My next 720 resto

[oakrun]

Keep talking, you guys- this is really helpful stuff!

have you drained the transmission oil yet?  have you checked the oil level?

[720inOlyWa]

No, I have not done anything with the transmission yet. But a drain and fill would be a good place to start, for sure. I wonder if synchro gear teeth will drain out. This poor truck was badly treated before I got to it.

[84720FourWheel]

Do you have a FSM for it? I think that will prove invaluable for the transmission work.

 

I saw a rebuild kit for the fs5w71b transmission a while ago for like 75 bucks. Maybe I can find that site again.

 

I wish I was closer, I'd gladly lend a hand. I want to see if I can everything out faster the second time.

 

Book time for a clutch job on a 4wd was 6.5 hours. Out in 3, .5 for the clutch, 3 to put her back together. That's crazy. Took me at least 10 to get it out, and probably 6 to get it back in. And another 3 to get it running. And throw in another 10 hours of rehabbing, degreasing, replacing seals and waiting on parts.

 

It was very rewarding, and I had the biggest smile on my face when I finally got to drive her again.

[Lockleaf]

Here is DMs testimonial of it. Further questions could be posted in his thread about it or pmed to him.

 

http://community.ratsun.net/topic/66496-gm-ac-delco-transmission-oil/

[720inOlyWa]

I have the FSM for the 85 720, and I think it is all in there. I am not aware if there is a 4x4 version for that truck too.

[84720FourWheel]

It should all be in there. I don't think they had the 4x4 additions after 82.

[720inOlyWa]

Okay, big news in our driveway... I bought another one today. An 84 King Cab, black. It runs, and doesn’t sound half bad. The valve cover gasket has been leaking for a long time. There is no sign of oil in the coolant, or visa versa, but is is running with what appears to be just water in the radiator. So there’s that. The clutch is good and, most important, the transmission feels very good considering the 216k miles on the odo.

 

This is a donor vehicle, of course. The body is pretty much hammered. The first thing it is going to donate is the passenger side seat bun and a few springs, to complete my amazing drivers seat rehab project  for my 2WD truck, and  to re-hab the driver’s seat on this one as well.

 

The engine will come out soon and will undergo a complete teardown and inspection with an eye towards a total rebuild for eventual installation into my 2WD truck. The transmission will get serviced and perhaps go into the 4x4 (this truck) if that seems to be a workable solution.

 

The donor truck also has a pretty good black carpet set, which will get yanked, cleaned and re-installed into the 4x4. Lots of truck stuff going on this weekend!

[84720FourWheel]

You can't just buy a truck without taking oics!

 

But extra parts are always good. Are the transmissions both short?

[Charlie69]

Pictures please.  It is always cheaper to buy a complete truck and use it for parts.  Is this truck an ST?

[720inOlyWa]

I am making a hole for it in the driveway- in a place that allows me to hide the right side of the donor truck, which has been rubbed pretty good against something solid. So it will arrive tomorrow and I will shoot pictures. The passenger door opens, but it is pretty wrinkly, all the way down the side, so we will keep that side against the giant azaleas to tone down the ‘junker in the driveway’ factor. I would really like to pull the shit I need out of it and move it off to the pick-n pull for others to enjoy the feast. This truck is a base model King Cab- no tach, no clock, no fancy stuff. Just like my 2WD King Cab, only far more abused. I was mostly concerned with the engine and trans, and the seat parts that I need. I m sure that I will find lots of other stuff in the donor that I will need, too. I picked up a jumbo can of foaming degreaser this morning, in anticipation of the didmemberment...

[720inOlyWa]

I have been going over the gear ratios / tire size / transmission info/ several times, and I think I finally get most of it. All of the information on the information plate is explained too, and that is enormously helpful. (The only truck chore I did tonight was to take mineral spirits and carefully wipe off the black paint carelessly sprayed over the information tag. It is like new again, along with the coolant sticker located near the radiator cap.) The 4x4 discussed ad nauseum in this thread has a CA 41 read end. So 4.11 gears. Since the 4x4 has the same 71B transmission as the donor 2WD, I will take Mike’s suggestion and cap the speedo input hole, as suggested, and use it.

[720inOlyWa]

You wanted to see it, so here she is:

 

 

My organ donor truck, a 1983 King Cab, in pretty tired shape. I drove it home and the adventure begins with hooking up the fuel pump wire to the battery terminal. Seriously, I laughed out loud. But it ran and drove pretty good, actually. I mean it is tired to the bone, but I bet that I could get it to Ellensburg, if I had to.  Anyway, I don’t have to and never will. Instead, I will stick it over to the side of our driveway, with the bad side towards the bushes, and finish my work as quickly as possible. 

