Guest catweazle (Banned Member) Posted April 18, 2008 Share Posted April 18, 2008 This is more like it ,great stuff. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted April 18, 2008 Share Posted April 18, 2008 First clue was that the center row of bolts holding the two halves of the box together were not pulled tight down, although they were wired! As a matter of interest, had the two halves of the box been sealed using silicone sealant? Mating flanges look too clean for Hylomar, Wellseal or Red Hermetite! Quote Link to comment Share on other sites More sharing options...
Adam Elsdon Posted April 18, 2008 Share Posted April 18, 2008 Excellent, i love horror shots, really good info to know about ( And I knew oily layshafts would feature somewhere!!) Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 18, 2008 Author Share Posted April 18, 2008 As a matter of interest, had the two halves of the box been sealed using silicone sealant? Mating flanges look too clean for Hylomar, Wellseal or Red Hermetite! No red, no blue but some sort of thin black stuff, maybe sabotage, but then silly cone wasn't about back then Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted April 18, 2008 Share Posted April 18, 2008 No red, no blue but some sort of thin black stuff, maybe sabotage, but then silly cone wasn't about back then Ah well, I did not know how long since the box was last split. Reason for asking was that using silicone in situations like this, it often has too much applied, pinches up "tight", but then the two halves fret and bolts come loose. There was a batch of Ferrets released, that had been in Cyprus, I have come across several of them with severe leaks form the transfer box. This is where silicone was used (not the offical recomendation) to seal the casings, and after a time it is working out, as too much was used and bolts are loose and unable to keep oil in it. Quote Link to comment Share on other sites More sharing options...
abn deuce Posted April 18, 2008 Share Posted April 18, 2008 Seems to me the end roller bearings look like they have too much clearance with the outer bearing race. Whats the parts availability like beyond the Bearings ? as in shafts and gears and housings???? Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 19, 2008 Author Share Posted April 19, 2008 Seems to me the end roller bearings look like they have too much clearance with the outer bearing race. Whats the parts availability like beyond the Bearings ? as in shafts and gears and housings???? New parts are hard to find, owners tend to hang on to any good boxes! Ah well, I did not know how long since the box was last split. Reason for asking was that using silicone in situations like this, it often has too much applied, pinches up "tight", but then the two halves fret and bolts come loose. There was a batch of Ferrets released, that had been in Cyprus, I have come across several of them with severe leaks form the transfer box. This is where silicone was used (not the offical recomendation) to seal the casings, and after a time it is working out, as too much was used and bolts are loose and unable to keep oil in it. The bolts where proud a fair bit and I reckon they were bottomed out in the blind tappings on stuff in the hole as I got a lot out. You got me worried there Richard as I used silicone and I have just had a look at the box and it's leaking a bit of oil now, no enough to drip just a covering. Will check the bolts etc when it stops raining! Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 19, 2008 Author Share Posted April 19, 2008 The gearbox has an oil pump. This is the bottom counter shaft oil baffle, which is a close fit inside the hollow shaft, it's job is to direct oil to the roller bearings within the gears and shafts through holes drilled in the wall of the tube to coincide with holes in the shaft under each set of needle rollers. The end has a plug fitted. This is the one from the top counter shaft, PLUG MISSING, therefore no pressure maintained within the shaft and no oil forced into the needle rollers, note the heat mark around the hole! This plate is to retain the selector rod in place, it was loose and a shiney mark can be seen where one shaft had been rubbung, the others could pass by without touching it! This shows marking where the bearing outer races had been moving. Only a couple of small chips on the dog clutches, made to take years of abuse. This is the output shaft with a bit of wear on the splines. Despite all this the gearbox still worked OK it was just very noisy! Luckily, a couple of yrs ago I had bought the complete brand new internals from a Constructor box that had laid under a bench for around 12 yrs only the output shaft, the front bearing and a few of the needle bearings were missing. (450 of them in all) so I re-used the old output shaft as it was worn to match the flange and miced up all the old needle rollers to get some to make up the difference, there was a surprising variation even among the new ones although they were all still mat and unworn. The selectors I didn't touch as they still worked OK after I did a field repair when the bush came loose and jammed the rod at W&P a few yrs ago. All done ready to put the top on! Bits left over to re-build another box with. This is just pure gearbox porn! inside the box that came with the Cummins Quote Link to comment Share on other sites More sharing options...
