What i get for not trusting my own knowledge/experience/ instincts....

[Bill R.]

Yesterday, i had a nissan truck come in with the same problems that some of you had described relating to the clutch not working after driving awhile on the highway but fine in town in stop and go... I looked at the clutch slave cylinder and saw no signs of leakage, peeled the boot back and still saw no signs of leakage, then did the same to the clutch master , nada no indications of leakage.... but then like a dummy i started thinking that maybe Paul was right when he talked about bypassing fluid without leakage , even though i haven't seen it happen, So i told the customer and then i changed the clutch master cylinder and bled.. test drove, same thing.. I pulled the transmission which was my first instinct anyway and found that the springs on the clutch disc had broken up and were bouncing around in there which enabled the splined hub on the disc to shift and bind up and also the pilot bearing was trashed which didn't help any either.... in this pic you can see the pieces of the spring which broke up and was trapped in between the disc pressure plate assy. None of which applies to the stock e34 since it doesn't have springs in the disc unless you have replaced the dualmass flywheel with an e28http://www.bimmer.info/%7Ebill/NissanClutch.jpg

[Hector]

been guilty as charged for not trusting my knowledge/experience/instincts. Sometimes a young buck will come along with a seemingly bright idea and such but in the back of my mind I'm thinking we should do it another way with less risk. In my case at work, I'm thinking this guy's got a degree from a prestigeous school... has done high quality work yakety, yakety... so what the hell. Let's give it a try to find out later the experiment took a wrong turn... but I like to try different things no matter how impossible they may seem.

I'm a big believer in Arthur C Clarke's quote, "The only way to find the limits of the possible is by going beyond them to the impossible."


Yesterday, i had a nissan truck come in with the same problems that some of you had described relating to the clutch not working after driving awhile on the highway but fine in town in stop and go... I looked at the clutch slave cylinder and saw no signs of leakage, peeled the boot back and still saw no signs of leakage, then did the same to the clutch master , nada no indications of leakage.... but then like a dummy i started thinking that maybe Paul was right when he talked about bypassing fluid without leakage , even though i haven't seen it happen, So i told the customer and then i changed the clutch master cylinder and bled.. test drove, same thing.. I pulled the transmission which was my first instinct anyway and found that the springs on the clutch disc had broken up and were bouncing around in there which enabled the splined hub on the disc to shift and bind up and also the pilot bearing was trashed which didn't help any either.... in this pic you can see the pieces of the spring which broke up and was trapped in between the disc pressure plate assy. None of which applies to the stock e34 since it doesn't have springs in the disc unless you have replaced the dualmass flywheel with an e28http://www.bimmer.info/%7Ebill/NissanClutch.jpg

[DaCan23]

Is heat the culprit, that the springs can not handle the heat it receives and it caused it to break?

[winfred]

it's like yester day with a 95 940 volvo that's been all over baton rouge trying to find the reason it's missed during a rev, it had this problem over a year and the last place it was looked at was the dealer who said it needed a motor, i looked at it for 10 minutes fixed for 5 and it's running great, whoever chnged the cam belt they didn't line up the gear that drives the distributor and it was off a couple teeth, it would idle fine but at a rev the rotor was too far out of position and the spark was crossing over to other terminals

[Brian C.]

:D

Who knows??? It's worth a try. What if it worked?? ;)

Brian C.

[DanDombrowski]

Bill,

Why do you think it was that the clutch went to the floor on the highway then? To me, that just seems like it would be grinding away all the time.

Anyway, I think I fixed my problem, but I'm not going to post it on my thread until I'm sure (going to go from West Palm to Tampa this Thanksgiving). I ordered the clutch slave cylinder and the master brake cylinder grommets to take care of that leaking. Took the resovoir off, and the grommets didn't look all that bad, until I tried to touch them. They were like a jelly. Anyway, for good fun I was going to post what was left of them and how black the brake fluid was, but I had to get cleaned up in a hurry.

The result is that the clutch is much firmer. I never really noticed it before, but the 1/4" (by random foot measurement) travel before the clutch hit friction is completely gone, and its much firmer now. Also, the shuddering I was talking about when leaving 1st which I wasn't sure was there definitely was, because its completely gone now and much smoother, and I haven't even gotten to the clutch slave cylinder.

So I think that does it, I'm still going to replace the clutch slave since I have it, but I don't have a lot of time now and want to see if the master cyl grommets did the trick first. I'll let you know.

[Bill R.]

that i heard at all, windows down driving around.. and his pedal didn't go to the floor,it felt the same just wouldn't disengage as is the clutch wasn't working.. to the point where you would have to force it into neutral, come to a stop , shut the truck off, push the clutch in and put it into first, then restart it and it would be okay untill you cruised again in 4 or higher gear for a few minutes.. I don't have any idea why the broken springs caused this , the pilot bearing was so wallowed out that it could not have been seizing.
New clutch disc,pressure plate, pilot bearing,throwout bearing and its fine now. Better than its been in 80k miles according to the owner. It had 200k miles on the original clutch.




Bill,

Why do you think it was that the clutch went to the floor on the highway then? To me, that just seems like it would be grinding away all the time.

Anyway, I think I fixed my problem, but I'm not going to post it on my thread until I'm sure (going to go from West Palm to Tampa this Thanksgiving). I ordered the clutch slave cylinder and the master brake cylinder grommets to take care of that leaking. Took the resovoir off, and the grommets didn't look all that bad, until I tried to touch them. They were like a jelly. Anyway, for good fun I was going to post what was left of them and how black the brake fluid was, but I had to get cleaned up in a hurry.

The result is that the clutch is much firmer. I never really noticed it before, but the 1/4" (by random foot measurement) travel before the clutch hit friction is completely gone, and its much firmer now. Also, the shuddering I was talking about when leaving 1st which I wasn't sure was there definitely was, because its completely gone now and much smoother, and I haven't even gotten to the clutch slave cylinder.

So I think that does it, I'm still going to replace the clutch slave since I have it, but I don't have a lot of time now and want to see if the master cyl grommets did the trick first. I'll let you know.