V8 Clutch Issues 4 speed LC

[Isotel]

Ok I am running a tbi 350, Put it in a month ago.. Brand new Flywheel.. Inspected my clutch then, and it all looked great!

New Clutch less than 10k ago..

Well the new motor is finaly running good and now ive been getting on it more than i should have.. On the highway i was in fourth gear and Floored it.. CLutch started slipping and by the time i realized it and got out of ithe gas i burnt the crarp out of my clutch (smelt Horible).. Ever since i cant even begin to go half throttle without it slipping

Now Whats the prognosis here?? Your an idiot why are you flooring your cruser in high gear?? Your using the wrong parts??

I am using a Chevy sm465 Clutch, some sort of unknowen belhousing adapter and what i belive is the stock LC Throwout bearing..

You guys think the Surfaces on my Flexplate and belhousing are all Glazed over with clutch material.. Anyway to cleen that crap off, or just get a whole new kit?? i want to prevent this from happening again!

 

[VTFJ40]

With the proper clutch adjusted correctly you should be able to stomp on it anytime.

 

[pbgbottle]

your probably hooped it . pull it apart . i floor mine in all gears no slippage was your throwout bearing adjusted properly the throw out bearing was probably rubbing the preasure plate . partaily disengaging it . is your adapter look like a chevy cast bellhousing with a plate adapter bolted to it .also does the plate adapter have dowel pins on it . if it does this may be an old downey one i still have mine works great .since then switched to a sm465 . it should be using a chevy cast fork low profile diaghram preasure plate and the front of the 4sp should have the nose cone (whatever it is called) either supplied with the bellhousing when you got it .or the toyota one turned down to fit the chevy throwout .. if using a adapter bellhousing with plate adapter you should be using all chevy clutch components . at least thats what worked for me .

 

[Isotel]

take a look at these photos.. i know they are kinda crappy.. but since i didint do the original install on the 350 i dont now the exact details.. The Bellhousing is a one piece design, i know i used the toyota throwout.. i remember having issues getting the parts rounded up the last time.. Yea its possible it wasent adjusted properly.. how much play should i have in the trowout?


can anyone identify the clutch fork.. i think its toyota..

oh yea btw i got an oil leek from the filter that i just cant figure out!.

 

[pbgbottle]

i have no time to look right now but i think that is toyota throwout . haven't seen one in awhile . not sure what bellhousing that is but it isn't the one i was talking about

 

[zebrabeefj40]

Bell housing looks like a Lakewood or similar scatter shield that's probably been modified to locate the Toyota trans in the right place. Common hotrod/racer part available through Summit and most other speed shops. Doesn't resemble most of the comercially available adapters that I've seen. Not quite enough to tell what clutch fork it is.

HTH,
Nick

 

[Bennett]

Looks similar to a Stamped steel Bellhousing as was mentioned above.

Here is a picture of the same/similar setup with a LC 4speed on it. No adapter plate needed .. the BH was machined to fit.

If you read the LCML and IH8MUD and PBB .. there are so many opinions on what should be used on SBC to LC 4speed to resolve cluthc issue. You could read all day. AA has a solution but spendy using a custome centerforce unit.
I went throught the same trauma. Finally with the help of a freind that runs a trans shop we came up with a solution. Chevy Clutch disc's do not belong on the LC input shaft ( sort of ..read on). There are different. They will slide on and work but there is a difference in tapered VS straigh cut splines . Also you should use a matched Clutch fork with T/o bearing. IIRC the curved cast Chevy fork goes with the short T/o bearing. The flat cast fork(SM465 truck) goes with the long T/O .. ( again CHevy )... since you are using a SBC bellhousing I'd go Chev with one exeption that makes a huge difference. I had the Toyota inner hub from a LC clutch disc mated to a Chevy 11" clutch outer disc. I used the curved cast fork and the short throw out bearing. I used the diaphram multi fingered short throw pressure palte . ( most common anyway) vs the hard to adjust 3 fingered PP. My guess is you have Toyota parts floating on the input shaft and a Toyota Clutch fork ... IMO , I would only use the Toyota input clutch hub and go Chevy the rest of the way as it was engineered.
I have a bunch of link to show the pain I went through to solve my similar problem. PM me if you want.
Oh.. I use a 69 Brake master on the clutch for more throwon the slave... Mark Whatley ( LCML) suggested that and it works well.

 

[Bennett]

More FYI..
You can't see it in the pic but the splines are different on LC verses Chevy, lots of people ignore it anyway.. that's why we mated the Toyota inner hub to the Chevy disc.
One more thing.. make sure you have the ball pivot for the fork adjusted out if need be or if your ball pivot is worn like mine.. replace it. ( $2.50 Chevy part that get's ignored) and you will eliminate allot of play that can inhibit fork throw. Again I learned the hard way. Just make sure there is no play between the ball pivot and it's seat with the reatainer spring in place. You can't fix the pivot , fork problem while the B/H and tarns are mated so check while it's out.
Ask me again how I know.

SBC..CHevy..B/H..Chevy PP/Chevy T/O..Chevyclutch(to)LC HUB.. LC 4 speed

 

[pbgbottle]

is that the preasure plate you used in pic . does it look like this one low profile

 

[Bennett]

is that the preasure plate you used in pic . does it look like this one low profile

*pretty much looks like the PP I use. Diaphram type

*BTW... your T/O bearing should not ride against the fingers of the PP. I have 3/32 " of free play before mine contacts the fingers of teh PP.

* one more thing while you are in there..
Starting in 1962 there are two flywheels used on SBC's-- 168 tooth and 153 tooth. The 168 tooth wheel used 10-1/2" or 11" clutches but the 153 tooth used only the 10-1/2" or smaller clutch. You want the 168 tooth which IIRC is the heavier = a little more rotating mass for torque.

 

[Gumby]

The bigger flywheel is much easier for the starter to spin as well.

i like the idea of a 69 brake master. I've been looking at Wilwood masters for the longer throw. I am tight to the pressure plate with the clutch releasing at the floor.