Need help: OM617 / NV4500 Swap Clutch Chatter (1 Viewer)

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
Gents, does this sound like a throwout bearing problem or something else? I'm going to pull the trans out when I can (I'm not anywhere close to having the Mule back on the road yet), but I'm pretty green when it comes to troubleshooting clutches so I'm trying to get a feel for what's going on.

Clutch is a Luk 11" low profile with AA TLC throwout bearing (spec'd for the low profile clutch) and GM cast iron clutch fork. Bellhousing is AA 712577, I centered the bellhousing to the crank. It was within .002". Out of spec tolerance is .005". Clutch slave is OEM AISIN.

Things I did trying to isolate the noise, but did not work:

- Return spring on the slave
- Completely removed clutch slave and held fork full forward (throwout bearing to rearmost position)

The noise completely resolves when the clutch is engaged.

Here's a video. I meant to say throwout bearing in the video. The video makes it sound pretty bad, it's not that insanely loud, but something isn't right...

 
Last edited:
Joined
Dec 13, 2012
Messages
1,200
Location
KY
Can you get someone to assist and try and pin point the noise better with a stethoscope or other listening device?

It almost sounds as if maybe part of the pressure plate is rubbing maybe the fork or could the trans be partially in gear and it is gear noise.
 

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
Yep, double checked it multiple times during installation.

I think the clutch fork is rubbing on the stamped steel face of the pressure plate housing.

Is it possible for the ball pivot adjustment to be so far out that the clutch fork, in the disengaged position can interfere with clutch components?
 

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
Just wanted to update this ongoing issue so maybe others can benefit:

It's not the clutch fork interfering or annoying hitting the pressure plate (no witness marks).

I added a 1.25 quarts of the spec'd AMSOIL lubricant so it's 5.25 total (I have a filter/magnet assy in the right PTO cover that holda about a pint)

I set the throwout bearing to .030" of free play and have verified that it isn't "riding" on the clutch face. I used a screw driver and the noise seems to be coming from the front side of the trans.

I'm going to pull the top cover when I get back from leave and check for anything that looks out of place.

If I don't find anything, is it possible to have this much gear rattle since it's a 5 cylinder?
 
Joined
Dec 13, 2012
Messages
1,200
Location
KY
I listened again and it almost seems like it may not be totally in gear. The other idea is that maybe it is gear contact with you filter assembly somehow.
 

davegonz

Keeping it Weird
SILVER Star
Joined
Sep 15, 2004
Messages
9,098
Location
Austin, TX
You think the clutch disk is hitting the flywheel mounting bolts? Did you use the thin bolt spacer under the flywheel or behind?

 

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
I don't think it's hitting the flywheel, but when I get back I'll pull the inspection cover and drain it to see if there's any metal shavings. I think it could be the adapter kit spud shaft putting some pressure on the main shaft ( I greased it and maybe it's not compressing?) I've got a call into the builders that I got the trans from and they're watching the video to help me troubleshoot.
 

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
Oh right, I used the bolt spacer on the face of the flywheel in the same orientation as the flex plate.
 

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
I called the shop that rebuilt the transmission and they reviewed the video and don't have any explanations other than it's gear chatter / clatter

I think what I have is just a noisy transmission. When I put it in gear and accelerate / put a load on it the gear chatter goes away, so I think it's just gear chatter that's a byproduct of an externally balanced 5cyl diesel. The GM diesel NV4500s had a dampener on them to help with reducing the chatter. I'm hoping once I get the transmission hump on and put lizard skin on it it'll not be so loud...either that or it's going to catastrophically fail.

I was going to pull the top cover this weekend but I went deer and coyote hunting instead...I still plan on doing that.
 
Joined
Aug 14, 2010
Messages
55
Location
New Jersey
My NV4500 (New GM) rattles a little bit when the clutch is in, but you really have to listen for it.
 

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
My NV4500 (New GM) rattles a little bit when the clutch is in, but you really have to listen for it.


Mine is quiet as a mouse when the clutch is in...just loud as hell when it's out.

Another thought I had was I left the output shaft a couple thou. too long (even though I measured multiple times and dressed it down, and assembly went together just fine) causing a preload, but the trans show said its impossible due to the plate that's bolted on the back that sets the preload and Advance Adapters said the same thing...
 
