1HD-FT timing belt replacement interval (1 Viewer)

[DaneDK]

I have been trying to find out which replacement intervals apply for the timing belt of a 1HD-FT (24-valve).
Apparently it is not stated in the FSM, or at least I cannot find it.

From what I understand, the replacement intervals can differ from region to region, so I am after the European data.

Does anyone know some corner of the internet, where this data can be found?

Probably I could try a local Toyota dealer, but sometimes these old engines are not their core capabilities.

Thanks

 

[IanB]

I would assume the same 100,000kms as the 1HD-T. You’ll get a dash light when it’s due.

 

[Dork]

From the HDFT engine FSM that I was able to find. I wouldn't see any reason why it would be different anywhere else.

 

[DaneDK]

Thanks for the replies. I appreciate it.
I saw this "hint" in the FSM too but was not sure if this in fact is the specified service interval for my region - but you are probably right that it is the same for all regions then.
Also normally the manafacturers would specify for example 100.000 km or 5 years or similar.
I just think that it is weird that it is not specified clearly under service requirements chapter in the FSM and only as a "hint" in a sub-chapter.

But 100K sounds realistic

 

[IanB]

Thanks for the replies. I appreciate it.
I saw this "hint" in the FSM too but was not sure if this in fact is the specified service interval for my region - but you are probably right that it is the same for all regions then.
Also normally the manafacturers would specify for example 100.000 km or 5 years or similar.
I just think that it is weird that it is not specified clearly under service requirements chapter in the FSM and only as a "hint" in a sub-chapter.

But 100K sounds realistic

The “hint” confirms the dash light interval, actual service interval won’t deviate from that. Most engines, the timing belt deals with the valve timing, on these engines it’s just the injection pump timing so that probably has something to do with the mileage only interval.

 

[DaneDK]

Probably why the 1HD-FTE has a 150K timing belt service interval with it's electronically controlled injection timing I guess.

 

[mudgudgeon]

Timing belt has no impact on IP timing. it drives the camshaft, not the IP.

With the timing belt, if in doubt, change it out.
A failure can be catastrophic for the engine, but even the wear on the timing belt rubber teeth can change valve timing by a few degrees.
They are cheap, and relatively easy to change.

 

[IanB]

Timing belt has no impact on IP timing. it drives the camshaft, not the IP.

With the timing belt, if in doubt, change it out.
A failure can be catastrophic for the engine, but even the wear on the timing belt rubber teeth can change valve timing by a few degrees.
They are cheap, and relatively easy to change.

Well s***, got mixed up, thanks for clarifying.

 

[pasquinel]

From the HDFT engine FSM that I was able to find. I wouldn't see any reason why it would be different anywhere else.

Do you know where I might find this manual? Thanks!

 

[Dusten]

Do you know where I might find this manual? Thanks!

FSM - Toyota 1HD-FT Engine Repair Manual - Publication Number RM437E (pdf)

Toyota 1HD-FT Engine Repair Manual - Publication Number RM437E (pdf) Jan 1995 factory diesel repair manual

forum.ih8mud.com

 

[pasquinel]

FSM - Toyota 1HD-FT Engine Repair Manual - Publication Number RM437E (pdf)

Toyota 1HD-FT Engine Repair Manual - Publication Number RM437E (pdf) Jan 1995 factory diesel repair manual

forum.ih8mud.com

So much thanks!

 

[Dave 2000]

A point here, I have the different 1HDT engine, the timing belt should be done at 62,000 miles and there is a reminder light on the left of the dashboard, and as mentioned it DOES drive the cam and a breakage will cost to say the least!

Some notes:

When resetting the belt change mileage it is very easy to break the reset button, ask me how I know!!

And whilst the 90,000 mile change is listed in the book 1HD-FTE, look at the type of miles that is. 90,000 miles is 90,000 miles assuming you are driving on the motorway most of the time, but what about a 1 or even half an hours traffic jam once ot more per week? Your sitting with the engine idling and the AC on, the engine is still running but the trip is not going around soooooo.

EDIT: Post corrected re mileage on timing belt for 1HDT engine corrected to 62,000 miles, but the 1HD-FTE is 90,000 miles.

Regards

Dave

 

[pasquinel]

A point here, I have the different 1HDT engine, the timing belt should be done at 80,000 miles and there is a reminder light on the left of the dashboard, and as mentioned it DOES drive the cam and a breakage will cost to say the least!

Some notes:

When resetting the belt change mileage it is very easy to break the reset button, ask me how I know!!

And whilst the 80,000 mile change is listed in the book, look at the type of miles that is. 80,000 miles is 80,000 miles assuming you are driving on the motorway most of the time, but what about a 1 or even half an hours traffic jam once ot more per week? Your sitting with the engine idling and the AC on, the engine is still running but the trip is not going around soooooo.

Regards

Dave

So actually happens when a belt breaks?

Also curious, when turning motor manually, what should it feel like? Is the resistance variable or consistent? If the timing happened to be off, what would you feel?

 

[jellis]

I remember a thread on here discussing timing belts, apparently Toyota made an across the board change on later model engines to a much longer change interval but I don't exactly recall why.

@mudgudgeon I just did my timing belt and it definitely routes to the IP, however that IP is actually DRIVEN by a gear isn't it? And the belt just ensures it's in proper timing with the camshaft?

Also does ANYONE know why the timing belt change procedure (at least in the 1HDT manual) has you remove the IP pulley? There is absolutely no purpose to this whatsoever so I didn't do it, it has you remove it and then put it back on.

 

[Dave 2000]

So actually happens when a belt breaks?

Also curious, when turning motor manually, what should it feel like? Is the resistance variable or consistent? If the timing happened to be off, what would you feel?

