Parsons Reverse Gear type DA

[lucas88]

Richard,

Returned early from 10 day trip. but not due to technical problems (put on about 16 hrs and box is doing fine except for reduction gear box slightly leaking over the shaft seal. But luckily I had another major problem to wrry about, namely a diesel leak which caused about 20 liters of diesel to lean into my bilge, before I noticed it. This now fixed thuogh)

 

Anyway, in preparation of winter box stripdown, I studued the pics a bit closer, and noticed that the reduction is actually not a seperate item, but integrated in the box end plate, and sharing the same main shaft bearing, which is acually lubricated from the reverse gear side aso is now for sure also shot.

 

I saw in the other trail/forum topic a part of a cross-sectional drawing of the box. Any chance you have the full cross-section drawing available (hopefully with the bearings oand oil seals part numbers...?) The the bearings/seals special parts (Mathway marine) or are they available at specialized bearing suppliers? (where did you get them?)

 

In fact, in my case, since I added a seperate thrust block, in theory, I would not even necisarily need conical roller bearings for the output shaft. But obviously I prefer to stick to the OEM parts/design.

 

R

Lucas

 

Tim,

With reference to above request, is it possible to get the full cross-sectional drawing of the below part view:

 

http://i559.photobucket.com/albums/ss38/Timleech_2009/Oldengine/Parsons-1.gif

 

This to get idea of the reduction gear bearing arrangement/type/size. Closest view I got is in Richards picture:

 

http://i993.photobucket.com/albums/af54/RLWPowell/Canals/Parsons%20gearbox/stateofplay.jpg

 

From this picture it looks like the aft gearbox bearing is installed (I notice a circlip is visible) and lubricated from the reduction gear end. So theory it may be possible to replace all the reduction gear bearings withoth a complete disassembly of the gearbox (so box could stay in boat...) Anyway, the cross section drawing should show this.

 

Thanks in advance and regards

[lucas88]

Update:

Job completed (the reduction gear part that is..)

I found an original manual on e-bay (very limited info, but with proper cross-sections and nice to have anyway)

 

Removing the reduction gear from the reverse gear (without imperial sized special tools) was an achievement by itself. Disassembling the reduction gear revealed that all bearing were in extremely poor shape. The cages were intact, but all rollers fell out and all raceways were like dirtroads... No wonder the noises were so loud) Anyway, a lot of googling and phone calls got me to a webshop where I ordered SKF (premium German bearing brand) bearings. Cleaning and reassembling was very rewarding. Cant wait to try it out...

 

For the next victim, hereby like to post the bearing nrs. The bearings installed were of the brand R&M which uses the same nrs that RHP (another bearing brand). In brackets I put the equivalent SKF bearing nrs:

Main (upper) shaft:

FWD ball bearing(imperial): LJ 1 5/8 (RLS-13)

AFT roller bearing (metric!????): LRJA 35 (NJ207) (the one installed had a bronze cage, but for these low speeds thats not required)

 

Lower shaft:

FWD roller (imperial): MRJA 1 (not sure on SKF nr, I bought/got supplied an RHP bearing)(also here I did not get a bronze cage)

Aft split ball thrust bearing (imperial): DMJT 1 3/8 J

 

Since I have a separate thrust block I changed this bearing for a regular ball bearing type MJ 1 3/8 (RMS 11)

 

Upper shaft oil seal: 2 3/4 x 2 x 3/8

Lower shaft oil seal: 2 1/4 x 3 x 3/8 (two installed)

 

As you can see, there was one metric bearing in the box. Very strange. Maybe the reduction was overhauled in the past and they machined the shaft/housing for this metric size. It did not look that way though.

 

A bigger problem at hand now is how to get the reverse gear off the engine (the reverse brake band is loose so I really need to take the reverse gear apart as well..)

 

I released the six bolts that attach the reverse gear to the flywheel housing and tried to pry the box off (even tried to hammer a chissel between) but no movement at all. Solid as a rock.

 

Anyone has an idea? Should the flywheel housing come of the engine with the box? How is the shaft connected to the flywheel?

 

Any thuoghts (or even better, cross-section sketches/drawings) are welcome. The engine the reverse gear is attached to is an old Perkins 4.107M

 

 

R

Lucas

[RLWP]

Which bolts are you undoing? They should be the blue ones between the flywheel housing and the engine

 

Richard

[Timleech]

Update:

Job completed (the reduction gear part that is..)

I found an original manual on e-bay (very limited info, but with proper cross-sections and nice to have anyway)

 

Removing the reduction gear from the reverse gear (without imperial sized special tools) was an achievement by itself. Disassembling the reduction gear revealed that all bearing were in extremely poor shape. The cages were intact, but all rollers fell out and all raceways were like dirtroads... No wonder the noises were so loud) Anyway, a lot of googling and phone calls got me to a webshop where I ordered SKF (premium German bearing brand) bearings. Cleaning and reassembling was very rewarding. Cant wait to try it out...

