ZF10 replacement

[neil1967]

It looks like the clutch cones on our zf10m gearbox have gone. Given that the gearbox is 27 years old, it might be that replacing the gearbox in toto is a sensible option. The latest version of the zf10m has a 2.05 ratio on forward, compared with the 1.86 on ours. If I just fit the new box, with no other changes, will this be ok. I have a darglow max prop fitted.

Regards

Neil

 

[Tranona]

The shaft revs will be a bit lower so you may need to alter the pitch. Think the Max Prop has adjustable pitch. Ask Darglow to run the new numbers and advise if it needs changing.

 

[Slipstream 34]

Are you sure you are replacing a ZF gearbox not a Hurth? I replaced a hurth with a ZF10M two years ago. It was almost a straight swap but the new box was a little longer. I had to reduce a packer between the gearbox and the flex coupling to keep the shaft sitting in the same place. I have a spur cutter so couldn't accept the extra length. I think it was 15mm difference between the gearboxes.
You will find you need more revs for the same speed with the different gearbox ratio.

 

[Plevier]

A ZF10M, or Hurth HBW100, same animal, doesn't have any cones! It has a stack of flat discs. Well 2 stacks, for forward and astern.
Have a look at http://www.bukh-bremen.de/files/346...Ersatzteilliste ZF3M bis ZF30M mechanisch.pdf

 

[neil1967]

Definitely a zf10m! I'll contact darglow - if I can make an adjustment to the max prop rather than changing the prop that would be great.

Neil

 

[parbuckle]

According to ASAP Supplies website the ZF10 has the A position 2.06 and the B position as 1.86 so you may be running your gearbox in the B position forward this could cause it to overheat and wear prematurely you can check the manufacturers plate on box for details of the two ratios the largest ratio will be the A position . If this is the case and your gearbox is whining then it may run ok in astern but of course the prop will then be wrong handed.

 

[Plevier]

According to ASAP Supplies website the ZF10 has the A position 2.06 and the B position as 1.86 so you may be running your gearbox in the B position forward this could cause it to overheat and wear prematurely you can check the manufacturers plate on box for details of the two ratios the largest ratio will be the A position . If this is the case and your gearbox is whining then it may run ok in astern but of course the prop will then be wrong handed.

According to the repair manual (see link I posted above) you can have the following gear combinations
A/B
1.482/1.864
1.792/1.864
2.045/1.864
2.722/2.150

It does look a bit fishy that the OP says he has 1.86 forward. (Manual confirms A is for continuous (forward) use, B is for reverse.)

 

[parbuckle]

If your gearbox has lasted 27 yrs then not too much is wrong I note that ZF10 at ASAP Supplies is £700 so it may be cheapest option and then run it either way then get a reconditioning kit for £200 and repair your old one and keep it for spare.

 

[neil1967]

Just checked the plate, A is 1.79, B is 1.86, so if A is forward, then that is 1.79. I will probably get a new box and adjust the pitch of the maxprop - I have emailed darglow for advice. I can't get the link to the manual to open, but that is probably due to my 3G connection. Thanks for the advice.

Neil

 

[Caer Urfa]

It looks like the clutch cones on our zf10m gearbox have gone. Given that the gearbox is 27 years old, it might be that replacing the gearbox in toto is a sensible option. The latest version of the zf10m has a 2.05 ratio on forward, compared with the 1.86 on ours. If I just fit the new box, with no other changes, will this be ok. I have a darglow max prop fitted.

Regards

Neil

Hi Neil

I note some of the replies you have had,however the HBW-1002R and the ZF10M are NOT the exact same gear ratio.

The HBW-100-2R is A=1.79 & B = 1.86, the ZF10M is A=2.05 & B=1.86.

I replaced my HBW - 1002R with a ZF10M gearbox with no problems (also replaced the R & D thruster plate at the same time).

My engine is 27.5 hp driving a RH bronze 3 blade x 15" prop and yes there is a difference but only slight running on lower RPM, I also did not have to make any other adjustments during the installation.

I did look to installing the equivalent PRM box (cheaper) but whilst it would fit length ways I would need to lift the engine 10mm for the input/output drop difference.

There is also some excellent reconditioned HBW boxes around from reputable suppliers, my friend bought and fitted one 3 years ago and still running fine.

My tip from ZF is change the gearbox oil every 100 hrs or 12 months.

Hope this may help

Mike

View attachment 43252

 

[neil1967]

Mike, thank you, most useful. My box is definitely marked as a ZF10M, but with the ratios as per your HBW100. I'm aware that the ZF10 is working at the top end of the power range when mated to a Perkins 4108, which is rated at 49HP, but if the current box is original then it's not done badly. The Previous Owner had the boat for about 14 years and I am sure he would have mentioned had he replaced the box. The gearbox has a water cooler on the side, which I think increases the HP rating a bit. I am going to install a new ZF10M with the new ratios and see how it goes - if I need to adjust the pitch of the prop, I'll do it next time she's out of the water.

Thanks again, Neil