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Member postings for Trev67

Here is a list of all the postings Trev67 has made in our forums. Click on a thread name to jump to the thread.

Thread: Car problems
21/06/2017 23:38:17

Hi Neil

Some of this has been covered by others, but this is what I suggest.

Sitting in the car engine off, does the clutch pedal feel normal?

Engine off, does the gear selection feel normal, as in everything still connected?

Now start the engine, depress clutch and select gears, particularly reverse, after not having first selected any other gear. If this is ok then clutch is clearing ok.

Now try selecting gears, engine running, but without depressing the clutch. If it is exactly the same as with the clutch depressed, i.e. no undue resistance on the forward gears, and no crunching on reverse, then clutch lining has probably broken up, or similar total clutch failure.

If there is some resistance when selecting the forward gears, but if you lean on synchromesh you can get it to select, and in reverse it crunches, then it suggests that there is at least some drive through the clutch. If this is the case, I'd look at the driveshafts, check for telltale twisted or split gaiters. If you can get an assistant to engage a gear and try and pull away, check the driveshafts, you may see one spinning. If the is no obvious driveshaft fault, then it probably best to remove them and check for stripped splines.

I've definitely had a Jag x type which is basically a Mondeo, loose drive because the spline on the inner end of a driveshaft stripped.

This may not be relevant, but if the RH driveshaft has a bolted flange on the inner end, rather than pushing straight into the gearbox, it may be the same as the ford galaxy gearbox. If it is the bit that goes into the gearbox is a short stub shaft, and it is quite common for the spline on that to strip. To remove it after the driveshaft is removed, there is a socket head bolt recessed in the middle of it that needs removing, and then it pulls out.

hope this helps

good luck


Thread: Holding drill bits
13/12/2016 14:08:52


I do it quite often using an ER collet in the mill. I'm sure I read somewhere that this was one of the benefits of using ER collets for holding drills as you get a more rigid setup, and don't necessarily need to use a centre drill first. It also helps if you have restricted height between quill and table. It may or may not be wrong but it works for me, wouldn't do it out of choice with a drill chuck though.

Thread: Lathe backplate chuck help
06/12/2016 15:38:28

Hi Christine

Just looked at your photo, you are actually measuring three threads there, so very close to 12mm would make it 4mm pitch.

Hope this helps


Thread: 14mm spanner
28/10/2016 14:07:56


14mm is common on a lot of jap cars, I think the thread is M10 but fine pitch, they also use 12mm heads on M8 bolts instead of 13mm. Also nowadays you get a lot of 15, 16, 18 mm heads that you never used to. Also come across 7 and 9 mm hex on bleed nipples and 9mm 12point bolts on a vw clutch. Along with all the various torx, ribe and other fixings, there's always something to spend money on!


Thread: Tooth belt suppliers
10/06/2016 15:49:12

I'd all but given up getting the belt in the uk, but decided to try Steve's link to Brammers catalogue. Checked it and found the right size.

The phone number was for a place in Manchester, when I rang they asked where I was and put me through to the nearest branch which is Guildford. Very helpful chap called Steve answered, I told what I wanted and left my phone number. About an hour later Steve phoned me back, he could get the belt, so I ordered it, paid by card and it should be in Monday. All very straightforward and painless.

The cost of the belt, carriage and VAT was £16, which is only a little cheaper than getting from the U.S. but a lot quicker.

So happy to recommend Brammers

10/06/2016 13:01:12

Thanks for the replies.

Brammer are getting me one and their Guildford branch is not far away, thanks for the link Steve.

Thanks for the description of the belt cutting machine Nigel, I knew the belts were made as very wide belts and sliced, just wasn't quite sure how.

Just for information, it seems that some suppliers have the belt cutting machine and can cut custom widths, or they can be ordered to almost any width.

Thanks again


09/06/2016 20:21:20


I'm trying to fix a lawnmower for the wife's Uncle and I need a drive belt.

It's an old Mounfield, but it seems that the toothed belt that drives the rear roller is no longer available. I've scoured the internet for a supplier but the only one I've found is in America, postage being about three times the cost of the belt.

The belt is a 384 - 8M - 12, this translates to 384 mm long, 8mm pitch and 12mm wide. It has half round profile teeth and there are 48 of them.

My questions are:

Does anybody know of a possible supplier ?

It does seem that a 20mm wide belt is more likely to be available in the UK, has anybody tried cutting a tooth belt down and if so how did you do it?

Many Thanks


Thread: Automotive Automatic Gearbox
01/04/2016 09:31:29


Why do you ask?

It depends on the type of auto box:

The traditional borg warner type with a torque converter must briefly disengage during gear changes to prevent lock up, but in practical terms they do not. The underlying mechanicals are the same whether they are electronically controlled or not.

The cvt type use a variable pulley system, with either some type of clutch or a torque convertor to disengage it for when the car is stationary.

The double clutch boxes like the VAG DSG use two clutches so they have very quick gear changes, so they are only disengaged for a fraction of a second, unless you confuse them by kicking it down when it thinks the next change will be up, or if it kicks down two gears, then the computer gets all confused and it feels like you loose drive altogether, while it sorts itself out.

