Universal 5432 Transmision Question

[Neil Gallagher]

Hello fellow Ericson Sailers, I have a question regarding the Hurth HBW100 transmission maintenance. I have had a few occasions where my engine does not intiatially shift into reverse. Which is a little disconcerting while approaching the dock! It does shift into reverse after a few attempts. I've have changed out the fluid and when looking up the details in the manuals I see the ATF capacity of a HBW100 as .55 liters (1.3pts). After adding .5 liters of ATF and checking the dip stick it reads considerably higher than the line on the tip of the stick. I've seen documentation that stated check the level by placing the dip stick in the fill hole "without" screwing the dip stick into the transmission. So the confusion is whch is the correct amount of ATF to add, the service manual capacity or the dip stick? I've always used the dip stick as the guage which is much less than .55 liters. Now I'm wondering if I have been running with low ATF for many years. The engine has 1670 hours and the transmisson is original as far as I know. I also checked the shifting cable and it appears to be extending and retracting correctly, ie the full distance. I have found some metal shavings in the fluid in the past during fluid changes. Thanks in advance.

 

[peaman]

A manual for the HBW100 is here. Section 1.5 describes the function of the clutches. My sense from that is that the unit may need a rebuild. Short of that, it might be worthwhile to change the fluid once or twice (with some use between changes) to see if there is any improvement. Is the fluid clean?

Section 3.2 shows how fluid level should be checked, which matches your description and what I have read for my ZF gear, which is similar or same design as Hurth. As to capacity, the manual shows the capacity of a "dry" unit, like right after a rebuild. If you drain the unit completely, there will be some fluid still clinging to gears, clutches, and bearings. That fluid left behind might account for the discrepancy you have seen. I would go by the dipstick reading, following the method shown in the manual.

 

[Neil Gallagher]

Great point peaman, I changed the ATF twice yesterday with a vacum pump, I assumed all the ATF was evacuated but perhaps not. Thanks for the manual. I'll go by the dip stick reading for refilling. Hopefully the fresh fluid will make it perform as intended.

 

[Loren Beach]

I catered to the whims of a Hurth 50 (Universal M25XP) for many years. I was able to, with futzing, actually drain the trans into a pan pushed under the engine. I could reach the drain with an end wrench, but could not actually put eyes on it. The factory info on total capacity was correct, and IIRC was about 8 or 10 oz. Checked it with the dip stick resting on the shoulder of the fitting and not screwed down.
Now we have a Betamarine25 with a different brand trans, and the fluid oz specified is about the same. But now I do have to use a vacuum 'slurper' thru the top. Works OK, and I refill until it's full. I agree that there is always some ATF left in the bottom of the case that does not quite get sucked out.
(The technical trivia of yacht ownership is... endless...!)

 

[Christian Williams]

I see now that I am not paying enough attention to the transmission fluid. Hurst says check once a month, which is unlikely. But I'll now check when changing the pencil zinc, which is about every eight months or so. Time for a fluid change immediately.

For troubleshooting, the manual (now in our Resources) says, essentially, to make sure the control cable permits full throw of the shift lever, and to test the lever with cable removed if in doubt. Basically that's about it.

 

[JSM]

I have found some metal shavings in the fluid in the past during fluid changes.

I went down this road a few years ago and tried to nurse my Hurth 50 along until it bit me in the ass. I ended up replacing the Hurth with a Twin Disc MG340 and installed a new damper plate as well.
I talked to three different trans shops and was advised under no circumstances to rebuild the Hurth trans as the rebuild parts are now after market and will most likely fail within a year.
On season four with the MG and have had zero issues.

 

[Pete the Cat]

One problem for those of you with the Hurth transmissions (or Kanaki on the Yanmars-- according to a 2007 service bulletin) is that it should not be left in FWD when sailing. Should be in reverse or neutral. Problem is that you can torture the discs as they lock by friction in one direction only. My mechanic friend who has rebuilt them suggests reverse is preferred. Both say that you might be OK if you have a folding prop leaving it, but that any fixed prop can cause issues. i am surprised that this was not made more clear in engine materials supplied with Universal and Yanmar engines.

