Clutch job for weekend mechanic

[clarkedj]

Had a question as to how big of a job is replacing the clutch in a 1978 Fiat 124. My sons 124 clutch is starting to give. On inclines of 20 to 30 degrees the engine revs but the car does not move any faster. It is not bad yet but I know from my past experience when I had an 850 as a kid this is a sign of the clutch being worn. I did the clutch job on my 850 as a kid and it was a b***ch. Is the same true for the 124. I have the normal tools to maintain the car. Hydralic jack, stands, assortment of metric wrenches, torque wrench. I do not have an engine pulley or any fancy stuff. I got an estimate from the mechanic here in Dulth Georgia of $700 including parts. I know from IAP that the clutch system and bearings etc will run me about $175. The basic question is this something a weekend mechanic can accomplish with his 18 year old son? Is there a good technical reference manual that goes through the steps?

Thanks

Ed

[Ernie]

Ed,

It's a lot of working on your back but not too hard to figure out, especially if you've done a clutch job on any other car.

Main things to disconnect you will see when you get under the car.

One tip is to get a clutch alignment tool at Advance Auto Pats. I only paid $1.98 for mine. Another tip is change the gear oil while you have the transmission on the bench or floor. It's a lot easier that way and cheap preventive maintenance.

I have a nice spring puller I use to reattach the clutch spring. On some cars this is one tough spring. I've read where guys have used coins in the coils to extend the spring. The coins fall out first time you press the pedal to the floor.

Oh yeah, if you want any of the switches for backup lights, emissions, etc, in the transmission to work afterward, hunt them down and disconnect before moving the trans. I learned this too late.

I'm editing this post to add -- disconnect the battery first, and this is a good time to check or change the guibo (big rubber thing on the driveshaft).

Ernie

[clarkedj]

Thanks Ernie

[manoa matt]

You will need to get the front and rear axle up on jack stands. Remove the center console then remove the chrome shifter extension. Remove the trans tunnel plate and disconnect the wires that come up through it. Remove the 6 bolts from the rubber flex disc at the rear of the transmission. Remove the trans inspection plate at the bottom of the bellhousing. Remove the clutch cable from the throwout arm.

Now comes the hard part. Remove the starter. You will need a universal joint/swivel joint and a few long extensions. Remove the two upper bolts that hold the bell housing to the engine block...also a P.I.T.A. Loosen the rear trans support bar to body nuts so that the nuts can be spun off quickly. Loosen the lower trans to block bolts and put a shop/racing jack(something with wheels) under the trans to support it.

Now with the stronger guy under the car and the other guy holding the engine block remove the lower trans to block bolts completely. The block has a bushing that engages the trans bellhousing so not to worry that it will immediatly fall, also the input shaft from the trans engages the crankshaft.

The trans is pretty light (60-75 pounds), however while on your back it will feel like 175 pounds. One guy will lower and slide back the trans while the other guy holds the block and tilts it backward. Watch you don't slam the shift extension housing or the shifter rod. Someguys take off the shift extension housing, but you can still take the trans out with it on, just slide the shifter rod into 3rd gear.

While you finesse the trans away from the block keep it supported by the jack. You don't want it to hang by the trans input shaft.

You will have to remove and replace the clutch plate and clutch cover with the engine block in the car. You will need to support the engine somehow as it only has the mounts on the two sides and will want to rock back and forth. You don't want to slam the cylinder head into the firewall.

Its always a good idea to surface the flywheel every time the clutch plate is replaced, so you will need to take off the flywheel. You can lock the flywheel if you get a piece of angle iron about a foot long and put one edge in the teeth and run it along the lower drivers side of the block against the trans to block bolt hole boss. A "C" clamp will help.

When you get it back together the clutch pedal should press down about 1 inch before resistance is felt. That equates to the throwout bearing traveling 2mm before it touches the face of the fingers on the clutch cover plate. The throwout bearing should NOT be in constant contact with that cover plate or it will wear out in short order.

[narfire]

WoW Matt. I'm gona print that off. I know there will be a day when I need it.
Thanks
Chris

[TulsaSpider]

Here's a thought...is it properly adjusted? don't overlook the obvious!

[manoa matt]

"Here's a thought...is it properly adjusted? don't overlook the obvious!"

I'll second that. Its easy to check the adjustment and see if all the return springs are there, but checking the friction plate thickness is difficult. You can remove the inspection plate at the bottom and use a small mirror to peer into the raised areas of the clutch cover. You may need to rotate the flywheel so one of the raised areas is accessible.

[So Cal Mark]

why on earth would you go to the trouble of removing the center console? There is no need for that.
I'd say this is not an easy job for a weekend warrior to do at home unless you have the right tools and some experience

[manoa matt]

"why would you remove the center console? "

How do you disconnect the backup light switch, and gear selector switch wiring? The wiring connectors are above the trans tunnel removeable plate but below the center console. I guess you could just remove the shift knob and lower the trans with the chrome shift lever extension installed, but its alot easier with it removed. I guess it also depends on whether your chrome extension is installed over or under your shift boot.

[So Cal Mark]

I unbolt the shifter from the bottom and leave the whole thing in place with the boot. No problem disconnecting the wires once you lower the back of the trans a few inches. Taking the console out is just a bunch of unnecessary work

[clarkedj]

Matt Great write up I will second the print for future use. Talk to me about the clutch adjustment. The only adjustment I am aware of is the cable tension adjustment on the side of the tranny. Good thought on checking the inside for the springs etc. But if the tension springs are shot or missing I will have to pull apart the clutch anyway. So what other adjustments are there to the clutch other than the cable?

Ed

[majicwrench]

If the clutch works smoothly now there is no need to surface the flywheel. I do 10 to 12 clutches a year in my shop and haven't surfaced a flywheel in years. Many manufacturers state NEVER to surface the flywheel as it throws the geometry off.
Keith

[So Cal Mark]

rarely do I find a flywheel that isn't glazed or uneven when the clutch is worn out. I'm surprised you find such good ones consistently

[kristoj]

I would say this is a job you and your son can do. I helped a friend do his and we got it done in a (long) day. Neither one of us had ever done a clutch before either. It's definitely not easy, especially getting the some of the bolts back in. But it's not worth $700 to get it done.

[majicwrench]

Mark,
For one thing, the clutches I am doing are not old Fiats, but more modern cars. Still, many have a glazed look, or some hot spots. Sometimes I go over em with a sanding board, most times not. They still work fine. Taking material off the flywheel starts moving the clutch itself away from the throwout brg, and starts changing everything. The flywheel is such a solid mass, it is pretty hard for it to warp or become uneven to any degree. The pressure plate, on the other hand, is prone to all sorts of issues.
Now if I have a clutch that is chattering, that is gonna make me nervous, and I am gonna give the flywheel a real good look. But still, can't remember the last time I surfaced one.
Keith