lucas88

This total lack of handling in reverse is a combination of several factors. Depending on hull shape, propeller dia/mass and rudder size/position determines severity of the individual factor. Therefore, below only the factors (in random order) 1-Wheel effect (of the propeller): If a mass is rotating in a certain direction and you change the rotation, a third axis moment is created pulling the ships out of course. You feel this also when you throttle down in forward, but then even without knowing you correct this with your rudder, which works very efficient in forward (with the propeller thrust flowing over it) For this reason, high powered/high speed ships/crafts, are fitted with counter-rotation engines/shafts/propellers. 2-Rotation direction of the propeller: Due to the rotation of the propeller, the thrust is not straight. With clockwise rotation, in forward, the stern is "pushed" slightly to starboard. But also here, when boating forward, this is easily (unconsciously) corrected with the rudder. In reverse (now with CCW rotation of prop) the aft is pulled slightly to port. In reverse though, with no flow of water over the rudder, this can hardly (if at all..) be corrected. 3-Rudder: A rudder only works when there is water flowing past it. In forward, with the propeller right in front, the flow of propeller water ensures swift/powerfull response of the rudder. In reverse you have to wait for the whole ship to actually move backwards in order for the rudder to have any effect. So even when your engine is in reverse, as long as the boat is still moving forward, you rudder will react as if moving forward (so cotrary what you would expect) These effects can never be eliminated, but you can use them to your advantage. As long as you know which direction and how fierce they are. Especially when approaching a quay to berth, I now approach over port in a 45 degr angle, and the a gentle reverse pulls the ship paralel. What also helped me was a 1000 kg of ballast. The added mass dampened the effects and gave me more draft and more thrust(less cavitation on prop in reverse) However, there is no substitute for practice. I almost sold my boat after the maiden voyage (which included a collision at a bridge due to the non-responsiveness in reverse....) But now after the ballast and practice its a piece of cake (most of the time..) Only with sidewinds its still a nightmare. Anyway, good luck. R Lucas

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)

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

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

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.....

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

For any Lister fetishists, I was scrolling through e-bay and bumped into some manuals for Lister being offered by Handymanuals. For example: http://www.ebay.nl/itm/LISTER-D-TYPE-D-TYPE-Restoration-Manual-Book-1997-/190716013370?pt=Non_Fiction&hash=item2c678f6b3a#ht_1256wt_1302 http://www.ebay.nl/itm/LISTER-D-DK-ENGINE-TECH-SPEC-DATA-MANUAL-FOR-OVERHAUL-/190716662343?pt=Non_Fiction&hash=item2c67995247#ht_1040wt_1302 I just found a purchased a manual for my Parsons DA reverse gear box. Good luck, 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

Tim, Only just saw your reply on the bearings. Thanks, at least that will make the bearing hunt easier. R Lucas

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

For sure the box will eventually come apart. If only for the brake band that has partially seperated. But the box itself is at the moment functioning relativetly well (I only have to keep it fully engaged in forward. I suspect this must be the shift fork, since it appears the the three toes dont travel far enough past the cone) The reduction gear I have obviously badly damaged by boating for so long with the noise (no oil....) , but now with oil in it, at least it doesnt make any noise. And additonally I have installed a seperate thrust block, so the engine/box is isolated from any external forces (besides shaft torque) Hopefully I can keep the reduction gear wheels and only replace the bearings. I assume I can get the brake band renewed/ recapped by a gear specialist. All in all, I really enjoy this forum and will keep you posted. Hopefully with pictures, once I find out how to attach/include (I dig mechanics rather well, but with computers I feel like a pianist with only two fingers) Can someone maybe explain how to include/paste pictures in this media? If I try insert an image it asks for an URL (whatever that is), but I cannot browse in my computer. R Lucas

Richard, I feel like the most stupid guy in the world... I'll be kiking myself for while. It was indeed item 4, no oil (at all!!) in the reduction gear... It was running on dust and metal parts. I obviously badly damaged the bearings and gears, but after adding oil the noise completely disappeared. I'll take the reduction gear out in winter and see how the internals are. But for now, smooooth boating withouth scraping noises.....(althuogh when warm, there comes a veery slight scraping. Same as withouth oil, when the scraping badly worsened when warm Anyway, thanks for all assistence. Lucas

Thanks Richard. I'll check your theory in winter when I'll take out the box. I am gambling it will hold out thruogh summer. In fact I am going on a 10 day trip on the boat tomorrow. I doubt thuogh that the band brake would make this noise, but I check by engaging revers. The noise should then stop (since the bandbrake mechanism is then fixated) Reverse gear is actually working OK and locks. Another question though: I notice on your pictures that your gearbox Identification plate is still on and states "..... engine oil for winter" and "......engine oil for summer", but I cannot make out the type specified. Can you advise what is stated on the box. (I am currently running on 20-W60 mineral oil, as specified in the Perkins 4.107M manual for the Parsons DA box) R Lucas

Hello everyone. What a wonderfull discussion above. I am Lucas from Holland and recently buoght and renovated an open boat (sloop) which was once a lifeboat (judging from the amount of dolly holes for oars I had to close/epoxy) It came with an ancient looking Perkins 4.107 coupled to a Parsons gearbox, which thanks to this article I now know is an DA-type. The boat is from 1975, the engine from prior, since the Perkins nr is from before 1974 (when the traceable engine numbering started...) Engine is running like clockwork but the gearbox however doesnt sound so well. It makes a horrible and loud scraping sound when engaged (when still cold it actually makes quite less noise) and does not remain engaged by itself (althuogh deducting from the above epistel, I do not think that these two are related) When in neutral, it still gives thrust (no true neutral) and only after slightly pulling to reverse, shaft stops turning and the noise from the box completely stops and only the muffled sound of the Perkins is audible (which actually sounds very nice) I opened the top hatch on box, and inside looks normal. I only noticed the lining on the reverse band brake partly seperated and is now vissible/slightly coiled up in the sopen section of the band. Following questions/theories I would like tested/commented on: -1 Is this scraping sound maybe normal/common? (since all the gear wheels have straith teeth) -2 From the above, I have ruled out the oil thrower being loose, since in Neutral, the oil thrower also spins (is this indeed the case) -3 Could it be the forward shift fork (that operates the sleef)is broken? (this one I could replace from the top, withouth completely removing the engine/gearbox from the boat) From another forum (about an F-type Parsons) I noted these can break as well. This would also explain why the sleef for forward does not travel far enough to stay locked. It just travels over the corner to the parralel part, but then slids back. -4 While I'm typing, I'm just realizing I did not check the reduction gear for the presence of oil.....who knows. -5 Since the sound increases when the oil gets hotter, I suspect it is a worn out bearing somewhere in the box. Any other ideas (that preferably do not invlove completely disassembling the box from the boat...) are very welcome. I tried to attach a photo to this reply, but I am obviously computer literate enough.... Thanks in advance. Kind regards, Lucas