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Move Engine to Repair Transmission?

cawinter

Member III
Me, too? Why...? E34 Transmission Woes.

Looks like I am the next victim of the 'no forward' virus. My transmission was starting the year a little rough, 'kicking' a bit at low RPM, and last night I just ended up drifting away from my mooring before forward eventually kicked in. I checked inside the binnacle to see if anything had come off or I if was hitting any limits (NO!), and I verified that I could manually toggle the switch lever on the transmission back to its limit without engaging the gear. :0 Thanks to our sails we actually had a nice evening even though we probably scared some folks in the narrow fairway.

Thanks for the good discussion here. Twin Disk MG340 or ZF10M it seems with some changes in the positioning of the cable and a loss of space to the shaft log. Has anyone removed the HBW50 transmission (on the E34; M25XP) without pulling the engine out?

We did our 300 miles this year, and I should be happy, but there are always more plans.

Thanks.
 

newpbs

Member III
Epidemic

Sound like there is a transmission epidemic. Mine lost it's forward gear 10 days ago. Stella (the boat) is having a twin disc trans installed today. The twin disc seemed to be a closer match tothe original. The mechanic who sold me in the twin disc says that the engine just needs to be lifted up 1/4 inch and the shift cable placed on the opposite side.

I am anxious to see how it all works out. The work is being done about a 2 hour's drive from home.

Paul
 

cawinter

Member III
No vaccine...

Paul,

Please keep us posted on the type of replacement transmission and any experiences. I am still baffled (why me? :confused: ). I have a PYI flex coupling installed, checked the travel, changed the oil, had all positive thoughts...oh, and we just came back from 300 miles of mostly motoring through Long Island Sound. I am glad it didn't happen out there somewhere.

I have a number of things on my mind should I have to pull the engine, but one of my concerns is that I don't have a lot of room for a longer transmission with the PYI Flex taking away quite a bit. I was already struggling to change the packing in the stuffing box this year. Let's see. This weekend is dedicated to digging into the problem.

Thanks.
Chris
 

fidji

Eric
tranny the enigmatic machine

After putting two hbw 50 and one hbw 100 and one zf 10m , the two last one fails after 400 hours I have some little experience with those things, first I found that the tolerance on the input shaft on the hurth+zf transmission are well out of the specs just take a brand new damper plate and put it on a brand new zf 10m and you will find a lot of play in all direction you move the damm plate (damper plate) and that is why there is a rattling sound when you cruising a very slow rpm. Torque is very important for these tranny because it insure thight locking between the mutiple clutchs disks in those transmissions, but when the rattling appear the output shaft go back and forth, slacks appear between the input and output shaft, every disks clutchs are press and released in a rythmic that is sound recongnisable. I have to be honest and I lost confidence in zf tranny and that is why I change for a twindisk, I was so sick and tired to remove the engine and tranny every three years I go for a radical change and I don't buy a twindisk MG 340 who will be an easy fit, but for a MG 360 rated for a 66hp diesel for my 21 hp universal and I had a oil cooler to be even safer. I have to put 1/2 inch aluminium flat bar spacer underneith the three motor mounts and cut the shaft log
1 5/8'' inch but because of my radicalism I found there is an absolute match between the brand new damper plate and the input shaft no play in any direction rotation, bending, torsion movement etc... What ever you try, those two metal parts fits perfectly thight (close tolerance) Now I enjoying a very heavy duty transmission with peace in mind. For the cable matter just buy the cable bracket from twindisck and put your transmission cable in place no problemo . I prefer the twindisck dipstick nothing to unscrew just like a car.

Eric
Decision
Ericson 35 MK III
 

cawinter

Member III
Great info

Thanks, Eric! Great information. I was just in Germany and looked at the ZF (and prices) over there. More pondering required, especially given the $$$, time, effort and impact on this season. I definitely want to get this one right!

I'll keep the group posted (as usual) on any progress and, of course, the resolution.
 

newpbs

Member III
Back in the Saddle (Lake) Again!

I replaced my original Hurth 50 transmission with a Twin Disc TMC 40P transmission. The Twin Disc unit is physically a very good match. The engine had to be lifted about .25 inch to make the new trans fit. The shift linkage is on the port side of the unit and not on the starboard side, as it was on the Hurth. The dip stick is still directly below the engine heat exchanger, but it is on the starboard side now.

I'm happy with the performance of the unit. It does have a higher pitched sound but it runs a little smoother (the Hurth may have been out of alignment). The feel, at the shift lever, is not as positive as I would like it to be, but the Hurth had a similar problem. Going from forward to neutral should have a positive "feel" to it. I cannot always tell when I am in neutral. I might be able to improve this with some linkage adjustments.

The Twin Disc trans costs about $1350, which is almost what rebuilding the Hurth would have cost. I needed to purchase another coupling, for the drive shaft, and another bracket for the shift cable. Those were an additional $110. The install was just under $2000. I might have been able to do the job myself is I were in my home port when the unit failed.

I considered taking photos, but there really isn't a good way to get in there and there isn't much to see.

Anyone need a Hurth trans with a blown forward gear?

Paul
 

fidji

Eric
tranny

Thank's to everybody , after one hundred hours of use I feel so good with my decision, the tranny is smooth and solid and it is right to say it shift so smootly than it is difficult to shift in neutral without going in reverse because the lack of feeling but it is nothing compare to my previous problems when I have to fight all the time with the tranny and have finally to change it every 400 hours.
Eric
 

Kenneth K

1985 32-3, Puget Sound
Blogs Author
I believe Ericson's OEM transmission for the M-25 diesel was the Hurth HBW-50. Caution that the Ericson manual says different things than the Hurth manual. I think Ericson said to change fluid annually or every 300 hrs. But, they also say the qty is 1.3 pints (~21 oz) while Hurth says 0.3 ltr (10 oz). The dipstick will show that 10oz is the correct quantity.
 

light24bulbs

E30+ 1984, San Juan Island, Wa
I believe Ericson's OEM transmission for the M-25 diesel was the Hurth HBW-50. Caution that the Ericson manual says different things than the Hurth manual. I think Ericson said to change fluid annually or every 300 hrs. But, they also say the qty is 1.3 pints (~21 oz) while Hurth says 0.3 ltr (10 oz). The dipstick will show that 10oz is the correct quantity.
Awesome and thorough reply, thank you. Any point to doing fluid analysis? It's a 39-year-old transmission and I'd like to know if it's going to fail early if I can
 

Donnie

Junior Member
Haven't heard of anyone doing that. Maybe call a transmission shop and ask them.

The main consensus here though seems to be: Never rebuild a Hurth-50, replace with something else.
I concur the hurth - 50 is going away this winter departing from my universal 25-xpb
 

JSM

Member III
I concur the hurth - 50 is going away this winter departing from my universal 25-xp
After nursing a slipping HBW 50 for six years I replaced it this past spring with a Twin Disc MG340 and a new damper plate.
More info here.
And here
 
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