Eaton Truetrack making noise

[crash340]

Truetrack people, My TT makes a clunky knock coasting up to lights etc at low speed, under acceleration and speed its great no noise at all but as i start to slow down in traffic etc, (I have an auto) in drive for ex as I coast through a low speed area, or up to lights or a stop, or just car park cruising etc, the diff makes a clunky knock, it almost sounds like the pre-load spacer block that you simply drop in when your using factory adjustable bearings is flopping around inside the centre. I have adjusted the axle pre-load to spec, and am using 85-140 oil, back lash is good, everything is tight, as I said, under throttle, all good no noice, nor at speed when coasting, only from abour 30mph and less.

Any thoughts? there are similar complaints if you google it but no one seems to be able to nail it down.

Thanks
Greg

[brads70]

   I have no idea? Mine is fine.

[crash340]

its not a backlash noise, its a real clunky rattle.

My only theory is, Im running an auto and as I slow up in drive to a set of lights etc, at no throttle maybe the tailshaft is not spinning loosly, I have had done about 2000Mile in it now, has done it all the time, since I rebuilt the pumkin. maybe I have pinion pre-load to tight , Im reading a lot of guys are reporting this clunk, Brad you dont have the thrust block fitted do you?,, it realy sounds like its the block flopping around inside, I could decreas the axle bearing pre-load to basically zero and test it round the block gently

[Chryco Psycho]

I would contact Cass @ Doctor Diff

[msbaugh]

Definately contact cass! That's who I bought my complete 489 truetrac from.  Mine makes no noise at all like that and I have stock adjustable axle bearings and the spacer block in the middle. Are your axle shafts long enough?

[brads70]

its not a backlash noise, its a real clunky rattle.

My only theory is, Im running an auto and as I slow up in drive to a set of lights etc, at no throttle maybe the tailshaft is not spinning loosly, I have had done about 2000Mile in it now, has done it all the time, since I rebuilt the pumkin. maybe I have pinion pre-load to tight , Im reading a lot of guys are reporting this clunk, Brad you dont have the thrust block fitted do you?,, it realy sounds like its the block flopping around inside, I could decreas the axle bearing pre-load to basically zero and test it round the block gently

Mine is in a Dana 60 that I bought from Cass. It was all assembled when I got it?

[crash340]

I actually bought the core from Cass, I would have loved to buy a complete built unit but freight costs killed that plan. I'll shoot him an email.

[734406pk]

Truetrack people, My TT makes a clunky knock coasting up to lights etc at low speed, under acceleration and speed its great no noise at all but as i start to slow down in traffic etc, (I have an auto) in drive for ex as I coast through a low speed area, or up to lights or a stop, or just car park cruising etc, the diff makes a clunky knock, it almost sounds like the pre-load spacer block that you simply drop in when your using factory adjustable bearings is flopping around inside the centre. I have adjusted the axle pre-load to spec, and am using 85-140 oil, back lash is good, everything is tight, as I said, under throttle, all good no noice, nor at speed when coasting, only from abour 30mph and less.

Any thoughts? there are similar complaints if you google it but no one seems to be able to nail it down.

Thanks

Hard to tell without hearing it but by your description of the noise on decel only, my guess is pinion bearing failure. When this happens, it usually takes out the ring gear and carrier bearings too. I would recommend removing the chunk and have it repaired ASAP to prevent further costly damage.
Greg

[crash340]

Pinion bearing is good, have disconnected the tail shaft and checked it again just the other day, all bearings are good, newly installed

[734406pk]

I can't say for sure without hearing the noise, but when you have this issue on decel, it generally means that the pinion/ring gear clearence is changing. As you know, this is not good. I would recommend at least pumping out the axle lube and checking for metal shavings or actually pulling the diff and visually checking it out. This can be a potentially serious issue, I am afraid.

[73EStroker]

I can't say for sure without hearing the noise, but when you have this issue on decel, it generally means that the pinion/ring gear clearence is changing. As you know, this is not good. I would recommend at least pumping out the axle lube and checking for metal shavings or actually pulling the diff and visually checking it out. This can be a potentially serious issue, I am afraid.

Take the driveshaft off the yoke and see if you can pry the pinion back and forth

[crash340]

Did that when I took the shaft off, nothing rock solid.

have been chatting with Cass about it, am pulling the centre out next week to change over to a b body housing, will inspect further