Clutch or Throw Out Bearing?


JayDiz
03-07-2005, 07:31 AM
All - I am a manual transmission noob. 2002 Xterra SC, 38,000 miles. Could someone lend me an opinion or method to test?

Situation - we never start from a dead stop in 1st, always in 2nd. Right now, depress clutch, engage 2nd, release clutch - vehicle moves fine. No obvious slipping or studdering. Get up tp speed to shift to 3rd, depress clutch, engage 3rd, release clutch and, as gas is applied in a normal shift pattern, I can hear the motor rev and the RPM's increase, but it feels like the vehicle got very sluggish. It feels like 3rd does not fully engage for a second or two. Eventually, it feels like the vehicle speed has caught up to the RPM's - but it takes a second. Even worse in the transition form 3rd to 4th.

Something is slipping somewhere....

While going uphill in 3rd, if I accelerate hard, you can hear the motor race, but the transmission never responds. Eventually, I have to get off the gas, let the motor come back down, and try it again until it catches and maybe I can get a little accleration up the hill.

Some say it may be the throw out bearing, some say the clutch is going. All I know is something has to be fixed - soon.

Any ideas or methods to verify what is breaking down? Also - what is a good online site with clutch/T.O.B. replacement on these vehicles? I am a manual trans noob and want to do this myself. Thank you all!!

chubbybubba1
03-07-2005, 08:50 PM
60k powertrain warranty? Dealership visit.

ChuckH
03-07-2005, 11:01 PM
Well, I'll tell you this much...

...if you're always starting out in 2nd gear then you've probably worn down the friction surface of the clutch disc and that's why it's slipping when it's hit with the torque from the change to 3rd.

So, my first advice is that you plan on forking over $800 or so to have the clutch replaced.

Second, don't tell the dealer that you start out in second gear and maybe you'll slip some clutch abuse by them...maybe.

Third, stop starting out in 2nd gear. There's a reason there's a first gear and it's there to start out in. Starting out in 2nd is only OK if you are starting out going downhill and you let the truck coast a bit before letting out the clutch. Who knows, maybe starting out in 1st will eliminate the problem (or at least buy you some time) since you won't be heating up the clutch nearly as much to get moving.

Finally, why ARE you starting out in 2nd gear anyway? :nono: :disappoin

JayDiz
03-08-2005, 10:48 AM
Didn't get the extended warranty - so SOL there.

As for starting in second gear, I guess I was never told different, so never changed the habit....just seemed easier....

Starting out in 1st now won't buy any time.....I did the parking break test and tried starting out in 4th and the motor ran way too long before it stalled out, so the whole clutch appears to be basically gone.

Truth be told, of all the manual transmissions we have had, we have never had to replace a clutch before so this whole situation is new for me.

I just ordered all the parts from Nissan:
Plate - 112.00
Cover - 199.00
T.O.B. - 46.00
Pilot Bush. - 9.00

So, I suppose if I do it myself, it won't be too tragically expensive....

Any sites or links that have any "tips or tricks" for replacing these clutches?

Schludwiller
03-08-2005, 09:49 PM
Situation - we never start from a dead stop in 1st, always in 2nd.

That's the "problem", not the "situation". Like Chuck said, get ready to cough up $800. Then sell the truck and buy one with an automatic. I'm confused by who would teach you to drive a manual transmission that way, or why you would think 1st was just a throw-away gear that manufacturers put in there for fun. :sly: But oh, well. We all learn through our mistakes.

Best of luck.

JayDiz
03-09-2005, 06:54 AM
So can anyone actually provide any help to me, or is this just a forum to ridicule and basically repeat what the last guy said?

I posted what the parts cost - $366. Not $800.

Can anyone else who has replaced the clutch before provide any insight for this? Tips? Tricks? What to watch out for?

Thanks.

Schludwiller
03-09-2005, 12:59 PM
So can anyone actually provide any help to me, or is this just a forum to ridicule and basically repeat what the last guy said?

I posted what the parts cost - $366. Not $800.

Can anyone else who has replaced the clutch before provide any insight for this? Tips? Tricks? What to watch out for?

Thanks.

I think you'll find that most people have had Nissan do it as many of the vehicles are for the most part under warranty. You can buy a Chiltons or Haynes manual to help you as I'm sure you already know. My advice would be to make sure you service or replace the pilot bushing while you're doing the work on the clutch. The $800 was from people's assumption that it was going to be done at Nissan. You're probably trying to save money, but have you considered a Centerforce clutch. The dual-friction will most likely be replacing my ailing clutch.

You might find someone who's done the clutch over at www.nissanoffroad.net

As the vehicles get old more people will be willing to do the work themselves, and more info will be available. Now there's not much out there.