 

Which began in earnest as soon as it hit the driveway. I looted two side springs and one main seat spring from the passenger side seat and used them to finish the total seat rebuild on my 2WD vehicle. The carcass was still warm when the first parts departed. Next, the serious stuff- engine and tranny. This will be my first pull, so I will have a good practice rig to learn on.

 

The goal is to zero time the Z24 and put it in my 2wd, rehab the tranny and put that into this 4x4. This tranny shifted great, very smooth, no noise. Fingers are crossed.

 

This rig has a totally salvageable black carpet set, which I will also yank for this 4x4 project.

 

Wait-  think that front bumper is better than mine, too!...

[720inOlyWa]

As I finish up my 2wd 720, my attention is turning back to my ‘86 720 4x4, as yet unnamed. I got it running okay once, but clearly, there is a transmission issue. So I parked it and concentrated on my daily driver 720 until it was done. Now it is time to cast my gaze back on this beast, with an eye towards getting it ready to roll into the Capital Forrest by this time next year. So it is time to dust off my 4x4 blog and shift attention over here as I move it closer and closer to the open road.

 

[720inOlyWa]

Im on the lookout for  short case transmission for this truck. Any clues / tips  are appreciated.

[wayno]

Im on the lookout for  short case transmission for this truck. Any clues / tips  are appreciated.

Look at all 2wd/4wd 1985/86 Nissan 720 regular cab short box trucks, they all have short shafts in them, you also need to look at all 83 plus 4X4s to see if it has a long shaft or a short shaft, 1980 thru 1982 all have long shaft transmissions.

You can convert over to a long shaft, but you need the short drive line and the long shaft console and cover plate, but I believe there is a reason they quit putting long shafts in the trucks with that short drive line.

[720inOlyWa]

Thanks, wayno. It took a couple of times, but I think get it, alrightie.

Good news is, there is a ton of head room under the 4x4 with a creeper! I can focus. I am going to spend a day with a wire brush and the shop manual, cleaning and figuring out the plan of attack. I am so smitten with my fresh engine, that I have to do the same treatment on this one, too.

 

Thing is, I already know that it makes a damn unpleasant sound when shifted into 3rd gear. I heard one second of that and grabbed neutral and limped back to the driveway in first and second. I also know that the clutch is way too grabby. I don‘t really know anything about what may or may not be the problem, but for 60 bucks, the local transmission shop will crack it and inspect it for me. So we will start there. With this one, I want to return it to stock, with the same transmission, so I will heed your advice in my search as I get this all jerked out and to the machinists / tranny folks.

 

Next weekend, I get to go out into the local woods with the neighbor kids and their 86 Toyota 4x4 beater. Should be a new experience, an adventure.

[wayno]

Once the transmission shop cracks it open your in it for the duration, or you bail right away and forfeit the $60.00, the transmission shops I have dealt with wanted a lot of money to rebuild a transmission, so now I just get them from the wrecking yards or from another forum member.

If you only went into 3rd once and it made a bad noise I would take it apart myself, you might not even have to pull it apart very far before you find the issue, pull the transmission and pull the front cover plate on the front of the transmission inside the bellhousing, now look at both bearings, are they both good?

Look at this article I wrote, it is not that hard to tear down one of these transmissions.

http://community.ratsun.net/topic/28473-how-to-put-together-a-shortshaft-5-speed-for-a-l20b/

If you get metal or ugly looking fluid when you drain the transmission, then just find another one in the wrecking yard, find it before you tear the transmission out, as it is a lot of work removing a transmission out of a 4X4 Nissan 720.

[Lockleaf]

I pull the engine to pull 4x4 transmissions. It can be done out the bottom, but it takes me longer to do that than to pull my engine. Since you plan to pull the engine anyway, just go that route.

 

The front diff has a large mount on the front cover, held in by one large bolt. Remove that large bolt, it will allow the diff to drop maybe an inch. While this may seem insignificant, it will save huge amounts of "oil pan catching on stuff" related frustration when removing and installing the engine.

 

Also, the short case can be swapped on to the long 720 trans I'm fairly sure. A little research should confirm that. So you can go with any 720 trans and assemble what you need.

