Clutch replacement, Nissan 720 4x4

[Syphious]

Hi, just to start off, I've already gone and read the other topics on the subject but just was wanting to know if someone knows step by step or something along those lines, of replacing the clutch on my '86 Nissan 720 4x4, Im not going to pull the engine, The clutch does disengage like it should, Its just very worn and slips in lower gears sometimes and has nearly no play or "gripping point" until the clutch is completely released nearly, That and the throw out bearing makes a supercharger like whine at certain rpm's (fairly sure its the bearing but of course theres no way to be sure)

 

Ive replaced a clutch on a Mazda B2600I and it was pretty simple and easy, we didnt use and jacks but just had a couple people under the transmission holding it up but I dont have the luxury of having extra hands but I will be able to get ahold of a car jack for the process. 

 

This all aside, whats the order that I would take things off and apart and the best or fastest way to do it properly? and what needs to come off and doesnt? Looking under the truck, In order to get the transmission moved any, the 4x4 model has quite a bit of extra hardware attached down there so what needs to come off, be loosened, and ive read that the transmission doesnt drop but an be moved back enough to get the new clutch and parts all in there? Would that be done by removing the driveline as well? Just want to make sure I get this done right and id only have two days to do it, probably a max of 6-8 hours to do the project and thats if I can get my friend to help because doing it on my own would take a while longer it seems.

 

Thanks in advance, Sorry for all the extra reading but im trying to be thorough!

[datzenmike]

Welcome to Ratsun. An '86 deluxe? Is that a King Cab then? If so it might have the shorty 26" long 5 speed. This will give you more room to remove it or maybe just move it to the rear enough to get at the PP. I have only done a long 31.5" transmission and it's very tight.

 

Wow a 4x4? I would lift the engine and transmission out together and do it..... but as you are not, I'll let someone that has done a 4x4 explain what needs doing. 

[Lockleaf]

I have an '85 on which I have done multiple clutches and pulling the engine really is the easier way.

 

Having said that, to pull your trans out the bottom, you will need to disconnect the half axles from the diff, remove the front driveshaft from the diff, remove the diff and crossmember from the truck.

 

Next remove front driveshaft from the tcase. Then remove the intermediate shaft from the tcase and trans. I think you need to remove the shifter from inside the cab. At this point you are ready to remove the engine to trans bolts and drop the trans crossmember and remove the trans. Some people have had odd interference with their exhaust, so sometimes that had to be taken apart somewhere to get more clearance.

 

Theoretically it might be possible to leave the trans in the truck body and simply slide it backward enough to do the job, but I think this is even more difficult and didn't make the job any easier and increases the likelihood of the clutch not going in right because you couldn't clearly see what you are doing.

[Syphious]

Thanks for the welcome, Ive been on the forums quite a bit before but just never joined. I have a Sach's Clutch kit as well that I didn't mention earlier, It was on sale for about half off and I saw nothing bad when researching the brand.  And yeah an '86 deluxe king cab, I wasn't sure it was the deluxe model until I saw on a vehicle report that the VIN checked it out as deluxe and was like well sweet!  And 26" long 5 speed? That a different transmission than most other models then or wha? 

Exact model is 1986 Nissan 720 DLX/ST 2DR Pickup 4WD M5, Just remembered I saved that on a text doc on my computer

 

And alright well shoot.. How long would it take to do the project for my first time then? Im really good at learning things like this and can figure out pretty quickly if somethings been done right or not, This just seems like a much larger project than I anticipated compared to that mazda I helped with, That was easy.. I dont think the place I have to work in has a cherry picker either to pull the engine with, much less anything more.. This may be a project I have to go to my dads and do and leave for a few weeks and be stuck with my car, Not that thats a problem but still, my dad could help a bunch though, hes done a ton vehicle work just not on a truck.... Theres just a lot more extra components to be removed in this case. How difficult is it to pull the engine? And yeah looking under the truck I saw that the exaust is probably going to be a problem. 

