There was a thread a while back where a new belt was tending to walk to one side on the pulleys. The OP tried reversing the new belt, still the same. People recommended trying a different brand of belt (iirc he had fitted a Dayco brand?). The OP did come back, he changed the tensioner mounting bracket and the problem was cured. (iirc, @Slotman had suggested that something might be bent? causing the tensioner to be out of line and affecting the belt run)
Technical First drive and a problem
- Thread starter GBGraham
- Start date
- Replies 54
- Views 1K
Currently reading:
Technical
First drive and a problem
Thanks for this information I obviously missed the post on my search. I am trying to locate a Gates belt locally, the one that's on is a belt manufacturer that I haven't heard of is a Federal Mogul TWR. I will also remove the adjuster and inspect the adjuster in the process.
TRW. And they are a big name.
Federal-Mogul is a leading global supplier of automotive and industrial components that previously acquired TRW’s engine valve and engine components business. Today, both the Federal-Mogul brand and parts of the former TRW aftermarket portfolio fall under the DRiV umbrella, owned by Tenneco.
Key highlights about their connection and current automotive operations include:
TRW Engine Components Acquisition: In 2015, Federal-Mogul acquired TRW's engine valve and components business. This allowed Federal-Mogul to integrate TRW's engine valves, guides, and seats into its powertrain portfolio to improve fuel economy and emissions.
DRiV and Tenneco: In 2018, Tenneco acquired Federal-Mogul. Subsequently, Tenneco created DRiV, a dedicated business line that manages both original equipment (OE) and aftermarket automotive brands.
DRiV | Quality Auto Parts
Current Brand Availability: You can still find parts previously associated with TRW and Federal-Mogul active in the aftermarket. DRiV manages popular brands including MOOG (steering and suspension), Ferodo (brakes), and Champion (ignition components).
Sorry I'm back again, today I fitted the new timing belt, no problems until I started to hand tighten prior to torquing the stud holding the coil of the spring and heyho it wouldn't even start to tighten and the removal found the first 10mm of thread damaged as in bruised/stripped.
I have no idea what the thread in the block is like, I measured the pitch and it's M8 x 1.0. I only have M8 x 1.25 and I have no shanked studs with this 1.0 pitch thread.
I have thought of a few options, the first is to locate a new 1.0 stud to try it and see if it bites, second is to tap out block to M8 x 1.25 and loctite the correct length of threaded rod and use a Nylock, Simmonds or a self lock flange nut to retain the spring. Lastly is the helicoil the thread which is not in the best place to do this and if something goes wrong it could end up being a major issue.
What are the thoughts of you guys, one of my options of maybe a suggestion I haven't thought of?
BTW while I'm on, I'm not at all impressed with the belt tensioner set up, for me very basic and agricultural. I definitely don't like the floppy pulley on the stud until the nut is tightened, they bush the i.d. of the bearing but they don't bush to the stud . . . or am I missing something?
I have no idea what the thread in the block is like, I measured the pitch and it's M8 x 1.0. I only have M8 x 1.25 and I have no shanked studs with this 1.0 pitch thread.
I have thought of a few options, the first is to locate a new 1.0 stud to try it and see if it bites, second is to tap out block to M8 x 1.25 and loctite the correct length of threaded rod and use a Nylock, Simmonds or a self lock flange nut to retain the spring. Lastly is the helicoil the thread which is not in the best place to do this and if something goes wrong it could end up being a major issue.
What are the thoughts of you guys, one of my options of maybe a suggestion I haven't thought of?
BTW while I'm on, I'm not at all impressed with the belt tensioner set up, for me very basic and agricultural. I definitely don't like the floppy pulley on the stud until the nut is tightened, they bush the i.d. of the bearing but they don't bush to the stud . . . or am I missing something?
Do you think the previous owners spent more time polishing the cam covers and less on the engine rebuild?
I don't have any details on your tensioner, perhaps @124BC1 has details, maybe there should be a large stepped washer around the tensioner bearing?
If the stud is good in the block but where a nut goes on I would take out and replace the stud as original if possible so all good, however if it is a bolt thread damaged in the block more of a problem.
I know accessibility is an issue, but I have had good success with this brand.:-https://cpc.farnell.com/recoil/37088/thread-repair-m8-100-pitch-kit/dp/TL24475?gross_price=true&mckv=sshopping_dc%7Cpcrid%7C491022676302%7Ckword%7C%7Cmatch%7C%7Cplid%7C%7Cslid%7C%7Cproduct%7CTL24475%7Cpgrid%7C45804914126%7Cptaid%7Cpla-370407927725%7C&CMP=KNC-GUK-CPC-SHOPPING-945678466-45804914126-TL24475&s_kwcid=AL!5616!3!491022676302!!!network%7D!370407927725!&gad_source=1&gad_campaignid=945678466
I don't have any details on your tensioner, perhaps @124BC1 has details, maybe there should be a large stepped washer around the tensioner bearing?
