How Tight Should The Cam Belt Be ?

[Mr2dude]

3SGTE engine.

There's about 11mm vertical travel between the 2 cam shafts when pressed down.

The belt will slide laterally a little on the cam cogs with out any leverage devices, not enough to pull it off, but a screwdriver lever might (dont want to find out really !).

Should it be so tight that it would not have any side ways movement on the cogs, unless a lot of leverage is applied ? And should the vertical travel between the cams limited to only a couple of mm, when pressed down ?

Or is it about right how it is ?

Cheers

Steve

[Bibbs]

Look in the stickies .. there is details about all the belt tensions etc ..

I think www.megeboost.co.uk/bgb will also have it ..

[Mr2dude]

I did have a look through the stickies and i have read the Repair manual PDF also.

Didnt find anything about a "finger in the air" guide to how tight it should be though.

I guess when the engines turning there is more tension in it anyway, just wanted to make sure it wasnt too slack before I put the cover back on that it was ok, and i dont wanna over tighten it either.

[Bibbs]

wouldn't the cam belt tensioner keep it within spec?

[Mr2dude]

aha, the tensioner actually tensions it according to spec, ok, didnt know that hehe, i'm a bit of a nuub on the engine bay atm, learning as I go.

i thought the tensioner was a static thing you could tighten too little or too less, from what you said its spring driven.

probably is ok how it is then

cheers

steve

[Bibbs]

Thought the tensioner was on a swinging arm .. DON'T TAKE THIS FOR GOSPEL .. I've never even looked at my belt ..

[daktari]

As a rule of thumb, you should be able with a little bit of effort to twist the belt in the middle of the longest run through 90 degrees.

I think the tensioner is clamped after tension is set. Not sure cos i`ve not done mine myself. :)

[Mr2dude]

sounds about right then, i could prolly twist it about 45' across the top (between the cams) which is not the longest run.

was a little worried that it could slide laterally at all on any of the cogs with finger effort, i guess that would be too tight though.

cheers

steve

[Jesus]

Did you replace your tensioner when doing the belt?

I didn't at first, and the belt was no where near tight enough. Leaving it over night to settle, it was pretty clear that there wasn't enough tension in the morning.

I couldn't tell you how much movement there was, but we played it safe and bought a tensioner from Mr. T for about £32.

New tensioner on, and it worked a treat.

The 'old' tensioner had a pin hole in the seal, and was very slowly leaking hydraulic fluid.

I'm surprised you didn't have to take the old tensioner off, and with a 1 tonne arbour press (or vice if you're careful) have to fully compress it and put the 'grenade' pin back in.

This is when my tensioner got a hole.

How did you put the belt back on with the tensioner fully extended???

Anyhoo... play it safe. Put a new tensioner on. £32 for peace of mind... and no, my belt didn't then freely move laterally on the pulleys.

[Uncle Bob]

As Jesus has said, the automatic tensioner has several fitting procedures when replacing the timing and setting it up, if you have just squeezed the belt back on, you stand every chance of the belt snapping or jumping a tooth :( .

[Mr2dude]

I'm no where near skilled enough to change a cam belt !

I've just bought the car, and the top timing cover was in the boot. This was because is a practically rebuilt engine, and the previous owner left the cover off so he could watch the belt for the first couple of K miles.

I was about to but the cover back on, and thats when I became a little suspicios the belt might not be tight enough.

I'll pop it into a garage I think !

Cheers

Steve

[Mr2dude]

There's a receipt in the documentation for a new Tensioner from Fensports bought in July last year, so its a bit wierd if its gone already, unless it was damaged on installation i suppose. Anyway gonna get it checked.

[stefan1]

belt tension should be 1.5kilo on the ecentric cam adjuster you can make the adjuster by using a lenth of flat steel bar about 200mm with two spigots on the end to fit the adjuster cam and hang the weight of that. thus pulling the cam to the right tension. hope this helps but the tension weight is just a guide so ask a toyota garage for the exact weight.

[urotsukidoji_badassdemon]

Ok, the cambelt tensioner is auto tensioning, and boy is it a VERY strong spring inside there. You need alarge vice to psuh the tensioner rod inside in order to ' reset ' the tensioner for replacing the cambelt. I hve actually seen it done when mine was changed. My car is only an N/A, but it's the same as the T's anyway I reckon, theres very little vertical movement of the belt between the cam pulley tops. There's 2 bolts I think which hold the tensioner onto the engine itself. and these bolts DO NOT hold the tensioner ' at a certain angle to tensionise the cambelt', cos it's auto tensioning!! Theresasuperdooper really strong srping inside it which pushes the tensioner pulley out to keep the belt nice and tight. And the belt isn't sposed to move at all without some exertion to the side of it.