AndyFowler Posted April 19, 2008 Share Posted April 19, 2008 Hello again Bernard , I have heard that the gearbox can be removed from underneath instead of through the cab floor ! I was just wondering which method you had used ? Just found this photo of Forcefull on my computer not sure where I uploaded it from now ! Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 19, 2008 Author Share Posted April 19, 2008 I think I posted that before the crash, maybe you got it then, that was the first time I got him running. I got the box out underneath, put a trolley jack under the transfer box, took out the bolts and spacers that hold the rear mountings to the chassis, then shoved a couple of spades or similar into the gap to act as guides. Then loosened the bolt that goes through the front mounting and lowered the back end first till it's near the ground. Then lowered the front end using a puller winch / snatch block hung on the lamp bracket at the rear of the cab (I have the canvas tilt hoop bolted to this so it's strengthened) then dragged it out sideways with my Landrover winch. Reverse this to put it back. A couple of other bits have to be taken off to make room, exhaust and brake rods I think. Not quite as easy to do in practice, took all morning by myself as it was too dangerous to have any one else under there, although someone should be watching for safety reasons. It went back in about the same time. Not much effort just to be careful and just took my time. I was never under when jacking or winching and did a lot of thinking! As a former contractors plant fitter I have the experience to do this, I would never suggest any one else tries this dangerous task, just saying what I did. Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 20, 2008 Share Posted April 20, 2008 ?? :idea: I think it was Geoff Rhodes who told of one which came his way because the recovery operator had cut off the gate in frustration, hoping to be able to skip a gear or two more than normal, but in so doing he made the gearbox totally unusable. Well I spoke with him this week, he said it wasn't him, so I know who it was now! Geoff said he's had several in over the years without gates, and they work very well without the gate - a case of experience and an intimate knowledge of "where to shove the lever"? I wouldn't want to do without the gate:sweat: Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 20, 2008 Share Posted April 20, 2008 As the sight of mechanical gore must be attracting quite a few views, I thought it might be useful, for those not familiar with the Scammell, to reveal the Scammell gearchange and gate in all its glory. First pic shows the gate - apart from being able to skip 2nd and 5th you have to go up and down the box in sequence. Sounds tedious, but it is a lovely box to use, and it ensures you are always in the right gear or not far away! For me the best part of Scammelling is changing gear :banana: Note there are several neutral postions (indicated by green line) - you would think the most convenient was between 1st and Reverse, but beware, the oil pump does not work in this position, so if left idling for any length of time you can run the bearings dry :shake: Second pic shows the gearchange mounted onto gearbox. This view is of a Constructor - I think I'm right in saying the Explorer unit does not stick out anywhere near as much as this (?), so vibration effect would be less than on a Constructor. Even so a lot of weight hanging out there! Tony Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted April 20, 2008 Share Posted April 20, 2008 This is more like the stuff we need to see thanks for posting. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted April 20, 2008 Share Posted April 20, 2008 All this talk of fitting Scammell gearboxes, has reminded me of an amusing incident many years ago when Explorers were in Army service. It was when I was working for REME and one of my workmates had just changed a gearbox and gone out on test. He came back and asked me to try it. All was going well, until the ignition suddenly cut out. It would not restart, so I turned the master switch off and back on, engine started and off we went again around the test circuit. Suddenly at the same place, it cut out again..........why, what was happening to do that? I realised that was the only point I had used the brakes. It was found that when tightening up the rear gearbox mounting brackets, the brake light cable had become pinched under a bolt head, when brakes were applied the cable shorted out, bringing the circuit breaker in. Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 23, 2008 Author Share Posted April 23, 2008 First pic shows the gate - apart from being able to skip 2nd and 5th you have to go up and down the box in sequence. Sounds tedious, but it is a lovely box to use, and it ensures you are always in the right gear or not far away! For me the best part of Scammelling is changing gear :banana: Second pic shows the gearchange mounted onto gearbox. This view is of a Constructor - I think I'm right in saying the Explorer unit does not stick out anywhere near as much as this (?), so vibration effect would be less than on a Constructor. Even so a lot of weight hanging out there! Tony I went for a quite a long drive yesterday and enjoyed every gearchange, beautiful ! :-D:-D Parked up and spotted a pool of oil under the transposing box :eek: the rear t/box cover drain plug had gone awol, but the oil in the main part of the t/box was still over half full so no damage done, phew! (Rear wheel drive does not go through the transposing box) Yes the Explorer gate lacks 4" spacer As the rubber couplings for the engine to gearbox shaft are now selling for £217.50 on ebay today I will post a different solution to this common Scammell problem. Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 23, 2008 Author Share Posted April 23, 2008 The clutch is connected to the gearbox by a shaft on a lot Scammell vehicles, this is fitted with composite alloy/rubber couplings to absorb engine vibrations and to allow the engine to move around relative to the gearbox. Here are the ones on my Explorer, getting a bit old now! Other types, here is a Layrub type, I think these were used more in Constructors and different type of flange is needed. This one is fitted to an Explorer with a Cummins engine and a Eaton/Fuller bell housing modified to take a Scammell (Constructor?) clutch shaft. Some Engine transplants use only one coupling, but ideally, to allow for engine movement (the gearbox movement should be almost zero) two should be used. As the correct very rare explorer rubber couplings are now fetching £217.50 on ebay without any guarantee that the rubber has not already degraded, an alternative solution is needed, Here is one pioneered (I know, wrong thread) by Graham Germany and which has been copied by other Explorer owners to good effect. Graham does a high mileage towing in his Explorer so it has had a good test. He uses slightly modified Explorer flanges, the cost is very reasonable. However, I was always told that a propshaft with universal joints should never be fitted directly to an engine without a vibration damper between, as the torque peaks generated could create spikes many times the rated torque for the propshaft, and also the vibrations would damage the needle rollers and sliding splines. Most vibration dampers are rubber/steel composite. I don't know weather the springs in the center of a clutch plate act as a damper (they help with a smooth take up though), but the rubber couplings do the job and it can only be assumed that is why they were fitted. If you have the original Meadows petrol lump still fitted with the original solid center clutch plate, you should think about this before changing to this modification. I have been told I worry too much, any one have any thoughts on this? I'd love an informed answer to this one please! Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 25, 2008 Share Posted April 25, 2008 I don't know much "informed" :sweat:, but the petrol Constructors had a similar looking rubber coupling to Explorer. Some reckon they are different, so I've just looked in parts books and discovered that the 20T (Meadows petrol) is the same type, but the 30T 5th wheel Tractor (Rolls C6 diesel) has a "Metalastik" type coupling at each end. Here are the Constructor part numbers (from WD parts books) - could you post the Explorer number so we can check that the 20T is the same coupling please? Constructor (20T) Coupling - 28/263 Constructor (30T) Coupling - 28/R212 Thanks, Tony Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 25, 2008 Share Posted April 25, 2008 I have been told I worry too much Well maybe, but you're in good company:n00b: Always good to anticipate parts supply problems, if not you could be off the road for a long time :thumbsup: Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 25, 2008 Author Share Posted April 25, 2008 As one worryer? to another, the Explorer pt.no. is 28/263, my memory of Layrub couplings is that they looked like second the one shown, (I had one on my Sunbeam S7) I assume that the 30 ton would have had this sort as apart from anything else it is more 'fail safe'. There is a pic of my Explore in 'Tugs of War' up on a trailer, this was because the couplings broke up the first time I took him to W&P, and I needed room to work! I managed to cut a new rubber bits out of an old army boot heels and wire them in place to get home! The one shown on my Explorer was "re-manufactured" by me about 11 yrs ago, and has held up well, apart from the alloy bits corroding away as can be seen, this is why we worry, once bitten twice shy, that's a lot of metal to get home!! Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 26, 2008 Share Posted April 26, 2008 I managed to cut a new rubber bits out of an old army boot heels and wire them in place to get home! That deserves a special award!:rofl::rofl: There is not enugh room to fit Layrub couplings at the gearbox end (well certainly not on Constructor with the extended gearshift tunnel). The 30T Metalastik couplings are effetively 3 pieces of concentric steel tube of different diameters about 100mm long, sandwiched with 2 layers of rubber (about 8mm thick), where the inner forms part of the driving flange and the outer is the driven flange - this gives a very small diameter coupling of great strength, but failure is a terminal matter, don't think army boots would do the trick :shake: Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted April 26, 2008 Share Posted April 26, 2008 That deserves a special award!:shake: Special award,more like a knight hood,did a similer thing with range rover panhard bush in france the new polybush didnt like the leak from p/steering box and decided to come out on a winding lane by the side of the riverThe wheel wobble caused a few anxious moments and to my amazement i found i could now speak french.The tempory repair was made by me cutting up the leather belt from my trousers.it lasted several wks.This problem arrose again this wk with a forum members car.(no names) it happens with oe but takes longer.Having given up the big trucks a long time ago for boats i am finding this thread very interesting.THANKS Quote Link to comment Share on other sites More sharing options...
radiomike7 Posted April 26, 2008 Share Posted April 26, 2008 Hello again Bernard , I have heard that the gearbox can be removed from underneath instead of through the cab floor ! I was just wondering which method you had used ? Just found this photo of Forcefull on my computer not sure where I uploaded it from now ! Andy If you bar the winch drum round you will find a large hole which is used to drop a hoist chain or cable from a beam or overhead gantry. Box can then be removed from below. Book time to remove a gearbox is 4 man hours, but we managed it in less never having done one before and despite both of us being sparkies! Mike Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted April 26, 2008 Share Posted April 26, 2008 Andy If you bar the winch drum round you will find a large hole which is used to drop a hoist chain or cable from a beam or overhead gantry. Box can then be removed from below. Mike, That has just brought it back in my memory. I thought we used to use a rope from above, to drop the box out. Too long ago now :-( Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 27, 2008 Author Share Posted April 27, 2008 Andy If you bar the winch drum round you will find a large hole which is used to drop a hoist chain or cable from a beam or overhead gantry. Box can then be removed from below. Book time to remove a gearbox is 4 man hours, but we managed it in less never having done one before and despite both of us being sparkies! Mike Hi Mike, I had a feeling you might have spotted this tread, your input is always welcome. It took me around 4 hrs to do it my way, I didn't know about the hole in the drum, I've now spotted a 2" ish hole in the winch just above the rear output flange, if a rope could be passed through this the job would have been easier. my way was a bit dodgy not having a proper hoist or a nearby tree in the field! The Explorer book says to pass lifting tackle between the cab and body and warns that the gearbox assembly will be unbalanced as it will be supported forward of the point of balance, I found doing it a bit scary as I value my fingers/limbs etc. hence my rather over the top 'self and hasty' warning, I hope no one thought I was belittling their abilities by this. Quote Link to comment Share on other sites More sharing options...
gritineye Posted April 27, 2008 Author Share Posted April 27, 2008 Special award,more like a knight hood,did a similer thing with range rover panhard bush in france the new polybush didnt like the leak from p/steering box and decided to come out on a winding lane by the side of the riverThe wheel wobble caused a few anxious moments and to my amazement i found i could now speak french.The tempory repair was made by me cutting up the leather belt from my trousers.it lasted several wks.This problem arrose again this wk with a forum members car.(no names) it happens with oe but takes longer.Having given up the big trucks a long time ago for boats i am finding this thread very interesting.THANKS We need more real life drama here, Catweazle, can't you feel a new thread coming on? Quote Link to comment Share on other sites More sharing options...
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