 

 

I would include some pictures for show but have no idea how to post them or get them linked like the option we have, It wont load my public google drive photos, Probably cause its not just the picture. Its in really good condition though, Cosmetically stock, Paint could be better but still shines real well in sun and the interior is nearly perfect aside from the dash being cracked in two small places. Picked her up for $1100 and I put a Weber into her, tuned it myself , Oil change, spark plugs and she runs great!  Stereo they had in it was wired up all wrong but that was an easy fix

[datzenmike]

The only difference between the 26" and the 31.5" 5 speed is the 5.5" difference.

 

I guess I did say engine and transmission. What I meant to say was just remove the engine to replace the clutch.

[Syphious]

Aah mkay and yeah ill have to see about the time constraints, id only have two days from 5pm to probably 10pm to work on it at the place thats nearest to me otherwise im gonna have to make a decent trip out to my fathers... And back. Be without my 720 for a while though and thatd suck but im excited for the new clutch

[Lockleaf]

If you pull the engine, you could probably do it in ten hours your first time. Take power steering and a/c off the engine and leave them connected in the engine bay. You don't need to drain the engine oil though you can if you prefer.

 

Pull fan shroud.

 

Draining the cooling system on our trucks is the worst. The petcock on the radiator is dead center over the front crossmember of the frame with no good way to not make a HUGE ridiculous mess. Many 720s have a union in the middle of the lower radiator hose. I usually jerry rig a funnel or series of funnels under that union and drain it there. Still a joke but it's better.

 

Once empty pull the radiator. That should give you the clearance to pull off the fan. Remove that.

 

You'll need to take off the exhaust manifold, the heater hoses, and the fuel line. Also the electrical connected to the carb, the oil pressure sending unit (under the intake manifold by the oil filter) and the coolant temp sensor. There's a couple other random connections to watch out for but I don't recall them all.

 

Remove the engine mount bolts and the trans to engine bolts. You can leave the intake manifold on the engine.

 

Clearing the diff with the oil pan sucks. Pulling it out is annoying enough but going back in is the hard part. The key is to tip the motor pretty far back so the the pulleys are pointing more upward. Then get the trans jacked up until it almost hits the tunnel. This will allow you to get the trans lined up and slip the pan past the diff. It's still a fight.

 

In spite of how much suck there is in that process, it sounds worse than it is and it still beats dropping the trans.

[datzenmike]

First thing... REMOVE BATTERY CABLES!!! Even remove the battery. Damn I have taught myself this several times by welding a wrench to the rad support or letting the magic smoke out of the wires..

 

You may find the three bolts on the down pipe easier to remove from the exhaust manifold and easier to slip the engine back in without the manifold in the way.

 

Support the front of the rad with a jack. It can be adjusted up and down to help split the case from the engine and when installing.

 

If rad or heater hoses are old enough to replace slit lengthwise with a carpet knife and peel off. This is preferable to tugging on old solder.

 

For under $5 you should replace the pilot bushing as well while in there. This can be done with the flywheel on and is quick and easy. Just slit lengthwise using a bladed screwdriver and hammer. Three slits, push sections into the middle and lift out. Takes 20 seconds and no special tools.

 

 

 

 

Start new bushing with a soft hammer and finish hammering in by covering with a block of wood. The bushing is really sintered bronze. This is a process where by bronze powder is compressed in a die under tremendous pressure then heated to fuse the particles together and then soaked in oil to permanently lube them. It's porous and softer than it looks.

 

[Syphious]

Well, Doesnt sound too bad but does sound like it could be a pain.. And be a lot worse on other vehicles.. Thanks for the instructions and when I find a place to actually get this all done at then ill have to use them! If I have any more questions ill just ask here.

 

And my hoses are all fine actually, The only things I dont like in the engine bay is the cracked radiator fluid overflow container, And the ground that goes to the engine block is partially dangling there and is really old and I feel that it needs replacing, Other than that the engine bay seems pretty clean and well kept.

 

If I had more money Id say screw it and do extra work to the truck while im at it.. I've wanted pacesetter headers and have been wanting to rebuild the engine and maybe paint the block and valve cover and all.. But I guess thats for another time and ill know the truck better then too

[datzenmike]

Just remember that the Z series are not screamers and not at all designed with any performance potential. Their head design limits what they can do and below 4,500RPMs they do an excellent job, but above they quickly run out of steam. All exhaust manifolds are more than adequate and a header will never see the RPMs where it might add something. Save the money and spend it on something you will notice.

