Intermittent Transmission Grinding at all times

[JackTuom1]

Got a 1988 7.3 idi zf5 with transfer case that grinds in every gear including neutral. Not to the point where it pops out or is difficult to get into gear, it drives fine, but I can feel and hear an intermittent grinding noise coming from the transmission during driving. Typically starts 5 minutes into the drive and does this for 10-20 seconds on and off. Starts grinding especially when you let off the throttle or go into neutral from 3rd gear. Been doing this for a few weeks now. Thinking maybe its the input shaft bearing? Haven't drained fluid yet had no time. Thanks for your time

 

[Jesus Freak]

If it has a single mass flywheel, then it's called "gear rollover noise". If you've still got a dual mass flywheel, park your truck until you can replace it with a single mass flywheel, because your dual mass is about to come apart.

If it's gear rollover noise, learn to embrace it.......RERRRRREREERRRRERRRRRRRERR!!!!!

I love my gear rollover noise......

 

[IDIBRONCO]

If it has a single mass flywheel, then it's called "gear rollover noise".

I don't think the symptoms describe gear rollover. That normally only happens at low RPM while moving in gear.

 

[Jesus Freak]

I don't think the symptoms describe gear rollover. That normally only happens at low RPM while moving in gear.

No doubt, but I thought it was close enough to consider.

And if you change the fluid, make sure it's synthetic ATF.

 

[KansasIDI]

Valvoline Synchromesh shuts ‘em up, still a little noisy but not as much.

 

[franklin2]

Got a 1988 7.3 idi zf5 with transfer case that grinds in every gear including neutral. Not to the point where it pops out or is difficult to get into gear, it drives fine, but I can feel and hear an intermittent grinding noise coming from the transmission during driving. Typically starts 5 minutes into the drive and does this for 10-20 seconds on and off. Starts grinding especially when you let off the throttle or go into neutral from 3rd gear. Been doing this for a few weeks now. Thinking maybe its the input shaft bearing? Haven't drained fluid yet had no time. Thanks for your time

The zf transmission is aluminum, and is basically a very large speaker. The input to the speaker is the engine. Any noise from the engine will be sent through and amplified by the transmission. That is what the gear roll-over noise is, it's just the engine doing it's normal hammering when it's idling. Some engines, thus some zf transmissions are noisier than others. If something is making your engine suddenly run a little rougher, it will be noticed through the transmission.

Next time it does it, press the accelerator pedal and see if it goes away or significantly changes.

 

[Jesus Freak]

The zf transmission is aluminum, and is basically a very large speaker. The input to the speaker is the engine. Any noise from the engine will be sent through and amplified by the transmission. That is what the gear roll-over noise is, it's just the engine doing it's normal hammering when it's idling. Some engines, thus some zf transmissions are noisier than others. If something is making your engine suddenly run a little rougher, it will be noticed through the transmission.

Next time it does it, press the accelerator pedal and see if it goes away or significantly changes.

This is brilliant........rock on with the new zf5 by Marshall amplification

 

[ROCK HARVEY]

I would drain the fluid and look at it closely, because I’m betting you have glitter in it. Here’s a video I came across that helped me diagnose the input shaft bearing in my ZF5.

xc_hide_links_from_guests_guests_error_hide_media

I would also drain and check the transfer case fluid, because it could could definitely be coming from there as well.