Diesel clutch replacement

[Long-D]

Anyone replaced a clutch on a SD22 720? It's been stuttering for a few months when going into first gear (moreso when cold, not as noticeable when warmed up and have been driving for a while)....but there's been a couple of occasions recently when under hard acceleration it seems like it's offically "slipping" . What is the best way to remove/access the clutch? Can it be dropped without having to lift the engine? Any advice appreciated!

[datzenmike]

Stuttering is generally a motor symptom. Do you mean grinding gears going into first?

[Long-D]

Maybe that's not the right word....it's definitely not a grinding sound....but when the transmission is cold, I just have to let the clutch out more slowly than when it's warm. It's like instead of being a smooth transition between fully engaged and fully disengaged there's a point where the clutch shudders. No gear sounds or shudders between any of the other gears once the truck is in motion, just from stop into first (or reverse), when first starting in the morning. But perhaps it is symptoms of another issue besides the clutch?

[datsunaholic]

Sounds like a glazed clutch. 

[wayno]

I call it chattering, I am really unsure why it does it, and it only does it in first, because we don't slip the clutch in the other gears, only in first when starting out.

Fact is, the 720 diesel is the only one I have ever had do it myself.

[Long-D]

It's not too bad at the moment, but I still expect the clutch would need to be rebuilt or replaced at some point before the next 10,000km. No info from the previous owner, but possibly it is the original.

Just wondering the ease of accessing the clutch on the 2WD 720, ie. would this be a 6 hour job or a 12 hour job for someone who has the tools/shop/knowledge? (Which is not me unfortunately, but I do have a trusted mechanic with family discount rates).

[wayno]

You have to at the very least move the transmission back far enough to access the bolts holding the clutch cover on, if you have to turn the flywheel, well that will likely take a couple people to remove, even though the SD22 engine has 22 to 1 compression ratio, it turns remarkably easy by hand, and since the transmission will be in the way, so impact would be out of the question, someone will have to hold the flywheel still with a breaker bar while the other loosens the flywheel bolts, but if you drop the transmission onto the ground, then you can get to the flywheel bolts with an impact. 

Anyway to do this is a lot of work, to separate the trans. from the engine, you have to remove the battery, the shifter, the driveline, maybe the tranny mount cross member(I can't remember), the starter, the clutch slave from the tranny case, then the bolts holding it to the engine, if you are just going to move it backwards, you might not have to disconnect the exhaust, then separtate them and move it back as far as possible, it's only going to go maybe 6 to 8 inches, just barely enough to get to the bolts holding the clutch cover on and it's just enough to pull the input shaft out of the clutch housing, it's kinda a hassle to put the clutch alignment tool in when putting it back together, but I have succeeded doing it in the past.

Something will need to be done to stabilize the engine also, having the exhaust hold it in position is asking a lot of it, it will want to drop towards the rear.

Someone that knows what they are doing can do this in 5 hours or less as long as they have all the basic tools, having air and all the good tools, it would be closer to 3 hours.

Someone that has never done it before that has the basic tools or can borrow what they need, and has the parts(clutch cover/disc) and will not be turning the flywheel, it will take all day, and maybe part of another, it just seems to take a lot longer the first time.

[mattthom1986]

Me and my brother can swap clutches in a 4wd gas burner in about 3 hours. We drop the front diff so we don't have to pull the engine. I imagine a 2wd coal burner would be less complicated. In all fairness we do have the shop/tools/experience. If your anywhere near North Georgia let me know.

[Long-D]

Okay great, thanks for the tips! And the offer from Georgia but unfortunately I'm about 2000 miles north west

[ggzilla]

Wayneo, that sounds exactly like the procedure of replacing a gasoline enigine 720 clutch ...

[wayno]

Wayneo, that sounds exactly like the procedure of replacing a gasoline enigine 720 clutch ...

 

 

It is, but he has likely never done it before, so I explained how to do it without actually dropping the transmission, most would drop it on the ground, but I used to have to put the transmission up in position before I could install the clutch cover, as it was a dogleg in a 521 and it would not even drop out without removing the clutch cover.

[scottfelsen]

I had to cut the exhaust and remove the transmission to replace the clutch. However, it really wasn't very hard to do and I have a diesel SD 22 720 so yours may be different. It would have been great if I could have just slid the transmission back enough to fit the new clutch on. I did try... But... The transmission had to be dropped. 

[datzenmike]

Yes the tail will only go back so far up onto the cross member that supports the torsion bars. I did one in a wrecking yard once that was crushed and upside down. I got it back just enough to rotate the flywheel and unbolt the clutch. With it out the transmission front would just clear enough to lift it out.