gears. Basically, the higher the gear, the more mechanical disadvantage you put your clutch under. I've only messed with a handful of bikes that had clutch problems, but 100% of them, this was the prime indicator. Low speeds will not highlight a weak clutch like high speeds will.

And when a clutch does start to slip, it does just that, start to slip. It doesn't go into a freewheel (unless it is a Rekluse and not properly adjusted).

Really dumb question, but when you put new plates in, did you put the same number of steels and fibers in that you removed? And are the all facing the correct direction?
 
DFW_Warrior said:
Really dumb question, but when you put new plates in, did you put the same number of steels and fibers in that you removed? And are the all facing the correct direction?
Click to expand...
Thanks. No Rekluse on the bike. Yes to correct number. Not sure of any direction requirement other than I put all the steel plates with the flat side facing out.

Got pulled away the bike by the stupid phone. Back at it tomorrow.
 
Spring tension is more likely an issue than length , used to check spring tension on valve springs with a tool that you could measure spring tension with . I don’t know where you would find one these days because it used a beam torque wrench . Possibly you could rig something with a pry bar to see if you can feel any difference between old and new by using a pry bar to apply a load on the spring and get a feel for it . Distance from the spring to the fulcrum needs to be exact to compare them . Once in my life I had a clutch overheat but it did not free wheel , it bound up and wouldn’t slip , and it was while trying to ride through a A enduro special test section on a 4 speed motocross bike . That one required a two beer rest break in the shade on the other side of the dead fall area . For it to go into a free wheel I would expect something mechanical to be causing that . If you were feeling any thing different in levar feel the cable could have been snagging somewhere in the core causing that , you will feel that when the cable is off the bike and compared to a new cable . Check the actuator lever on the engine case to be sure it moves smoothly too all the way thru to the release rod . Bark busters have been known to make a clutch slip too but that one is pretty easy to see .
 
Cagiva 549 said:
Spring tension is more likely an issue than length , used to check spring tension on valve springs with a tool that you could measure spring tension with.
Click to expand...
Probably a little much for this project, but just in case. :)
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It does sound like something mechanical to me as well. Plus from what it sounds like, the hills that the OP went up were pavement, and then the clutch freewheeled. You know this as well as I do, the only way to overheat a clutch is from slipping it in tough sections like you did on the motocrosser. Riding it up a paved hill while not touching the clutch lever isn't generating any heat at all since the plates aren't slipping. Something is amiss inside the clutch, or like to you said, the actuator arm.
 
Thanks for that info guys.

Yes the clutch freewheeled or slipped twice, both times on pavement (rode all pavement north from Cottonwood, then east, then south to Chisos Basin). Both times it was after hills.

I remember a couple times during that ride thinking it should have more power on the hills and I remember downshifting a couple times on hills and thinking, “this is it?” I also thought that on some small dirt hills at Zar's and I thought the same thing in Cloudcroft but attributed it to the elevation. I don’t have experience with that bike to know exactly what normal is.

I think this might be an issue: I was positive there was free play in the clutch lever. When we got to Chisos and I was whining about it, friend checked my lever and I checked his on his DRZ, and we both agreed the free play was about the same. I couldn’t think of anything else to do, so I loosened the cable up as much as possible and still disengage the clutch. I like 2 fingers on the lever and 2 on the bar, and I had it so loose I had to use 4 fingers on the lever or I couldn’t disengage it, and it engaged immediately after the lever leaves the bar. And I had zero problems for the rest of the 100+ miles that day other than forgetting and smashing my fingers every so often. Matter of fact the 57 mile all pavement run back to camp I think it had more power. Or maybe there was free play, but the cable was adjusted at a spot where it hung up. Or the throwout pushrod was adjusted to a bent area. I have a new OEM cable for it.

Good info on spring tension. I’m familiar with pistol and rifle mag springs and know that shorter springs = decreased ability to feed rounds. Just never thought it through to clutch springs other than shorter = bad. Guess I could rig a tester up with a torque wrench. I’m replacing them anyway so probably won’t do that.

I looked yesterday for a spec or something about how much the pressure plate should sit above the hub, and how much it should rise when the lever is pulled. Didn’t find anything.

Going to try an actual motorcycle wet clutch oil and not use the Rotella Tripe T that I put in there.

I’d prefer to change only 1 thing at a time so I knew exactly what the problem is, but this is riding/traveling weather and combined with hurting my wrist, I’m out of patience and want this thing fixed yesterday so I'm throwing everything I can think of at it. HAHA
 
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Fixed. Thanks for the help.

Clutch cable was as sticky mess. Good grief. So sticky I’m not even saving it for a spare.

On the new clutch springs I had to compress the spring just a bit to start the bolts. Was curious and started all the old springs and the spring had no tension when the bolt started to thread. Amazing what 1.8 – 2.0mm can do. Put new spring washers in also just because.

Put in real motorcycle wet clutch oil.

If I had to guess, I’d say the cable was most of the problem with the springs being second. Can’t say about the oil, but I plan to keep using it.

Bike has quite a bit more power, and the lever feels much better and springs back better.

When I bought the bike and rode it, I wondered if it should have more power, but I have little experience there so just didn’t know. Glad I kept working the problem. Someone told me that since I loosened the cable and that fixed the problem, the only problem was I had the clutch cable too tight.

My fan quit working and the bike overheated at about 8 miles of trail riding today. Something else to fix.
 
Monday morning QB. I was gonna say play at the lever doesn't mean play at the other end. Glad you sorted it out.
 
My second maintenance blunder in 10 yrs...I forgot to tighten the radiator cap all the way.

Fan wouldn't run Wed and I read that it wouldn't run when there was no fluid. First I ran power directly to the fan to make sure it worked...it did.

Wed when my friend said my bike was leaking I looked down and saw rad fluid on my boot and front of the bike so figured I had blown a hose or something. So next I looked for that and saw the rad cap wasn't on all the way. Filled the rad, tightened the cap, ran the bike, fan came on. Fixed.

I was in a hurry to ride the new suspension and I missed it. Gotta slow down.

First blunder was I forget to tighten a skid plate bracket and lost that on the trail somewhere.
 
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