86 4x4 720 Project

[powderfinger]

Picked up an 86 720 4x4 today that I plan to fix up. The guy I bought the truck from got it from his neighbor who was an old man who bought it brand new. Unfortunately, as the original owner got older and used the truck on his farm he hit a tree along the passenger side while hunting in the woods. Going to take a bit of work to fix. He also shot a hole in the roof somehow LOL.

 

Luckily I have a spare bed in good shape and another door. The back corner of the body is going to be difficult part. Looking for some advice on the best way to tackle it. The cab on the parts truck I have has a perfect passenger side. Was thinking it may be easier to cut the dented up section off the 4x4 and replace it with the straight metal from the parts truck. May be easier than trying to straighten this massive dent out?

 

Truck only has 56000 miles on it. Has a blown head gasket of course 🙂 but ran decent enough to pull onto my trailer and then into my shop. Still has paperwork from original purchase.

 

 

[powderfinger]

[powderfinger]

[powderfinger]

Here is another pic of the side damage. Truck has almost no rust, floors are perfect. Going to take me a while to get this finished so pictures may not come too fast but I will keep this thread updated.

[powderfinger]

[powderfinger]

[powderfinger]

I would not have wanted to go hunting with the original owner of this truck. Not only did he shoot a hole in the roof, he also shot one in the floor!

[powderfinger]

I am really torn on what to color to go with on this truck. If I decide to stick with the factory blue has anyone found any of the spray on "dye" that matches the factory blue interior color? The interior is in good shape but some of it is faded.

 

If I don't go back with the factory blue then I will most likely go with tan exterior and a black interior. I have always liked tan on the 4x4s and I definitely prefer the black interior.

[bottomwatcher]

One caveat on the black interior. I just swapped some Maxima black leather seats in my 720 a few months back. If I leave the truck parked in the sun for five minutes then jump back in the is a sizzling sound and searing pain ass when my ass catches on fire and this is in Maine. Whenever I get out of the truck I have to cover the seat with a beach towel.

[Charlie69]

Wear some pants!  LOL

[powderfinger]

20 hours ago, bottomwatcher said:

One caveat on the black interior. I just swapped some Maxima black leather seats in my 720 a few months back. If I leave the truck parked in the sun for five minutes then jump back in the is a sizzling sound and searing pain ass when my ass catches on fire and this is in Maine. Whenever I get out of the truck I have to cover the seat with a beach towel.

 

What year maxima and did it raise the seat height any? Seems most replacement seats raise the seat height and I do not want the seat raised at all. I have tried civic seats that were way too tall and most people are saying neon and rodeo seats also raise the seat height.

Edited September 9, 2020 by powderfinger

[bottomwatcher]

That had been a problem with just about all the seat swaps. I am 6ft and it would drive me crazy to brush my head on the headliner and I got a smaller steering wheel for one of my previous seat swaps. I ran old Sentra seats for years until the springs started getting exposed and biting my ass. The latest swap is from a 2003 maxima. Power 15 different ways on the drivers side. Passenger seat is simpler. Not any higher than stock. I added the console from the car and then went back and got the seatbelts.

[powderfinger]

Awesome, I'll have to keep my eyes open for those. Especially the black leather powered seats those would be perfect.

[powderfinger]

Finally got around to working on this truck some today, got side tracked with work and a hernia surgery. Started tearing into it to replace the head gasket in order to get it running so I could drive it around a bit to check everything out before doing more work on it. I was hoping since the truck is supposed to have so few miles on it that the motor had never been torn into but that is not the case. The exhaust bolts and nuts came off easily which never happens and the cam pulley bold had been scuffed up some. Looks like it may have been by an impact wrench.

 

On top of that when I took the valve cover off and looked down into front of the engine to see the timing chain I noticed a plastic piece sitting loose in the bottom that looks like it bolted somewhere on the outside of the engine and held a hose in place at one time. I guess someone accidentally dropped it in there and left it. Didn't get the head off yet because I am having a hard time getting my timing chain wedge in place. It seems like there isn't as much room between each side of the chain as the last Z24 I worked on to fit the wedge in there. Seems impossible unless there is a LOT of chain stretch which would certainly mean either this truck has more miles on it than I was told or at least the engine does and it's not original.

 

Either way it looks like I will have to take everything off the front of the motor to get to the timing chain which I was hoping to avoid.

[datzenmike]

Try and fish out anything loose in there first.  There is a chance that the timing chain tensioner has dropped out from someone taking this head off before and screwing it up That always presents as a chain with lots of slack. Perhaps they jammed a piece of garden hose in there to hold the tensioner and forgot to retrieve it after? If the tensioner is out the timing cover has to come off to fix it. The damage is done and best to get a replacement timing chain kit. 

 

Why again is the head coming off??? 