The automatic operated manual boxes, use normal clutch and gearbox, but with electric or hydraulic actuators, the feel like they disengage for ages during gear changes.

hope this helps

Thread: Thread major diameter
18/03/2016 22:42:20

Interestingly looking at the thread tables for the Mikes thread the maximum major diameter for an external thread is 0.625, and the minimum major diameter for the internal thread is 0.625, so both parts could be made within tolerance but not fit together!

Thread: What Did You Do Today (2016)
18/03/2016 22:33:06

I had the microsoft phonecall played him along a bit then told him I used Linux, this didn't put him off, he still wanted me to go to my PC, so I told him he'd have to wait half an hour until I got home as I was in the car, he then hung up! was it something I said?

The accident ones I ask if I bumped my head, they get all excited when they think I had an accident until I tell them that I must have bumped my head as I don't remember anything about an accident.

I don't know why so many diesel cars have low mounted air intakes, I used to be a bit paranoid with my pug 406 as the intake was low down behind the bumper. Heard about a 306 that inhaled a load of water on the motorway, the resulting hydraulic lock shattered the engine block and dumped all the fluids on the road, causing a pile up and a big court case about who was going to pay.

Range Rovers don't like getting wet either, the starters and alternators aren't designed to go in the water, but seeing as most people only use them in town, it's cheaper for Land Rover to replace some under warranty than to engineer the cars properly in the first place. The suppliers don't mind because they only supply to Land Rover's spec. and it means the sell many 1000's more alternators!

Thread: Thread major diameter
18/03/2016 21:55:24

Hi Mike

I'm not an expert on screwcutting, but I have done a bit. This post got me thinking, so I looked on the web for some reference to the thread data for UNEF and found this site **LINK** so this is what I am referring to.

Firstly not wishing to be pedantic but some of the terms in your first post are a little confusing and not quite correct:

The major diameter is the overall size over the peaks of the thread crests.

The minor diameter is the diameter at the bottom of the thread troughs, or the core diameter.

What you have described as the major and minor diameters are actually the maximum and minimum tolerances for the major diameter, namely 0.625 and 0.6178.

Again the pitch diameters you state are not major and minor, the are the maximum and minimum tolerances.

As regards cutting the thread with a single point tool as opposed to a full form insert, the important thing to remember is that you cannot get the crests the correct shape, and they don't do anything anyway, so you want to start with the major diameter undersized. I think I recall 10% of the thread form. The fundamental triangle height for this thread is 36 thou, so 10% off would bring you down to the lower tolerance for the major diameter, namely 0.6178 ish.

Your cutting tool, obviously needs to be ground to 60 degrees as you have already stated, it also needs a bit of a radius on the tip. The size of the radius is not super critical, but it must no be too big or it will leave to the minor diameter oversize and the thread could bind on it's matting component. The nearer the tool is to having a pointed tip, the deeper you have to cut the thread. This should be obvious from the picture of the thread form.**LINK**

To actually cut the thread, turn your stock to 0.618 even a little less should be ok. Cut the thread using your preferred method. The overall depth of cut will be approx 20 thou ( the difference between the basic major diameter and the basic minor diameter is approx 45 thou). Obviously if setting the topslide over this will need calculating to get the correct amount to feed the topslide. The overall depth of cut will vary depending on the starting major diameter and the radius of the tool tip. The more pointed the tip of the tool the deeper the thread will have to be cut to get the correct size on the flanks.

To get to final size either use the matting component as a gauge, or in you case if you have the correct wires to measure the pitch diameter. measure the it and when it is between 0.5979 and 0.5949 it should be done.

There will probably be a bit of burr on the crests which I would clean up with a file and just take the sharp edges off and it should be good to go.

hope this is helpful


Thread: Long-term battery charging
14/03/2016 12:45:21

Thanks John,

I thought that might be the answer!

What is the best way to store NiMH batteries when not in use, they do seem to self discharge quicker than Nicads.



14/03/2016 11:17:23


It never ceases to amaze me the wealth of knowledge on this forum, thank you to all those contributing it's is very interesting.

I don't wish to hijack the thread, but it does seem to have evolved from the original lead acid battery question.

I have a number of NiMH drill battery packs, they where fine when being used regularly, but since being stored unused for some months, a number of them whilst appearing to charge ok, have little or no power. Is there a way to revive these?


Thread: Brain Teaser
05/03/2016 08:41:11

This might help, or not!


Thread: Jan Ridders Coffee Cup Stirling
04/03/2016 09:47:15

Congratulations Dave,

well done for persisting with it. A few finishing touches and it's a very attractive little engine. It's amazinging how much interest you'll get if you demo it to people, they all think it's magic.


04/03/2016 09:47:14

Congratulations Dave,

well done for persisting with it. A few finishing touches and it's a very attractive little engine. It's amazinging how much interest you'll get if you demo it to people, they all think it's magic.


