Finally got around to testing, and then replacing the glow plugs.. 4 stuck.

[MJGenay]

Since the entirety of the clutch ib attached to and only makes contact with one part of the flywheel, this thought process makes no sense whatsoever to me. Can someone please explain it to me?

I don't know if I'm right at all. In my mind the clutch is only spinning when the flywheel is and the clutch is engaged. I might completely not understand though.

 

[MJGenay]

I was wondering if anyone knew where the hell thing this was supposed to be plugged. Its on a harness that heads from the IP towards the passenger side. Found that plug kinda sitting on the passenger valve cover.

 

[IDIBRONCO]

That's for your Water in Fuel light. You may not have a sender on the bottom of your fuel filter.

 

[MJGenay]

That's for your Water in Fuel light. You may not have a sender on the bottom of your fuel filter.

Okay, thank you. I don't.

 

[MJGenay]

For those still following this I'm thinking it is probably the DMF. My only confusion is why does it go away when it is warm?

At any rate, clutch in seems to reduce the rattling. Riding the clutch in a gear or having clutch out in gear and the rattling disappears.

I'm planning on having the timing checked if anyone up here can do it but tomorrow I think I'm going to have to put in a call to a transmission shop down in BV and start making some unpleasant decisions.

 

[The_Josh_Bear]

1. Earlier in this thread, didn't you say that the rattling sound was accompanied by a loss in power? Is that not the case anymore?
2. Did you change the transmission fluid before losing 4-5th synchro? If so, what did you put in there?
3. Did you check the freeplay in the flywheel yet? Only two bolts hold that inspection cover on. It only takes a couple minutes. Also you can take a picture of what's inside and the boys here can likely help with a visual, if you see something worth sharing.
4. The flywheel is always moving if the engine is running. So clutch in or out doesn't engage or disengage the flywheel, but rather the clutch disc which turns the input shaft to the transmission.
5. The cold start advance adds 3 degrees to the base timing, which does help cold idle. One way to tell if your timing is retarded is to drive away while it's still cold-- sometimes it runs better cold than once the cold idle/advance drops down. If that's the case, you're retarded!

Edit: of all the words this site is censoring lately, I'm quite surprised I got away with "retarded".

 

[MJGenay]

1. Earlier in this thread, didn't you say that the rattling sound was accompanied by a loss in power? Is that not the case anymore?
2. Did you change the transmission fluid before losing 4-5th synchro? If so, what did you put in there?
3. Did you check the freeplay in the flywheel yet? Only two bolts hold that inspection cover on. It only takes a couple minutes. Also you can take a picture of what's inside and the boys here can likely help with a visual, if you see something worth sharing.
4. The flywheel is always moving if the engine is running. So clutch in or out doesn't engage or disengage the flywheel, but rather the clutch disc which turns the input shaft to the transmission.
5. The cold start advance adds 3 degrees to the base timing, which does help cold idle. One way to tell if your timing is retarded is to drive away while it's still cold-- sometimes it runs better cold than once the cold idle/advance drops down. If that's the case, you're retarded!

Edit: of all the words this site is censoring lately, I'm quite surprised I got away with "retarded".

Thanks!

1.) If I attempt to drive away immediately or shortly after (within a couple minutes) cold start up the truck stutters a bit physically (power drops off occasionally) That is still the case now and has been for the past few weeks. Wasn't such an issue back in the fall.

2.) I did, it was fine on the 700 mile drive here on the old fluid. The fluid was grayish when I drained it. I filled it with Mercon V, after the synchro issues popped I drained and refilled with something I saw (can't remember what) recommended to "fix" partially worn synchros. Might've had "Red" in the name, I'll have to see if I still have any in the garage.

3.) I haven't, I need to remove the cross pipes to be able to pull that cover off. I did remove the heatshield on the bottom of the cab this evening, just in case that would stop the rattling. It didn't, but strangely, the rattling is much less.

4.) Yeah that makes sense. If it was the DMF, could that potentially mean the clutch is keeping it from rattling around?

5.) I currently have the cold idle disconnected. It kinda stutters a bit if I try to drive it away right after a cold start. Runs well when warm.


Maybe the site knows that word has a legitimate use haha.

 

[The_Josh_Bear]

So you might have 2 or 3 things going, and I know you don't want to hear that. But stuttering under power says IP or injectors to me. Not DMF. I guess if it was me I'd really give it some skinny pedal under load and see what she does. Either bogs down and can't get out of her own way(fuel issue) or takes off and maybe the stutter is something else. But as you describe it I'm thinking more and more fuel delivery not fuel supply/pickup.

