Many issues now need to remove Hurth plate

wileecoyote

wileecoyote

Member
TECHNICAL Contributor
Oct 18, 2008
949
Southern MD/ Potomac river
Boat Info
1989 340 EC
Engines
7.4LX2 Hurth 630A Drives
6.5Kw QS Genny
Long story, but a joyous one! I was on vacation and came back after not running the boat for 3 weeks. I tried to start port engine and it cranked and stopped. Loud noise from starter.
I removed the starter to find the nose cone broken off.
Oh S*&T! I knew what that meant and started to pull plugs. Sure enough, water in # 5.
I pull manifolds and look in cylinder with bore scope, but saw nothing obvious (running water). With all the water removed (vacuum and small hose) I squirt a little oil in and wait to see if more runs in. Seems OK.
I replaced both manifolds and risers today and started the engine. It ran alright, but there is another problem. There is a LOUD rattle from idle to 1K RPM (like usual drive plate noise, but WAY louder) and when it's shifted into gear the whole trans shakes and makes a REALLY loud racket.
I'm assuming that when I cranked, and the motor hydrolocked that the starter broke the nose cone and also the drive plate (I hope thats all)
My real question is: Has anyone ever removed the Hurth 630 in a straight inboard without removing the engine? There has to be a way to support the rear of the engine enough to do this, just wondering how? I don't have access to an inflatable airbag (which I think would be ideal) and I'm not sure I want all that weight hanging on the deck. Pics would help if you have done it before!!
On a side note, I have lots of bubbles coming out of exhaust, like a blown head gasket, or exhaust getting into the exhaust water. May be my imagination, but seems more foamy than ever before. I am waiting a while for the water to be able to leak in if there is. I am going to pull all the plugs again to be sure there isn't water. Already pulled #5 and clean and dry.

Sorry this is so long. I am done with the boat for this year I think. May have it yanked and start over next year.
 
We've done it with a Hurth/ZF 800V series v-drive.

The trick is to make/buy/beg/borrow some type of lifting aid. I built one to straddle the stringers and rest on the floor of the boat. Then built a trolley to enable movement of the uncoupled transmission from the engine bay to the center of the boat where it could be lifted out of the boat with a forklift. This transmission weighs about 275 lbs so even 2 men couldn't man-handle it. I suspect your 630 gear is lighter so you may not need to do as much engineering for removing it.

Here is a photo of the support frame before paint and another as we removed the transmission to let you see how it works. Planning this one in advance of doing the job is important........we had the old transmission and all associated parts removed, sanded and ready for paint in about 2 1/4 hours.
 
I cannot seem to get the CSR system to accept photos as an edit. so here:
 

Attachments

  • transsupport.jpg
    transsupport.jpg
    103.5 KB · Views: 360
  • boat trans.jpg
    boat trans.jpg
    107.3 KB · Views: 385
Frank, from looking at the last photo it appears you are using the device to hold the trans, what did you do to support the engine once they were seperate? Yours may be different, but I believe mine has 2 mounts on the engine towards the front and two mounts on the trans. Once separate the engine will want to fall in the rear. According the the book I have the trans only weights in at 100 Lbs.

By the way Frank, that is an impressive operation you have going on there!!
 
Last edited:
You first mark the aft motor supports and remove the jam nuts and washers on the top, then pick up the engine and transmission together before separating them. Next block up the engine with 4X4, 6X6, 2x4, plywood or what ever it takes against the hull to hold up the engine with the aft motor supports clear of the bolts, however, in my case we had to remove everything from the top of the stringer to get the transmission to clear as it was moved to the center of the engine room.

Once you get the engine blocked up, and the load off the hoist, you break the transmission bolts loose and pick up the weight of the transmission with the hoist. The slide in/out of the coupler splines quite easily this way.

The center carriage on the frame I built has 4 bearings supporting the load so moving the transmission toward the center was so easy that it moved almost too fast.
 
