SM465. What clutch do you run?

Bigbluechevy

Member
Joined
Jan 20, 2009
Location
indian trail
So I am having that throwout bearing noise issue, and I am going to put a new clutch kit in. I am looking for yalls feedback about which would be best. I have a 1979 K10 with a relatively stock motor. I dont pull a trailor, I just drive it about 100 miles a month to the trails. I want something that I wont have to mess with again. I had issues before with those OEM pilot bushings, and I was thinking about running the brass pilot bushing they offer as an upgrade. As far as which clutch, I havent tried any aftermarket ones yet, just OEM from Autozone. Does anyone on here have a good recommendation? Kevlar? Thanks, Connor.
 
I've been running a centerforce dual friction clutch in my 78 f150 with a mild 351m, a np435 granny tranny, and 42s. It's been in the truck since February 07 with a little street time, but a lot of wheeling. It gets slipped every trip out til it smells, lol. It's got a little chatter on take off on the street but you don't feel it in lowrange. It still looked good enough that I didn't replace it when i built the motor this past winter.
 
I've been running a stock clutch on my sm465 for 10+ years. no issues,
 
My truck has never been separated at the trans and has 85xxx miles so I know that my clutch is getting old. I saw the centerforce, and was hoping someone would mention their luck with it. I believe that is what I want. Does it have the characteristics of like a stage 3 racing clutch, or does it retain mild streetability? I dont want to hate my truck because of my clutch like my honda. I put a stage 3 kit in it, and I am glad she got totaled two weeks ago. DONT TEXT AND DRIVE, IT CAN HAPPEN TO YOU!!!

Thanks for the feedback guys, much appreciated.
 
The centerforce is a little stiffer than a stock diaphragm clutch, but it seems about the same as the stock "3 finger" or Borg and beck clutch that was in my truck. It doesn't really bother me even after wheeling all day, hell my tow rigs southbend clutch seems stiffer. Definately has more grip than a stock clutch. My chatter is from the flywheel getting hot spotted. The chatter was bad before the engine build, the flywheel was blue, lol. I had the flywheel machine, but decided to keep running the same clutch since the disc looked good and the plate was not blue at all. The chatter is gone for now but im sure itll be back once i warp up the flywheel again, unless i get my doubler built. I'm a little undergeared for my trucks weight and tire size for the really technical stuff.
 
I might take your review and try the same clutch. What pilot bearing did you go with? like an OEM steel one, or the nice brass ones?

Should I get my flywheel machined when I have it apart, or just put the clutch in and go? I am gonna bring my truck in the shop one saturday in july, and try to do it all in one day since I have two transmission jacks, and air tools there.

ALLDATA says 3.8 hours to do the clutch and to me that seems a little low, but they always seem to be dead on for labor hours.

Like it says 3.5 hours I believe for SBC head gaskets, and thats about how long it took my buddy and I to do his the other night without air tools.

**See my main obvious clutch issue now is the crazy noises when I push it in, but I keep having to adjust it further out (mechanical not hydraulic) to get it do engage all the way when I push the pedal to snatch reverse or else it grinds. But when it is in gear with the pedal to the floor, its not trying to roll or anything. But that seems odd to me that I have adjusted it twice in 100 miles. I almost feel like the fingers on the pressure plate lost their "spring"
 
I had a brass pilot bushing, but now I'm running a steel needle bearing one cause I couldnt get another brass one in time after the motor build. I'd get the flywheel machined for sure, it'll make it that much better of an install. As far as your adjustment issues, its most likely a "finger" broke on the three finger style clutch, it will cause release problems. My dad had a 79 K10 where one of those fingers broke and it wont pull the pressure plate evenly back causing it to drag. I also had a finger break on my 78 F150 and on my 67 Fairlane. I believe the diaphram style clutch is much more reliable long term.

However check your body mounts and body mount surfaces good as well, cause last year I had to adjust my clutch on two separate trips to uwharrie. I couldnt get the clutch to release when flexed out on rocks, the cab had rusted away from the body mount on the drivers firewall and it was falling lower on the frame. That was throwing the length off between the pedal and the z linkage, so the pedal wasnt moving the fork enough. This may not be your issue but it drove me crazy till i figured that out.

You should follow the break in for sure that centerforce recommends (I think its just dont go WOT for a couple hundred miles or so and try to do some stop and go driving). Also you may have to pop the overcenter spring (the coil spring on the pedal under the dash) if you have one or if the pedal wont come back up. A diaphram clutch doesnt have as much pressure as coil spring clutch. The install instructions should mention that also. I didnt have to remove mine, but I thought I'd mention that so your not surprised.
 
Tim C said:
I had a brass pilot bushing, but now I'm running a steel needle bearing one cause I couldnt get another brass one in time after the motor build. I'd get the flywheel machined for sure, it'll make it that much better of an install. As far as your adjustment issues, its most likely a "finger" broke on the three finger style clutch, it will cause release problems. My dad had a 79 K10 where one of those fingers broke and it wont pull the pressure plate evenly back causing it to drag. I also had a finger break on my 78 F150 and on my 67 Fairlane. I believe the diaphram style clutch is much more reliable long term.

