I want to change the Cambelt on my UT. Bought the belt and tensioner in preparation. Now how long will it take and is it a complete arse to do on this engine and confined space? Should I also change the alternator belt too while I'm in there?
Technical Cambelt on a UT
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Technical Cambelt on a UT
Oops - I thought you'd sold the Uno Turbo!
I think it might make a difference if it's the Mk2 rather than the Mk1. Simply because, when I changed the cambelt on a 1372cc Tipo, it was considerably harder than on a 1301cc Uno, because the crankshaft pulley has to come off (the oil seal casting has an extra 'wall' to protect the cambelt, meaning there's no way to get the belt out with the pulley in place.)
It is a reasonably easy cambelt to change, compared with newer cars. Not as easy as the 999cc FIRE (the easiest of them all), though.
The alternator belt has to come off, so yes, it would be worth replacing if there is any glazing/cracks, i.e. if it looks anything less than 'new'.
There is probably a little sliding window in the back of the cambelt cover (again, assuming it's the same as the Tipo's 1372cc engine). With the cover slid fully open, a peg forms the timing mark - it aligns with a notch between two teeth on the back of the cam pulley. It may of course take two turns of the engine before this mark lines up - careful
Also look for the flywheel marks through the bellhousing window. You want the leftmost mark for TDC.
Then the cambelt cover comes off, and I think you'd be wise to mark the auxiliary drive pulley (the front pulley) because (unless I'm very much mistaken) this drives the distributor on the Mk2 Turbo engine?
And you then get to possibly the trickiest part of the job - slackening off the alternator. I think on the Turbo you may have to do this from under the car - very little access on top.
To slacken the large crank pulley nut, you will need a giant socket (I have a 36mm and I'm pretty sure yours will be this size). I usually use an air impact gun, but on a few occasions when that hasn't worked, I use the 'whack' technique. Fit a long bar to the socket and leave it hanging in front of the engine near the floor, unplug the ignition coil, make sure the gearbox is in neutral, and flick the starter.
That's the hardest parts of the job over - now you need the special FIAT tool for setting the tension of the new belt... hahahaha... how about two M5 bolts in the holes of the tensioner and a thick Phillips screwdriver threaded across them to act as a lever?
Please, please, please turn the engine over at least two complete turns after you have fitted and tensioned the belt... don't even think about starting the engine until you have re-checked the belt tension several times...
I once had some hassles with cam timing (kept getting it wrong on my 128's 1498cc engine), repositioned and retensioned the belt and tried to start the engine - it didn't start, but when I released the key there was a 'clunk'. Many hours later the engine did start but ran roughly - I had bent one inlet valve. That head removal was an extremely time-consuming alternative to the option of double-checking the belt tension...
I have found that with these engines, it is easy to over-tension the cambelt. People use the '90 degree' rule of thumb (which says it should be just possible to turn the belt through 90 degrees along its longest run), but I personally feel this is too tight in most cases, because you get a whining noise and possibly other strange 'skirfing' noises at idle.
What I do is start with the '90 degree' tension, then slacken slightly in several small adjustments until the strange noises go away. I base this decreased tension on the comparison with the old spring-loaded tensioners on 128s and very early Unos... they leave the belt with relatively little tension.
Now please note that I take no responsibility for bent valves, engine damage... so please feel confident that your tension is sufficient and if not confident, then leave it tighter rather than looser.
On the engines where I've had to remove the pulley, I can do the job in one hour. Plus an extra hour if I decide to replace the camshaft seal (evidence that this is required appears as excessive oil on the inside of the belt cover). You might think that's a lot of extra time, but it's mainly because of the cleaning and the difficulty in removing/retorquing the cam pulley.
-Alex
I think it might make a difference if it's the Mk2 rather than the Mk1. Simply because, when I changed the cambelt on a 1372cc Tipo, it was considerably harder than on a 1301cc Uno, because the crankshaft pulley has to come off (the oil seal casting has an extra 'wall' to protect the cambelt, meaning there's no way to get the belt out with the pulley in place.)
It is a reasonably easy cambelt to change, compared with newer cars. Not as easy as the 999cc FIRE (the easiest of them all), though.
The alternator belt has to come off, so yes, it would be worth replacing if there is any glazing/cracks, i.e. if it looks anything less than 'new'.