The crankshaft drives various things via gears, power steering, vacuum pump and of course the fuel pump, which in turn is connect to the camshaft. If the belt breaks the crankshaft continues to rotate for a few seconds as the engine comes to a stop, the pistons will hit any valves that are open and often even partially open, this will entail a complete top end overhaul, new valves and more often than not guides as they will have some wear, if you are really unlucky a piece of valve (or pieces) will damage one or more of the injectors.

Resistance will vary as each piston comes up on compression stroke resistance increases, and as the piston goes over TDC the resistance reduces and then another piston starts to rise and the process repeats.

I remember a thread on here discussing timing belts, apparently Toyota made an across the board change on later model engines to a much longer change interval but I don't exactly recall why.

@mudgudgeon I just did my timing belt and it definitely routes to the IP, however that IP is actually DRIVEN by a gear isn't it? And the belt just ensures it's in proper timing with the camshaft?

Also does ANYONE know why the timing belt change procedure (at least in the 1HDT manual) has you remove the IP pulley? There is absolutely no purpose to this whatsoever so I didn't do it, it has you remove it and then put it back on.

I am not sure why the procedure was changed, the reason for being able to move the injection pump pulley, and on some versions the camshaft pulley is to maintain correct cam/pump/crank timing, this is to allow for small differences in the manufacturing process of the timing belt, if the belt was a little longer for example then camshaft would in fact run 'a little late' if that make sense. Pretty much every modern vehicle uses this system now, the camshaft is locked in relation to the pump/crankshaft and the belt is fitted with the camshaft pulley loosened from the actual camshaft, that is there is no woodruff key, the camshaft pulley to camshaft bolt holes are slotted, again allowing for variations in the belt manufacturing process. If you just fitted the belt and did not have the IP pulley loose then there is a distinct possibility the camshaft timing is slightly out.

Years ago when I was building performance engines it was not unusual to use offset woodruff keys to get the camshaft timing spot on, it could be the difference of as much as 10 BHP.

Stay safe,

Regards

Dave

 

[mudgudgeon]

I remember a thread on here discussing timing belts, apparently Toyota made an across the board change on later model engines to a much longer change interval but I don't exactly recall why.

@mudgudgeon I just did my timing belt and it definitely routes to the IP, however that IP is actually DRIVEN by a gear isn't it? And the belt just ensures it's in proper timing with the camshaft?

Also does ANYONE know why the timing belt change procedure (at least in the 1HDT manual) has you remove the IP pulley? There is absolutely no purpose to this whatsoever so I didn't do it, it has you remove it and then put it back on.

I would stick to the earlier FSM service interval of 100k km (60k miles), and ignore the later change to 150k km (90k miles). Timing belts are cheap.

As @Dave 2000 is alluding to, wear on timing belt teeth changes the timing by several degrees. Even if the belt is strong enough to last 150k km, the effect on timing and performance through timing belt tooth wear is measurable and significant. Toyota makes no provision for adjusting this out.


Not sure why I was called out above?

But to clarify, Yes, the timing belt is driven from the IP gear.
The timing belt is not keeping the IP in time with the cam, it's keeping the camshaft in time with the crank and pistons. It happens to be connected to the crank indirectly via the IP gear.


I would also leave the IP gear bolted in place while changing the belt

 

[Dusten]

A point here, I have the different 1HDT engine, the timing belt should be done at 80,000 miles and there is a reminder light on the left of the dashboard, and as mentioned it DOES drive the cam and a breakage will cost to say the least!

Some notes:

When resetting the belt change mileage it is very easy to break the reset button, ask me how I know!!

And whilst the 80,000 mile change is listed in the book, look at the type of miles that is. 80,000 miles is 80,000 miles assuming you are driving on the motorway most of the time, but what about a 1 or even half an hours traffic jam once ot more per week? Your sitting with the engine idling and the AC on, the engine is still running but the trip is not going around soooooo.

Regards

Dave

The 1hdt light comes on at 62,500. Not 80. Where is 80 referenced?

 

[Dave 2000]

@Dusten I have no idea, unless the European versions are different? The 24 valve 1HD-FTE which is 90,000 miles but I always recommend it is done earlier?

Either way post has been corrected.

Many thanks,

Regards

Dave

 

[jellis]

@mudgudgeon I was curious if you knew WHY the FSM might call for the IP pulley ("No. 2 Camshaft Pulley") to be removed as part of the timing belt job when it doesn't have to be? Dave's comments above about pulley position adjustment are moot at least on the camshaft because it has a woodruff key, and looking at the FSM similarly the IP has a pin that goes thru a plate and into the pulley along with 4 bolts that go into the IP body = no adjustment either.

So why does it say to remove it and put it back on when it's not necessary? I guess now that I think about it if you just wanted to swap out the timing belt you probably wouldn't need to pull the camshaft pulley either? Just loosen the tensioner, replace belt, be done?

 

[TonyP]

@mudgudgeon I was curious if you knew WHY the FSM might call for the IP pulley ("No. 2 Camshaft Pulley") to be removed as part of the timing belt job when it doesn't have to be? Dave's comments above about pulley position adjustment are moot at least on the camshaft because it has a woodruff key, and looking at the FSM similarly the IP has a pin that goes thru a plate and into the pulley along with 4 bolts that go into the IP body = no adjustment either.

So why does it say to remove it and put it back on when it's not necessary? I guess now that I think about it if you just wanted to swap out the timing belt you probably wouldn't need to pull the camshaft pulley either? Just loosen the tensioner, replace belt, be done?

The "Engine Mechanical - Timing Belt" section of RM617 isn't just for the timing belt itself, it's for the removal and installation of the belt and it's components.