Replacing the clutch?

[bluesfella]

I have a '66 C10 with the 250 straight six and three-on-the-tree manual. The clutch just went out, so I need to replace it this week. I have two basic questions:

1. How do I know if I have the 10" clutch or the 11"? It looks like both are available everywhere I check, but without pulling mine apart I have no way to tell which one I have.

2. Is there a simple walkthrough around for doing this? I've pulled engines and transmissions in a few cars, and even did a full rebuild on the 700R4 tranny in my BelAir, so I'm perfectly comfortable with automatics, but I've never replaced a clutch before. Any info specific to these trucks would be especially helpful.

Thanks in advance! I'm not able to get on this board nearly as much as I used to, but I know this is the place to ask!

[jocko]

Unfortunately, dealers list both 10" and 11" for your engine... (ref http://www.lmctruck.com/icatalog/cbe/full.aspx?page=73). I would give LMC a call and ask if they can help (IF you can't get an answer on here). Maybe both will fit, but if it were me, I'd yank it and measure before ordering. I realize that can be a problem if she's your daily driver. But you did say the clutch went out, so might as well start tearing into it I suppose.

Not too awful hard to replace one. Remove the shift linkage at the easier end to do it, pull the driveshaft (by removing the u-bolts at the rear and sliding the driveshaft aft - same as an automatic (I apologize if over-simplifying, this is probably too much info since you've already changed an automatic trans before)), pull the trans (this part IS different than an automatic trans, the tip of the trans input shaft rides in the pilot bearing at the back of the crankshaft, so you can't drop the trans straight down, you have to pull it aft first all the way out of the pilot bearing and out of the clutch splines and clear of the bell housing, THEN down), drop the clutch and pressure plate out the bottom of the bell after removing the pressure plate-to-flywheel bolts (or if your bell hsg has no removeable access plate, remove the bell hsg and do this). Now - reinstall your new stuff. The only "trick" is that you need something to hold the clutch in proper alignment while you tighten down the pressure plate bolts (then the pressure plate will hold the clutch in place for you - the clutch friction disk has to be properly aligned so that when you slide the trans forward later, the tip of the trans input shaft will line up and go into the pilot bearing properly). A clutch alignment tool is a must (imo). I've done it successfully with a broom handle, but was pure luck! If you have an old input shaft lying around with matching splines - great, if not, then I recommend buying the tool, and often they will come with the clutch/pressure plate combo if bought as a "kit". Either way, when you use the alignment tool - make sure it is pressed all the way forward and the tip of it slips into the pilot bearing. Also, highly recommend replacing the throwout bearing while you're in there - and take care to notice the orientation of the old one before you yank it so you don't install the new one backwards. Anyhoo - once the pressure plate is bolted down, you remove the alignment tool by sliding it aft - then just push the trans in its place through the throwout bearing, clutch disk splines, and the tip goes into the little pilot bearing into the back of the crank (preferable a new needle pilot bearing) and bolt the trans to the bell hsg mounts. (Note - if you had no bell hsg access plate, you'd install the bell hsg after the pressure plate is bolted down). Reinstall driveshaft. Hook up your shifter linkage again and you're done. Ok, it just SOUNDS simple - it can be a pain, but there's no pressures to set up, etc like on a 700R4 install. You may want to adjust your pedal, etc linkage once the install is complete to fit the pedal height, pedal throw to engagement, etc. One more note - inspect your flywheel for any cracks - and replace it if you see anything suspicious. It's also good to re-surface it or replace it if it's worn. Good luck. Sucks when they go out on you.

[bluesfella]

Wow, Jocko...thanks for the thorough instructions! I'll probably start taking it apart in the next day or so and measure the old clutch to see what I have.

[markeb01]

A couple of tips with any clutch replacement:

First - pick up at least two long bolts (preferably four) to temporarily replace the transmission to bellhousing bolts. Saw the heads off and cut slots in the ends to assist installation and removal, as shown below:



This allows removal and installation of the transmission without the risk of your arms getting tired allowing the transmission to hang down (even momentarily) bending the clutch disc.

Second - after carefully aligning the clutch disc with the tool, it is still possible there will be difficulty sliding the transmission all the way home into the pilot bearing. If this is ever a problem, just have someone push down on the clutch pedal while you apply pressure to shove the transmission all the way home. This will disengage the clutch allowing it to float, eliminating any possible binding.

[jocko]

markeb01, that is SMART!! I never thought of the long bolt idea. Now I can quit goin to the gym for a month before my tranny swap! When I first saw that pic, I was thinking that you could just slide the trans aft, support it in the rear, and then replace the other stuff from beneath the bell hsg - but obviously that wouldn't work if the bell hsg has no inspection cover (I was spoiled, my 57 chev bell hsg had open access from beneath). But still, that is extremely helpful. I would be nervous about resting any trans weight near the end of the sawed off bolts and snappin the threads off in the bell hsg (knowing my luck...)

[javadoc]

Wow, brilliant! I'm going to have to do that for when I rip out my trans (AGAIN) to try and get the correct t/o bearing in it. That's pure genius.

[markeb01]

I’ve been using this technique since the 60’s after I bent a clutch disc when my arms finally gave out. A Dremel tool with a cutoff wheel makes quick work of the bolt modifications. As seen in the photo, the engine is supported by a 4x4 under the oil pan on a floor jack. If the transmission cannot be pulled straight back the length of the bolts due to interference with the floor, simply lower the jack a tad angling the transmission slightly downhill. If you have a V8 engine, just make sure to remove the distributor cap first so there is no risk of damage if it hits the firewall.

[Heater63]

I would (and do) use 11". 10" and 10.5" is car size.

buy a clutch and pressure plate set, make sure your input spline count matches your transmission input shaft (10, 14, 26 ??).

do not assume that the throwout bearing that may be included is the correct one; make sure you have the proper clearances.

There is a good tutorial at www.Novak-adapt.com under knowledge, clutches

[bluesfella]

Thanks for all the help, guys! I really appreciate it.

[CVA59]

As Jocko mentioned. I would definitely replace the pilot bearing/bushing with a needle style pilot bearing while it is apart. I always throw in a new pilot bearing when i do a new clutch install..

[Heater63]

Originally Posted by CVA59

As Jocko mentioned. I would definitely replace the pilot bearing/bushing with a needle style pilot bearing while it is apart. I always throw in a new pilot bearing when i do a new clutch install..

Actually, many on here swear by the standard pilot bushing, and swear AT the needle bearings. The needle bearings are easy to damage/distort during install, and are not necessary. Do your research, you decide.
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[markeb01]

My transmission guy advised against the needle pilot bearing and my local independent parts store stopped carrying them because of bearing failures causing expensive damage to the pilot shaft.

[Zack Methvin]

Wow, I guess i have been lucky with them. I have yet to have one fail. They are probably made in China today is why they are crap, LOL. Bluesfella.......As they said i would go with the bushing instead.