 

For the next victim, hereby like to post the bearing nrs. The bearings installed were of the brand R&M which uses the same nrs that RHP (another bearing brand). In brackets I put the equivalent SKF bearing nrs:

Main (upper) shaft:

FWD ball bearing(imperial): LJ 1 5/8 (RLS-13)

AFT roller bearing (metric!????): LRJA 35 (NJ207) (the one installed had a bronze cage, but for these low speeds thats not required)

 

Lower shaft:

FWD roller (imperial): MRJA 1 (not sure on SKF nr, I bought/got supplied an RHP bearing)(also here I did not get a bronze cage)

Aft split ball thrust bearing (imperial): DMJT 1 3/8 J

 

Since I have a separate thrust block I changed this bearing for a regular ball bearing type MJ 1 3/8 (RMS 11)

 

Upper shaft oil seal: 2 3/4 x 2 x 3/8

Lower shaft oil seal: 2 1/4 x 3 x 3/8 (two installed)

 

As you can see, there was one metric bearing in the box. Very strange. Maybe the reduction was overhauled in the past and they machined the shaft/housing for this metric size. It did not look that way though.

 

A bigger problem at hand now is how to get the reverse gear off the engine (the reverse brake band is loose so I really need to take the reverse gear apart as well..)

 

I released the six bolts that attach the reverse gear to the flywheel housing and tried to pry the box off (even tried to hammer a chissel between) but no movement at all. Solid as a rock.

 

Anyone has an idea? Should the flywheel housing come of the engine with the box? How is the shaft connected to the flywheel?

 

Any thuoghts (or even better, cross-section sketches/drawings) are welcome. The engine the reverse gear is attached to is an old Perkins 4.107M

 

 

R

Lucas

 

 

There's probably a sort of 'half-coupling' bolted to the flywheel, & the gearbox input shaft will need to be a good fit in this. I have more experience with the bigger 'F' type, which does it the other way round - stub shaft on flywheel and hollow input shaft in the box. They are often pigs to separate from the engine, you need to support the weight of the box at the same time as applying just the right amount of brute force judicious leverage to separate the two without damaging anything.

 

Don't be too surprised about finding a mix of Imperial & Metric bearings, it's not unusual.

I rebuilt a 1930's gearbox recently, had to get new gears cut for it, they were a mix of Imperial Diametral Pitch and Metric Module (Not running together, though!).

 

Tim

[lucas88]

Which bolts are you undoing? They should be the blue ones between the flywheel housing and the engine

 

Richard

 

It looks like the only option (but that's not gonna happen this winter, I'll need the complete engine out for that, which will require a small crane)

 

It contradicts however the Perkins manual. In the Perk manual there is section that describes how you have to check the alignment of the flywheel housing relative to the flywheel after reassembling the housing to the engine. If you would need to install the housing with the reverse gearbox already on, you could never check that alignment.

 

Tim's response also suggests otherwise (even though the "judicious leverage" is not easily applied anyway while the engine/gear are in the boat....)

 

Anyway, I'll have search a bit further and hopefully find confirmation/certainty on what to do (and how to do it..)

 

to be continued.....

[Timleech]

It looks like the only option (but that's not gonna happen this winter, I'll need the complete engine out for that, which will require a small crane)

 

It contradicts however the Perkins manual. In the Perk manual there is section that describes how you have to check the alignment of the flywheel housing relative to the flywheel after reassembling the housing to the engine. If you would need to install the housing with the reverse gearbox already on, you could never check that alignment.

 

Tim's response also suggests otherwise (even though the "judicious leverage" is not easily applied anyway while the engine/gear are in the boat....)

 

Anyway, I'll have search a bit further and hopefully find confirmation/certainty on what to do (and how to do it..)

 

to be continued.....

 

The only Parsons box that I've dealt with on a Perkins (also on a 4/107 or 108) was a 'Marine-o-Matic' semi-hydraulic box which I think was based on the guts of the D type. That one was driven via a conventional spring drive plate.

When I bought the 4LW Gardner for my own boat, I had no end of trouble getting the gearbox off. This was a big heavy Self-Changing Gears MRF 350 HD. It had been in a sea boat & the splines on the spring drive plate had rusted together. I had to force things apart just enough to be able to get a spanner in to undo the drive plate from the flywheel, it was a long & painful process!

Just wondering....

 

Tim

[RLWP]

The manual you have describes a self-contained gearbox, not one with an integral flywheel housing - which is what your picture shows

 

These are the fixings to undo:

 

 

Richard

[Timleech]

The manual you have describes a self-contained gearbox, not one with an integral flywheel housing - which is what your picture shows

 

These are the fixings to undo:

 

 

Richard

 

Surely it should come apart with either set of fixing undone?

 

Tim

[RLWP]

Surely it should come apart with either set of fixing undone?