Again, best of luck (I was sincere when I said that in my last post).

JayDiz
03-09-2005, 11:32 PM
I have not been able to locate any manuals for a 2002. I have been told that they are not being distributed yet, probably because like you said, they are not that old yet. I have also found out that there are no third party OEM parts available yet, which I thought was weird...

I just ordered everything including the pilot bushing. As I am not positive on what is failing, I ought to do it all.

The only info I have found to date is an online reference manual...http://www.expressautoparts.com/repairmanuals.

I have not even considered a centerforce clutch as I am fairly new to manual transmissions. I just figured I would replace it with Nissan parts and start using first gear a bit more...LOL...

I suppose the best I can do is try...I can post the results for anyone who may be interested later....maybe a picture or two and perhaps someone can see what went wrong as I may not be too sure what a "bad" part would look like.

Thanks all.

Schludwiller
03-10-2005, 02:32 PM
There is no mechanical difference between your 2002 and a 2000-1, so yes there are manuals out there. If it's your first clutch job, yeah it's probably safest to go stock.

chubbybubba1
03-10-2005, 11:43 PM
http://www.nissan-techinfo.com/nissan/
2002 service manual $315.00 USD
Bought my set, and it's money well spent.

Schludwiller
03-11-2005, 12:25 AM
I haven't bought the Chiltons/Haynes, but I think I would get that first and see if it gives you the info you need before dropping 300 clams.

chubbybubba1
03-11-2005, 11:33 PM
I find that the Chiltons are to vague. What's nice about the Nissan manual is that they give you diagnostic flow charts for repairs.

JayDiz
03-31-2005, 12:18 AM
I wanted to thank everyone for the help....here is an update -

I was unable to find an actual manual, perhaps not enough dedication on my part, but I found some online resources. Basically, it breaks down like this:
At the time of this reply, the parts were moderately expensive and only available from Nissan. It ended up costing me almost $450 because I had to have the clutch cover overnighted from AZ, but that was the worst.

For the XTerra, you basically have to pull the entire under-body apart.

Start with removing both driveshafts. Do youself the favor of removing them, don't just undo one half of the front shaft - you'll pay for that shortcut later. Also, if your shafts are on as tight as mine were, remember your friend PB Blaster and a small torch...

Also, do yourself the favor of removing the exhaust. Un-bolt it from the left and right at the flanges in the middle and then slide that Y pipe out of the muffler and get it out of your way. Also, unbolt the connection to the rear of the trans.

Pull the starter and the hydraulic slave cylinder from the front of the trans. Mark your starter bolts....they look like trans bolts but are just a bit longer, plus they don't work if you try to use them to re-attach the trans. Careful of the slave cylinder hydro line. Remove the small bolt that holds it to the frame so you can move it and get the starter out of the way. Un-clip it fom the frame clips for more wiggle-room.

Good luck getting the 4x4 and 5 spd shifters out of their boots in the cab. You may have to cut the rubber boots a bit. If you go slow, you can get the shifter rods out. You will need to completely disassemble the 4x4 assembly to get it off the transfer case and the body.

As you work to get the torsion bars off, try to remember how you removed the bars from the cross-member...write it down. They are not as easy as they look to put back on. Kinda tricky. Try to back the adjusting bolts all the way down so the tension arms are hanging all the way down. The torsion bars will slide right out and also go back in much easier. Then remove that cross-member.

Before you remove the final cross-member that supports the trans, remove all the wiring harnesses. There are 7. Be sure to lable them as you pull them apart - there are 3 plugs that can all interchange and are difficult to tell apart from underneath. 2 on top of the trans and 1 at the rear of the trans. LABEL BEFORE UNPLUGGING! Since we are on electronics, read this part carefully.....The Crankshaft Position Sensor (CKP) is on the top of the bell housing, right next to the block. Very hard to see if you are not expecting it - plus, there is hardly any slack wire. I destroyed mine and pulled the wires right out of the plug. Had to dismantle the the plug and re-solder the wires, plus I added some wire to make them longer. The CKP sensor is gonna cost you about $30 if you break it. You probably will too because as you pull the trans off the motor, the CKP sensor will smack on the fly wheel and crack. Just prepare yourself.

Before you drop the final cross-member...get a trans jack! It will be easier than trying to use your floor jack on top of a creeper. Support the trans and drop the cross-member. Do not lower the trans to low while still bolted to the motor - it will tilt the motor and then you will cramp the motor against the firewall...just use caution.

Now pull the bolts from the trans - you will need really LONG extensions and universal joints for the top bolts...some patience too. Once the trans is down, replace your clutch, cover and pilot bushing.

