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help! replacing the timing chain on my 82 720 4x4.


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#1 hurts donut

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Posted 09 February 2013 - 07:49 AM

 so im new to this. were replacing the timing chain and its going ok so far. im nervous that well overlook crucial little things that can save us time, money and make the truck run better. Is there a good how-to section that might have a step by step..videos, photos, and common problems\ tasks that might ease the process. I wish i had joined this forum 3 yrs ago when we got the truck. thanks for any feedback. also found a tiny ring in the oil pan..looks like a bearing race. bout the size of a ladies wedding band..that supposed to be attached somewhere i bet..any ideas? ill try and get photos going too.



#2 datzenmike

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Posted 09 February 2013 - 10:47 AM

Loosen but don't remove the crank pulley bolt. Usually a 24mm socket? and a breaker bar wedged against the frame and gently bump the starter to loosen it.

Loosen but don't remove the cam sprocket bolt. Lock the cam so it won't turn by placing a socket extension through the holes in the cam sprocket to jam it.

Set motor to TDC compression stroke on #1 and place in neutral so someone doesn't lean on truck and bump the motor off.

Remove battery cable

Drain coolant, remove rad and shroud. Don't let your dog drink that shit.

Remove (2) distributor hold down bolts and lift it with the mounting pedestal from the timing cover.

Remove crank pulley now.

Remove PS belt if equipped.

Remove water pump and fan

Remove the oil pump. it will drip so be ready

Remove timing cover bolts including the small 10mm ones at front and sides of the bottom of the head.

Loosen the front and side oil pan bolts so the timing cover can slide out to the front. Hopefully the pan gasket does not tear. Behind the timing cover on the crank is a thin concave metal 'washer' called the oil slinger... don't loose it.

Remove cam sprocket (noting it's numbered position ...No.2?) and lower the chain through the front of the head and off the crank sprocket. The tensioner will immediately pop out of it's retainer. This is OK as it is (or should) be replaced.

Remove the tension side (left and slack side (right) rubber coated chain guides. (also replaced.

 

Clean all mating surfaces.

 

Replace the crankshaft front seal in the timing cover now.

 

The small crank sprocket will have a dot punched into it around the 4 o'clock position. The new timing chain will have two corresponding dots or perhaps bright links.... one to mate up with the crank sprocket and one up on the cam sprocket about the 2 o'clock position when looking from the front. Instal chain on crank and cam sprocket and bolt cam sprocket in place loosely by hand (don't disturb the motor) Be sure sprocket dots line up with the bright links. instal chain guides and tensioner, pushing the bottom of the guide above the tensioner as far to the right (looking from the front) before tightening bolts down. Tension side should be just against the chain.

 

If pan gasket is torn, cut the front off a new one and instal with a dab of RTV in each corner to seal it. Top gasket under the head only has to seal fumes and some oil spray in so seal with RTV. Install timing cover. Other than mentioned all gaskets go on dry without sealer or silicone.


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#3 hurts donut

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Posted 09 February 2013 - 02:23 PM

thanks for the response. im all good to this point ..but then the chain kit i bought for the truck that supposed to fit doesnt exactly. the chain is maybe a link too small. i mesured it compared to teh old chain and its 18 links in between the brite links..the old chain has 19 between the brite links. Maybe the place sent the wrong kit? or is there somthing i dont know and shoulda orderd a different kit. this is a bummer . any tips or a link to specs about chain sizes and which one i might need?



#4 datzenmike

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Posted 09 February 2013 - 03:01 PM

The '82 is a Z22 motor and should have 38 chain links between bright links. A Z24 will have 40.

 

PC140004.jpg

 

 

 

Check your motor size. Look between the manifold exhaust pipes , it's stamped into the top of the block just below the head. Use wire brush to clean the flattened boss where it's stamped. Maybe you have a Z24 and they gave you a Z20/22 chain.

 

ZengineID.jpg


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#5 discobandaid01

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Posted 12 May 2014 - 08:32 PM

doing a timing chain replacment..which way does the crank bolt turn to loosen? and its a 27mm other then the starter trick any other tricks to break it free?I tried useing the starter with a breaker bar on the frame and well that sob is really on there..so you think a impact will get it off..?



#6 ggzilla

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Posted 13 May 2014 - 01:10 PM

Already asked and answered at http://community.rat...-3#entry1093431


doing a timing chain replacment..which way does the crank bolt turn to loosen? and its a 27mm other then the starter trick any other tricks to break it free?I tried useing the starter with a breaker bar on the frame and well that sob is really on there..so you think a impact will get it off..?


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#7 discobandaid01

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Posted 13 May 2014 - 07:36 PM

which way does the oil slinger face



#8 ggzilla

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Posted 13 May 2014 - 07:41 PM

Can't recall but there's a photo of it in the repair manual
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#9 datzenmike

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Posted 13 May 2014 - 07:58 PM

It's roughly bowl shaped. Face the bottom of the bowl into the block. It flings oil off so it doesn't flood all over the crank seal.


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#10 captain720

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Posted 01 January 2018 - 12:27 PM

This thread is a little ancient, but I am bringing it back instead of starting a new one.  :poke:  B)

 

I am trying (emphasis on trying :)) to replace the timing parts on this motor. (2.4l Z24 out of my "parts truck" build)

IMG_20171231_153915592_BURST000_COVER_TO

I have a new timing kit and oil pan gasket, the oil pan, water pump, and vale cover are off ant the motor is on the stand. The big bolt that holds the timing gear on has backed off? a little and so the timing gear has slipped off the peg, so the bottom and top end are spinning separately. 

