The Stovebolt Site Forums The Parking Lot Big Bolts Replacing Clutch in 1946 Two Ton Truck

My clutch is slipping and I’m pretty sure I need to replace it. Is this a job for a DIYer or do I need to go to a shop? I’ve done quite a bit of mechanical work, but I haven’t tackled a clutch yet.

As long as you have the right equipment and a place to do it, why not? Just remember, the bigger the truck, the heavier the parts.

An engine hoist through the passenger door after removing the 'tin' floorboards will take care of moving the trans back after removing the driveshaft. If a torque tube, the whole works needs to be moved back. No need to remove trans unless it needs attention. Lower two bolts(3/4" hex wrench) might remove from inside bellhousing. Loosen clutch pressure bolts one at a time while rotating flywheel, last one requires attention to not drop whole works. Inspect pressure plate and disc for unusual wear pattern. Get new pilot bearing and new throwout bearing. Should come with plastic realignment tool, or a spare trans input shaft will work.

Insert pilot bearing, ask if not know how. Place new clutch disc upon flywheel, only goes one way, insert tool to hold disc in place, insert throwout bearing in pressure plate fingers, and clutch release arm, several configurations exist, while starting one bolt to hold it all in place, continue to insert bolts in alternating holes. When all started, tighten alternating bolts a little at a time, soon will start to take up clutch spring(normal) until all tight, blue locktite useful, remove tool, making sure it easily comes out. If tight, loosen pressure plate bolts and tighten again maintaining easy movement. Reinsert trans making sure release bearing and release arm stay aligned.

Ed

Another idea if you dont have an engine crane is use a motorcycle jack under the trans. Of course, if its an open drive shaft setup.

Thank you. That’s exactly the information I needed.

I used to use a scissors jack on a roller skate, employ better methods now.

Ed

A regular transmission jack with 4 wheels under it and a strap to go around the transmission is handy for the job. A motorcycle jack may work just as well as suggested above, I'm not directly familiar with a motorcycle jack.

If your clutch is slipping are you sure it doesn't just need adjusting? Do you have any free play at the top of the clutch pedal? Free play is where the clutch pedal pushes down easily for maybe an inch, and then pushes harder as the throwout bearing begins to push on the pressure plate. In case you are not familiar with the term.

If one is not sure a clutch is slipping or not adjusted properly, a slipping clutch will slip more in high gear, more torque load on engine, improperly adjusted clutch will slip in many gears, plus the throwout bearing will soon expire.

Ed

I did adjust the clutch to get an inch of free play. It seems to slip a little bit in each gear, and is worse in 3rd and 4th. I might try to adjust it again before I take it apart.

I used a plastic tool for centering the clutch and it worked really well. I also used a scissors jack on roller wheels to support and move the transmission back. I made a wooden rest to sit the transmission on and used the straps on the jack.

Tip on new clutch discs; try it on your input shaft to be sure it is free to move on the spline.

Just did my clutch on a 42 ton and a half. Best to use a good trans jack on smooth firm hopefully concrete floor. Don't try and rig it and get yourself hurt.

Also why you are there, replace the clutch, pressure plate and throw out bearing. I would also take the flywheel off and have it resurfaced. You don't won't want to go back in there anytime soon. I spent around 250 to completely do mine, well worth the money.

Only do what you are comfortable with. Be safe.

Odds are that if you have sufficient free play and its still slipping, its clutch replacement time.

As mentioned, this is definitely one of those "while I'm at it" repairs. Consult your shop manual for details, but plan on replacing driven disc, replacing/rebuilding pressure plate, new throw out bearing, new pilot bearing/bushing, and resurfacing fly wheel. Also clean and re-grease fork pivot.

Be sure to wear appropriate PPE. Driven discs on older vehicles contained asbestos, so take proper precautions when handling/cleaning components. When you're done you'll have many trouble free miles ahead of you.

Not sure what the configuration of your trans looks like. Mine has studs on each side, so I made a couple of L-brackets, attached them to the sides, then borrowed my buddy's motor cycle jack. Put a little plywood platform on it with holes to accommodate a ratchet strap tie down. Worked great. If I were to do it again, I would include the driveline angle in the design - but the threaded feet allow enough adjustment to slide the trans in and out with no issues.

Best Regards....