If the stud is good in the block but where a nut goes on I would take out and replace the stud as original if possible so all good, however if it is a bolt thread damaged in the block more of a problem.
I know accessibility is an issue, but I have had good success with this brand.:-https://cpc.farnell.com/recoil/37088/thread-repair-m8-100-pitch-kit/dp/TL24475?gross_price=true&mckv=sshopping_dc%7Cpcrid%7C491022676302%7Ckword%7C%7Cmatch%7C%7Cplid%7C%7Cslid%7C%7Cproduct%7CTL24475%7Cpgrid%7C45804914126%7Cptaid%7Cpla-370407927725%7C&CMP=KNC-GUK-CPC-SHOPPING-945678466-45804914126-TL24475&s_kwcid=AL!5616!3!491022676302!!!network%7D!370407927725!&gad_source=1&gad_campaignid=945678466
Attachments
Congratulations - you've just managed to find the only 8x1.00mm thread on the entire engine (afaik). 
It shouldn't be a stud, it should be a bolt.
I've checked and RiAuto don't list it but Autoricambi list it in stock. Here's the page:-
(there may be other suppliers or perhaps a good engineering suppliers, idk the bolt length but you could work it out from the components it holds in place and add say 10mm for the length, it's a standard Fiat '80' type bolt which afaik is metric 8.8 grade, so nothing special)
Also shown on the page is a kit of parts for attaching the tensioner to the engine incl. the stepped washer that seems to be missing from your engine:-
The very early engines didn't have a spring loaded tensioner, it was necessary to attach a spring balance to a hole in the tensioner bracket and exert a pull of 60 lbs to set the belt tension, later engines, such as your's has a spring to tension the belt. (the spring end actually goes into the hole that used to be used for attaching the spring balance).
The tensioner is locked in place after belt adjustment by tightening the long stud (10mm) that passes through the tensioner bearing and the bolt with the odd 2 x hex shapes that acts as an abutment for the tensioner spring and the pivot for the tensioner mounting bracket. The 8x1.00mm bolt only holds the tensioner spring in place, in fact, once the belt tension has been set, I reckon that the 8x1.00 mm bolt, its washers and the spring and it's spacer could be removed and left off the engine. (all you'd be doing is reverting to the earlier tensioner arrangement without the spring).
Here's a pic of the tensioner spring mounted on the 8x1.00mm bolt - there's not a lot of room to work on it. (and your twin carb manifold makes access even worse). You might be able to get an 8x1.00 mm tap (if you can find one, it's an odd size) in from the front to clean up the thread.
The stud that passes through the centre of the tensioner bearing/bracket should have a stepped washer fitted (as you surmised, for support) topped by a heavy washer (iirc, c. 6 or 8mm thick) and a Belleville washer (a type of dished spring washer favoured by Fiat, you'll see these in various sizes all over the car), and then a plain nut. Here's a diagram from the Haynes manual showing the tensioner components:-
Here's a pic of the original pulley marks to be aligned when installing a timing belt (I know you have non standard adjustable cam pulleys fitted) but note the auxiliary drive pulley has a timing mark/small hole - I've marked it with a red dot in the approx. position - this is what is mentioned in the text above about setting the aux. drive pulley to 34* from the 12 o'clock position (= approx 3 teeth on the circumference) - this is to prevent the fuel pump drive eccentric on the auxiliary drive shaft from making contact with the big end of no. 2 cyl.
It shouldn't be a stud, it should be a bolt.
I've checked and RiAuto don't list it but Autoricambi list it in stock. Here's the page:-
(there may be other suppliers or perhaps a good engineering suppliers, idk the bolt length but you could work it out from the components it holds in place and add say 10mm for the length, it's a standard Fiat '80' type bolt which afaik is metric 8.8 grade, so nothing special)
Also shown on the page is a kit of parts for attaching the tensioner to the engine incl. the stepped washer that seems to be missing from your engine:-
The very early engines didn't have a spring loaded tensioner, it was necessary to attach a spring balance to a hole in the tensioner bracket and exert a pull of 60 lbs to set the belt tension, later engines, such as your's has a spring to tension the belt. (the spring end actually goes into the hole that used to be used for attaching the spring balance).
