My 1982 720

[SDP45]

I've had this truck for 5 years now, and am the second owner of it. The first owner kept meticulous notes. Some were written on the sun visor, some on the air cleaner, some on the toolbox in the bed. That said, the first owner told me that near every replaceable part had been changed out during his time, except the clutch. About 200 miles after I got it, the clutch went. Payment for the labor to replace the clutch was 1/2 gallon of whiskey plus parts.

 

I've got a parts truck for it, but I think it is a 1981 720, with the older L engine, instead of the Z22 in mine. I've tried to grab as many parts off of it I might need, as my uncle has been using this same part truck for his 1982 720 diesel king cab.

The seats in my truck were pretty shot, but the parts truck had a bench seat in perfect condition that was a near perfect fit.

 

The carb was changed to a Weber 2 years ago. It seems to run better now. That said, I've not been able to use it for the last month, as it blew the head gasket. I had a pretty hard time with a very inept staff at the part store getting a gasket kit. Then I had a hard time finding head bolts. Ugh! It should be back in service tomorrow.

 

My buddy made a headache bar for it, so I can strap long loads over the cab, without beating the cab up. Its got some body rust, so I've had to sand it from time to time.

 

The radio is held in place with a bungee cord, but still works. The speakers are held in place with baling wire.

 

I'd like to put more time into it to get it in better shape.

 

Dan

Ephrata, WA

[datzenmike]

The head bolts are reusable as long as they are in good shape.

 

Be sure the block and head are spotlessly clean and clean the bolt hole threads as well. Use NO gasket sealant! Torque in sequence in three stages of 20 then 40 and a final 60 ft lbs. I'll post the sequence for you when I get home.

[SDP45]

Thanks for the info! Unfortunately, one of the bolts was stubborn and broke during removal, so I had to get a new one anyway. I figured I might as well replace them all.

 

Dan

[SDP45]

Truck is back and is working great. The headgasket was shot, but not blown. Did find that the oil pressure sensor had blown out!

 

Dan

[datzenmike]

Keep good quality anti-freeze in it that is changed every 2-3 years.

 

After driving for a few weeks with multiple warm and cold cycles, loosen each bolt one at a time on a cold engine and re-torque to 60 ft lbs. It's now properly torqued till the next tune up. There's no need to follow any sequence here just do one at a time. This is right out of the Nissan factory service manual and is to address the h/g failure problem. Over time the gasket compresses and the bolts are not bearing down with the proper torque and eventually it fails. Only takes 10 min to do at every tune up.

[wayno]

Keep good quality anti-freeze in it that is changed every 2-3 years.

 

After driving for a few weeks with multiple warm and cold cycles, loosen each bolt one at a time on a cold engine and re-torque to 60 ft lbs. It's now properly torqued till the next tune up. There's no need to follow any sequence here just do one at a time. This is right out of the Nissan factory service manual and is to address the h/g failure problem. Over time the gasket compresses and the bolts are not bearing down with the proper torque and eventually it fails. Only takes 10 min to do at every tune up.

 

I did not know this, 60 lbs. is for the 82 720, correct? Is this re-torque procedure for all datsun vehicles or just the Z block models?

[SDP45]

Thanks for the tips about tightening. I'll be sure to do this.

[datzenmike]

I did not know this, 60 lbs. is for the 82 720, correct? Is this re-torque procedure for all datsun vehicles or just the Z block models?

 

Z series. They tend to blow the h/g at 100K. I have an '84 FSM (the Z24s were the worst) and that is the procedure at every tune up. The problem is that not all owners know this. Re-torquing once or twice a year keeps the head tight against the gasket as it shrinks or compresses with age and 10s of thousands of heat/cool cycles. All you have to do is snap the head bolt loose and right away torque to spec, about 60 ft lbs for 2 liter and larger motors. No order just one at a time and get all of them.

 

The L series is not known for blowing the h/g but it couldn't hurt to do this every year or so. My 300Km L20B blew it's h/g for no apparent reason... just blew. No over heat, no warp, not driving hard. Perhaps if I had re-torqued the head once or twice this could have been avoided??? Who knows?

[Jester]

Great info Mike. Thanks