 

[Neil Gallagher]

Great comments folks, thanks for the input! I do have an Autoprop which is actaully a feathering propeller. I've noticed that sailing with the gear shifted in reverse I still get some shaft spinning so I place it in foreward and it stops the spinning. I've seen where that is not recomended but I assumed since the prop blades feather with the flow of the water there is little pressure in the transmission. So that brings another quesstion to mind. If sailing with the gear in forward will the reverse cluth plates get impacted? I wonder if that could be a symptom? The transmission shifts into foreward well and I've never detected any slipage or difficiulty shifting into and out of foreward. Or perhaps the shaft spinning while in reverse indicates an issue with the reverse plates?

 

[Pete the Cat]

Great comments folks, thanks for the input! I do have an Autoprop which is actaully a feathering propeller. I've noticed that sailing with the gear shifted in reverse I still get some shaft spinning so I place it in foreward and it stops the spinning. I've seen where that is not recomended but I assumed since the prop blades feather with the flow of the water there is little pressure in the transmission. So that brings another quesstion to mind. If sailing with the gear in forward will the reverse cluth plates get impacted? I wonder if that could be a symptom? The transmission shifts into foreward well and I've never detected any slipage or difficiulty shifting into and out of foreward. Or perhaps the shaft spinning while in reverse indicates an issue with the reverse plates?

Feathering prop, transmission is in reverse while you are going forward and you are getting the shaft turning?--that seems strange---like something is wrong here--perhaps you are on to something. If you look at the guts of a Hurst transmission, you can see how it works. The plates are only there for the transition to stop the spinning while the gears engage. Once engaged they press to hold the gears (forward or reverse) in place but are rotating with the shaft when fully engaged. I am guessing that the problem is when the engine is not turning the main transmission shaft the prop in forward can exert a twisting motion on the plates which are stopped by the engine output not turning. Hence, friction on plates that will wear them down. If your shaft is turning when the engine is off, you are sailing and the transmission is in reverse--I would say something is not right.

 

[Dave G.]

I always leave mine in neutral, fixed 2 blade prop. So far so good. Also you need to be particular about what fluid you use. ZF has a bulletin which lists approved fluids for all Hurth models. The backwards compatible dexron type of fluids is not what to use in these trannys.

 

[peaman]

I've noticed that sailing with the gear shifted in reverse I still get some shaft spinning so I place it in foreward and it stops the spinning.

Interesting, but it makes sense. I think that when in gear, the respective clutch is engaged, but not enough to transfer much torque, with the result that the clutch will simply wear if the shaft is able to turn at low speed. The Autoprop is different from a feathering prop, in that reversing and feathering are accomplished by torque (or absence of it) within the hub, while folding props reverse only with adequate centrifugal force.

The bottom line, as I understand it is that the transmission, when sailing, should either be in neutral, so that clutches are entirely disengaged, or in gear as long as the shaft will not turn.

 

[s/v First Light]

Hello fellow Ericson Sailers, I have a question regarding the Hurth HBW100 transmission maintenance. I have had a few occasions where my engine does not intiatially shift into reverse. Which is a little disconcerting while approaching the dock! It does shift into reverse after a few attempts. I've have changed out the fluid and when looking up the details in the manuals I see the ATF capacity of a HBW100 as .55 liters (1.3pts). After adding .5 liters of ATF and checking the dip stick it reads considerably higher than the line on the tip of the stick. I've seen documentation that stated check the level by placing the dip stick in the fill hole "without" screwing the dip stick into the transmission. So the confusion is whch is the correct amount of ATF to add, the service manual capacity or the dip stick? I've always used the dip stick as the guage which is much less than .55 liters. Now I'm wondering if I have been running with low ATF for many years. The engine has 1670 hours and the transmisson is original as far as I know. I also checked the shifting cable and it appears to be extending and retracting correctly, ie the full distance. I have found some metal shavings in the fluid in the past during fluid changes. Thanks in advance.

My Ericson 32-3 Hurth transmission was showing signs of its clutch slipping. Your situation with reverse or with the shaft turning while sailing (engine off) while shifted into reverse, may actually be your Hurth’s clutch slipping. In my case, I drained my transmission and added ATF Type F transmission fluid to the dipstick’s full indication )with the dipstick screwed fully down. Problem solved.