 

More or less the question is "what am I doing?!?".

 

Do I need a pulley pulling thingymajig? 


1986 and 0 Nissan 720 kc with a 1984 Z24 (third engines the charm?) http://community.rat...y-first-pickup/
1986 and 0 Nissan 720 kc 2wd http://community.ratsun.net/topic/71766-one-wasnt-enough/

 

 

Datsun=Project


#11 datzenmike

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Posted 01 January 2018 - 01:46 PM

So right now you have the timing cover and valve cover off?

 

Are you removing the old timing chain?


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#12 captain720

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Posted 01 January 2018 - 01:51 PM

No I haven't got the timing cover off yet, going to go back and work on that now. I have a new chain and gear and sprocket and guide and tensioner

1986 and 0 Nissan 720 kc with a 1984 Z24 (third engines the charm?) http://community.rat...y-first-pickup/
1986 and 0 Nissan 720 kc 2wd http://community.ratsun.net/topic/71766-one-wasnt-enough/

 

 

Datsun=Project


#13 captain720

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Posted 01 January 2018 - 02:11 PM

I am trying to figure out how to get the pulley off. Ideas?

1986 and 0 Nissan 720 kc with a 1984 Z24 (third engines the charm?) http://community.rat...y-first-pickup/
1986 and 0 Nissan 720 kc 2wd http://community.ratsun.net/topic/71766-one-wasnt-enough/

 

 

Datsun=Project


#14 Lockleaf

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Posted 01 January 2018 - 02:13 PM

No crank puller necessary on this engine. Just tap on the back of the pulley with a mallet to work it free.

There is a timing cover bolt hidden behind the oil pump, so pull the pump first.

Follow the process in the fsm and ask particular questions as you have them

Half Pint ('71 510 Goon) http://community.rat...agon/p?=1269361

 

Audrey ('69 Roadster 1600) http://community.rat...rey-the-ratster

 

Tiny Havok ('85 720 DIY built Crewcab 4x4) http://community.rat...ache/?p=1395455

 

720 Shenanigans http://community.rat...20-shenanigans/


#15 datzenmike

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Posted 01 January 2018 - 02:35 PM

I am trying to figure out how to get the pulley off. Ideas?

 

 The bolt or the pulley? I have never used a puller on the crank pulley.

 

Bolt

Put 28mm? socket and breaker bar on nut and position so bar arm is against the truck frame nice and snug. Hit the starter quickly. Engine will rotate clockwise around the bolt and loosen it with breaker bar locked against the frame..

 

Pulley

Use same socket and tap on the rear side of the pulley, striking towards the rad. Take your time... may take 40-50 taps but the pulley WILL move forward and off. DON'T hit with hammer and fuck the harmonic balancer up just use taps. 


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#16 captain720

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Posted 01 January 2018 - 02:50 PM

The 27mm bolt is the problem, when the motor is not in a truck you can't turn the starter.

Edit- I have the oil pump off and I think I just have to figure out how to remove the 27 mm bolt up front with the engine not in a truck.

1986 and 0 Nissan 720 kc with a 1984 Z24 (third engines the charm?) http://community.rat...y-first-pickup/
1986 and 0 Nissan 720 kc 2wd http://community.ratsun.net/topic/71766-one-wasnt-enough/

 

 

Datsun=Project


#17 datzenmike

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Posted 01 January 2018 - 03:02 PM

Sorry. Slip a long socket extension through the hole in the cam sprocket so that it is locked in place and the engine cannot turn. Use the breaker bar to rotate the engine backwards (counterclockwise) against the extension till locked. Now position the breaker arm to the side at a slightly downward angle. Make sure the engine cannot tip over (important!) and is well secured and the bar handle positioned so you can do the following....

 

Position yourself so you can safely step down HARD on the handle to loosen the crank bolt. Take a few practice steps and when ready do it KICK DOWN HARD and you'll only have to do it once. I've popped crank bolts on engines laying on the wrecking yard ground without rods and pistons or a flywheel on them using just the crankshaft inertia. Wear work boots and be careful.


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#18 captain720

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Posted 01 January 2018 - 03:07 PM

Thanks great idea! But the cam sprocket has slipped forward so far that it is just barely hanging there and not contacting the pin on the end of the cam anymore. So I am not sure if it will hold up to any kind of force?

1986 and 0 Nissan 720 kc with a 1984 Z24 (third engines the charm?) http://community.rat...y-first-pickup/
1986 and 0 Nissan 720 kc 2wd http://community.ratsun.net/topic/71766-one-wasnt-enough/

 

 

Datsun=Project


#19 datzenmike

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Posted 01 January 2018 - 03:24 PM

What can I say? that shouldn't be off till the timing cover is. oh well.

 

If the flywheel is on find a way to lock it.


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#20 captain720

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Posted 01 January 2018 - 04:03 PM

Yeah the entire reason I am doing this is because that bolt backed out.

Going to try an impact that I am going to borrow.........

1986 and 0 Nissan 720 kc with a 1984 Z24 (third engines the charm?) http://community.rat...y-first-pickup/
1986 and 0 Nissan 720 kc 2wd http://community.ratsun.net/topic/71766-one-wasnt-enough/

 

 

Datsun=Project