 

 

On 9/6/2020 at 8:22 PM, powderfinger said:

I would not have wanted to go hunting with the original owner of this truck. Not only did he shoot a hole in the roof, he also shot one in the floor!

 

 Did Dick Chaney own it????????

[Charlie69]

I have never seen a triangular bullet!  Looks more like a hole punched for an AC condensate tube drain.

[powderfinger]

The head is coming off because the truck has a blown head gasket. I am starting to think this is the second time it has had a blown head gasket. The head looks too clean. I'll try to get a pick in the next day or so. Looks like the head was either cleaned by a shop before resurfacing or the PO put a reman head on it possibly.

[datzenmike]

Changing the oil will also do this. If well maintained they can surprise you.

 

Make sure you check the head is flat. If you can't do this have it resurfaced because a shop will say it needs resurfacing weather it does or not.

 

The Z24 tends to blow the head gasket every 100K miles. In the future, once a year when the engine is cold re-torque the head bolts. This consists of loosening a bolt and then immediately tightening to 60 Ft lbs. Do in any order you like but only one bolt loose at a time. This keeps the gasket freshly and uniformly clamped between the head and block.

[powderfinger]

Even the outer surface of the head looks too clean. Looks cleaner than the block. I am wondering if maybe someone changed the head gasket and possibly the head as well and never went back and re-torqued the bolts after a few temp cycles and ended up blowing the gasket again.

 

I have a machinist straight edge to check for flatness, will for sure do that before reassembly.

[datzenmike]

Not really necessary to re torque right away but certainly every tune up or about once a year.

 

Aluminum will degrease almost like new, unlike rusty half painted blocks.

 

I also have an $80 straight edge and run it in an X pattern and lengthwise in 3 positions. The max allowable is 0.004". I had an L head that had a low spot between 2 and 3 that was 0.016". 

[powderfinger]

Well, life got in the way of working on this truck and unfortunately it appears I have let it sit too long with a blown head gasket. I ended up pulling the engine and transmission out this past weekend and it's a good thing I did because it would have had to come out anyway. Cylinder #2 had water/antifreeze sitting in it too long and now it is pitted and will need to be bored to get this engine back in working condition. It's a shame, there is a possibility that if I had did this work right when I got the truck this could have been avoided. Hopefully the crank is ok but I am worried. Will hopefully remove the pan and inspect this weekend now that the engine is on a stand.

[NC85ST]

Your crank will be fine. Water goes to the bottom of the pan and the oil rises. I used a crank out of a Z24 that sat outside for, I don’t know how long. It cleaned up beautifully, no rust. That block may clean up as well.

[powderfinger]

1 minute ago, NC85ST said:

Your crank will be fine. Water goes to the bottom of the pan and the oil rises. I used a crank out of a Z24 that sat outside for, I don’t know how long. It cleaned up beautifully, no rust. That block may clean up as well.

I had hopes that the block would clean up when I first saw it but I think after going back and looking at the pictures that it is pitted in places. I just got home so I'll go back over to my shop and have another look at it.

[powderfinger]

Question for everyone here who has plenty of experience driving 4x4 720 trucks. I recently purchased another 720 that runs and drives but needs the transmission repaired and I believe the motor might be a little tired to say the least. How much of a power difference have you noticed with a taller tire? The truck currently has 30.5x9.5x15 tires on it and it came stock with 235/75/15. The 30.5s are about 1.5 inches taller than the stock tires and I believe these particular tires run on the tall end of that size spectrum as well. They are also mud tires and are pretty heavy. Just curious how much that could be playing into the lack of power this truck has.

 

My 2wd will run circles around this truck but it has a fairly fresh motor in it with a Weber carb. This truck feels decent in 1st and 2nd gear because they are so low but as soon as I shift into 3rd on any kind of incline acceleration is barely there. The truck still has the original catalytic converter on it as well so not sure if that could be a little clogged. Haven't checked yet.  

 

I did a compression check and all cylinders were low (around 120psi on a cold engine that hadn't been cranked in 2 weeks) but I am not sure how accurate my gauge is. I will check my 2wd this weekend to see what that reads. I also noticed that even though all cylinders were fairly even, #1 plugs were black while the others looked like they should. Not sure if that cylinder isn't firing properly or if the valves need adjusting, planning to do that regardless. I would think if it was the valves way out of adjustment the compression would have been lower on that cylinder. 

 

I may just swap the wheels and tires from my other 4x4 720 and take it up the road since they are factory size but they are VERY dry rotted and it doesn't seem like the safest thing to do lol. Here is a pic of the truck.

 

 

[powderfinger]

I also noticed when I changed the drivers side wheel bearing that when I put the caliper back on the inside brake pad was dragging on the rotor quite a bit causing a lot of resistance to turning the wheel. I know the lines have air in them because I have to pump the brakes at least once before they feel normal so that is something else that could be causing a major impact to acceleration.