Then also gotta figure out that DMF thing. If it's letting go I have heard of them taking out the transmission case, but they rattle pretty good when shut down before that happens. Mine rattled every shut down for 5 years before I went to a LuK SMF. I'm not saying do that, but it's what happened. I didn't know about it then.
Mine started to slip on steep hills pulling my 4,500lb trailer. Just about got stuck once in downtown Seattle. Not cool!

For the transmission that actually makes a lot of sense. Grey fluid probably had a lot of friction material suspended in it and made the syncrho work better than it actually does. Point is the OP didn't take care of it.
I love Redline MTL for these ZF-5's. My transmission was chattering into 2nd and especially 3rd gear when I got the vehicle 16-ish years ago. Moved to MTL at some point and I'm still driving the same rig. Needs a rebuild for sure now, but still drivable, just have to shift slower. So it may be worth a shot to get you through for a while. I can't say it'll be better than the Mercon V but it might be.
I would think of all the synchros that's the easiest one to work around, so that's something.

 

[MJGenay]

So you might have 2 or 3 things going, and I know you don't want to hear that. But stuttering under power says IP or injectors to me. Not DMF. I guess if it was me I'd really give it some skinny pedal under load and see what she does. Either bogs down and can't get out of her own way(fuel issue) or takes off and maybe the stutter is something else. But as you describe it I'm thinking more and more fuel delivery not fuel supply/pickup.

While I'd prefer nothing was wrong I knew I wasn't signing up for that with an old truck. I'm an "action" guy so action points, or a direction, helps a lot.

I'll give it a go, aka punch it. You're suggesting I do that when the truck is cold, correct? I'm wondering if the stutter when cold may be because I removed the plug from the cold advance. I'll have to stick it back in and test.

Then also gotta figure out that DMF thing. If it's letting go I have heard of them taking out the transmission case, but they rattle pretty good when shut down before that happens. Mine rattled every shut down for 5 years before I went to a LuK SMF. I'm not saying do that, but it's what happened. I didn't know about it then.
Mine started to slip on steep hills pulling my 4,500lb trailer. Just about got stuck once in downtown Seattle. Not cool!

Yeah if I have time tomorrow those cross pipes are coming off and I'm going to remove that cover. I've heard about them taking out the transmission case as well. At some point I am going to a SMF, probably a Luk as I've read good things about them. I'm just hoping to wait until I can have that tranny rebuilt too.

For the transmission that actually makes a lot of sense. Grey fluid probably had a lot of friction material suspended in it and made the syncrho work better than it actually does. Point is the OP didn't take care of it.
I love Redline MTL for these ZF-5's. My transmission was chattering into 2nd and especially 3rd gear when I got the vehicle 16-ish years ago. Moved to MTL at some point and I'm still driving the same rig. Needs a rebuild for sure now, but still drivable, just have to shift slower. So it may be worth a shot to get you through for a while. I can't say it'll be better than the Mercon V but it might be.
I would think of all the synchros that's the easiest one to work around, so that's something.

Yeah I know people joke about "junk" holding stuff together but I think that is exactly what it was. At any rate the "Red" stuff I was talking about was Redline MTL, I went out the the garage and checked the bottle. That's what is in it now and unfortunately it hasn't fixed the problem. 5-4 ain't really bad at all so I'm in no rush. Biggest issue I foresee is maybe having to downshift on a long grade pulling a trailer... but I haven't pulled a trailer with this truck yet.

Thanks for all the help.

 

[Brian VT]

I'm quite surprised I got away with "retarded".

That's because you didn't spell it right.
Retaahded.

 

[MJGenay]

Spent so much time on this truck the past month I had to stop for awhile as I was falling behind on work...

Pulled off the cross pipes so I could remove that cover on the flywheel today. Asked my neighbor to come over and take a look as he used to work on mining equipment. The mysterious rattle doesn't jump out at him as one thing or another. Thinks I could be the flywheel springs or something.

At any rate the flywheel doesn't have any play. The springs on the flywheel are rubbed flat on one side, some are barely loose, some have close to 1/2 inch of play if not more (I could only reach 3 of them I believe.

For those who think it could be something else, including maybe me as I have no idea what I'm doing, here is some food for thought: On cold start, I can press the pedal to bring it up to 1k RPM and it will jump around a bit there, according to the dash tach it'll move by about 100 RPM up and down, maybe a little less. Not sure if that is normal or speaks to anything else.