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Scammell Explorer fixes and workarounds


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In reply to Andy and croc, here are a couple of shots of the modification I did to the selector housing after it cracked nearly right off, this method means it is not important to re-weld the alloy casting although it makes a better job if you do. You need to reduce the thickness of the gate bracket on the coupling side to allow the use of the original bolts, and to allow room for the coupling as it is very tight in there.

 

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notice R/H gate support reduced in thickness, bolt through casing inserted from inside to avoid fouling gear lever

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How common is this problem? mine is intact and of the other Explorers I looked at only one was broken (and held in place by bits of rope) the one I posted in the gallery thread didn't look broken but had the extra stays, that Explorer was a very late RAF one so maybe this was a preventative modification?

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How common is this problem? quote]

I know of one Explorer unit which broke - a good condition vehicle too. These gearchanges stick out a bit and get a lot of vibration, it is surprising how much movement there is with the gearbox jumping and kicking around at times on Constructors, I don't know about Explorers.

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This thread has reminded me of when I worked on Explorers whilst they were in Army service. The gearbox has to be shimmed and aligned spot on to the engine, because the Metalstik coupling does not allow for much misalignment, the rubber can melt if trying too much out of line. It was on a rare occasion that you had one in where the gear lever was a blur when driving, due to vibration, guess this is why they break sometimes.

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I have heard of a few that have had this problem, I think Richard has put his finger on it, there is a lot hanging on four small studs. The front gearbox bearing on mine had been assembled incorrectly (shims on the outside of the support brackets!) at some point prior to disposal and the rubber inside it had worn away causing metal to metal contact. This caused a lot of vibration and and yes it was a bit blurry!

 

Here is another take on reinforcing a welded one, this time with a plate sandwiched between and strapped to the housing.

 

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I've been wondering why Scammells would have built in such a weak point and have come to the conclusion that the gate was an afterthought, the six speed box was and is an unusual box being "sequential" in operation (ahead of it's time!) so there must have been a lot of very miffed operators and wrecked boxes until a gate was added. The attached photo seems to bear this theory out as it is a Rigid Six of around 1935-39 which used the Gardner 6LW & six speed box, (the rear mounting casting appears the same and the PTO is blanked off) there is no gate. Interestingly what looks like universal joints used here were later replaced by rubber couplings, but I may be wrong here it's hard to see too well!

 

The gate and supports were most likely designed by a different hand hence the massive bolts used compared to the very small ones designed to just hold the gear lever ball, unless of course someone knows different

 

 

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there is no gate.

 

?? :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.

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If that operator didn't have the patience towork out how to unbolt the gate he certainly wouldn't have been bothered to learn the skill to change gear without it, or even with it! :rolleyes:

 

I'm sure that once you have got to grips with it smooth changes are possible without the gate................anyone care to demonstrate?

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If this is a common problem and one thats bound to happen sooner or later I wondered if the Scammell owners as a group using their combined buying power and the internet would either find an outfit to make new castings in aluminum which seems wrong or go to something stronger like steel and solve the problem properly once and for all ?

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Hi Bernard , you have documented your love of the Meadows petrol engine and I know Forcefull now has a Cummins Diesel and that you had several Meadows fail ! I was wondering if the same fault occured or was it several different failures and do you think anything would have helped possibly to prevent them occuring ? I am hoping to keep my Daisy Meadows powered if possible so any tips will be much appreciated ! Andy F DSC02897.jpg

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I admire your wish to keep it petrol if you can Andy, the sound needs to be preserved as well as the look, and even the smell of an old vehicle as it is so evocative!

 

I kept mine petrol as long as my endurance would let me for the above reasons but in the end gave up , amongst the problems were,

 

magneto:1st one packed up, re-conditioned one packed up (on the biggest hill on the A21, pushed it up into a pub car park with my 110 which was on an A frame, lot of tyre smoke!) modified a mag to act as distributor, coil overheated, points burnt, various condensers failed etc etc. all at different times.:-D Magnetos don't seem to last, maybe because of the positioning and heat, I have a patent cure for this problem though. And I still have the last reconditioned one which has only done about 30 miles, should any one be interested.

 

Head gaskets: 1st engine had a weeping one so I attempted to remove the head, this was stuck fast due to stud/head corrosion, after getting it to move a tiny bit I found I had bent it and wrecked the studds (long pole in inlet port!) so decided to get another engine.

 

Fitted next engine only to find it had a slight out of balance feel, did all I know to cure it, never did. Then the exhaust manifold cracked when leaving W+P show, lots of steam, towed home!