There is probably a little sliding window in the back of the cambelt cover (again, assuming it's the same as the Tipo's 1372cc engine). With the cover slid fully open, a peg forms the timing mark - it aligns with a notch between two teeth on the back of the cam pulley. It may of course take two turns of the engine before this mark lines up - careful
Also look for the flywheel marks through the bellhousing window. You want the leftmost mark for TDC.Then the cambelt cover comes off, and I think you'd be wise to mark the auxiliary drive pulley (the front pulley) because (unless I'm very much mistaken
) this drives the distributor on the Mk2 Turbo engine?And you then get to possibly the trickiest part of the job - slackening off the alternator. I think on the Turbo you may have to do this from under the car - very little access on top.
To slacken the large crank pulley nut, you will need a giant socket (I have a 36mm and I'm pretty sure yours will be this size). I usually use an air impact gun, but on a few occasions when that hasn't worked, I use the 'whack' technique. Fit a long bar to the socket and leave it hanging in front of the engine near the floor, unplug the ignition coil, make sure the gearbox is in neutral, and flick the starter.
That's the hardest parts of the job over - now you need the special FIAT tool for setting the tension of the new belt... hahahaha... how about two M5 bolts in the holes of the tensioner and a thick Phillips screwdriver threaded across them to act as a lever?
Please, please, please turn the engine over at least two complete turns after you have fitted and tensioned the belt... don't even think about starting the engine until you have re-checked the belt tension several times...
I once had some hassles with cam timing (kept getting it wrong on my 128's 1498cc engine), repositioned and retensioned the belt and tried to start the engine - it didn't start, but when I released the key there was a 'clunk'. Many hours later the engine did start but ran roughly - I had bent one inlet valve. That head removal was an extremely time-consuming alternative to the option of double-checking the belt tension...
I have found that with these engines, it is easy to over-tension the cambelt. People use the '90 degree' rule of thumb (which says it should be just possible to turn the belt through 90 degrees along its longest run), but I personally feel this is too tight in most cases, because you get a whining noise and possibly other strange 'skirfing' noises at idle.
What I do is start with the '90 degree' tension, then slacken slightly in several small adjustments until the strange noises go away. I base this decreased tension on the comparison with the old spring-loaded tensioners on 128s and very early Unos... they leave the belt with relatively little tension.
Now please note that I take no responsibility for bent valves, engine damage... so please feel confident that your tension is sufficient and if not confident, then leave it tighter rather than looser.
On the engines where I've had to remove the pulley, I can do the job in one hour. Plus an extra hour if I decide to replace the camshaft seal (evidence that this is required appears as excessive oil on the inside of the belt cover). You might think that's a lot of extra time, but it's mainly because of the cleaning and the difficulty in removing/retorquing the cam pulley.
-Alex
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Just realised that my post above has come out sounding very much like a string of commands... I suppose it's just my writing style, I don't mean to ask you to do anything... so please disregard if you already know what you're going to do
Cheers!
-Alex
Cheers!
-Alex
OP
OP
Cheers for the advice, I knew you'd come up with the goods Alex and No I don't really know what I'm doing when it comes to Cambelts!
I had sold the car but the young chap that bought it (19) said he couldn't get insurance so pulled out the deal after a bit of hassle.
Doesn't sound that difficult just a bit tricky and time consuming. I'm tempted to take it to my local Fiat specialist and get them to do the value clearances at the same time. Might just be easier, less hassle and safer. Trouble is it'll probably cost quite a bit.
And don't worry if I have a go and cause some damage I won't blame you!
and No I don't really know what I'm doing when it comes to Cambelts!I had sold the car but the young chap that bought it (19) said he couldn't get insurance so pulled out the deal after a bit of hassle.
Doesn't sound that difficult just a bit tricky and time consuming. I'm tempted to take it to my local Fiat specialist and get them to do the value clearances at the same time. Might just be easier, less hassle and safer. Trouble is it'll probably cost quite a bit.
And don't worry if I have a go and cause some damage I won't blame you!
Well, at least the insurance is a valid excuse (didn't we find out with Bushboy's yellow Mk2 that insurance was much more expensive even than with a Mk1 Turbo?)
Time-consuming... only took me one hour, remember
I reckon you should still do the cambelt yourself. Valve clearances - you should check them yourself I reckon, as it's unlikely that they need changing. Feeler gauges are cheap!
