I hardly ever run past 2500 rpms, but tonight in some traffic, I ran it up to 3000. Once past 2600 or so, I got a strong vibration and when I released the pedal to shift, it was almost as if the truck wanted to de-celerate before I could push the clutch in, like an electric motor does when something out of balance is tied to the shaft and you cut the power. The vibration will also occurs in any gear and when sitting in neutral. Power up to 2500 is normal and strong.

Could it be the dual mass flywheel starting to go, harmonic balancer, HPOP falling flat, or an injector problem?

Truck only has the mods in my signature and 179,000 miles with 17,000 miles on biodiesel.

 

Sounds like DMF.

Hell, I got a SMF and I get a vibration like that as well. Flywheel takes up a lot of stuff, but if that DMF goes, it can do that.

I don't think its HPOP or Injector though.

 

From the sounds of it .......DMF....I am an auto guy......Neal or Cody would be the go to's on this....I am sure one will chime in sooner or later.....but I have not seen Neal on here for at least a week or so.

 

I sent him about 50 sheep Ron.
He's probably really busy out in the barn.

 

I thought he was married with a youngin'......oh well....I dont know about you sheep guys....LOL.....must have amish blood in ya or something

 

He's a pedophile?

 

I tthought all you sheep guys were

 

OK guys this has gone too far!!
Yes I am married but maybe that explains the sheep

Anyway, I believe it could possibly be the DMF. Although I don't see how you can drive and never go over 2500 RPM's. Heck I don't spool up till 2200 RPM's. Most of our speed limits are 70 MPH and I hit 2500 at 65 MPH. Shoot i would never get anywhere at those RPM's. But then again I have 4.10's.

Usually the DMF will be sporatic. It will drive fine then all of a sudden vibrate so bad the whole truck can shake, and it will do it at any RPM. Sometimes it will give a baby vibration then go away. So there is a broad range there.

Another thing that it could be is thetires out of balance. If the truck doesn't see 2500 often then it obviously doesn't regularly get Interstate speeds.

If it has a two piece driveshaft I would check the carrier bearing and all u-joints as well.



And for the reason I haven't been on here lately is because I have been busy with the Holidays and other things.
What I mean by other things is there is a Coal fired steam plant across the lake from me in Kingston, TN. Google "ash spill in Kingston, TN". It will pull up all kinds of things. It dumped millions of cubic yards of hazardous fly ash in the lake across from me. It created a tidal wave about 8-10 feet tall and wiped out most all the docks and boats on my side of the lake. I lost one dock and a 28' pontoon boat completely. It also damaged my other dock. All other docks are a total loss. The people on the other side of the lake lost homes. I feel lucky...kinda. This all happened on Dec. 22nd, just before Christmas. You can read more at TVA.gov or WBIR news in Knoxville or knoxnews.com or WATE news in Knoxville. Heck I was even on CNN once during a town meeting.....SUPERSTAR LOL



Sorry for the

 

hey Neal......all kidding aside...hope your holidays went well after all that

 

Yup they did. Thanx. Same to you. Did Santy do you good?

 

WOW!! Sorry to hear about the coal spill and property loss, Neal. Just think if a 7.3 could roll the coal like that!! Maybe with bigger injectors and a huge fuel tank?

Sounds like it's getting close to clutch and flywheel replacement time. Valair is the clutch you want. I'm sure Cody (Rubber Duck) has a connection for those and the DMFs.

 

Oh yeah and disregard the tires and carrier bearing if it does it sitting still. I missed that in your original post. Sorry.

The thing about slowing down as you let off before you get the clutch pushed in sounds normal to me. Tese will slow down quickly when in gear at a high RPM.

Maybe more examples or explanations will help us diagnose it.

 

We just bought for the kids this year......too many in the family got laid off (GM and affiliated companies) and Dad was a forced retirement from GM......funds were low this Christmas

 

[quote=Neal 97 250;6975364]
Anyway, I believe it could possibly be the DMF. Although I don't see how you can drive and never go over 2500 RPM's. Heck I don't spool up till 2200 RPM's. Most of our speed limits are 70 MPH and I hit 2500 at 65 MPH. Shoot i would never get anywhere at those RPM's. But then again I have 4.10's.

Usually the DMF will be sporatic. It will drive fine then all of a sudden vibrate so bad the whole truck can shake, and it will do it at any RPM. Sometimes it will give a baby vibration then go away. So there is a broad range there.

Another thing that it could be is thetires out of balance. If the truck doesn't see 2500 often then it obviously doesn't regularly get Interstate speeds.

If it has a two piece driveshaft I would check the carrier bearing and all u-joints as well.


Thanks to everyone. Where is the best place to get a SMF and what brand should I get?

I guess I have an excuse to get a SMF now!. It does vibrate sitting still in neutral also, so I know it is not tires or driveshaft. Plus I am running 355's so that is why I never see high rpms. I do regularly drive the I, but last night I was running 80-85 and never pulled over about 2700 rpms.

I had an 87 with a DMF, but it just started slipping when it went.

I am also sorry about your loss of property Neal. Losing it that way makes it hurt even worse I bet.

 

everyone goes to valair....Cody (Rubberduck) knows someone there that will give you a good deal