For the throw out bearing, watch you clutch fork! There is a retaining spring behind it. If you pull too hard on the bearing, you will pull the fork and that spring will pop out. Just look at everything before you pull on stuff. You will have to pound the clutch fork adapter out of the old bearing and gently pound it into the new one. As you put the bearing assembly back in, be sure that the holding clip is properly reattached to the bearing adapter and it firmly holds the new bearing assembly. When it is all back together, press on the clutch fork from the outside of the bell housing - where the slave cylinder actuates it - and make sure it still slides on it's own and returns to the released position. May want to re-grease the input shaft since you are there.

Now, I did not use a clutch alignment tool for the disc and the cover. Use your best judgement and line it up visually as you tighten down the cover. The trans should go right back in with no problem - DON'T FORCE IT.

And that's it. To put it back together, read this backwards....

Hope this helps at least one person. :smile:

Schludwiller
03-31-2005, 01:14 AM
Thanks for the writeup. Ugh. Not sure it really encouraged me to do it on my own though. :D

ILUVMYX
03-31-2005, 07:29 PM
Although it's too late since you already replaced it, and it certainly sounds like it was shot, you should also check your clutch pedal freeplay before determining the clutch is shot. If it's way out of adjustment, it's possible to have a perfectly good clutch and have it still slip if it isn't fully engaging.

Schludwiller
04-01-2005, 09:59 PM
Although it's too late since you already replaced it, and it certainly sounds like it was shot, you should also check your clutch pedal freeplay before determining the clutch is shot. If it's way out of adjustment, it's possible to have a perfectly good clutch and have it still slip if it isn't fully engaging.

It's a hydraulic clutch. There isn't a whole lot of room for adjustment. Or am I missing something?

ILUVMYX
04-01-2005, 10:23 PM
It's a hydraulic clutch. There isn't a whole lot of room for adjustment. Or am I missing something?
The adjuster is on the push-rod cylinder itself. If you have too much freeplay in the pedal, the clutch won't fully disengage when you push it to the floor, which will make the clutch wear prematurely. And if you don't have enough freeplay, the clutch won't fully engage when the pedal is released which can cause slippage and premature wear.

According to the service manual, there should be 9-13 mm of freeplay measured at the pedal.

Granted, you're right that it's not as important as a cable actuated clutch, but something you should keep in check anyway.

JayDiz
04-05-2005, 12:21 AM
Thank for the after-thought. I can tell you that I did "experiment" with what I was comfortable with and verified there were no leaks in the hydraulic system, checked the fluid in the master and also verified when the clutch was pressed that it was pushing the clutch fork to what appeared to be a normal position based on the wear and tear of the rubber boot below the bell housing. There was no play or slop in the pedal itself, nor was there any play between the fork and the slave cylinder piston.

Altough I did not get into details of the damage to the clutch, it was completly gone. There were some "hot spots" on the fly wheel and it did have to be turned at a shop because several of the rivets on the clutch disc were in contact with it - not pretty. Also, being that is was so heavily damaged from, no doubt always starting in 2nd gear, the entire starter and all of the bell housing was completely covered in the "dust" from the disc. Not fun to clean...but necessary.

So thanks again, and like I said above, I hope it helps at least one person....

ILUVMYX
04-05-2005, 08:06 AM
There was no play or slop in the pedal itself My point was that there SHOULD be play in the pedal. According to the service manual, 9 - 13 mm. If there's no play then the clutch isn't fully engaging. Think about it... if there's no play, that's like having pressure already on the clutch just like if you were putting pressure on the pedal with your foot. It only takes a little bit of pressure to keep the clutch from fully engaging... again, hence the 9 - 13 mm recommended by the manual. You should check your new one now. If there's really no play in the pedal, fix it!

JayDiz
04-05-2005, 09:57 AM
OK, that makes sense. So I physically measure the pedal movement from a resting position and pull it up toward the dash? Or, do I measure from a resting position and then depress it until the slave cylinder starts to move the piston toward the fork? Or is it the distance the piston travels before it actually contacts the fork and begins to move it?

Thanks for the extra info....I had no idea....

ILUVMYX
04-05-2005, 10:06 AM
Or, do I measure from a resting position and then depress it until the slave cylinder starts to move the piston toward the fork?
Yeah, just measure it from the resting position until it starts to depress the slave. The actual measurement (9-13mm) is measured at the pedal itself. I don't think it's critical that it measures exactly 9-13mm. All you're really doing is verifying that the clutch pedal isn't "preloading" the clutch. Any preloading will make the clutch more likely to slip and shorten the clutch life in the long run.

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