Tranny Fluid & Heat Exchanger

Aug 23, 2020
27
Catalina 310 323 Mamaroneck
First, thanks to everyone for such wonderful help for this newbie. This is my first sailboat, and you have been a great resource. I'm looking forward to when I can help others, but for now, I have another question. Yesterday I changed the tranny fluid for the first time, and as the prior owner told me, it's a challenge. A friend helped me move the engine block to have enough room to remove the dipstick bolt (photo attached). We even had to remove the bolt that holds the Heat Exchanger in place. I've surmised that I have model 80 based on the manual, but there's no indication on the actual tranny near the serial number), so I put in 1 quart of fresh tranny fluid. There is only ONE marking on the dipstick itself (manual says there should be two - LOW/FULL). When testing, the ATF level was about 2/3 up the dipstick, which is much higher than the diagram in the manual suggests.

Two questions:

1) Is 1 quart of ATF about right?
2) Does everyone have the issue of having to remove the bolt to pull the engine block to remove the dipstick? Any advice?
 

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Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
OUCH :facepalm: ! ! ! !

Seems like you've just lost any alignment you may have had between your Xmission and your prop shaft when you shifted the block. This is somethting you don't want to do as you are looking for approx. +/- 0.001" (per inch of flange dia.) axial alignment. A good alignment job takes about a full day depending on engine accessability plus you will add many, many new and salty words to your vocabulary. The archives has a few good articles on alignment.

IMG_1025.JPEG

My suggestion would be to do an alignment job and then look at making an access path into your dipstick as you will be changing Xmission fluid every year. Also, loads of photos showing access to the dip stick will go a long way to coming up with a path to your dip stick.

I know this is a hell of a lot to swallow (as a newbie) after merely shifting the engine block but in the long run ........................ :doh:

@Stu Jackson will be the best person to advise on fluid and level if he's listening in.
 

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Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
1) Is 1 quart of ATF about right?
2) Does everyone have the issue of having to remove the bolt to pull the engine block to remove the dipstick? Any advice?
1. Have you looked in your owners manual? Whenever I remove transmission fluid, I put it in a clear plastic cup, and start out the replacement by pouring the same amount in another clean cup, then cvheck the dipstick. And before you ask, yes it is hard to read the fluid on the dipstick, so you roll it on a paper towel to see where the fluid line is.

You might be interested in these links within this link. Don't have to reinvent the wheel.

Transmission Fluid 101 Transmission Fluid 101

2. No. You should be able to adjust your HX so there is "better" access, although it is difficult to make it clear all the time. I have to get behind my engine to get the dipstick out, although when I was younger and more adept I could do it from the top. One solution is to remotely locate theHX by getting it off the engine, but not too many folks have done that. But given your picture, you don't have a problem, it's just close. For a once a year job, what's your problem? Mine's pretty much like that and I've had my boat for 23 years.

Good luck.
 
Aug 23, 2020
27
Catalina 310 323 Mamaroneck
OUCH :facepalm: ! ! ! !

Seems like you've just lost any alignment you may have had between your Xmission and your prop shaft when you shifted the block. This is somethting you don't want to do as you are looking for approx. +/- 0.001" (per inch of flange dia.) axial alignment. A good alignment job takes about a full day depending on engine accessability plus you will add many, many new and salty words to your vocabulary. The archives has a few good articles on alignment.

View attachment 192349

My suggestion would be to do an alignment job and then look at making an access path into your dipstick as you will be changing Xmission fluid every year. Also, loads of photos showing access to the dip stick will go a long way to coming up with a path to your dip stick.

I know this is a hell of a lot to swallow (as a newbie) after merely shifting the engine block but in the long run ........................ :doh:

@Stu Jackson will be the best person to advise on fluid and level if he's listening in.
@Ralph Johnstone : Ugh, that does make sense. This is exactly what the PO said he had to do: pull the engine, on the HE, toward the bow to access the dipstick.

Any advice on how to determine if I'm thrown the alignment is off? This sounds like something I should get a professional to do. Is just my engine built this way / does anyone else have such an issue?
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
Is just my engine built this way / does anyone else have such an issue?
Is it the engine, or just the housing around the engine that is causing the problem ?

Any advice on how to determine if I'm thrown the alignment is off?
Use just the first part of the write-up I sent you to determine if the alignment is off, and by how much. This will tell you veeeeeeeeery roughly how much you're out. If it's much over 0.006", better call in a certified mechanic. Be careful though, there are countless yard apes who would love to charge you for a day's work who haven't got a clue in hell as to how to align the Xmission to the shaft. With the moving of the block, it's likely quite a ways off. The other thing to avoid at this time is repeatedly loosening and tightening the "bolts" holding down the engine block. They are likely lag bolts which are screwed into wooden stringers and if you strip one, it wouldn't be pretty. Imagine replacing the stripped one without removing the entire engine. Worse still, imagine removing the engine and all the attachments.

Don't ya just love working on boats ?

BTW, what year is your boat ?
 
Aug 23, 2020
27
Catalina 310 323 Mamaroneck
@Ralph Johnstone : Ugh, that does make sense. This is exactly what the PO said he had to do: pull the engine, on the HE, toward the bow to access the dipstick.