Joined
Aug 14, 2010
Messages
55
Location
New Jersey
Mine is quiet as a mouse when the clutch is in...just loud as hell when it's out.

Another thought I had was I left the output shaft a couple thou. too long (even though I measured multiple times and dressed it down, and assembly went together just fine) causing a preload, but the trans show said its impossible due to the plate that's bolted on the back that sets the preload and Advance Adapters said the same thing...

I think we are using different terminology for when the clutch is engaged... With the NV4500 in neutral and the clutch engaged such that the input shaft rotates (foot off the clutch pedal), I get a slight gear chatter. Sounds almost like the rattle of a diesel engine, except much quieter. Most people don't notice it. The rattle varies in frequency slightly.

Yours sounds different in that the frequency sounds fairly constant, which leads me to believe something is hitting the rotating assembly. However that doesn't explain why it goes away under load....
 
Joined
Sep 18, 2005
Messages
2,410
Location
Willamette Valley-Oregon
so I think it's just gear chatter that's a byproduct of an externally balanced 5cyl diesel. The GM diesel NV4500s had a dampener on them to help with reducing the chatter.

I've been following your thread, and in particular this problem.

From what I remember/learned of reading about the OM617,
1- it is an externally balanced motor, balanced by the flywheel, which you also state in the above quote
2- all of the OM617 powered cars officially imported had auto transmissions, meaning that they had the light weight flywheel for an auto transmission and not the heavy flywheel that was needed for a manual transmission and clutch

With this in mind, I have some questions for you.
1- what I get from this is that to find a manual transmission flywheel balanced specifically for the OM617 here in the states would not be an easy thing, this flywheel probably would need to come from Europe wouldn't it? Where, from whom, did you get your flywheel?
2- This may be a long shot, especially since you state that the motor runs smooth when the clutch is disengaged, but could a bad flywheel be contributing to your transmission vibration/chatter?

This keeps coming to mind when reading of your problem and I just can't seem to get it out of my mind.

Don
 

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
I've been following your thread, and in particular this problem.

From what I remember/learned of reading about the OM617,
1- it is an externally balanced motor, balanced by the flywheel, which you also state in the above quote
2- all of the OM617 powered cars officially imported had auto transmissions, meaning that they had the light weight flywheel for an auto transmission and not the heavy flywheel that was needed for a manual transmission and clutch

With this in mind, I have some questions for you.
1- what I get from this is that to find a manual transmission flywheel balanced specifically for the OM617 here in the states would not be an easy thing, this flywheel probably would need to come from Europe wouldn't it? Where, from whom, did you get your flywheel?
2- This may be a long shot, especially since you state that the motor runs smooth when the clutch is disengaged, but could a bad flywheel be contributing to your transmission vibration/chatter?

This keeps coming to mind when reading of your problem and I just can't seem to get it out of my mind.

Don

Don, thanks for the contributions.

The flywheel is an aluminum body with steel friction surfaces Fidanza flywheel that was made by Fidanza per Luke at 4x4 Labs' specifications for a GM 11" clutch. It has been used in many conversions successfully. When I tore down the OM617, I marked the crank and the flexplate's 12 o'clock position. After removal I had the new flywheel match balanced (to mimic the external balance the OM617 uses) per the engine tech manual. I used brand new mercedes crank bolts torq'd to the proper specs with the final 90 degree method.

I don't think it's the flywheel, but I don't rule thing out until I know what the problem is.

I've been super busy with my job lately but I hope to do some more trouble shooting this weekend.
 
Last edited:

DPV7070

ForceFed40
Joined
Jun 13, 2010
Messages
930
Location
Vestavia, AL
Dave, I did see those earlier during my quest for answers on the inter webs.

Pulled the top cover today and from what I can see everything looks great, but then again I don't really know what I'd be looking for besides obvious wear and tear, broken teeth, metallic shavings, or silver colored trans lube...which there were none. Everything seems to be in good order.

Money shot
ImageUploadedByIH8MUD Forum1412218025.732693.jpg


Input bearing
ImageUploadedByIH8MUD Forum1412218039.631059.jpg


Bottom of top cover
ImageUploadedByIH8MUD Forum1412218114.019344.jpg


I did get a short video of some of the gear movement which seems to have the same sound...


So, I'm still at a loss. I'll probably just run it since either option involves pulling it.
 

Users who are viewing this thread

Top Bottom