I tend to agree that if the valve clearances do need adjustment (and, they only need adjustment if less than 0.35mm or greater than 0.50mm, practically)... then it probably is best to get the specialist to do them, as you need shims and some sort of special tool (can be improvised at a pinch).
Personally I still find adjusting valves to be a pain, it usually takes me several tries, and at least three hours... but then I do go for +/-0.025mm, and specialists usually only get 'near enough'! (Correct clearances: inlet 0.40mm +/- 0.05mm, exhaust 0.45mm +/- 0.05mm). I would say it rates as a 'five spanners' Haynes job whereas changing the cambelt would be a three-spanner job in my opinion.
Cheers,
-Alex
Time-consuming... only took me one hour, remember
I reckon you should still do the cambelt yourself. Valve clearances - you should check them yourself I reckon, as it's unlikely that they need changing. Feeler gauges are cheap!
I tend to agree that if the valve clearances do need adjustment (and, they only need adjustment if less than 0.35mm or greater than 0.50mm, practically
)... then it probably is best to get the specialist to do them, as you need shims and some sort of special tool (can be improvised at a pinch).Personally I still find adjusting valves to be a pain, it usually takes me several tries, and at least three hours... but then I do go for +/-0.025mm, and specialists usually only get 'near enough'! (Correct clearances: inlet 0.40mm +/- 0.05mm, exhaust 0.45mm +/- 0.05mm). I would say it rates as a 'five spanners' Haynes job
whereas changing the cambelt would be a three-spanner job in my opinion.Cheers,
-Alex
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OP
OP
Yeah the buyer said that his usual insurer declined to insure and the best quote he could find was £2000. Hopefully he'll check he can get insurance before committing to buy a car.
Got the feeler guages and some shims off the 60s I scrapped so maybe I'll check myself. I doesn't sound that tappety. I think the special tool is probably the pain. Why don't Haynes include a template in the manual to make one?
I tend to mess around when working on my car. A 1 hour job is likely to turn into a day long job! Right well I'll probably do it myself and see how I get on.
Got the feeler guages and some shims off the 60s I scrapped so maybe I'll check myself. I doesn't sound that tappety. I think the special tool is probably the pain. Why don't Haynes include a template in the manual to make one?
I tend to mess around when working on my car. A 1 hour job is likely to turn into a day long job! Right well I'll probably do it myself and see how I get on.
alexGS said:Well, at least the insurance is a valid excuse (didn't we find out with Bushboy's yellow Mk2 that insurance was much more expensive even than with a Mk1 Turbo?)
Time-consuming... only took me one hour, remember
I reckon you should still do the cambelt yourself. Valve clearances - you should check them yourself I reckon, as it's unlikely that they need changing. Feeler gauges are cheap!
I tend to agree that if the valve clearances do need adjustment (and, they only need adjustment if less than 0.35mm or greater than 0.50mm, practically
Personally I still find adjusting valves to be a pain, it usually takes me several tries, and at least three hours... but then I do go for +/-0.025mm, and specialists usually only get 'near enough'! (Correct clearances: inlet 0.40mm +/- 0.05mm, exhaust 0.45mm +/- 0.05mm). I would say it rates as a 'five spanners' Haynes job
Cheers,
-Alex
Of course, the special tool is only used for changing the shims - clearance measurements are simple to do - you know this, but just to clarify for anyone else that finds this thread in the future
The old Haynes manual for the 128 dealt with the same problem by showing you how to improvise if you don't have the special tool (part no. 60421).
You can pry down the tappet with a large flat-blade screwdriver. It helps if the shaft of the screwdriver is slightly curved, because you need to get under the 'depressed' cam lobe.
With the tappet pried down, you need a second screwdriver to hold it down by the rim of the tappet, which is only a few mm wide. Basically, you take a small screwdriver (e.g. Phillips) with a shaft about 5mm diameter, bend it to more or less 90 degrees, then bend the tip another 90 degrees so that it can rest against the inside back of the cambox. Or, you could make up a crescent-shaped tool from a chunk of steel, which would be almost as good as the correct FIAT tool.