Any advice on how to determine if I'm thrown the alignment is off? This sounds like something I should get a professional to do. Is just my engine built this way / does anyone else have such an issue?
Actually, I just moved the Heat Exchanger, and did not adjust any bolts on the actual engine block, so I think I'm ok
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
If you didn't disturb the hold down bolts, then life is worth living again :dancing:.

Next winter, you might want to check out the alignment. It's probably never been done before and it does cause problems if too far out.
 
Aug 23, 2020
27
Catalina 310 323 Mamaroneck
Is it the engine, or just the housing around the engine that is causing the problem ?



Use just the first part of the write-up I sent you to determine if the alignment is off, and by how much. This will tell you veeeeeeeeery roughly how much you're out. If it's much over 0.006", better call in a certified mechanic. Be careful though, there are countless yard apes who would love to charge you for a day's work who haven't got a clue in hell as to how to align the Xmission to the shaft. With the moving of the block, it's likely quite a ways off. The other thing to avoid at this time is repeatedly loosening and tightening the "bolts" holding down the engine block. They are likely lag bolts which are screwed into wooden stringers and if you strip one, it wouldn't be pretty. Imagine replacing the stripped one without removing the entire engine. Worse still, imagine removing the engine and all the attachments.

Don't ya just love working on boats ?

BTW, what year is your boat ?
Hi Ralph -- she's a 2007. I just loosened the one bolt that holds the Heat Exchanger (shown in picture) - there are two rings that loop around the heat exchanger and are bolted to the back of the engine. I loosened one of them to remove the dipstick.
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
If all you have are the two big hose clamps that hold the HX, then get something to place under the saddle that holds the HX to adjust its location to clear the dipstick. Many of us have inserted nice, soft bicycle inner tubes to do this. Saves rubbing metal to metal, and gets you the clearance you need.
 

Tom J

.
Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Hi Ralph -- she's a 2007. I just loosened the one bolt that holds the Heat Exchanger (shown in picture) - there are two rings that loop around the heat exchanger and are bolted to the back of the engine. I loosened one of them to remove the dipstick.
Very common issue. My dipstick actually cleared the HX originally, but when I upgraded to the heavier clamps, I found I had to use a prybar on one of the clamps to regain the clearance for the dipstick.
Changing the tranny fluid is a pain, but is doable with a small hand held transfer pump from an automotive parts store. Insert the small hose as far as possible into the dipstick hole, and pump out the fluid.
 

JRT

.
Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
This is the write up I use.

 
Sep 4, 2007
764
Hunter 33.5 Elbow, Saskatchwen, Can.
The manual you posted shows you need only 1 pint of atf. If you put a quart in you will have to drain some.
 
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Likes: justsomeguy
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Also, check the level with the dipstick screwed in, not screwed out.
The manual for that transmission (page 33) says to check with the dipstick not screwed in. Might be different for yours.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
This is the write up I use.

In that thread someone mentions draining by removing the bottom drain plug. I tried that once, and after dumping most of the oil when removing the small aluminum pan I used to catch the fluid, I figured that removing it from the top was fine for me.
 
Feb 20, 2011
7,990
Island Packet 35 Tucson, AZ/San Carlos, MX
The manual for that transmission (page 33) says to check with the dipstick not screwed in. Might be different for yours.
Not according to the OP's posted images. Screen snip-
Screenshot 2021-04-05 092443.png
 
Dec 16, 2011
257
Catalina 310 Atlantic Highlands
Changing the transmission fluid had been on my list for a while, and I'm embarrassed to say it was one of those, "I'll get to it post-launch" activities that I never got to. Reading this thread made me put it at the top of yesterday's list, and I found it was a pretty easy process. As someone in this (or another) thread mentioned, I purchased this item, cut off from the hose the piece intended to go to an outboard, swapped the hose and the "straw", and it worked perfectly!

Device.jpg

As you can see, I followed the recommendation to get two identical containers, one to hold the old fluid and one to pour the new fluid into, so I'm replacing the same quantity as I've removed.

Colors.jpg

You can see the stark color difference. I do need to go back and check against the dipstick to make sure I wasn't already low, but I forgot that step and moved on to replacing the fuel filters, which was a much harder and messier job than the transmission fluid change.
 
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Likes: Tom J
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Not according to the OP's posted images. Screen snip-
View attachment 192400
Good point. He says it’s the PRM 80, but most of the 310s I’ve seen have the ZF 5M (HBW 50), which is done with it not screwed in. Capacities are quite different between them.

Also, it looks like the PRM 80 transmission has the shift lever on the port side, but the OP picture doesn’t show it there. The ZF 5M has it on the starboard side, which is consistent with the picture. The name plate is right next to the dipstick, but it’s hard to read.
 
Last edited:
Dec 29, 2017
124
Beneteau Oceanis 411 Baltimore
Wondering if anyone on this thread has this transmission setup on their boat and if so, where do I find the drain plug as well as the measuring stick. I looked in my owners manual (universal Mx25) and nothing about where to look for these two items. Thanks in advance.
 

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