Well, at least I think it's the clutch. I'm just looking for insight and opinions on my situation.

Here's the deal. I put a Magnacharger on my 4.6, 5-speed F150 a couple years ago. I hadn't had any issues other than one time that I let some one drive my truck and there seemed to be some clutch slippage for a few miles. It went away. Earlier this year I upped the boost from 5 to 9. I hadn't had any problems there either. Recently someone lent me a 12lb pully to try out. I put it on there for about an hour, maybe 50mi. With that pully if I got on the gas hard the engine would sound like it was revving slightly faster than I was going, just for a second then would even out. This freaked me out which is why I took it off so quickly. I put the 9 back on and all seemed fine. Then the temps started really dropping around here. Throttle response is crisper and I see a full 9lbs, and have even seen it hit 10. The thing is is it's doing that revving thing again. I think that there is more power than the clutch can handle. I believe the clutch is slipping. Anyone think this makes sense? There is no slipping when I take off in first or at any time other than while cruising I get on the gas enough to build more than say 7lbs of boost.

Is it possible to overpower the clutch and cause it to slip when I already have good momentum? What else might be slipping? Is it possible that the clutch or flywheel surfaces are "glazed"? Need any more detail?

Thanks!

Edit: I was just checking some things. I see it could be the flywheel, the clutch disc, the pressure plate, the slave cylinder or the input shaft pilot bearing. I'm thinking clutch disc or pressure plate.

 

I know that there aren't that many of us with the manual transmission so I understand why no one has any comments on this. JMC, where have you been? I thought you might be able to give some insight.

I actually had something interesting happen yesterday. I had to drive a bit of a distance on the highway. There were several occations where I was in boost. The clutch (or what ever is slipping) didn't slip once. The one difference this day was the ambient temp. The other days that it slipped it was around or below 40 out. Yesterday we had temps in the 60s. I wasn't haveing this issue over the summer. It didn't start untill it cooled down. At this point I'm wondering if it is actually the clutch wearing or that with the cooler tems the engine makes more power than the clutch can handle. I know I will need to upgrade the clutch but maybe I'll be ok for a while.

 

Have you ever thought that maybe the cooler temps may be keeping the fluid in the tranny cooler and maybe that is having something to do with the slipping problem you are feeling. I dont have a standard, but in cooler weather my auto tranny doesnt bang into the gears as hard as it does when its hot outside.

 

The cooler weather does effect the operation of this transmission. It makes it harder to get into gear. These syncros aren't the best even when it's warm so the cold does effect the fluid which makes it harder to shift.

The clutch is a dry system and wouldn't be effected by the fluid. It could be possible that there is something else in the transmission that is slipping. I guess that's why I'm here looking for input, because I may not know all the possible causes.

Thanks beastie for your input.

 

I'm thinking you've got a burnt clutch. If you didn't get out of it right away on the occassions where you suspected slippage, you probably crystalized the surface. It's been more than 2 years with the stock clutch that wasn't designed for the power you're making. I'd say it's time to upgrade to a high performance clutch regardless of the cause of slippage. If that's not the problem, then you should find out what is during the switch.

http://www.performanceintl.com/shop/...L%20280%20ENG.

 

Yes, your right. I will need to upgrade the clutch no matter what. Thanks for the link. I've been thinking about that Dual Friction for a while now.

Thanks Odin's Wrath. Nice ride. I like the color .

 

 

Witton,

I just notice this post. You need a new clutch. It will not slip in the lower gears till it gets realy bad. 5th gear at low speed and lots of gas will stress the POS clutch and make it slip. Go for the Centerforce. You will not regret. The OEMs are junk. My next one will be a centerforce. By the looks of it that might be in the spring.

JMC

 

Thanks JMC. Yah, it looks like I'll be doing the clutch in the spring too, if it will hang on till then.

 

Where is everyone planning on getting the Centerforce? I just checked Summit Racing online and no listing for our trucks.

 

LeanNCut,

look up the part number on the centerforce web site and call Summit and they will quote you a price on the phone.

JMC

 

Cool thanks Jean-Marc.