Belt tensioner / nevo equivilent / bearing

[TooF]

ok lads...

ive got a pickle. my SC belt tensioner exploded the other day. the bearing is a little collapsed as the photos below indicate

I need either... the part number of the bearing used in the nevo tensioner iirc it contains 6008 as the number.. i obviously cant read it as who knows where the seals and hence the number are currently.. somewhere up the putty rd i suspect.

My other option is to fashion up another idler. i was looking at a 4age timing belt idler and thinking it looked pretty suitable but im just worried about max speed of the bearing.. which im sure is what killed this one.

in terms of a replacement idler i need something with a max OD of 72mm with an ID to go over the bolt of 10mm and needs to be suitable for constant operating speed of around 10,000rpm with a peak of around 20,000rpm

i dont know what the 4ag timing belt tensioner will handle but i doubt that much. any suggestions ? ive heard thrown around down the grape vine a tensioner from a ford windsor 5L is of suitable dimensions ?

im not looking to buy second hand or scab a few quid i just am looking for a solution that works. im guessing that if i just go and buy another 6008?(number) bearing for the nevo pully.. thats if i can even get the outer race out of the pulley inner .. then it'll have the same speed limitations.

suggestions ?

[hemi twofifteen turbo]

your best bet is to take the bits down to a bearing shop. one where they know their stuff and see if they have a HD replacement bearing.

[TooF]

yeah im just looking up skf now and they have one rated to 32,000rpm but thats the same bearing that has just muched itself to bits


oh and for reference from measuing it up looks like the bearing code is 6300-Z* for the 32k unit.

[Mathew]

looking at your pictures it looks like the bearing has been running very hot and also very dry. ie: no grease I suggest that you ask for a high temp bearing and double steel seals. Once you do this just check every so often when adjusting by loosening the belt and feel by hand!
Cheers Matt

[Mathew]

Also if the outer of the bearing is very difficult to remove from the pulley one trick is to run a small weld around the inside centre of the bearing outer when this cools and contracts it will come out easily.

Cheers Matt

[Adsport]

daewoo lanos main idler pulley

[TooF]

yeah but is the bearing thats in the daewoo idler going to be suited to anything near 20,000rpm ?

[TooF]

just for reference ive done some chasing up on sourcing a bearing.

6300-2ZC3 is the suited bearing it has larger clearances between the balls and the races and is rated at 32,000rpm and *should* do the trick.

[JBs]

I need either... the part number of the bearing used in the nevo tensioner iirc it contains 6008 as the number.. i obviously cant read it as who knows where the seals and hence the number are currently.. somewhere up the putty rd i suspect.

Again glad to hear you didn't lose an eye mate, just a quick question, I didn't get a Nevo tensioner pulley when I bought mine? Is it possible an aftermarket tensioner would do the job?

[inertia]

perhaps contact John@Nevo, he has always been helpful.

Otherwise I have seen people use spare timing belt idlers, reversed.

[TooF]

jb: you didnt get a new tensioner as you used a 165mm pulley which can still fit with the factory tensioner. however the 175 or in my case 180 dosent even come close to fitting with the factory tensioner

infact my pulley/tensioner needed modifications to fit my crnak pulley in place.


i have spoken to John in the past and yes he has been very helpful but in believe he is currently overseas and i really need an answer pronto. looks like ive found the solution after speaking to the bearing man with that 6300-2xc3. i told him the application and the speeds about 10k constant and 20k peak. and given the temp of the engine bay he thinks this is the best pick.

tthe thing i like about the timing belt tensioner is that its a double row bearing (or at least looks to be) where this is only a single row. given the ammount of pressure on the bearing also as a result of the ammount of belt tensiona double row would be nice..

that said i dont need it to last forever, one, now im aware its a weak point ill just keep a spare bearing and inspect/replace at service time (the high speed bearing is only $10)

and to boot all the SC gear is about to be pulled and replaced with a turbo so im not stressed.

[Mathew]

There is a double row deep groove ball bearing (4202 ATN9), but this bearing has an injection moulded glass fibre cage (not apprropriate) and also internal diameter is 15 millimetres so it would need a bush or similar.

[Mathew]

Only other option is make a new pulley with as large a bearing as possible that would reduce the actual rotational speed of the individual balls in the bearing.
Cheers Matt

[TooF]

a larger pulley is pretty much out of the question given size constraints.. althogh yo ucould make one such that the pulley itself is pretty muhc just a thin sleeve over the outer cage of the bearing... or the pulley IS the outer cage of the bearing.

make a bush with the ID say 50mm of the bearing and the 10mm ID of the spindle. press it in and have a step at the back to prevent it fouling. then the outer race of the bearing cage would be the actualy pulley surface... hmm i like this idea... illl look into what bearings are avaliable.

hmm i like that idea ill look into it.

[Mathew]

Where abouts are you in NSW, I live in Greystanes and have a small workshop in my garage with a lathe and mill - could possible give you a hand if needed!

cheers Matt