Ok guys, I have done a bunch of searching and I am not finding too much on this. I am guessing it is because the ZF6 is such a stout trans that it rarely has issues. On our trip to Texas this past week, the truck performed flawlessly. The only thing that kinda had me concerned is that my trans has always had this little whine to it. It's hard to explain, but when I go to shift and the RPMs drop, it sort of whirs and makes this sound. I tried to get video, but you can't hear it. Also, it would get hot on hard pulls, like hot enough that the boot and the floor would be pretty warm. Is this normal? My cooling lines were flowing because they were hot, so the pump was working. It never overheated so to speak, but I did smell fluid once or twice....BUT, my boot is kinda trashed and doesn't seal real well,so I am not sure if that contributed or not. Fluid was flushed Schaeffers All Trans with back in August when the new clutch went in.

Anyways, hopefully that's enough info. Again, never leaked or had performance issues, but not sure if the pump is whining or the syncros are not happy? Anyways, thanks for any input.

 

Don't have much to add, Slider. I demerger when mine would have REALLY BAD gear rollover. I tried every mixed drink to minimize it, but at the end, stuck with good ol' merc V and some syncromesh stuff... Also think a good clutch helps too. As for heat, anyway if getn actual temp? Mine, towing 10k, in dead heat, peaked a tad past *160. Temp sensor plumbed in line with aux trans filter....
. I also want to add, that even during cooler months, after a period of driving, things in my jumpseat, tend to be warm..i dunno. Figured its radiant heat from floor/trans...

 

You have the boot you see and another underneath that seals. The one that seals is a pain to get correct if it is old and stretched like mine. Once I got it fixed it made a big difference in noise. I need to get a new trim piece as mine is broke.

 

Midwest transmissions has all of that odd stuff.

As for the noises you are hearing, not really sure. I know my truck has a bit of a whir or whine when letting up on the throttle and pushing in on the clutch. Has always done it, so I don't see anything wrong there. Especially since Jason had it and said nothing about it when I asked about anything else he saw on the truck that might need some attention.

 

Well, when I did the clutch, the boot was in great condition, but maybe it's not sealing? I didn't notice any heat on our trip to Montana back in June, but that was before a new clutch.

That's exactly what mine does Sous, so maybe I am worrying over nothing? I guess I'll just keep driving it until it tells me it need serious attention. And yeah, I am guessing Jason would have definitely let you know if anything was amiss.

 

I am referring to the white rubber piece that is under the shift boot. just want to make sure we are talking about the same thing.

 

Like Brandon, the white-ish inner boot is torn to crap. I think I may have even removed it when I was filling the fluid from the top. There is the white boot made of thick rubber material, then there is the black boot that is more of a decorative piece with the plastic frame around it.

 

Yes we are talking about the same thing in mine is in really good condition, but I have heard those deteriorate. I guess I got a good one. Now the black boots, the decorative piece, is a different story

 

You said when you shift, kind of like a throw out bearing whine?

 

No, more like constant gear rollover, but higher pitched. Hope that makes sense. It is definitely RPM related. I can very faintly hear it going down road at 65.

 

If the decorative boot is loose or worn, start by replacing it. I'm still amazed how much noise that magical piece of rubber keeps out(after I forgot to tighten mine back down once).

Although it seems like it was mostly exhaust, engine and road noise from what I remember. Have you checked your carrier bearing, or perhaps the rear end fluid to make sure you're not hearing something from one of them?

And I'll second the good old Merc fluid with a bit of synchromesh added to the mix.

 

Thanks Chris. The rear end was one of the first things I changed. The sound definitely comes from under my feet. I hadn't thought of the carrier bearing. I have Scahffers in there, but I'll think about changing it out.

 

Have you ridden in another 7.3 zf6 truck? I thought mine was loud till I rode in the EX wifes grandfather's. It is a little more noisy than mine and has been for 15 years.

 

The next time I am out and about in the truck I will see if I can get a recording. Not sure how it will turn out, but I will try to mount the device near the boots.

 

I have ridden in Travis's (another member on here), and that was sometime ago. I don't remember the whine being present, but that could be from me just not paying attention.

Thanks Sous. I'll try to do the same and see what I can come up with.

Again, I am not too worried from the sound of things. It may be one of those things I just have to ignore until it breaks, which it may never do. I know the clutch is good and the fluid is good and I just towed 1300 miles without any performance issue. I am probably just being dumb. LOL