ZF Hurth HSW 800V1 Manual

[JVM225]

Are you sure it wasn't 7/8 with paint on it?

Lol!
Could very well be.
I actually had both in the bilge with me, and the 22mm was the one that fit.
Purposely used a combination wrench instead of a socket so that I would get the better feel for it.
It would be a home run if the head was 7/8” and threads were 1/2” like Frank’s.
Should have taken a time out when the drain plugs were out and taken a ride to the hardware store to verify the thread size. I’d really hate to cross thread the transmission cases.

 

[dtfeld]

I just purchased several fittings for adding pressure and temp senders. All the ports on this transmission are metric. Makes sense...ZF is German.

 

[techmitch]

I just purchased several fittings for adding pressure and temp senders. All the ports on this transmission are metric. Makes sense...ZF is German.

That's what I originally thought as I deal with ZF a lot in the automotive industry, but when Frank said that his weren't metric all I could think of was heavy paint build up on Jim's.

 

[JVM225]

I just purchased several fittings for adding pressure and temp senders. All the ports on this transmission are metric. Makes sense...ZF is German.

That’s my thinking too. The Allen key needed to remove the filter is a 6mm metric, and the 22mm wrench I used to remove the drain plug was a perfect fit on that hex head so it’s unlikely that this model transmission would have any SAE bolts, threads or fittings like Frank’s does.
The Ace Hardware stores around here have a pretty extensive collection of nuts and bolts available.
I should have taken the drain plug to that store and tried to figure out the thread size, but didn’t think about it until after I finished the job.

 

[fwebster]

Here is what I know: My boat was delivered from the factory with Hurth HSW-800-IV transmissions. ZF acquired Hurth and changed model numbers. The ZF80-IV replaced the HSW-800-IV, then when I needed a replacement transmission in 2009, the ZF 85-IV was an identical replacement and an improved model. When I built the oil change drain, I matched the threads on the drain plug to the hydraulic hose fittings at the place the makes my hoses and a 1/2" NPT fit perfectly. I installed the drains the old HSW -800-IV's and switched it to the ZF-85-IV in 2009 when we changed the transmission.

The 1/2" NPT fitting fit the transmissions and it wasn't even a questionable call or a matter of paint on the threads. I just used Teflon pipe dope, started the threads by hand then tightened them with a wrench.

I have no idea what thread type you will use if 1/2 NPT won't work for you, but I suspect the cost of metric hydraulic hoses and fittings may make you rethink this project. I have about $5 worth of fittings, bolts and washers, $16 worth of double wall hydraulic hoses, a couple of ball valves and about an hour on a milling machine making brackets out of scrap aluminum in my version.

 

[dtfeld]

Frank has the ZF85, a new and improved version, so quite possibly that model has SAE threads.

I’ll measure once I drain mine and post. So far everything is metric on the HSW800.

 

[fwebster]

Re-read my post.........I had 2 Hurth 800's and had one fail on the port side (get ready, BTW!). We changed it to a ZF 85-IV so now I have one of each transmission. I installed the same 1/2" pipe thread fittings on the new ZF 85-IV that I removed from the Hurth HSW 800-IV.

I feel like I'm trying to sell something here and I'm not. I think you all are making more out iof this than there is. Somebody crawl down in the bilge with a caliper and mic the thread diameter and the length of the exposed threads and just see what you have. That is how I sized the hardware when I first started.

 

[JVM225]

Frank,
Might be a case of apples and.....well........a slightly different apple.
The tags (data plates) on my both transmissions identify them as HSW 800 V1 that were manufactured by ZF Hurth in Arco Italy.
It looks like it’s possible that ZF didn’t change the model number immediately after acquiring Hurth.
That could explain why yours (which is Hurth) is SAE and mine (Which are ZF Hurth) are metric.
Dave,
What company and place of manufacture do your tags (data plates) identify your transmissions as?
Also, Frank’s original transmission model number as “HSW-800-IV”, mine are HSW 800V1.
Wondering if yours are the same as mine (Made after ZF acquired Hurth) or if yours, like Frank’s, was made by Hurth before they were acquired by ZF.

 

[fwebster]

I accidently reversed the IV suffix so don't read anything into the different numbers. Hurth/ZF continued operation under the Hurth brand name for a while, then changed to ZF exclusively and abandoned Hurth model numbers at or about the same time.

What I do know is that My transmissions had 1/2" plugs in them from Hurth/ZF and the new transmission mfg. in 5/2009 did as well. I fitted the oil change plumbing to them using all 1/2" NPT fittings.....and they hold the fluid in the transmission. I'm just trying to give you guys a leg up on assembling something similar to the photo I posted so you won't waste several days running around buying plumbing supplies when you change your transmission fluid.

Please post what you end up doing..............

 

[JVM225]

I accidently reversed the IV suffix so don't read anything into the different numbers. Hurth/ZF continued operation under the Hurth brand name for a while, then changed to ZF exclusively and abandoned Hurth model numbers at or about the same time.

What I do know is that My transmissions had 1/2" plugs in them from Hurth/ZF and the new transmission mfg. in 5/2009 did as well. I fitted the oil change plumbing to them using all 1/2" NPT fittings.....and they hold the fluid in the transmission. I'm just trying to give you guys a leg up on assembling something similar to the photo I posted so you won't waste several days running around buying plumbing supplies when you change your transmission fluid.

Please post what you end up doing..............

Thanks Frank! Will do.
I should have done this mod last month when I changed the fluid and filters but didn’t think about it until afterwards so I’ll only be gathering the parts once I have the size and won’t be doing the install until the next fluid and filter change.
A quick google search indicates that the conversion for 1/2” NPT is 15 MM.
That could explain things a bit.
The next time I’m in a hardware store with a few minutes to spare I’m going to play around and see how well the two fit together.

