ZF 280 Gear Pressure too high?

[MATTHEW]

6cta 450’s, zf 280 transmissions.  

Typical cruise is 2250rpm and I typically see gear pressure of 300psi Port and 225psi Stbd. 

Coming back in last weekend and I was cruising at 2400rpm just for the fun of it, probably for 30 minutes.  At some point the port pressure climbed up above 400psi.  I don’t know if it is due to the faster cruise or some other reason.

No funny vibrations, sounds, always shifts smoothly and easily.

Is this something to be concerned with?

Topic

[Clark Leighs]

OVer the years I have fixed goofy reading guages by reterminating them.     THe actual guage and sender were OK but the connections were not.

I found many of my terminals had light corrosion on them and it showed on the wire.

I would clip off the old terminal,  strip the insulation back,  use ROSIN paste to dip the wire end into,  heat it with my soldering  iron  so the paste would clean the wire strands  and then reterminate with new terminals    AND a good crimper.

Sometimes I could cut off the old terminal by CAREFULL snipping of the crimp barrel so it would let go and without damage to the wire or maybe at works one or two strands. 

 

Just another idea.

ONLY ROSIN solder flux paste should be used.      Never ACID flux or you will make things worse.  

 

If the terminations are poor and lightly corroded the ROSIN will remove it so a good connection low resistance  can be made.

 

Many guages , electrics, can be affected by high resistance , dirty connections. 

It is time consuming but beats pulling and replacing wires especially when the wires disappear into a loom or bundle.          

 

 

[Rob Schepis]

Engine off the oil is in the sump, and some in the gear cooler. 

[MATTHEW]

Thanks for the reply, that does make sense.  I have some funky stuff going on w/other gauges now that you mention it.  I have a hunch that there could be a bad ground somewhere as my voltmeters are reading a couple volts lower than actual battery voltage when checked with a multimeter.

I think I will clean up all the connections and see if that changes anything.  Next I will swap the gauges and finally the senders if necessary.

Here is another question–can you swap the senders (engine off) without losing fluid?  Or are the sender ports below the static level of the fluid?

[Tony Athens]

If you are concerned, your true pressures need to be verified with a decent quality liquid filled 0-1000 PSI gauge on a proper hose. At this point I’d assume your analog gauges and / or sending  are the issue

[Author]

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