 

Tim

 

Sorry, yes - my mistake

 

I'm trying to remember how Luctor's boat was put together. I know that the input shaft had a large flange fitted to it, so I guess it was a separate box with a flexible shaft connected to it

 

In the workshop I have a box with a complete cast housing and flywheel casing that would only come apart the way I described, I've confused that with this box

 

What will be on the end of the input shaft Tim - stuck key perhaps?

 

Richard

[lucas88]

The manual you have describes a self-contained gearbox, not one with an integral flywheel housing - which is what your picture shows

 

These are the fixings to undo:

 

 

Richard

Thanks for putting the picture in. (I do not know how to do that)

I've sent you an e-mail of the relevant page from the Perkins 4.107M manual (I've found on the internet somewhere). There you can see, the flywheel house is identical to mine and not integral with the gearbox.

In case it is a spline issue (as Tim suuests), it will not matter which bolts I release, it will remain to be as stuck as it is. I'll could full the bathtub with WD 40 and soak the complete engine/gear in it...

R

Lucas

[RLWP]

OK, that manual describes how to align the housing before dowelling it in place. Hopefully you won't get involved with any of that stuff.

 

I can't see the bit that couples the gearbox input shaft to the flywheel in that document. There must be a driveplate, or a coupling in there. As Tim suggests, that the bit that has stuck.

 

More brute force is probably the solution - don't break the flange off the gearbox casing

 

Richard

[Timleech]

OK, that manual describes how to align the housing before dowelling it in place. Hopefully you won't get involved with any of that stuff.

 

I can't see the bit that couples the gearbox input shaft to the flywheel in that document. There must be a driveplate, or a coupling in there. As Tim suggests, that the bit that has stuck.

 

More brute force is probably the solution - don't break the flange off the gearbox casing

 

Richard

 

If it's a simple coupling with key, it needs to be a good fit otherwise it'll soon fret away in service. Quite possible it has rusted on if it hasn't been used for a long time, but even if not it may not come off easily - as I've described for the F type, which has a simple keyed stub shaft on the flywheel which is (or should be) a close push fit into the gearbox shaft, it can be hard work getting them apart.

 

Tim

[RLWP]

Sounds like we have converged to the same solution Tim. Make sure all of the nuts are off the studs, then use more force

 

Perhaps you could try bumping the output flange sideways to see if you can start things moving

 

Richard

[Timleech]

Sounds like we have converged to the same solution Tim. Make sure all of the nuts are off the studs, then use more force

 

Perhaps you could try bumping the output flange sideways to see if you can start things moving

 

Richard

 

Also, with some force applied, maybe try cranking the engine over. Make sure it can't fire up, though!

 

Tim

[RLWP]

I like it - a bit like wobbling the box from side to side, only easier!

 

Richadr

[lucas88]

Also, with some force applied, maybe try cranking the engine over. Make sure it can't fire up, though!

 

Tim

 

Great idea indeed! (using the starter) However, I took the starter motor out for a preventive check-up/overhaul..

Besides that, the boat is now in winterstorage and I have her completely wrapped up. Probably around March I'll unwrap her and start work on her again.

But anyway, thanks for the help guys. Much appreciated.

R

Lucas

[luctor et emergo]

Have you supported the 'box at all, whilst unbolting it from the engine?

[lucas88]

Have you supported the 'box at all, whilst unbolting it from the engine?

No, not yet supported. I put my car-jack under the engine, then unbolted the supports and then the 6 bolts. Nothing moved even a thou. The two flanges remained closed as an oyster all around. Then tried to hammer a sharp chisel between the flanges, but still, not even a tenth of a mm between the flanges.

 

Once I get to it, I am thinking of bolting one support back on and use another jack between the support and the flywheel housing (so on one side only) and then as Tim suggested crank the engine (while pulling the engine stop cable...) Once I see any movement I'll start thinking of properly supporting the box (probably use some wood and lower the jack under the engine)

[Speedwheel]

When are we getting the BM 'box rebuild thread Richard?

[RLWP]

When are we getting the BM 'box rebuild thread Richard?

 

When I stop taking them to bits...

 

Richard

 

MORE: which will probably be after the owner stops buying them

Edited November 23, 2012 by RLWP

[Batavia]

When I stop taking them to bits...

 

Richard

 

MORE: which will probably be after the owner stops buying them

Then you need to get Speedwheel to stop sending me links to ones for sale!

 

Chris G

 

 

[Speedwheel]

Then you need to get Speedwheel to stop sending me links to ones for sale!

 

Chris G

 

Moi?!

 

I hear you got it running Chris.

[RLWP]

Moi?!

 

I hear you got it running Chris.

 

He has, but appears to be ill and will only run lying on it's side

 

Richard

[Batavia]

He has, but appears to be ill and will only run lying on it's side - personally I blame Frank's strange Swedish diesel, which smells like no diesel I have ever come across before - enough to make anyone ill.

 

Richard

And it wants to run in forward and reverse at the same time!

 

Chris G

 

 

[BM 1051]

And it wants to run in forward and reverse at the same time!

 

Chris G

i got a workshop manual for the gearbox too !

 

Christian