Broken timing belt

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JoeIsuzu
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Re: Broken timing belt

Postby JoeIsuzu » Sat Jul 07, 2018 1:44 pm

makaraft wrote:I’m ordering a rocker arm assy, push rods and a new tensioner bearing.

Really? From where? The only source I know of for rocker arms and pushrods is the used/salvage market.

Jack

dorf
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Re: Broken timing belt

Postby dorf » Sat Jul 07, 2018 2:49 pm

Looking back...I guess I've done 5 belt changes on my 81

Always used NAPA belts...never a problem and used the same book as yours

Good luck...I mean that sincerely

Just my 2 cents

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Re: Broken timing belt

Postby makaraft » Sat Jul 07, 2018 3:38 pm

Update: I found the cam sprocket had a small amount of play forward and aft, tried unscrewing the bolt and it seems like it’s spun off in the cam. I know it had a key way so I know the sprocket didn’t spin, but perhaps the forward and aft play messed up the belt as it spun. I’ll try to get the bolt out and replace it.

FiatSpider2
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Re: Broken timing belt

Postby FiatSpider2 » Sat Jul 07, 2018 9:20 pm

Did you check the timing marks before you started disassembling things? If the cam sprocket did not spin it would indicate a lot of thrust was put against it potentially from having the thrust bushing out of place.

How accurate is your torque wrench? Clickers are notorious for slipping the setting or jamming and over-torquing things. I am at the point where I trust my old beam and pointer over the clickers.
FiatSpider2 (4FB1 Isuzu Diesel powered 1978 Fiat Spider)

makaraft
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Re: Broken timing belt

Postby makaraft » Sun Jul 08, 2018 10:56 pm

JoeIsuzu wrote:
makaraft wrote:I’m ordering a rocker arm assy, push rods and a new tensioner bearing.

Really? From where? The only source I know of for rocker arms and pushrods is the used/salvage market.

Jack



They're all used, I found someone with some spare parts on the forum.

makaraft
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Re: Broken timing belt

Postby makaraft » Sat Jul 21, 2018 5:52 pm

Update: got all new parts installed and redid the timing procedure properly. Everything is running, but now I’m paying attention to the temp gauge. It’s not cooling itself properly, temp keeps climbing and never stabilizes. I’ll try taking the thermostat out to see if that’s what the issue is.

That may have been my original issue; overheating and then seizing the cam/crank, then as it cooled it was able to move again. I do have all new temp sensors on top of the thermostat housing (ordered off rock auto). I’ll post once I have the chance to do more trouble shooting.

dorf
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Re: Broken timing belt

Postby dorf » Sat Jul 21, 2018 6:38 pm

I had similar problem ...installed 180 degree thermo from GM 350 cu inch engine

ALSO PUT springs in all radiator hoses to prevent collapsing hoses

No more problems ...runs in center of gage now...if extended climb .....the fan engages at the top of gage marking

makaraft
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Re: Broken timing belt

Postby makaraft » Sat Jul 21, 2018 7:18 pm

My fan is set up to run all of the time, just mounted on the water pump pulley. I hadn’t thought about it being engaged or not until now.

makaraft
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Re: Broken timing belt

Postby makaraft » Sat Jul 21, 2018 8:10 pm

Yeah, took the fan off and spun the water pump pulley while looking in the thermostat housing, no fluid movement. I may be in the market for a pump here shortly.

dorf
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Re: Broken timing belt

Postby dorf » Sun Jul 22, 2018 4:26 am

The fan has a fluid coupling set up......temp activated sort of......it slips when demand is low ....as temp and demand increases it locks up to provide max cooling and fan flow

You can hear it engage ....and then you will see your temp gage decrease

makaraft
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Re: Broken timing belt

Postby makaraft » Sun Jul 22, 2018 10:23 am

You’re right, I just took another look at it. However, turning the water pump by hand is still not pushing water so I need to remove it and see what’s wrong.

dorf
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Re: Broken timing belt

Postby dorf » Sun Jul 22, 2018 11:26 am

When you remove the water pump, be sure to keep tract of where the bolts came from.....they are different lengths...so if you mix them up chances are you will bottom out in a hole and not be able to torque down properly...thus a leak

Be sure to use some sort of ...good.....sealant on the water pump gasket...both sides

I don't believe you can verify pump condition by just turning the fange flange....also change the small hose on water pump top

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puttputtinpup
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Re: Broken timing belt

Postby puttputtinpup » Sun Jul 22, 2018 12:49 pm

Dittos to what Dorf said. If you can find a tap to clean out the threads for the bolt holes that hold the water pump on, do it. Even if you have the correct bolt in the hole it came from, the new water pump and gasket might be a bit thinner than the old. The bolt will get hard to turn once it reaches the depth it used to be. If you see RTV squishing out, you'll probably be okay. If no RTV squishes out and bokt is tight, pull it back out and stack a couple of washers on the head as shims

makaraft
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Re: Broken timing belt

Postby makaraft » Sun Jul 22, 2018 2:28 pm

So waterpump checked good, reinstalled with no leaks. Put everything back together WITHOUT thermostat and had good flow. Temp stabilized at 170, checked with a Fluke thermometer at both the radiator cap and the top of the thermostat housing (through a sensor hole). Also, checked the spring on the fan clutch and that checked good as well.

Here’s the thing, the needle in the cab climbed until it was between the middle and the top of the gauge, about 3/4 of the way up. That’s when the thermometer read at 175. I shut it off and restarted, needle pegged out at H but thermometer still read at 175. So this is a wiring/sensor/gauge issue, not cooling. I only have the side sender wire installed (single wire) and the sensor wire (double wire on the top). Am I supposed to have the second sender installed as well? I thought it was just to the glow plugs.

I may just do an aftermarket gauge inline with a coolant hose to take out the guess work with the original wiring/gauge.

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Paul
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Re: Broken timing belt

Postby Paul » Sun Jul 22, 2018 2:46 pm

There is a 7V voltage regulator built into the instrument cluster which possibly has gone wrong. The 7V output serves both the temperature gauge and the fuel gauge. So, I suggest that you keep track of both gauges to see if they both go too high at the same time. If so, it is probably a voltage regulator problem.

Also, it is possible that you have an intermittent short to ground on the temperature sensor wire.

Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.