[720inOlyWa]

Wayno, thanks. You understand that I am not here to NOT tear into it and learn something. Lockleaf, I agree and thanks for the front diff tip. It is all coming out. Tips like that really help.

 

Of course, it would be stupid to remove the engine and trans, ‘rebuild‘ it all, then find out that I messed something up in the transmission and now get to pull it all out again. THAT is some learning I would like to avoid. I figured the most likely scenario is that for my $60, I find out what the story is from guys who know what they are looking at. At least that way, I know what I am up against. Wayno is right when he says they charge an arm and a leg to rebuild a tranny. I have heard rumors up to 2 grand. I could never go there. But even with trannys that I have driven and know to be okay, I would still spend the 60 bucks to confirm their relative health for the miles ahead. Cheap insurance, I figure.

 

I met a guy who did Nissan service work and knew these transmissions inside and out. He is gone now. He also told me not to sweat it- they are pretty simple. He said that could show me how to totally rebuild one in an hour, and for not many bucks. THAT encouraged me. Whatever the diagnosis with this trans, I may take a shot at fixing it myself. What is the worst that could happen?- I have to buy another wrecking yard tranny? Could be worth it for the lessons learned.

 

One more factoid which may be relevant: I have noticed that since it has been parked in the same place for over a year, there is some leakage under the tranny. I haven‘t investigated, I just kicked a drip pan underneath and went about my business. I know that the truck sat for three years before I got it. Maybe it is low on transmission oil. Could be a significant part of the problem.

[wayno]

You see that is the thing, if you seen oil leaking from the front of the transmission case, then the front cluster gear bearing is likely bad if it is transmission oil, you don't even need to tear it apart to see that, first get the tranny out and look at the front cover that goes over the input shaft, if it is cracked or broken in any way, that will confirm that you lost a front bearing and would account for the oil leak as if the front cover is good, then it should not leak, then I would look at the rear engine seal for leakage.

It is not that hard to pull the front case off of one of them transmissions, if I can do it then you can do it, the first time I did take one apart I did it without any help from anyone or any book, I just took the front case off of a longshaft transmission, and then I put it on a short shaft transmission just to see if it was possible, I heard it was and I was very tired of buying and installing dogleg transmissions into my work truck, after putting in the 4th one in in 5 years I needed to find something else, so I figured out that 1985/86 regular cab short box trucks had short transmissions in them, I took a chance that it would work and it did, that first transmission I made lasted me 5 years, and the only reason I pulled it was because the 2nd gear synchro was shot and I was tired of it grinding into gear every time I shifted into second.

[720inOlyWa]

I will begin removing parts from the engine bay today, in preparation for pulling the engine and transmission. The leaking seems to be coming from the drain plug, not the case. But no matter, I‘d bet you are right anyway.  I‘ve got a line on an 85 regular cab 4x4 720 that should have a short shaft transmission. The truck is said to be dissolving, but the running gear is said to be there and free for the taking. It is worth the ferry boat ticket to investigate free 720 truck parts on Vachon Island. Agreed?

[720inOlyWa]

Well, the Vashon Island transmission score did‘t quite work out for me, but I still have my antenna up, looking for a short shaft tranny. Maybe I will just have to rebuild the one i have, and learn about transmissions. I dunno. n the mean time, we have an engine in the cradle (came out of the Fudgecicle) ready to head down to Johnstons machine shop after I tear it all down this week. As you can see, the head, which I had re-done on this engine, has the round intake ports while this engine has the squarish version intake manifold. It worked okay for 15,000 miles, but I wonder if it was ideal. Anyway, the 4x4  already has a squarish intake port Aussie head that has ten minutes on it since buying it brand new, so we are good to go there.

 

Old Man Winter isn't going to stop progress on my 4x4 720!

 

[720inOlyWa]

What a difference a day makes.

 

 

We‘re continuing our teardown indoors...

[Rhino13]

In progress or with old man winter?

[720inOlyWa]

Old man winter keeps the smoking lamp lit, says vey little, ironically wears fingerless gloves..

Meanwhile, I tear off clutch parts, front end bits, filling labeled paper latte cups with now familiar nuts and bolts.  I figured out that I can hook a garden hose to the hot water faucet on the old concrete sink in the garage and wheel this entire engine out into the driveway for a degreaser and hot rinse action. This works amazingly well. when I am done,  I can wheel it back into the garage and bake it dry overnight, next to Old Man Winters cot in the corner.