 

Cylinder heads: after the manifold incident I got hold of some NOS head gaskets and took off the heads (easy this time, lucky me!) to realign them so the manifolds weren't stressed, only to find the little port that runs from the exhaust port to the inlet manifold hot-spot had corroded through due to a MOD mod that blocked off one pipe to each head so trapping corrosive soot inside and causing a lot of pitting. Explained the wet black stuff out of the exhaust every startup.

 

Bought two more complete engines, one turned out to be a dud, the other looked to be the best one as it was untouched, nothing had been undone since it was painted, and it was perfect except that every top ring was broken, the top ring should have a bigger gap than the second, seems someone didn't know! result all bores badly scored.:rofl:

 

Every engine I had would run fine until I needed to full power like up hill where a change down was called for, then it would misfire all the way to the top, only just making it, when I changed to Cummins I found out the reason, I had to cut the the fuel pickup pipe and inside was a badly cast elbow on the top resulting in a tiny hole for the fuel to pass through, and a snot of brass hanging down in the way as well! so I didn't have a hope of finding it, and it could never pass enough fuel.

 

All cylinder heads I have seen have had the port corrosion problem to some degree, all engines have been full of oil thick oil sludge and need flushing, and the sumps and meshes cleaned.

 

Well you did ask!:)

Edited by gritineye
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Thanks for taking the time to list your problems Bernard ! You have obviously had a lot of grief ! We done for persevering for so long ! My engine has had second hand heads fitted by the previous owner and I bought two N.O.S heads of Ebay as well as two N.O.S. head gaskets from a chap up north who had previously had all sorts of ex-military vehicles ! The previous owner had fitted a points and condenser ignition system and I hope to keep that system as I don't have any experience of magneto's at present ! It is my intention to do a couple of rallies a year but my main aim is to preserve the old girl as best I can ! It really is a labour of love ! Thanks again for the reply ! Andy F.

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There were more problems that I have thought of since but enough is enough!

 

A couple of points re oil,

Be sure to check that the oil feed pipes to the heads are not blocked with sludge, and oil is squirting out between the rockers.

The crankshaft has large bore holes in the big end throws, this traps sludge and metal particles (centrifugal filter) which can in extreme cases cause oil starvation as it builds up past the holes, not usually a problem on average mileage engines, until you put detergent oil in one that has been run on straight non detergent stuff, as this loosens it all up.

Other wise the bottom end should last you forever

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Croc has a Leyland 680 powerplus diesel donk in his Explorer, i can honestly say i have never seen ANY engine start faster from cold, its amazing, sounds sweet and runs smooth, nice sized alternative if you want to ditch the Meadows! ive got some video of it running, which i will get onto HMVF TV soon.

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Croc has a Leyland 680 powerplus diesel donk in his Explorer, i can honestly say i have never seen ANY engine start faster from cold, its amazing, sounds sweet and runs smooth, nice sized alternative if you want to ditch the Meadows! ive got some video of it running, which i will get onto HMVF TV soon.
Look forward to watching the Vid Adam ! Bit of off roading video in those beautifull mountains would brighten my day no end also ! Andy F.
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Here we go with Gearbox rebuild photos then,

 

 

 

My Explorer had a vibration problem right from the day I first drove it, other owners said "Oh they're all like that mate, it's the prop-shaft!" It was a bit slack so in went a new prop, (both flanges were straight) still the same. After a bit someone suggested it might be the front mounting rubbers, although they looked OK a slight bit of lift was there

This was because some pratt had not tightened the two nuts enough allowing metal to metal contact, so I got hold of some good s/h ones and fitted them.

 

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Guess what, the vibration was now unbearable so a look inside the gearbox was called for.

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! Second was the nut was undone on the top counter shaft, although strangely the keep-ring was still in place.

 

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Third clue was the front layshaft keep-ring lying in the front of the casing.

 

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As the rear keep-ring had been cut off to save the trouble of drilling more than a tad into the shaft, the fitter must have had a grudge against some one or some organization, or poor defenseless vehicle (how low can you get!) or was just lazy, or was only issued with a hand drill!

 

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Spot the difference.

 

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Then I found a broken circlip in the sump, turned out to be from the first reverse cluster, which was floating about.

 

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The consequence of all this was that the top counter shaft was able to oscillate back and forth (blimey this is MV porn) and so giving both ends a good bashing, the rear bearing retaining cap has two studs projecting through and these had dug corresponding holes in the nut, presumably by the nut repeatedly coming to the end of it's thread, a good source if vibration if ever I saw one. Just like a hammer drill !

 

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The inside of the primary shaft got a battering as well.

 

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Well, lucky old me, it couldn't get worse could it?

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