Gearbox oil level again!

[sunquest]

Ihave ZF Hurth 220A gearboxes with connected oil coolers. Originally when I checked the oil level it read over the full line. Assuming the oil circulating in the cooler effectively reduces the level in the gearbox, should you overfill to allow for this? Thanks in advance. Geoff.

 

[VicS]

Ihave ZF Hurth 220A gearboxes with connected oil coolers. Originally when I checked the oil level it read over the full line. Assuming the oil circulating in the cooler effectively reduces the level in the gearbox, should you overfill to allow for this? Thanks in advance. Geoff.

Can you or even should you check the level while the engine is running....... Like i do with the auto box in my car

 

[Caer Urfa]

Ihave ZF Hurth 220A gearboxes with connected oil coolers. Originally when I checked the oil level it read over the full line. Assuming the oil circulating in the cooler effectively reduces the level in the gearbox, should you overfill to allow for this? Thanks in advance. Geoff.

No you should NOT overfill a ZF gearbox!!
Fill only to the level mark on the dip stick!

Mike

 

[sunquest]

Thanks Vic and Mike. My observation is that when the engine is running, due to the cooler containing oil during this running, effectively the gearbox is low on oil. I will check the level when running next time I am at the marina .

 

[chrisclin]

Surely the oil level should be checked with the engine not running and after a period to allow the oil to drain down - just like your car.

 

[VicS]

Surely the oil level should be checked with the engine not running and after a period to allow the oil to drain down - just like your car.

Sorry to draw the parallel with the car but my autobox is checked with the engine running. If I check it while the engine is not running the oil level is way over the mark but falls when running. I dont know if thats because the oil drains back from the oil cooler or from the gearbox internal gubbins, I just know it has to be checked while running.

Surely there should be some guidance in the manualfor the ZF gerabox ???

 

[lynall]

If comparing to car autos, dont forget some have two sets of marks on the dipstick hot and cold and other have to be checked at specific temperatures.
Surely ZF would have taken all that into account?


Lynall

 

[VicS]

If comparing to car autos, dont forget some have two sets of marks on the dipstick hot and cold and other have to be checked at specific temperatures.
Surely ZF would have taken all that into account?


Lynall

yes you are right. mine has two marks.

Another reason to follow the guidance in the manual.

 

[VicMallows]

A real problem I find with both small engines (mowers etc) and boat gearboxes is knowing whether the dip stick should be pushed home/screwed down when taking the reading ... or just allowed to gently rest in place. This typically makes about 5mm difference which is similar to the difference between the 'low' and 'high' marks. No manufacturers instructions I have ever read are specific on this which I would have thought is somewhat important. I always end up just having to make a best-guess.

If you ask a single random 'expert' you are likely to get a definitive answer one way or the other. If you ask 20 you will probably get close to 50:50

 

[sunquest]

Thanks for your input chaps. Spoke to Lancing Marine this afternoon who amongst other things work with ZF gearboxes. After describing my predicament a very helpful man advised me to run the engine for a minute, switch off and set the oil level then. Basically it leaves a certain amount of oil in the cooler and therefore the residual oil in the cooler is accounted for. Geoff

 

[macd]

A real problem I find with both small engines (mowers etc) and boat gearboxes is knowing whether the dip stick should be pushed home/screwed down when taking the reading ... or just allowed to gently rest in place. This typically makes about 5mm difference which is similar to the difference between the 'low' and 'high' marks. No manufacturers instructions I have ever read are specific on this which I would have thought is somewhat important. I always end up just having to make a best-guess.

I looked at a couple of Hurth manuals in the (unsuccessful) hope of finding a definitive answer to the OP's question. They were pointedly clear about what to do with the dipstick in measuring oil levels: rest it on the oil filler hole, do not screw home.

 

[VicMallows]

I looked at a couple of Hurth manuals in the (unsuccessful) hope of finding a definitive answer to the OP's question. They were pointedly clear about what to do with the dipstick in measuring oil levels: rest it on the oil filler hole, do not screw home.

Great! ... that's one solved. I've just gone through the ZF BW6/BW7 manuals again and no such helpful advice .... only a (less-than-helpful??) comment to the effect that overfilling is as bad as under-filling.

 

[Caer Urfa]

I looked at a couple of Hurth manuals in the (unsuccessful) hope of finding a definitive answer to the OP's question. They were pointedly clear about what to do with the dipstick in measuring oil levels: rest it on the oil filler hole, do not screw home.

Yes +1 and I agree with Mac, the ZF10 manual does tell you to rest the dip stick on the top and not screw home to measure the oil level.

Mike

 

[Bojangles]

I have the ZF 220a gearboxes and have just read the manual, it makes no mention on not seating the dipstick fully (resting on top) when checking the level. Surely this measure only applies to gearboxes that have instructions that state that specifically? My instruction book does mention the need to run the engine at idle for a short while before checking the level, it also warns that overfilling can cause leakage at shaft seals and the transmission breather as well as causing operating temps to rise