Help with 2LTE Timing Belt Tensioning Procedure

[JSQ]

I recently replaced the head on the 2LTE in my LJ78 with an updated 3L head and encountered a problem with tensioning the timing belt.
I was working from the FSM and thought I had properly tensioned the belt, however, on start up things sounded bad. I tore back into it and took off the timing cover to find the belt completely slack. As a result I bent several valves and damaged shims. Head had to come back off and go to the machine shop.
I don't know exactly how the belt went from taught to slack. When I installed it, I hand turned the crankshaft over by hand several times to check timing with the camshaft and injector pump.

Needless to say, I was bummed and this was a lot more work and expense. Now I've re-installed the head and have arrived back at the point of installing the belt. I understand how to release the tensioner but the FSM shows hanging the belt between the crank and injector pump pulleys and then turning the crank. It shows the same between the injector pump and the camshaft. I don't understand how to create tension on the belt between those three pulley prior to releasing the tensioner.
What am I missing?

The machinist is not familiar with this motor but thought the tensioner should be pried against the belt before tensioning.

I don't want to try to start this up again unless I'm totally sure I got the timing belt on correctly.

Any help is much appreciated.

 

[coldtaco]

bummer. hopefully someone with knowledge will chime in.

 

[Eurasiaoverland]

Pictures would be helpful. Especially if you have any from your previous installation which led the engine damage.

 

[coltonriver]

Just to be clear, when you installed the belt the first time, did you lock the cam and pump in place while routing the belt from the crank up? Also, was the tensioner fully compressed and pinned before installation? These engines are picky, and if there’s slack between the crank and pump when you release the tensioner, it can unload after rotation.

 

[Lil Pete]

I am at the point of dealing with the tensioner. When I removed everything to do the head replacement, the bolt in the slot of the tensioner was tight. So, on reassembly I let the spring do the tensioning through several rotations checking the marks to see if they were still all lining up. Then I tightened all of the tensioner bolts. Now, I am not so sure if I did it correctly. Time to search the resources section to hopefully find the truth.

 

[Dprio34]

@Lil Pete , Fingers are Crossed for you brother!! Hope to hear you are driving her around town this afternoon!

 

[JSQ]

Just to be clear, when you installed the belt the first time, did you lock the cam and pump in place while routing the belt from the crank up? Also, was the tensioner fully compressed and pinned before installation? These engines are picky, and if there’s slack between the crank and pump when you release the tensioner, it can unload after rotation.

No. While the camp and pump didn't move out of timing when I installed the timing belt, I did not lock them in place with a SST or other tool. This is the step from the FSM I don't think I followed correctly. The tensioner was released and tightened per the FSM but I did not put any additional leverage on the tensioner.

 

[JSQ]

Pictures would be helpful. Especially if you have any from your previous installation which led the engine damage.

This is what the timing belt looked like before I put the timing cover back on and started it up. I had released the tensioner and turned the engine over several times by hand to check the timing marks.

 

[Dprio34]

@Lil Pete & @JSQ , here is a video (part 3) on a 5L. Should be pretty darn close. Not sure if you have seen it. There are several other videos out there on 3L, 5L, and 2L timing belt services on the Tube. I only remember removing the spring, setting the new pulley, and installing the new belt, and finally putting the spring back on. IIRC, the timing belts on early 2LT and later 2LTE are different. Please double check me on that. But make sure you have the correct timing belt for your application. I cannot speak if the 3L or 5L belts are different, but I would definitely triple check that. Again, like you did, make sure timing marks line up through several manual turns on the crank bolt. Should work out. Maybe the Belt jumped a cog the previous time you did it, unfortunately. The PO on my LJ70 actually had marker paint in the wrong spot on my cam pulley. Just make sure, triple check all the marks are lined up and do several manual turns. Can't imagine what else could have went wrong. Good luck, keep up posted. Hope you are driving again soon.

 

[JSQ]

At the 5:10 minute mark in that video he leverages a screwdriver against the idler pulley before tightening.
I did not do this step. I only released the tensioner and tightened it under the pressure from the coil spring.
Do we think that was what made the difference?

 

[Dprio34]

@JSQ , Not sure. Hard to say. A lot of folks say, after doing multiple turns by hand from the crank pulley bolt, their timing belt jumped a tooth when they started the engine with the key. Not saying it never happened. Just something to consider, I suppose. I've done head gasket jobs on other vehicles and later after start, oil in water, although I followed the torque sequence exactly. It is just painful and unfortunate. I'd just make sure you have the correct belt (I believe the L motors have several), get everything lined up (Timing Marks). Watch a couple more videos on the Tube. And give it another shot. Fingers Crossed! There is another video on the Tube, that I watched on a 5L, and that guy claimed there should be no more than 90 degrees of deflection on the longest part of the belt (greatest distance between pulleys). If you try to twist the belt. I can't personally say, I've tested that method, but sounds reasonable.

 

[Lil Pete]

POOP!!!
The timing belt cover is coming off to add a smidge of tension to the belt.
Speaking of belts. They used a Gates belt in the video. It would be nice to have the Gates belt number for the 2lte. I ordered a "Toyota" belt for my engine and it is much thinner than the original Mitsubishi belt. The Mitsubishi one looks to be in good shape so I kept it since I don't have confidence in my possibly fake Toyota belt.

BTW I am also stressing about the valve clearances. Exhaust should be .40mm-.50mm and Intake .20mm-.30mm. All of my lash feeler readings are at or below the low end of the spec.. My guess is that it will only get tighter, not looser as the motor breaks in.
Which brings me to shim availability. The Aussies won't sell shims to us Tariffing Yanks. Our brothers in the Great White North are pretty hamstrung by the the process also. Dubai seems to be the only place that some sizes of shims can be got. Maybe I can find a machine shop with a magnetic table to mill my thick shims down.
Why am I rebuilding a 2.4 when a 3.0 would give me more motivation to deal with the woes of having a non-domestic motor?

I don't know whether to spit or wind my watch....

 

[Eurasiaoverland]

It's not really clear to me what the issue is, the photo does not show the tensioner and spring. Just follow the steps in the manual. IIRC, the manual states to put the belt on, ensure the timing marks align, then release the tensioner bolt and allow the spring to tension the belt, then tighten the tensioner into position. I don't think it says to add tension to the belt, and if it doesn't instruct you to do it, I recommend you not to do it. The posted video is by an Asian back-yard mechanic (in my neck of the woods) who uses an impact to do up the cam pulley bolt and does everything by feel. These guys are a self-sustaining business. Clearly you don't have this level of experience, but maybe have a better set of tools, so do what the manual says.

You need to ensure that you use the correct belt for your vehicle, which you do by running your chassis number or VIN in a parts database. The original belt may be Mitsuboshi (not Mitsubishi) or Unita, suppliers have switched during the 35+ years since the second generation of L engines was launched. I would use Gates for a fan belt or radiator hose in case originals were not available, but I would never, ever use an aftermarket timng belt. Buy the correct genuine belt from a reputable supplier. Buy a new tensioner spring while you're at it, in case you've not already done so.

As for valve clearances, the common workaround to not having a range of correctly sized shims is to grind the valve stems. Or get onto parts suppliers like Impex. Amayama etc and get the shims you need. Again, you will need part numbers.