A main will knock warm or cold ,(may be worse warm) I would bet my last dollar( not far off) its not the tranny ....

If it is a main, at least you won't likely end up with windows 7.3. Just an ERRRRP...

 

i don't think it's a main, but i guess it could be. i would guess a main would continue to knock even when i downshift to 4th and its running 2500rpms and decelerating.

 

Possible its in the clutch disk damper.

Bill

 

huh?!?!?!

 

mains knock under load , rods knock after you have leveled out .. (Bill) trans Knock would be less work ( expense) than a main...Just my un educated opinion (as far as trans goes) never heard one knock before (it might have to be real bad shape )...

 

I have had springs rattle/bang around in the dampers.
Also even had 1 spring fly out and jamb the clutch.

I dont believe motor. It would be rpm related (more/less with rpm)
Iam at clutch and trans as of now.

I just have not got a grasp on what strokin states.
He states Knock, and gets louder with speed and load.
Might be a bad choice of words to describe the issue for me.

Bill

 

ok i will try to change the way i say it. when your driving in 2nd and 3rd gear it's not bad, you can barely hear the sound at all if u hear it at all. 4th gear is where it gets to the point where you can hear it pretty good and only does in while under load. at this point if you get into it hard the noise will get louder and faster in the upper RPMs. if you get it up to a certain engine speed and hold it there lets say 2300rpms, where i'd normally shift, hold it at 2300 rpms for a second then push in the clutch, but keep the engine at the same 2300rpm. the sound goes down a little bit then when you shift it to neutral with the engine still at 2300rpm the sound completely goes away. get it into 5th gear and it will do it as well. cruising at 70mph you can hear it a little bit, clack.... clack.... clack.... get into it a little to pass a car and the sound speeds up and gets louder until you let off then it stops and get back to cruising speed and hold it there and it sounds exactly the same as before.

Also, if you speed up very slowly it won't do it near as bad as when your hard on it. if your going WOT it's quite loud, if your being easy just normal driving then it's not near as bad.

 

sounds like a loose nut............behind the.......steering wheel LOL. seriously tho I'm kinda thinkin maybe those DMF clutch springs. Does it rattle like hell when you shut the motor off Travis?

 

I think that it's safe to say that Travis ditched the DMF a very long time ago haha. I could be mistaken but I'm about 99% sure he did.

 

yep, ditched the DMF the week after i bought the truck 3 years ago. Valair doesn't make DMF clutches... The tranny does make a ton of racket when i shut the engine down though unless i push in the clutch when i shut it off. haha.

Update for Bill, i checked EOT vs. Ambient temp this morning and it was good. on my drive into work the EOT got up 199*, but mostly stayed around 197*. did another CCT and got cylinders 1, 2, and 3 contribution/balance fault. ran the buzz test again and everything sounded good and got system pass.

IPR dc% stays around 12% cruising and peaks at 48% @ WOT so i guess the HPO system is doing well. haha.

 

3rd, 4th, and 5th load the countershaft in the trans.

Bill

 

so this means??? big $$$?? i am going to pick up another tranny today thats supposed to be in good shape for $300. probably going to take it by the tranny shop and have them check it out and probably go ahead and rebuild the whole thing b/c my truck has 304k miles now with the original, nonrebuilt, ZF5 in it. it might be nice to have a new trans in it.

 

So.. Say you have a decent fuel leak and your engine knocks a little bit harder under load especially if you hammer on it. Is this an easy indication that your getting low pressure or possibly air in the lines?

 

I'm not sure. i did crawl under my truck with it idling today and notices lots and lots of little air bubbles in the bottom of the 2 micron fuel filter bowl. its clearish yellow so you can see through it and while idling you can see air bubbles moving around in there. didn't think that would be a good thing, but i'm not sure. could always find a way to hook up a FASS or AD2 to it, but don't wanna go thru the trouble of finding a way to hook up the return from them.

On a side note, i bought an extra transmission on Saturday and took it up to the tranny shop today. considering getting the shafts and gears cryo'd at 300 below while he has it taken apart. anyone think the syncros or shift forks or anything else would benifit from cryo treating?

 

I would do the syncros, then them dam things will be bullet proof. Hell send all the parts there and have the strongest ZF-5 you can have.