transmission hesitates

[parado]

Hi All
I have a Perkins 4108 whith a Hurth HBW 10 transmission. Cold starting the transmission goes into reverse with no hesitation or excessive clunking to exit my slip. When cold, shifting into forward often hesitates, and is getting worse. This weekend it started to happen even when it was warmed up some. Any ideas on what parts I should be ordering now, before I take this apart? I used to rebuild my Muncie transmissions for my cars, this has to be dead simple...

[S/V Illusion]

Before pulling out the wrenches, check the shift cable operation.

[stormalong]

Originally Posted by S/V Illusion

Before pulling out the wrenches, check the shift cable operation.

Absolutely right. Be sure there is enough travel on the shift lever to engage the transmission.

[parado]

I will check that, but doubt this is the issue. Until this weekend, if the gearbox is warm, there is no issues at all. When cold,it can take a full 30 seconds to kick in. Warm it shifts right away.

[stormalong]

Originally Posted by parado

I will check that, but doubt this is the issue. Until this weekend, if the gearbox is warm, there is no issues at all. When cold,it can take a full 30 seconds to kick in. Warm it shifts right away.

Them check your fluid level. These trannys are hydraulically shifted. When was the last time you changed your ATF?

[Uncle Bob]

Originally Posted by stormalong

Them check your fluid level. These trannys are hydraulically shifted. When was the last time you changed your ATF?

Are you sure about that?

Originally Posted by parado

Hi All
I have a Perkins 4108 whith a Hurth HBW 10 transmission. Cold starting the transmission goes into reverse with no hesitation or excessive clunking to exit my slip. When cold, shifting into forward often hesitates, and is getting worse. This weekend it started to happen even when it was warmed up some. Any ideas on what parts I should be ordering now, before I take this apart? I used to rebuild my Muncie transmissions for my cars, this has to be dead simple...

I had the 150 behind a 50 hp kubota based engine which started to do much the same, became worse and eventually required rebuilding. I am not confident with gearboxes so off to the engine mariniser for advice which was, sorry we no longer use that gearbox because it simply does not last very well, we can have it rebuilt for you, cost around A$1600.00 last time we had it done, or we can supply a PRM gearbox, much stronger, for around $200.00 more. No brainer for me, very happy with the outcome.

[stormalong]

Originally Posted by Uncle Bob

Are you sure about that?

I had the 150 behind a 50 hp kubota based engine which started to do much the same, became worse and eventually required rebuilding. I am not confident with gearboxes so off to the engine mariniser for advice which was, sorry we no longer use that gearbox because it simply does not last very well, we can have it rebuilt for you, cost around A$1600.00 last time we had it done, or we can supply a PRM gearbox, much stronger, for around $200.00 more. No brainer for me, very happy with the outcome.

Well, I don't have the shop manual with me - it is on the boat. I seem to recall reading that.

I had a 150V on my Perkins 4.108. It outlasted the Perkins. I put it on my Beta 50 where it lasted another 5 years. Then replaced with the same tranny, now ZF marine. The only thing wrong with the old one was that it was dripping ATF. The cost of opening one up is so high that it makes more sense to buy a new one. That replacement is now 12 years ago and it hasn't missed a beat.

I was in a marina one winter when a mechanic told a guy on a neighboring boat that his transmission was shot because it wasn't shifting. This was after the mechanic replaced the shifter cable. The only problem was that he did not adjust the cable properly. A few minutes adjusting it and I saved that guy a few thousand dollars.

PS. When you shift a Hurth/ZF with the engine off you can hear a slight click when the shift lever has moved enough to engage the gears.

[Sailmonkey]

Originally Posted by stormalong

Them check your fluid level. These trannys are hydraulically shifted. When was the last time you changed your ATF?

These are not hydraulic boxes. They use three (if I remember correctly) balls in a ramp plus torque to squeeze the discs together.

[parado]

Looks like it's just thrust washers and clutch plate packs. The bearing kits are really expensive, and I'm not sure why. Does anyone know if these are made just for Hurth/ZF? Usually they are stamped with a part number and be purchased through a bearing manufacturer, has anyone tried this? With the tranny still in the boat I won't be able to do this.

[a64pilot]

Doesn’t really help much, but I have never not been able to take a bearing to a bearings and drive shop and them not be able to match them.
But you are correct about the markings, I’m sure somewhere there actually is a special bearing made for just one purpose, but I’ve not seen it.
Althing if the fluid has been changed even infrequently it’s unlikely they are damaged / worn.

[parado]

I did some work for Tugboat Annie, one of her companies she had was BC Bearing. Se passed a couple years ago. She was a tough nut, I liked her.
I'm going to consider a new ZF150 if my bearings need replacing, they are showing up at 350 USD on line, this is crazy.

[stormalong]

Originally Posted by parado

I did some work for Tugboat Annie, one of her companies she had was BC Bearing. Se passed a couple years ago. She was a tough nut, I liked her.
I'm going to consider a new ZF150 if my bearings need replacing, they are showing up at 350 USD on line, this is crazy.

The cost of servicing these is crazy expensive. So much so that if this is an old transmission it makes more sense to replace it that repair it.

[a64pilot]

Originally Posted by Sailmonkey

These are not hydraulic boxes. They use three (if I remember correctly) balls in a ramp plus torque to squeeze the discs together.

Assuming it’s like my KBW20 which is actually a Hurth I believe, what he said above is the way I believe they work, the clutch packs have weak springs to keep shifting force to a min. They use the torque thats fed through the transmission to push the plates together so the more engine torque, the harder they are pushed together.
I’m going to guess that it’s a shifter issue not shifting all the way, and if not that then somethings sticking to prevent the ramp function that presses the packs together.
The clutches shouldn’t be worn or burnt, if they are then the fluid will be black and smell like Hell, ever smelled a burnt up automatic?

I’m other words I’d disconnect the cable and shift manually and see if that makes it work correctly, just leave it tied in the slip for this.
Of that makes no difference then I’d pull if and tear into it, what do you have to lose? Have to take it out anyway if it’s not working.

Has the shifter cover ever been off?

[Compass790]

Originally Posted by parado

I did some work for Tugboat Annie, one of her companies she had was BC Bearing. Se passed a couple years ago. She was a tough nut, I liked her.
I'm going to consider a new ZF150 if my bearings need replacing, they are showing up at 350 USD on line, this is crazy.

Whilst I'm not familiar with your gearbox I've bought bearings for gearboxes & NEVER off the OEM always from a bearing supply place.
You can get seals, o-rings, snap rings & circlips as well.
You will be amazed at the price difference

[parado]

I have bought many bearings by number and manufacturer only to replace anything I have come across so far. Key words so far. I cannot imagine a company marking up these by a factor of ten, and it seems it is just that by the price. If I knew beforehand what I need its a no brainer. It would suck to have the boat laid up with all the covid concerns and travel restrictions. In my part of this world, there is heaven on earth right at my yacht club gate.....