The tensioner is locked in place after belt adjustment by tightening the long stud (10mm) that passes through the tensioner bearing and the bolt with the odd 2 x hex shapes that acts as an abutment for the tensioner spring and the pivot for the tensioner mounting bracket. The 8x1.00mm bolt only holds the tensioner spring in place, in fact, once the belt tension has been set, I reckon that the 8x1.00 mm bolt, its washers and the spring and it's spacer could be removed and left off the engine. (all you'd be doing is reverting to the earlier tensioner arrangement without the spring).
Here's a pic of the tensioner spring mounted on the 8x1.00mm bolt - there's not a lot of room to work on it. (and your twin carb manifold makes access even worse). You might be able to get an 8x1.00 mm tap (if you can find one, it's an odd size) in from the front to clean up the thread.
The stud that passes through the centre of the tensioner bearing/bracket should have a stepped washer fitted (as you surmised, for support) topped by a heavy washer (iirc, c. 6 or 8mm thick) and a Belleville washer (a type of dished spring washer favoured by Fiat, you'll see these in various sizes all over the car), and then a plain nut. Here's a diagram from the Haynes manual showing the tensioner components:-
Here's a pic of the original pulley marks to be aligned when installing a timing belt (I know you have non standard adjustable cam pulleys fitted) but note the auxiliary drive pulley has a timing mark/small hole - I've marked it with a red dot in the approx. position - this is what is mentioned in the text above about setting the aux. drive pulley to 34* from the 12 o'clock position (= approx 3 teeth on the circumference) - this is to prevent the fuel pump drive eccentric on the auxiliary drive shaft from making contact with the big end of no. 2 cyl.
Thanks once more for all your info, greatly appreciated. Yes and the congrats of the only M8x1.0 is marked Fiat 80, should I feel lucky or get a prize.
I think with your info it would be prudent for me to tension the belt and then remove the components of item 4 in the exploded view that you supplied so nothing care occur at a later date.
The auxiliary pulley is only driving the oil pump now, dizzy is on the camshaft and the fuel pump is electric.
.I think with your info it would be prudent for me to tension the belt and then remove the components of item 4 in the exploded view that you supplied so nothing care occur at a later date.
The auxiliary pulley is only driving the oil pump now, dizzy is on the camshaft and the fuel pump is electric.
That was a bit bitchy #bugsymike but you could be quite possibly correct
I definitely wouldn't of wasted any of my life doing the same.The engine is a 1608cc so it will be older than the 1973 car and I would imagine in all those years all sorts of hidden abuse can and probably will raise it's head.
Thanks for the link but the last thing I want to do is helicoil in situ, it's at the wrong side of the engine for me as I have had wrist fusion to the left hand. To be confident I would need to remove the bonnet and radiator and I have decided from reading #124BC1 post I will remove the tensioner once the belt is tensioned.
The issue I feel is a bit off about is the movement of the pulley on the stud, go into the Video about a minute . . . . I'm sure even Fiat engineers could have made a better effort
Do you think the washers and spacer in @124BC1 details, above are missing in your tensioner pulley issue re access movement as I mentioned in #26?That was a bit bitchy #bugsymike but you could be quite possibly correct
The engine is a 1608cc so it will be older than the 1973 car and I would imagine in all those years all sorts of hidden abuse can and probably will raise it's head.
Thanks for the link but the last thing I want to do is helicoil in situ, it's at the wrong side of the engine for me as I have had wrist fusion to the left hand. To be confident I would need to remove the bonnet and radiator and I have decided from reading #124BC1 post I will remove the tensioner once the belt is tensioned.
Re the "bitchy comment"
as an apprentice we had a customer with a Morris 1000 convertible, he was a member if the Insitute of Advance Motorists and clearly loved his car, the coil, radiator and rocker cover had been burnished so you could see your face in them, however I was less impressed when after driving the car half a mile from his home to the garage and pointing out to my boss that the clutch was slipping, the owner then accused me of burning the clutch out, which I certainly did not, and also we noted that the chassis was so weak that on jacking the car up it was impossible to close the doors due to body flexing.To me a vehicle should be in good mechanical condition first and foremost, the ability to see your face in the rocker/cam cover is not a high priority.
Last edited:
You should know as well as I do that people don't always do things the same way as ones self but sometimes it's difficult to apportion blame, I'm not particularly annoyed, well maybe a little peed offAs an apprentice we had a customer with a Morris 1000 convertible, he was a member if the Insitute of Advance Motorists and clearly loved his car, the coil, radiator and rocker cover had been burnished so you could see your face in them, however I was less impressed when after driving the car half a mile from his home to the garage and pointing out to my boss that the clutch was slipping, the owner then accused me of burning the clutch out, which I certainly did not, and also we noted that the chassis was so weak that on jacking the car up it was impossible to close the doors due to body flexing.
