Technical Twincam timing belt
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Technical Twincam timing belt
I'm going to do my belt and tensioner bearing, water pump, all the coolant hoses, and what ever my radiator needs, have some of the parts but need to order a couple of things first, will likely have a couple of questions as well so hope this thread keeps going!
Iirc, your Spider has an Auto, trans?
I came across something while perusing one of the 124 Spider parts w/sites that I thought I'd mention to you to keep in mind if you're ordering parts.
It seems that the rear transmission mounting (rubber/metal support) is different on the Auto trans. version of the 124 compared to the normal 5 speed manual trans. type. (it's also unfortunately, dearer
).Its also interesting to reflect that on the Spider this job is DiY, costs sub £50. If I took a VW Golf to a dealer a timing belt change is £600-800 and the water pump seems to have become an integral part of changing the timing belt!
If your Golf has one of the petrol TSI engines (2017> in 1.0, 1.2, 1.5 and 1.6 litre), that price for a timing belt change is probably a bargain, as the book time is 4 hrs, the special tools needed are very pricey and it's one of the most complicated belt changes I've seen - lots of fine adjustments using the special tools, including (possibly) the use of an inclinometer that can measure -0.1*up to +2.3* down....
I've just been reading an article on this timing belt job in Car Mechanic's magazine, February 2025 issue, here's a pic of the special tools needed:-
Older models of VW had timing belts that were some of the easiest to change, but not anymore it seems.
Incidentally, many of the timing belt manufacturers have technical installation guides on their websites as do some of the suppliers of special tools/kits needed to change a belt, so you can check beforehand just what is involved before you commit yourself by buying the belt kit and tools.
Of course, entrusting the job to a dealership/independent workshop is not an absolute guarantee of correct installation...
EDIT:-
I've just checked the cost of the above mentioned special tool kits used in the magazine article
Laser set 8900, as shown above = £1489.49
Laser 9133 = £202.97 may also be needed depending on engine
Laser set 9155 = £ 1633.73 is a similar set to set 8900.
The Company's advice is to provide your car's VIN to your tool supplier to ensure you get the correct toolkit for your engine.
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Hi! Although I have not yet started disassembling my motor for the timing belt change I think I understand everything except for one...did I misunderstand that the crankshaft outer belt pulley that drives my alternator can be left on? I don't have a great view of things currently but it looks like to remove the lower metal timing cover the outer pulley needs to come off? I'm really hoping not to have to and risk bumping the timing mark indexing...thank you in advance for your wisdom! Terry
If you need to remive the crank (to change the oil seal etc) then the pulley needs to be removed.
For info if you haven’t got one?
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There is also a fee Fiat 131 manuals on line which use the same engine and transmission in some models
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I have the big yellow spider service manual, and a crappy Chiltons manual and they both mention removing the outer crankshaft belt pulley that drives the water pump and alternator, and then the lower metal cover to get to the timing belt..it will be great if I don't have to...when it was mentioned the crank pulley doesn't need to be removed I thought perhaps I confused the crank pulley that drives the timing belt , with the outer belt pulley thinking the belt pulley doesn't need to come off but I can't see how that lower metal cover can come off with the outer belt pulley that drives the water pump and alternator still on....this is because I can't get a good look in that area. And my inexperience having never done the task before , I will be removing the radiator beforehand so then I can get a better view...going to give my back a rest as ive been feeling a bit of sciatica coming on, seems to happen this time of year and i dont want to get a full blown case of it, timing kit still coming in the mail anyway...thank you!
, I will be removing the radiator beforehand so then I can get a better view...going to give my back a rest as ive been feeling a bit of sciatica coming on, seems to happen this time of year and i dont want to get a full blown case of it, timing kit still coming in the mail anyway...thank you!Here you go, try these, might need some coloured pencils to highlight the different components on the sectioned view of the engine!I have the big yellow spider service manual, and a crappy Chiltons manual and they both mention removing the outer crankshaft belt pulley that drives the water pump and alternator, and then the lower metal cover to get to the timing belt..it will be great if I don't have to...when it was mentioned the crank pulley doesn't need to be removed I thought perhaps I confused the crank pulley that drives the timing belt , with the outer belt pulley thinking the belt pulley doesn't need to come off but I can't see how that lower metal cover can come off with the outer belt pulley that drives the water pump and alternator still on....this is because I can't get a good look in that area. And my inexperience having never done the task before
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Thank you for the info! Perhaps I should have used the term "V" belt, (that spins the water pump and alternator), in front of the timing belt covers..it still sounds like that pulley needs to come off to get the lower cover off, please excuse my inexperience! It will all become clear once I'm doing it..