However check your body mounts and body mount surfaces good as well, cause last year I had to adjust my clutch on two separate trips to uwharrie. I couldnt get the clutch to release when flexed out on rocks, the cab had rusted away from the body mount on the drivers firewall and it was falling lower on the frame. That was throwing the length off between the pedal and the z linkage, so the pedal wasnt moving the fork enough. This may not be your issue but it drove me crazy till i figured that out.

You should follow the break in for sure that centerforce recommends (I think its just dont go WOT for a couple hundred miles or so and try to do some stop and go driving). Also you may have to pop the overcenter spring (the coil spring on the pedal under the dash) if you have one or if the pedal wont come back up. A diaphram clutch doesnt have as much pressure as coil spring clutch. The install instructions should mention that also. I didnt have to remove mine, but I thought I'd mention that so your not surprised.
Click to expand...

Good info for sure thanks. I actually added a spring to my clutch by the release fork then mounted to the frame to stiffen it up. Just a cheap piece from autozone, but makes my pedal come up a lot faster, which I like. I am just trying to soak up all the info so I dont have to do it again. I had my elbow reconstructed april 12th, so I am kinda weak for a job like this, and I know it'll be a nightmare since I might do it alone.

I have new body bushings and body lift all around, and everything is solid. It seemed like my truck took a 20 year nap, and never got abused. Still has AC, and everything original. The only thing I changed was carb and intake manifold because when I rebuilt the qjet, I ported it so heavily it dumped fuel and only liked WOT and raked out timing. Now she is reliable except the clutch. I've had to shut it off at traffic lights, put it in gear and fire it up to avoid grinding gears, so I know it has serious issues. I ordered a lot of new stuff today, and I plan to get the clutch in the next week or two, so I will keep you updated on whats going on. I am excited to do the job (I'm weird, I know).

I took the front drive shaft off today, and put new u-joints in it, and got it ready to go when I get the clutch done.

My last question is, how does the shifter come out of the trans? Is it like a t56 with a few bolts and plate holding it in, or is there a trick to it?
 
the pilot bearing (bushing) is most likely bad. if the truck doesn't try to move with the clutch pushed in, it's most likely the bearing. the pilot bearing's (bushing) job is to slow the input shaft down to output shaft speed. i would only use a brass bushing on your truck, and most importantly do not grease it. i repeat, do not grease it, as much as your instinct tells you it needs grease, do not grease it. it is a self lubricating bushing and grease will clog the "pores" in the bushing.
get the flywheel turned, and most competent machine shops will tell you if a shim is recommended.
make sure the ball and socket on your linkage looks good(z bar)
make sure the ball and bearing fork look good
make sure the input shaft looks good where the pilot bearing ride
the bearing retainer on the front of the trans needs to be smooth

the shifter will have a round piece at the top. if you push it down and turn it counter clockwise 1/2 turn it will pop up and the shifter will come out.
 
transman731 said:
the pilot bearing (bushing) is most likely bad. if the truck doesn't try to move with the clutch pushed in, it's most likely the bearing. the pilot bearing's (bushing) job is to slow the input shaft down to output shaft speed. i would only use a brass bushing on your truck, and most importantly do not grease it. i repeat, do not grease it, as much as your instinct tells you it needs grease, do not grease it. it is a self lubricating bushing and grease will clog the "pores" in the bushing.
get the flywheel turned, and most competent machine shops will tell you if a shim is recommended.
make sure the ball and socket on your linkage looks good(z bar)
make sure the ball and bearing fork look good
make sure the input shaft looks good where the pilot bearing ride
the bearing retainer on the front of the trans needs to be smooth

the shifter will have a round piece at the top. if you push it down and turn it counter clockwise 1/2 turn it will pop up and the shifter will come out.
Click to expand...
as for the (z bar) is the ball and socket the plastic bushing that gets held in by the cotter pin? I am confused because when I think of ball and socket, I cant picture where it would be on My linkage. I have 3 parts connected and held together by cotter pin-type fastners, and the one that pushes the fork is threaded to be adjustable. I currently have it in the bottom eyelet for a far out adjustment, but I can move it up to the second one to get the clutch to throw further if I cant grab gears when I start driving it next week daily.

We use Mullis machine shop just south of the NC state line in SC and I am going to call him about the flywheel when I have my new clutch.

I wish I had the money today for the stuff I need because I will have to drive this thing very soon and I don't want to lose my clutch on the way to work one day or it will be a nightmare. Might have to go credit card this stuff because I'm nervous to drive off not knowing what could happen.
 
transman731 said:
the shifter will have a round piece at the top. if you push it down and turn it counter clockwise 1/2 turn it will pop up and the shifter will come out.
Click to expand...


^ The shifter may have a bunch of grease covering it too so you may have to wipe it off to see the piece he's talking about.
 
There is a full 12inch clutch available if you can find the flywheel to match. I ran one in front of my SM465 from a dumptruck with a big block. It bolts to small block also, if memory serves it weighs somewhere around 65 pounds! GREAT for crawling.
 
transman731 said:
your flywheel may have a dual bolt pattern where it will take the 11 or 12
Click to expand...
I was wondering that also because when I go to look it up on summit, it doesnt specify if its 11" or 12" and autozone says it can be 11" or 11 7/8" The last thing I want is to tear my trans out and have ordered the wrong size kit.
 
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