 

[techmitch]

Thanks Frank! Will do.
I should have done this mod last month when I changed the fluid and filters but didn’t think about it until afterwards so I’ll only be gathering the parts once I have the size and won’t be doing the install until the next fluid and filter change.
A quick google search indicates that the conversion for 1/2” NPT is 15 MM.
That could explain things a bit.
The next time I’m in a hardware store with a few minutes to spare I’m going to play around and see how well the two fit together.

That's odd since: 13mm= 0.5118110in

 

[dtfeld]

I’d have to look at the tag but of the top of my head, it’s ZF. I remember when I bought the boat being very confused about who exactly WHO made the transmission, and how to service it.

Be gentle with the threads, the SAE and metrics are close enough that you’ll get one ito the other a few threads, but will damage them if pushed to far.

The other thing to consider is the ports on my transmission are a metric machine thread, not a pipe thread (tapered). The adaptors I purchased fit perfectly, and I thought I posted the sources. The pressure and temp senders ARE NPT.

Changing metric out to SAE seems pretty prevalent in the auto world, so I expect to be able to easily source the parts.

 

[ttmott]

Why don't you get one of each? Not like it's going to break the bank.... McMaster Carr has them all.
Mine (2000 400DA with one Hurth and one ZF) were NPT by the way.

 

[JVM225]

I’d have to look at the tag but of the top of my head, it’s ZF. I remember when I bought the boat being very confused about who exactly WHO made the transmission, and how to service it.

Be gentle with the threads, the SAE and metrics are close enough that you’ll get one ito the other a few threads, but will damage them if pushed to far.

The other thing to consider is the ports on my transmission are a metric machine thread, not a pipe thread (tapered). The adaptors I purchased fit perfectly, and I thought I posted the sources. The pressure and temp senders ARE NPT.
Changing metric out to SAE seems pretty prevalent in the auto world, so I expect to be able to easily source the parts.

Just called ZF Hurth and asked the service department if they knew the thread size for the drain plug. The guy was nice enough to spend some time trying to look it up, but he could only see the part number and not a description of the plug.
He took it a step further and got his hands one one and measured it.
He verified that the hex head is 22 mm, and he got a measurement of 3/4 NPT on the threads.

 

[dtfeld]

Thats one crazy plug!!! I never would have guessed a metric hex on a SAE thread.

 

[fwebster]

See........I'm not crazy after all.

You will find that the ZF guy probably grabbed a plug from a larger transmission to measure. The one for the HWS 800, ZF 80, and ZF 85 is 1/2".

 

[dtfeld]

See........I'm not crazy after all.

You will find that the ZF guy probably grabbed a plug from a larger transmission to measure. The one for the HWS 800, ZF 80, and ZF 85 is 1/2".

Not crazy at all Frank. Keeping 15+ year old boats running and finding parts is a major PITA, so getting info on how to here on CSR is a real time and money saver! I know I appreciate all the input, and try to leave a few crumbs of knowledge for the next guy.

But now we have a good idea of what is there and can plan to get parts ready for when its time to do the job. Nothing worse that planing to do something and finding out once at the boat you don't have what you need.

 

[fwebster]

My boat is a 1996. I keep it at a Sea Ray servicing dealer. Their parts guy is superb, can find anything, usually cheap. I suspect I know who your nearest Sea Ray dealer is (good luck !), so I'd try to develop a good relationship with his parts guy and get to know him. Between my google skills and our parts guy I have found everything I've needed for my boat, usually OEM at that. If you get stumped, let me know and I'll get you the contact info for our marina's parts guy......He has about 35 years experience in marine parts and is very professional.

 

[JVM225]

See........I'm not crazy after all.

You will find that the ZF guy probably grabbed a plug from a larger transmission to measure. The one for the HWS 800, ZF 80, and ZF 85 is 1/2".

Frank,
I think it might also be possible that he may not have been clear about how to measure NPT. If he took a measurement of the diameter of the 1/2” drain plug he would have come up with about 3/4”.
He was a good guy and I didn’t want to seem ungrateful so I just thanked him for taking the time to measure one for me, but a 22mm hex head on a plug that is 3/4” NPT would mean the hex head would be smaller than the diameter of the threaded end, and after having had mine out last month I know that isn’t the case.
He was clear on the 22mm, so coupled with your knowledge and experience, I’m pretty sure it is 1/2” NPT.
That’s the good news!
The less good news for me and Dave is that because of the angle of the hull, it is going to be tough to put together a setup like you have on the port transmission on our 410’s using stuff from the plumbing aisle. Whatever we use would have to be considerably shorter. There isn’t a whole lot of room to work with there.
Fumoto does have L-Type drain valves with an elbow hose joint, but they don’t show one on their website with 1/2” X 14 thread.
Might have to give them a call next week to see if they can come up with one.

 

[JVM225]

Thats one crazy plug!!! I never would have guessed a metric hex on a SAE thread.

Me either.
I’m going with Frank (see above) and the 1/2” NPT.
The next hurdle is the Port transmission. There isn’t a lot of room behind the drain plug before the angle of the hull will start to be a factor.
That one will have to be “L” shaped for sure.
Putting something together with stuff from the plumbing aisle may result in not enough clearance between the transmission and the hull. If it can be done, it will be tight and will wind up costing as much, or more, than a simple Fumoto Drain valve.
Hopefully they can come up with one that is L shaped with the right threads.
If not, we might have to just sell our boats and look for 460’s lol