How does your Marine gearbox work ? ZF HURTH 

I really appreciate you taking the time to break down the gearbox mate. I learned a lot. Cheers

These gearboxes were a mystery to me. After watching your video, they make much more sense. I will, no doubt, use this video while rebuilding my HBW250 transmission. Thank you!

Great demonstration of the operation of my boat's transmission. Thank you.

I have done loads of these gearboxes and have never changed the clutch plates it is nearly always the thrust washers worn so just change them and gearbox as good as new

I love the educational format of your videos. In my exerience, problems can easily be facilitated by operator ignorance, and in some cases can be a catlyst for component failure. As you rightly touch on, having even a basic awarness of how something works is a fundamental aspect of basic care and maintenance. Cheers Darren.

very interesting video!! Learned a lot, thank you

Thanks, very informative video. Keep on the good work!

This is really good! Thanks so much for these videos!

Very, very helpful. Thanks!

great details on a Hurth transmission. Thanks.

Sub'ed I purchased my first sailboat and motored almost 100 miles up the Columbia river to Portland Oregon. (almost zero hrs at the helm) As I made it to my new marina I approached very cautiously. I rolled in at idle and just at the slip, I had to make one correction with reverse. when I did, I failed to let the prop stop, and shifting into reverse made a hard connection and then it was stuck in reverse. I said a few choice words and then dropped the outboard (fortunately) and maneuvered into the slip. This is what brings me here. I'm currently researching how to remove the gearbox. This video Helped. Thank you!

Thanks for dismounting that gearbox. I hoped that you show rebuilding and adjusting that gearbox, too. We got this Hurth in a Vetus engine in a sailboat. We only get reverse and neutral gear and nearly never forward gear.

Thanks for your dedication to do these videos. I have a HBW 150v (40 years old now) transmission that is getting more stubborn when shifting into forward (reverse is never a problem). The linkage and cable adjustment seem right on so I'm thinking about rebuilding the transmission myself. Your video has definitely helped me understand what I'm getting myself into. Thanks again.

Great video. Thanks. I have the same box. The oil is brown i discovered today.😢 Sometimes when I start the engine with some revs the gearbox is in reverse 😮

Loved this. I have. Zf 25a equivalent and am looking for a video that show the servicing of the control block. I think its the reason why i have loud clunks when i go into fwd or reverse

Much appreciated for the video. It is perfect for me having trouble with my Hurth ZF 250. I noticed that you didn’t exactly point out a the specific problem but said it’s those disks. If I hope to repair mine would I just order a bunch of those disks new? My ZF is only working in reverse and no forward. Thanks again 🙌🏼

Thankyou.

Just watched your video very good information iam put bigger engine in my boat so need bigger prop which is right hand could I put a left hand prop on or not reply would be appreciated David

Thanks for the video mate I have been following it . Can you tell me where the 3 springs connect to l can see the top hole where they connect but can't find the bottom location . Thanks

Thank you for your information! I have a Hurth HBW5 and a 32 HP Watermota Seapanther engine. Occasionally the gearbox will not slip into forward unless I first make it go backwards. Is there a simple way of adjusting this to make it work better?

I have a problem I cannot figure out with my HWB50- just had it rebuilt with a standard rebuild kit, clutch plates, seals, bearings, all new. After the rebuild at the transmission shop, turning by hand confirmed everything was fine- fwd, N, rev all evident with normal shift lever travel. Right after being installed back in the boat, where it worked great for 5 minutes it suddenly stalls the engine when shifting into fwd. Reverse is fine. Back at the shop with the transmission removed again, I thought I could recreate the binding problem in fwd, but NO! It moves freely and clutch plates are slipping. What happened? Any guesses? Do you recommend bench testing with drill at 1k RPM?

I' interesting a gear ratio please give me thanks

Do you happen to know if I can directly replace a hbw 100 for a zf12? Asap says its the closest thing. My question really is about the dimensions and gearing. Is the gear ratio the same? Will the ratio matter? Also will the adaptor plate fit to my bmc 1500? Will I have to lift or lower the bmc to line it up with the shaft? Any advice is much appreciated as I'm a bit lost..

Hi I just received a new ZF45A Gearbox. I have an issue with it. When I put it in gear either forward or stern and turn the input shaft the propeller shaft is not turning. Surly this is not right It was supplied with no oil in it. Does that make a difference? Any help would be greatly appreciated

What modern transmission would you recommend to replace one of these to go on a BMC 1500 still keeping the same ratio. Also would I need to buy some kind of mounting plate to make it marry the engine? Many thanks 🙏

i'm just rebuilding one now, i managed to press everything onto the shaft ok. i'm just wondering if there is a sequence and torque spec for rebuilding the case?

I have a zf30m, very similar to this GB. The gearbox takes approx 30-60 seconds to go ahead, and instantly goes into gear going astern. We've have the gearbox reconditioned many many times but after a few hours of taking it out, the same issue happens. Any suggestions or what may cause this and how to fix?

If ZF are S.A.E boxes does this mean that all ZF boxes only attach to engine's that run CCW as seen looking at the flywheel

Can you please inform me which is the right oil for ZF HURTH 45a ? The boat manual recommend oil 15-40 and the ZF manual ATF .

Hi Super Movie where buy new bits have an HBW125 I am missing the pieces for 2: 1 link please

Hei, i need to learn something.. saildrives have 2.7 or 2.3 times reduction.. or whatever nm is. Where is reduction.. in knee of saildrive where propeller is or inside gear box.

I have that transmission. I have to get it to stop slipping in forward. Can I make a shim just to add to the clutch pack?

Can the cam plates be swapped around for reverse rotation engines?

Hello Mr Crouch. I am very much interested in your channel lots of good advise practical how to, just what we need. Thanks very much. Can I ask a question? We have a 1800 BMC - Thornycroft T108 diesel in a boat and we are having problems with the water temperature gauge. The gauge shows the engine overheating when in fact it clearly isn't . The control panel is a Thornycroft and the gauge is electrical, the sender has two blade connectors, The gauge on the panel says VDO as are the other gauges. I think the sender is at fault, have you any idea where I might be able to get a replacement? Thanks in anticipation, John Beck

What's the difference between ATF and Dexron 3

I bought a pair of motors that have the Hurth model HSW 450 A2-2,0 ser n 22 15223 A they have been sitting for years from what I was told they were took out of a boat after 20 to 40 hours run time and replaced because the owner wanted more power what do I need to do to make sure there ready to be used again I have manuals on them but I’m wondering about the seals or gaskets effect of stagnant fluid or no fluid on them

What’s the drop in replacement?

I have an oil leak from the coupling. I can't figure out how to remove it to replace the oil seal. Do I need that press machine you used to remove the coupling?

Sorry to disagree its well known that the bronze thrust washers at both ends wear and cause the slipping not the clutch plates and many have just replaced the washers and are good to go. Also as per the manual it is only rated at 17hp and limited use and must have a cooler installed for constant use and moves the HP to 34hp double. It only holds 350ml of dextron 2 which is hard to find mineral oil based .Never use semi or sythetic oil or it will fail ,its too slipppery and causes plates to slip. Also as per manual it must be kept in reverse direction during sailing as the prop spins and wears the bronze washers ,thus causing slipping. Oh and as a Millwright i have personally built 100's of complex gearboxes epicyclic in the printing industry ,even ones made in UK on Baker Perkins G16 .G14, G12 printing presses. I have reashearched this box to death and machined my own cooler and have 1500 hrs on my box (no failures ) in my beneteau