03/03/2016 10:29:42

Hi Dave,

I am by no means an expert, but I have made one of these and it runs. I used available materials for mine, so I have a steel piston, silicone sealant on the top and bottom plates, and the spacers are made stainless, as I didn't have any plastic available. So those factors shouldn't stop it running.

I think your problem is the displacer.

As you have made the displacer piston thinner have you made corresponding adjustments to the length of the piston rod and or the connecting rod to bring the top face of the displacer piston as close as possible to the under side of the top plate at tdc.

Have you made the displacer cylinder length such that the displacer piston almost touches the bottom plate at bdc.

If you have too much dead space, then I think this would stop the engine running.

Other factors that will stop it running:

Air leaks, I tested mine by removing the power piston and sitting the engine in water covering just over the top plate. I sealed a bit of tube into the power cylinder with blu tak and blew down it, any leak is obvious from the bubbles. you don't need much of a leak to stop it working.

It helps if you achieve reasonable balance, I took the bottom plate off, then give it a spin, a bit of blu tak will do to get it fairly close.

Obviously the whole thing needs to be as free running as possible, but it seems like yours is ok, also the power piston needs to be a good fit, but it sounds as if you are happy that yours is ok.

If it were mine I would:

Take the displacer cylinder apart and check how close the diplacer comes to the top plate.

Put the tube on and check how close the underside of the diplacer comes to the bottom plate, obviously making allowance for the groove in the bottom plate.

These measurements need to be pretty small, probably 1mm or less. If not before doing any re engineering, get some better material for the displacer piston, either polystyrene or balsa.

If it is any consolation I was talking to Martin Gregory on the SMEE stand at ME exhibition, and when I told him I'd built one of these Jan Ridders engines and it ran, his comment was that i was the only person he'd come across that had made one work. Apparantly the proportions are not quite right, but I can't quite remember what is wrong. Martins own engine will run on the heat from your hand, the one I made from the Jan Ridders design needs a good cup of boiling water to work. But that aside it definately can be made to work. No disrespect mean to Jan Ridders he has done some great work designing engines and giving them away free.

Hope this helps

Good luck


Thread: Advice sought
03/03/2016 09:12:37


Does the car have an external key lock,(it may be hidden), if so have you tried this?

The external key lock may not have a mechanical linkage on this car, so it still may not work with a flat battery.

If the car is truly deadlocked, then the interior locks are disabled, so you will not be able to use a coat hanger on them.

Your options would seem to be:

Jack up the nearside front of the car and support safely. It may help to remove the front wheel. Find the main positive battery cable that goes to the starter motor( you may have remove the undertray, but if you're lucky it may be accesable through the wheelarch) If you get this far connect a pair of jump leads positive to the main terminal on the starter and negative to a bare bit of metal on the engine or gearbox. Then connect these to a good battery or a battery charger, this will probably set the alarm off, but you should be able to cancel this with the key fob and hopefully open the doors.

The other option is to hook the bonnet release inside the car with a coat hanger or similar, but I'm not sure how easy this is on the Saab. If trying to do this it helps to pry the top of the door out as much as you dare, a couple of wooden wedges help and don't really cause any damage.

It may be possible to reach the bonnet release cable under the car, but these are usually pretty inaccesable, made this way on purpose for security reasons.

Obviously there are any number of destructive options, such as breaking a window, but it would be best to try non destructive first.

Hope this helps

Good luck


Thread: Wet Belt
21/02/2016 09:08:38

The Ford Ecoboost does indeed have a wet cambelt, it has a designed life of 160k miles. The belt is not designed to be replaced anyway, so it is a throwaway unit. This is all part of the effort to reduce emmissions, tiny engines, with all sorts off little tweaks to reduce internal losses, the wet cambelt being one of them, I think there is a Fiat or Nissan that even has an on demand oil pump!

The belt vs chain debate always makes me laugh, as the general perception is that belts are high maintenance and chains maintenance free. There are a good number of chain drive engines in which the chains probably have a shorter life than most belts, but are a lot more labour intensive to replace. Notable exambles being the small GM petrols that always rattle, the GM / Fiat 1.3 diesel, any chain drive VAG also some Mercedes. BMW messed up their 2 litre diesel when they redesigned it and put the chain on the back, but believe it or not it is actually now easier to replace, as long as you do it before it breaks and destroys the engine.

Anyway there seems to be plenty on things on cars nowadays that will make them uneconomic to repair, besides throwaway engines. Apparantly Renaults have a designed life of 5 years, after which they go in the shredder to be recycled!



06/02/2016 17:54:20

Hi Martin

Bore: 11/2"

Stroke: 2 1/8"

wheels: 4 3/8" on the tread

Grate length: 5 5/8" ( distance between firebox plates)

Grate Width: 2 3/4"

Firebox Height 5 3/4" at the front, 4 5/8" at the back ( these are the dimensions of the plates, the grate sits inside slightly, reducing these a little)

Firehole : 1 1/2"

tubes: 13 x 7/16 20swg

Superheater flue: 1 x 1 1/8" 16swg

Tube length: 11 3/162

working pressure: on the drawing 110psi , (but I don't know if people run them this high?)

Safety valve: 2 x 3/16" bore

Hope this helps


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