Yes I have the older style 38mm with right hand threads
If you are referring to the timing belt cover (usually plastic, sometimes aluminium) you dont need to remove the crank pulley to remove the timing belt cover and change the timing belt
That might explain my confusion..I'm under the impression there are 2 covers, the yellow plastic one, and a second metal one behind the crankshaft V belt pulley underneath the plastic one that needs to be removed...I need to stop asking dumb questions and wait until the front of the motor is off so I know more about what I'm talking about...thanks everyone for putting up with me! Terry
A good photo would be useful too.
Be careful about doing this, it's always best to use the correct manual for your specific car.
And while there is a lot of carry-over/interchangeability of parts between the various models of 124 Spider, there are also a lot of changes e.g. Fiat changed the cyl. bore spacing at some point during the model's life, which affects things a lot in terms of parts but admittedly not much in terms of working on these cars. On cars as old as the 124 is now, it's always possible that a later, or maybe even an earlier engine has been installed at some point in your car, so it would be advisable to correctly identify exactly which engine you're working on before ordering any parts.
Be especially careful about working on the manuals transmissions, Fiat re-designed these incorporating needle thrust bearing and in some applications a different style of driveshaft (on sliding splines where it exited the transmission)( I well remember this change because I had to replace c. 50 trans. tail-housings and complete driveshafts as a result of a warranty recall).
Now you're really going to confuse @Slotman as these pictures and descriptions are for the early 1438cc engine and show/explain how to remove the centrifugal oil filter that was fitted on the crankshaft 'nose' on this early model. His pulley doesn't have this filter, just a big 38mm nut with a r/h thread...
Stop worrying, replacing the timing belt on a 124 twin cam is one of the easiest timing belt jobs possible., doesn't even need any special tools. It's hard to get it wrong if you follow the steps in the manual. Don't worry about losing any timing marks or indexing of things, the marks are easy to find, they're not going to disappear, things can be easily reset.-------------------------------------------------------------------....this is because I can't get a good look in that area. And my inexperience having never done the task before
Don't worry about 'bending the valves'. If you remove the spark plugs (to make turning the crankshaft easier) and only turn the crankshaft slowly using a wrench (or socket and ratchet if you prefer), you are highly unlikely to bend any valves even you make a complete mess of the valve timing and accidentally bump a valve with a piston. You can't make a mess of the timing if you have all of your timing marks set-up as per the timing diagram in all the 'shop manuals.
The 'Golden Rule' with any timing belt job, is before trying to start the engine, you always turn the engine 2 compete turns by hand slowly using a wrench, then check your timing marks are still correctly aligned and that the belt tension is still correct.
Removing the radiator is a good idea for improved access and proper sight of what you're doing.
Given your back problem, you might give consideration to also removing the hood (bonnet) for even better access and visibility. It's not very difficult. One trick I use when removing hinged panels is to drill 1/8 inch holes through the part of the hinges that are bolted to the body - doing this means that I, working alone, can very quickly re-align the panel as per original when re-fitting it using a couple of the same 1/8 inch drill bits. In some applications, the hinge pins can be simply pulled/knocked out to avoid any unbolting of hinges - I did this on some of my cars' hoods, removed the hinge pins and replaced them with bolts and self-locking nuts (or pins and 'R' clips if you prefer).
I'm not aware of any metal plate in the vicinity of the crank belt pulley.
You likely will have to remove the little ignition timing plate located at about the 10 o' clock position to the crank pulley to remove the timing belt and fit the new belt, but this timing plate is afaik not adjustable and just bolts back on.
For clarification, when I say 'pulley' I mean the part that has V grooves in it to drive the fan belts, if I say timing gear, I mean the toothed 'sprocket' that drives the toothed timing belt. The pulley and the timing gear are separate parts both secured with that big 38mm nut, both are on a keyway on the crankshaft 'nose', so if they have to be removed e.g. to replace the front crank oil seal, they can both be refitted in their original positions due to the keyway, no need to mark either before removal, they'll only fit back on in the one (correct) position.
