Clunk when starting

[pdxrealtor]

So- I've got this clunk upon start up. Almost positive it's coming from the transfer case.

It only occurs after it's sat for the night.

I'm pretty sure it's only happening when parked nose facing downhill incline. (still working on verifying this)

It only started happening after I did the TC fluid change.

The truck was level when I did the fluid change. I used Redline DT4.

Does it need more fluid maybe? I went through the recommended amount and it did come out of the fill hole while filling up.

[pdxrealtor]

Anyone with any ideas suggestions or info?

[pdxrealtor]

Hmmm.. No one? Did it again today and It never did this before the fluid changes.

It sounds like gears that aren't quite meshed up 'clunking' into sync

[glennf1]

Don't know what the problem is but on your next fluid change put in the better Dexron VI or equiv., either Redline's D6 or others.

[[__--MUD--__]]

There is nothing thats turning in the transfercase when you start the motor. And your not switching between any functions of the transfercase.

When are you hearing this noise? as the engine is rolling over, after it fires, after it starts and you take it out of park?

Someone else over the last 3 months was talking about a clunking noise. They were nose down in the ditch at the end of their driveway, or their driveway had a drop off at the end. Did you make any other posts about this? It was either here or the hammerforums. If you didn't, I'll see if I can find that thread.

[pdxrealtor]

This is the only thread I started here. Slim chance I posted the same on the other forum.

This noise is heard the second the key is turned to engage the starter, but I swear it's coming from under the truck.... So yes, as the engine is rolling over.

It sounds similar to the tranny going from park to reverse.....you know ... That clunk sorta sound the tranny makes when at a stand still and running it through all the gears via the hand shifter.

[[__--MUD--__]]

have you looked at engine, tranny and transfercase mounting points? Make sure everything is secure, no broken mounts. Sometimes you have to brake torque it for a second person to visually see a broken mount.

I'll look for that thread...pretty sure I replied in it.

[[__--MUD--__]]

found the thread i was thinking of, but the vehicle was shutting off when parking on a hill.

[twinmill28]

Been meaning to post my "start-up clunk" for awhile to see if anyone else's duece does it. I'm not so concerned with mine as it's been doing it for awhile and randomly (more than a year) and everything is good.
Mine is just at startup when it's cold, just after the key springs back from starting, right as the engine has started. I'd been thinking it felt very similar to engaging the transfer case, but not as pronounced or loud. You can feel it more than hear it (but can still hear it). It feels like it's going into gear with the trans or something on those lines. Once the engine is actually running, it is all smooth and all is good.

I'm so tired of sorting out car noises and peculiarities that it usually takes a catastrophic failure for me to worry too much any more--one of our last cars was a Ford and it did all kinds of stupid things that the dealers kept laying on "normal operating condition", right up to the tranny taking a dump at 64K miles, and the engine throwing a rod shortly after 84K miles.

[Hellz]

possibly a starter issue?

when you hear the clunk, does the vehicle move as if the tranny and Tc were engaging the drive line?kinda like when shifting from park in to drive or reverse, you get that clunk in a way and feel it shift.

can you feel it at all when it clunks?

If it is more of a noise, i at a loss but i would think the starter when it engages the flywheel.

could it be just a coincidence after the fluid change... possibly.. double check the cans to very it is certified for the Tc....

guess one theory would be that the Tcase with the new fluid doesnt need to work hard as opposed to the old thick fluid that was in there.

i would hate the thought of recommending you to change the fluid... not sure how much all the fluid cost.. but i want to throw some royal purp in mine... and that aint cheap!

[pdxrealtor]

Redline d4 in the TC.

After reading about the bushings under load it got me thinking.

This clunk, pretty sure, has only happened after the tranny brush guard has come off. I took it off to do the headers and it was off for the tranny flush.

I hadn't heard the clunk for a while until after the header install. I've read about clunks being caused by warped skid plates. My tranny brush guard is warped.

Not for sure but it does make sense at this point. Once it loosens up a bit after torquing it down the clunk goes away.

I'll continue to monitor and I'm also going to check all the bushings.

[Lucky1]

I've had the same clunk for quite a while now but it's soo random that I don't even worry about it anymore. My guess would be with the flywheel and starter. I also think it happens when parked on a hill. It hasn't really affected anything soo far so as the phrase goes, "so far, so good." Just do what I do and keep on truckin. If it is serious it will definitely let you know.

[pdxrealtor]

Thanks for looking MUD.

I guess I'll just keep monitoring it and not worry about it at this point