Ford Motorcraft® ATF Type F is a high-static friction fluid developed for Ford automatic transmissions manufactured during the 1970s and earlier and is still available. Good luck with yours if you try this and if you do with success, please let me know how it worked for your Hurth.

 

[s/v First Light]

Hello fellow Ericson Sailers, I have a question regarding the Hurth HBW100 transmission maintenance. I have had a few occasions where my engine does not intiatially shift into reverse. Which is a little disconcerting while approaching the dock! It does shift into reverse after a few attempts. I've have changed out the fluid and when looking up the details in the manuals I see the ATF capacity of a HBW100 as .55 liters (1.3pts). After adding .5 liters of ATF and checking the dip stick it reads considerably higher than the line on the tip of the stick. I've seen documentation that stated check the level by placing the dip stick in the fill hole "without" screwing the dip stick into the transmission. So the confusion is whch is the correct amount of ATF to add, the service manual capacity or the dip stick? I've always used the dip stick as the guage which is much less than .55 liters. Now I'm wondering if I have been running with low ATF for many years. The engine has 1670 hours and the transmisson is original as far as I know. I also checked the shifting cable and it appears to be extending and retracting correctly, ie the full distance. I have found some metal shavings in the fluid in the past during fluid changes. Thanks in advance.

 

[peaman]

I drained my transmission and added ATF Type F transmission fluid to the dipstick’s full indication )with the dipstick screwed fully down. Problem solved.

How long since that change did/has the fix worked? Is this likely something that can be done just to get through the season, or does it look like a long-term solution? Any other observations following the change? For example, is there a lag in gear engagement, or any other effects?

 

[s/v First Light]

In reference to my recent reply regarding slipping clutch and my comments about using ATF Type F HIGH STATIC FRICTION fluid to prevent clutch slipping, I did my final fluid level check with the dipstick screwed down although realized that the HURTH manual calls for checking oil “without screwing dipstick down”. Anyway, my clutch slipping problem has been resolved.

 

[s/v First Light]

How long since that change did/has the fix worked? Is this likely something that can be done just to get through the season, or does it look like a long-term solution? Any other observations following the change? For example, is there a lag in gear engagement, or any other effects?

Changed to ATF type F fluid during 2022 season. Still OK in 2024.

 

[s/v First Light]

Changed to ATF type F fluid during 2022 season. Still OK in 2024.

BTW, I had considered flushing the trans with an appropriate ARF solvent before adding the ATF Type F fluid but decided did not do so.

 

[Dave G.]

Based on attached ZF approved fluids I found MOBIL DELVAC 1 ATF locally and have had good luck with it(knocking on noggin)....

 

[G Kiba]

I have posted this before because I think it is useful and I am on my 4th season without any issues. I solved my slipping problem by ditching the ATF and replacing it with 30W motor oil. I figured the slipping in forward was so bad, I would need to rebuild or replace it anyways (i had to back in to the marina entrance and into my slip). The motor oil works so well, that I forgot I did it 4 years ago. My trans mission has been flawless. Additionally, it has given me enough time to buy a used backup for $300, just in case. So my plan is now to see how long it will keep working!

 

[Pete the Cat]

I have posted this before because I think it is useful and I am on my 4th season without any issues. I solved my slipping problem by ditching the ATF and replacing it with 30W motor oil. I figured the slipping in forward was so bad, I would need to rebuild or replace it anyways (i had to back in to the marina entrance and into my slip). The motor oil works so well, that I forgot I did it 4 years ago. My trans mission has been flawless. Additionally, it has given me enough time to buy a used backup for $300, just in case. So my plan is now to see how long it will keep working!

Keep us in the loop with your experiment. The Kanaki transmissions that come with Yanmar engines specify 20W or 30W oil rather than ATF. I have not taken either apart, but the diagrams of their innards look like the principles are the same--though there appear to be a lot more tiny parts in the Hurst brand: perhaps this explains the mechanics' general disdain for them. I am thinking you might be on to something.