To me a vehicle should be in good mechanical condition first and foremost, the ability to see your face in the rocker/cam cover is not a high priority.
I knew when I bought it there would be problems and issues and I am prepared for such things but I feel I'm getting near the end.
Any thoughts on the spacers and washers at tensioner bearing?You should know as well as I do that people don't always do things the same way as ones self but sometimes it's difficult to apportion blame, I'm not particularly annoyed, well maybe a little peed off
I knew when I bought it there would be problems and issues and I am prepared for such things but I feel I'm getting near the end.
For me I see it generally as a pisspoticle design and I suspect this may be the reason why the belt was running a tad off line.
I wondered if it was a combination of missing locating stepped spacers at the tensioner pulley and aftermarket cam pulleys and belt.For me I see it generally as a pisspoticle design and I suspect this may be the reason why the belt was running a tad off line.
Were you able to compare it with the picture that @124BC1 had at #27 of the pulley/tensioner and stepped spacers.
I have seen a similar design on 2.5/2.8 Sofim engines and where mechanics unfamiliar with it caused premature cambelt failure and destroyed the engine bending conrods etc.
Incidentally I have rebuilt several of those engines with no issues.
No, everything is there that is supposed to beI wondered if it was a combination of missing locating stepped spacers at the tensioner pulley and aftermarket cam pulleys and belt.
Were you able to compare it with the picture that @124BC1 had at #27 of the pulley/tensioner and stepped spacers.
I have seen a similar design on 2.5/2.8 Sofim engines and where mechanics unfamiliar with it caused premature cambelt failure and destroyed the engine bending conrods etc.
Incidentally I have rebuilt several of those engines with no issues.
And how does that happen
I have seen a similar design on 2.5/2.8 Sofim engines and where mechanics unfamiliar with it caused premature cambelt failure and destroyed the engine bending conrods etc.
Operator error usuallyNo, everything is there that is supposed to be
And how does that happen
I have seen a similar design on 2.5/2.8 Sofim engines and where mechanics unfamiliar with it caused premature cambelt failure and destroyed the engine bending conrods etc.
Trouble is you are coming back to someone else's work, something I hate.
Yes and how many times have you asked have you touched anything and from one memory it went something like "I just pulled on to my drive and and the next time I went to it the car wouldn't start" and after checking everything without finding a reason except the HT lead sequence was mixed up!Operator error usually
Trouble is you are coming back to someone else's work, something I hate.
We used to go out on breakdowns Monday morning, car will not start, husband gone to work , we look at car and ask wife has any one touched it, answer no!
Open bonnet , new spark plugs , new contact points wrongly assembled and going straight to earth!
Ask wife again and she sheepishly replies husband may have done a "service" on car, thinking, after all it is so easy if the "oily rag" down at the garage can do it then a highly intelligent person like her husband would have no problem!!!
Last edited:
A prize? Mmm.Thanks once more for all your info, greatly appreciated. Yes and the congrats of the only M8x1.0 is marked Fiat 80, should I feel lucky or get a prize
I think with your info it would be prudent for me to tension the belt and then remove the components of item 4 in the exploded view that you supplied so nothing care occur at a later date.
The auxiliary pulley is only driving the oil pump now, dizzy is on the camshaft and the fuel pump is electric.
I know, how about a free membership of *I.F.R.A.?
You're welcome.
Yes, probably best to remove the components of item 4 if you can't sort out the 8x1.00mm thread to your satisfaction - you wouldn't want anything becoming detached and caught up in the timing belt.
Despite your distributor being exhaust cam driven and the fitting of an electric fuel pump, the auxiliary drive shaft still has an eccentric on its end to drive the originally fitted mechanical fuel pump - it's this eccentric that can collide with the con rod big end of no. 2 cylinder - that's why I pointed out the correct positioning of the auxiliary drive pulley when fitting a timing belt to avoid this possibility.
{Iirc, this fuel pump eccentric was omitted on the 2 litre engines as they had all gone over to electrical fuel pumps by this time.}
Here's some pics of the aux. drive shaft, firstly showing the eccentric (arrowed in red) and secondly showing a modified aux. drive shaft with the eccentric removed.
* In case you were wondering...
IFRA stands for International Fiat Renovators Association
(P.S. I made this up
)
Last edited:
