1HDT Noise, T/Belt tension loss (1 Viewer)

[Sixhead1]

Hey guys,

First time post here, use this site religiously for any landcruiser info and 8x out of ten usually find what I'm looking for, however not this time round.

I will give background on it, bought vehicle with snapped timing belt, tensioner stud snapped and wrecked the belt, snapped camshaft in two places along with a cam cap. Pulled motor and motor has been put through intensive rebuild since, motor has had most accessory components replaced or rebuilt, new alternator, a/c pump,pulleys, injector pump rebuilt, injectors tested and repaired if required, all new seals gaskets washers etc, new turbo,billet torque converter, more probably forgotten at this stage.

Got vehicle running, idling sweet, oil pressure is good, fuel system bled, no leaks no worries at idle, went to run idle high for new turbo and ran into the terrible noise at 1900-2000rpm, switched off and pulled timing belt cover, found belt went loose, so redid timing belt checked tensioner bought another genuine tensioner rechecked it all, ran vehicle again with no cover on and same thing happens at exact same rpm, switch off and belt is loose as a goose. Since have removed injector pump and checked over, and checked camshaft and clearences reassembled and now I'm here to see if anyone has encountered a similar problem or could offer some help/ideas that may help me resolve my problem, I will attach a video so you can see exactly what's happening.



Thanks All!

 

[mudgudgeon]

Wow, that's scary

Did cam timing stay correct when this happened?

Did the spring on the tensioner get replaced?

Tensioner springs can get stretched out of spec when changing timing belts.

Have you had the rocker cover off?
Check the cam and valve spring buckets are getting properly oiled?

 

[Sixhead1]

Wow, that's scary

Did cam timing stay correct when this happened?

Did the spring on the tensioner get replaced?

Tensioner springs can get stretched out of spec when changing timing belts.

Have you had the rocker cover off?
Check the cam and valve spring buckets are getting properly oiled?

Hey Mudgudeon

Yes cam timing remained correct, certainly not wanting to try it too many more times before it does ha..
Yes to the spring, spring was genuine new and plenty of tension, is a wrestle to get that spring over.
I have removed rocker cover and checked had plenty of oil and even still remnants of assembly lube on few buckets and cam lobes.

Thanks for response.

 

[KaisoCruiser81]

Might be dumb, but are you sure you have the right timing belt? 1HD-T had 92 teeth, 1hd-ft has 105. Not sure how it would even look with the wrong belt, but maybe there's enough tension at lower rpms to hide it.

 

[Sixhead1]

Might be dumb, but are you sure you have the right timing belt? 1HD-T had 92 teeth, 1hd-ft has 105. Not sure how it would even look with the wrong belt, but maybe there's enough tension at lower rpms to hide it.

Hi Kaiso,

Fair question, but yes timing belt is correct for it.

Cheers

 

[mudgudgeon]

I think there's an issue with belt tension. The drive side of the belt should stay basically tight with minimal deflection. It's under tension, its being pulled by the drive pulley on the injection pump.
You can see the tensioner gives up as the load increases with RPM.

If you are 100% the belt, tensioner, spring are all the correct parts, genuine and new, not sure what to suggest.
The spring is a $20-ish part, maybe swap it out?

 

[Sixhead1]

I think there's an issue with belt tension. The drive side of the belt should stay basically tight with minimal deflection. It's under tension, its being pulled by the drive pulley on the injection pump.
You can see the tensioner gives up as the load increases with RPM.

If you are 100% the belt, tensioner, spring are all the correct parts, genuine and new, not sure what to suggest.
The spring is a $20-ish part, maybe swap it out?

Yes the drive side should stay tight, but even when switched off after a short start up the belt goes very loose on the drive side and tight on tensioned side.

The parts all new genuine, and have tried 2x new genuine tensioners, have not tried another spring but that spring is new and very tight to fit, but worth another shot.
Im feeling like something doesn't seem right from the drive side, hence rechecking injector pump, engine rebuilders have assured me drive gears and bearings are fine, but could it be possible they arnt ?

 

[Skter505]

The only way for the drive side to become loose is if you are off a tooth or have the wrong size belt, belt is stretched or wrong pullies. Make sure you are using the correct marks and everything is installed and torqued correctly.

 

[Sixhead1]

The only way for the drive side to become loose is if you are off a tooth or have the wrong size belt, belt is stretched or wrong pullies. Make sure you are using the correct marks and everything is installed and torqued correctly.

I have not long managed to get a hold of original owner today, and I questioned on any noises before the cambelt let go, he's somewhat mechanically minded and mentioned he pulled from an intersection and heard a very similar rattle noise to what you hear in the video. Everything has been torqued to spec and I have full access too autodata which has given me full belt install and removal procedure, always lines up perfectly. I will take some photos or video of it timed tomorrow. Belt has seen about 20minutes of run time since coming out of the box from toyota.
It has got me stumped, and have double checked pretty much all timing components and injector pump condition, I have even trial fitted a dayco timing belt to see if there is a difference.

 

[MUDZLLA]

Tried a new tensioner?

 

[Sixhead1]

Tried a new tensioner?

as stated above yes

 

[Sixhead1]

just an update, have fitted this evening another genuine toyota 94 tooth timing belt kit, new tensioner new cambelt new tensioner spring and checked camshaft and Injector pump bolts torqued, all timed up perfectly, felt like it had a bit more tension (Could've been in my head) ran it up, did a 2000rpm run was sweet as, thought hell yeah problem solved, let it idle for a minute then ran it up again and hit 2000rpm and it did it again rattled and belt tension all over the show! DAMN IT!!! had someone put a bar to the power steering pump to see if he could hear the noise through the pump or drive gears as it happened again at 2000rpm, and he can certainly hear the noise from that area, is it possible to get drive gears to bind up or a vacuum pump and power steering pump to jam up to cause this?

Thanks again !!

 

[Skter505]

How about drive gear timing and injection pump timing? Is it possible your injection pump is too far advanced and you're hearing knock? I'm thinking if everything is correct maybe something like knock is rotating your engine slightly reverse at shutdown and that's moving slack of the belt to the drive side instead of tensioner side. Another thing to check is if all of your dowels and reliefs in the gears are in good shape and not oblong or missing.

Seems like a real strange problem without being next to the car it's hard to help.

 

[mudgudgeon]

Open the video with YouTube, go to settings, run it at 0.25x speed.

There's a bit of a wobble in the pump belt gear, and cam gear that becomes more noticeable is RPM climbs.

You can see the belt flutter, then the tensioner gives up.

I'm wondering if this is enough to make the belt unstable?

How where belt drive gears removed from cam and pump?
When I tore down my 1hd-t, the gear was so tightly wedged onto the taper of the camshaft, I bent the gear pulling it. I had to replace the gear.

 

[mudgudgeon]

Both gears/pulleys are less than $20.

MIght be the next thing to fire parts cannon at.

 

[Sixhead1]

Hey, guys sorry for the reply, I had completely forgotten about my thread, havnt managed to get back to it untill tonight, checked pump timing and was at 1.60mm so I've adjusted it back within spec at around 1.23-1.24 and it has removed the knock at 2000rpm was able to rev out to 2500rpm but still observing belt and at 2000rpm it still flaps about but with no engine noise, so I'm at least onto something there thanks guys! Some minor progress made at least now to figure out what else is upset.