I was wondering if the hull was sufficient enough to support the weight. I know most of it will still be on the mounts, but I don't need to repair another hole in the bottom!
Now I need to look and see if I can even get in to see the rear edge of the oil pan, and where I can put blocks without getting near the oil dipstick connection. I'm seriously thinking about pulling it for the year, I may just leave it and use it as a place to stay and hang out, but I think any trips for this year are cooked.

Thanks for all the info Frank. Thats kind of what I was thinking, but wanted to ask someone who has done it before I started.
Always nice to have some piece of mind.
 
What happened Frank that required you to do this?
 
Jon,

Bearing failed on the port transmission input shaft. The transmission had metal particles everywhere in the case. It didn't seem like a reasonable approach to try to clean up all the ferrous metal in the remaining bearings, pump and clutch assy's, since that would be virtually impossible and could very likely mean a repeat transmission remove and install at some future point. So, that meant finding a re-manned transmission or buying a new one. For those of you who have never had transmission problems, finding a re-manned one is harder to do than you might think. Nobody will tell you what they did.......all new parts and bearings in an old case?.... or just replace the bad stuff and send her out with used clutches/bearings, etc. The cost for re-manned ones were within $1000 of the cost of a new one with a full factory warranty, so we replaced the old HSW 800 with a new ZF-85V.

Also, the boat was hauled on Monday at 3 pm, pressure washed the bottom, the transmission was removed and in the shop by 9AM on Tues, we repainted the end of the engine, bell housing, starter, etc. and the new transmission on Wed and reinstalled the transmission on Thursday morning..........splashed the boat at 11AM and went boating Thursday afternoon. I think we have the record time for r & r v-drives on 450's.
 
Thanks Frank, I figured it was a new unit from the tag on the dip stick. I guess after 14 years of use you don't have much to complain about. My 630's have 15 years and about 900 hours on them. I agree with you, there is no justification for rebuilding these things considering the labor to R and R them. I just hope mine out last the engines as I would plan on changing them out togther. Thanks for the update.
Jon
 
Jon,

I wouldn't worry...........this particular gear, the Hurth HSW 800, has a known weakness for bearing failures on the side that runs in reverse. This is the 4th or 5th boat I know of that has had the port transmission replaced. After ZF bought Hurth, this transmission has had 2 updates to fix the problem.

The other point worth noting is that this was not a surprise and the transmission did not fail under way somewhere. I change the fluid and clean the filter every year. The filters are washed separately and I look at what comes out of them. I began seeing more solids in the port transmission 4 years ago and began straining the filter wash solvent and checking the remains with a magnet. I was getting lots of aluminum and increasing ferrous metals, so I knew there was gear case damage and most likely a bearing was coming apart. Finally, I began to hear a rumble when the transmission was in gear and a constant rattle when in neutral, so I knew it was time to figure out how to change the transmission without tearing the boat apart and how to fix the problem on my schedule instead of as an emergency.
 
Nice lifting rig. I'm sure you would have paid a pretty penny to have the yard do that job.

Doug
 
Everybody runs away from Sea Ray dealers, but in this case, I had the local dealer do most of the work and could not have been happier. They saved me over $1000 on the transmission, got the core charge waived, were able to get it in 2 days, and provided the travel lift, forklift and "heavy lifting". The fellow you see in the photo has worked on my boats since 1989 and is not only a friend now, but is most probably the best boat mechanic in the Southeast. The labor total was 6 hours for everything. But, I scheduled the replacement after the busy season and they helped me tweak the design for the lifting frame. The mechanics loved the frame and would not let me take it home.........its still in the shop at the SR dealer.
 
fwebster said:
Jon,

I wouldn't worry...........this particular gear, the Hurth HSW 800, has a known weakness for bearing failures on the side that runs in reverse. This is the 4th or 5th boat I know of that has had the port transmission replaced. After ZF bought Hurth, this transmission has had 2 updates to fix the problem.