Then, with the tappet held down, you can turn the camshaft so the cam lobe is out of the way, and use a strong magnetic pickup tool to remove the shim (strong compact magnets were probably not available back in 1973 when the Haynes manual was written, so they suggest compressed air or fiddling around with a tiny screwdriver.)
Using the correct tool is slightly different: the tool does two tappets at once, with the cams pointing away from the tappets. There is no need to rotate the camshaft when the tool is inserted, and indeed I broke one tool doing this (I was dealing with a reground camshaft that left insufficient clearance to get the tool into place unless the camshaft was rotated while trying...)
There is of course the easier no-tools way - measure all the clearances, then take the cambox off completely and change all the shims at once. Or, I found you can get away with removing the other shims and fitting one at a time temporarily, so you can refit the cambox and measure the clearance. It's quite easy to take the cambox off when you have the belt removed already. Take care to slacken the bolts evenly to reduce risk of distortion. One of the bolts is 'outside' the others, near the pulley, and is easily missed. Be aware also that the bolts are three different lengths.
Just remember not to turn the engine over with the cambelt removed and the cambox in place... before bolting down the cambox, it's safest to turn the engine to 90 degrees before top-dead-centre, so that all the pistons are halfway down the bores.
In your case I doubt that many of the valves will need any adjustment, so the cambox-removal way is probably the way to go - but you will probably need a micrometer to measure the shims (and their replacements) accurately. Though, these days, digital vernier calipers would probably suffice!
I never trust the thin paper gasket under the cambox - I always augment it with some 'Loctite 518 Master Gasket' red goo - non-silicone, sets anaerobically. This will increase the clearances by a small amount, but not enough to worry about. So probably a good opportunity to clear up any oil leaks if you have them, too.
Wasn't it great not having to do this job on your Stilo? (hydraulic tappets)
Cheers,
-Alex
The old Haynes manual for the 128 dealt with the same problem by showing you how to improvise if you don't have the special tool (part no. 60421).
You can pry down the tappet with a large flat-blade screwdriver. It helps if the shaft of the screwdriver is slightly curved, because you need to get under the 'depressed' cam lobe.
With the tappet pried down, you need a second screwdriver to hold it down by the rim of the tappet, which is only a few mm wide. Basically, you take a small screwdriver (e.g. Phillips) with a shaft about 5mm diameter, bend it to more or less 90 degrees, then bend the tip another 90 degrees so that it can rest against the inside back of the cambox. Or, you could make up a crescent-shaped tool from a chunk of steel, which would be almost as good as the correct FIAT tool.
Then, with the tappet held down, you can turn the camshaft so the cam lobe is out of the way, and use a strong magnetic pickup tool to remove the shim (strong compact magnets were probably not available back in 1973 when the Haynes manual was written, so they suggest compressed air or fiddling around with a tiny screwdriver.)
Using the correct tool is slightly different: the tool does two tappets at once, with the cams pointing away from the tappets. There is no need to rotate the camshaft when the tool is inserted, and indeed I broke one tool doing this (I was dealing with a reground camshaft that left insufficient clearance to get the tool into place unless the camshaft was rotated while trying...)
There is of course the easier no-tools way - measure all the clearances, then take the cambox off completely and change all the shims at once. Or, I found you can get away with removing the other shims and fitting one at a time temporarily, so you can refit the cambox and measure the clearance. It's quite easy to take the cambox off when you have the belt removed already. Take care to slacken the bolts evenly to reduce risk of distortion. One of the bolts is 'outside' the others, near the pulley, and is easily missed. Be aware also that the bolts are three different lengths.
Just remember not to turn the engine over with the cambelt removed and the cambox in place... before bolting down the cambox, it's safest to turn the engine to 90 degrees before top-dead-centre, so that all the pistons are halfway down the bores.
In your case I doubt that many of the valves will need any adjustment, so the cambox-removal way is probably the way to go - but you will probably need a micrometer to measure the shims (and their replacements) accurately. Though, these days, digital vernier calipers would probably suffice!
I never trust the thin paper gasket under the cambox - I always augment it with some 'Loctite 518 Master Gasket' red goo - non-silicone, sets anaerobically. This will increase the clearances by a small amount, but not enough to worry about. So probably a good opportunity to clear up any oil leaks if you have them, too.
Wasn't it great not having to do this job on your Stilo? (hydraulic tappets)
Cheers,
-Alex
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