The other point worth noting is that this was not a surprise and the transmission did not fail under way somewhere. I change the fluid and clean the filter every year. The filters are washed separately and I look at what comes out of them. I began seeing more solids in the port transmission 4 years ago and began straining the filter wash solvent and checking the remains with a magnet. I was getting lots of aluminum and increasing ferrous metals, so I knew there was gear case damage and most likely a bearing was coming apart. Finally, I began to hear a rumble when the transmission was in gear and a constant rattle when in neutral, so I knew it was time to figure out how to change the transmission without tearing the boat apart and how to fix the problem on my schedule instead of as an emergency.
Click to expand...

Thanks for the information. As a result of your instruction I have been cleaning my filters that same way for a number of years now. All I ever find is very small particles of what I assume is material from the friction plates in the clutch packs
 
I have an update, and it's not good. Following the manifold replacement I decided to wait a few days and pull all the plugs again just to be sure. Once again #5 is full of water! I'm guessing maybe a cracked head. My issue is due to the fact that the engines are so old, and they are RWC the head bolts are almost rotted away and I'm guessing there is rot all through the engine.
I've come to the conclusion to start over and replace both longblocks and purchase and install new FWC kits.
Jasper is quite pricey, and they want to have them installed by a Jasper installer, has anyone had any luck finding a good source for reman'd 7.4L Mark IV engines? I have found a few who have good pricing, but am interested in word of mouth recommendations. Merc doesn't have replacements, so I'm looking for remans. Going the route of 6.2L or 8.1L is not an option, as I'm not into a science project.
 
What kind of access do you have to the port engine? I would make the effort to pull the head and see what is going on. You really have nothing to lose by doing it. The worst that can happen is that you will confirm your thoughts that engine cannot be saved. At best...you might be able to repair it and get a few more years out of it.

A couple of hours of work will answer the question.

-John
 
I would have to grind most of the heads outside of the valve cover. There is no way I can turn them out without grinding/cutting the heads off and pulling the head up off of the stud thats left. At this time, after looking around the engine (the corner of the port intake rotted off last year) I'm not sure how long it will last anyhow. I think the engines will be pulled, and torn down. Then I can tell what I have. I already know the trans has to come off, I'm just getting tired of patching her up.
 
I'm sorry....I was hoping it wasn't as bad as you indicated. It's time for your two engines to be replaced which is not a cheap exercise. Where do you plan on having it hauled? The only reason I am asking is that if it is Fort Washington, I know the folks down there pretty well.

The easiest way to get it done is to find someone to give you a fixed price for the whole job. It is much easier to pull the trans and the engine at the same time. The only question you will be faced with is replacing the transmissions. Unfortunately, rebuilts transmissions don't last long and they will be the next thing to go on your boat. Find the best prices you can find on the web and use them when you negotiate. Trust me....it isn't something you want to take on yourself.

-John
 
Last edited:
My plan is to get at least one engine and look at the other. I am going to remove the exhaust manifolds and trans coupler etc. I will have the yard pull both and place them on an engine crate which I will load in the truck to take home (3miles) there I can build the longblock up for install. I plan on leaving the other eng/trans on a similar crate to wrap up and take home once the first engine is on the stand.
I would just rebuild them both myself, but time is a factor.
I don't have enough, and I dont feel like wasting it rebuilding 2 BBC's!
 
Well if you are going to do the work...... I probably would change the sequence and build the long-block before I pulled the engine. There won't be much you can reuse from the old engine other than the new exhaust and intake manifolds. That way you can still use the boat. I had a friend who went a whole season on one engine while he built a new longblock in his garage.

If you do it that way, when the new long block is ready..... pull the old engine/trans. Bolt the old trans on the new longblock and put it back in the boat.


I checked these guys today who I have bought engines from and their reman long-block price is around $3,500. You might be able to do better than that locally.

http://www.perfprotech.com/store/catalog/Rebuilt-GM-Marine-Long-Block-Engines-8-Cylinder,5982.aspx


-John
 
You must log in or register to reply here.

Forum statistics

Threads
113,253
Messages
1,429,373
Members
61,133
Latest member
Willbeckett
Back
Top