[Syphious]

Yeah I know that, haha.. They arent fast at all but arent bad off the line and handle fairly well for an old truck. I mostly wanted the exaust header just for looks and ive got an exaust leak. Although the leak could likely be fixed as is..Exaust header thats stock on it is missing some bolts and im not wanting to break anything off in the block either

[Syphious]

Oh and btw, While looking under my truck at what would need to come off, I found a power steering fluid resevoir cap sitting there, Anyone need an extra? Haha.. Its been carb cleaned and I have no use for it

[Thisolddatsun]

My experience in my 81 king cab 4x4 if yours is divorced this will help. As of recently I pulled the whole transmission out. But to do the clutch WITHOUT taking the engine out. Take the 2 bolts out of the front diff support. Leave the 1 in front in but loosen it you can unbolt the cv axles if you want to but isnt necessary. Unbolt the transmission mount from the transmission and the crossmember the transmission mount is on. unbolt the slave and take the shift lever out and unhook any wires going to the trans. With some "finess" bench press the transmission and slide it back. You might have to rotate the transmission an wiggle it. Mine was the 31.5" Transmission yours is probably shorter so you dont have to fight as much stuff in the way. If you want to go the extra mile take the front diff out and you can drop the whole transmission and push it out if your way and you can put your clutch on. Take the exhaust manifold atleast unbolt it from engine, take the starter off, primary and your front driveline check your U joints and grease them, I think thats about everything. You will need open ended wrenches and a socket wrench lots of extensions maybe a elbow/wobblie the sizes you should need are 14mm for transmission,starter,slave, driveline bolts. 12mm for clutch and exhuast manifold bolts.

17mm maybe 18mm for the crossmember, tranny mount bolts. 22mm for the front diff. I that should be all the tools you need. Atleast I hope so cause thats what tools I took with me to the junkyards today. Haha

 

I have done it without loosening the front diff and it is a royal bitch. You have to put everything on throwout bearing collar fork PP and disk on the imput shaft then onto the flywheel to bolt it all on because to get your hands in you need the transmission at this spot but when your at said spot the disk and PP wont go into the flywheel because the input shaft is in the way. Just from what I noticed pulling my transmission the extra time spent loosening some bolts and moving the front diff even a little makes a huge difference. You also don't have to undo the front diff if you unbolt the trans and find out if theres enough room without loosening the front diff by all means dont worry about it. And if you do have to unbolt the diff then just push the transmission out of the way and unbolt it. Enless you have a king cab your transmission is most likely different but its only 5" difference. Everything else is the same for the most part.

[datzenmike]

 I mostly wanted the exaust header just for looks and ive got an exaust leak. Although the leak could likely be fixed as is..Exaust header thats stock on it is missing some bolts and im not wanting to break anything off in the block either

 

Looks? 99.9999% of time no one is going to see it not even you. Get a stock manifold and spend the money towards a weber 38/38 or 32/36 carb. The Z24 carb is a bit undersize and while it gives good mileage, it isn't that fast. Most owners that have carb swapped find it gives you a pleasant and noticeable improvement, the header won't do anything. The bolts have to come off anyway and at least they are super easy to get at on a Z series engine.

[Syphious]

Lol, ik, ik, im just saying.. Nothing wrong with a bit of flashy pointless crap right? Lol. And as for the carb ive already done that, i installed a new weber 32/36 and have it tuned properly. I just think im gonna get new bolts for the exaust head though to stop the leak and call it good cause the truck is good otherwise. Had a family friend test my.clutch and he bled the clutch and it works fine. First damn thing i should have thought of but i have an extra clutch i can keep for later or sell now.. Got it half off new anyway

[Syphious]

And as far as vacuum lines, I just need the dist. Line going into the carb right? The rest can be removed? Or should i T the dist. Line with the EGR and AAC? Since it probably is important that they are still used beings as the trucks use the extra set of plugs.. Anything else need to be run anywhere like what lines need to go into the water temp sensor looking thing that has vac lines? (Forgot what it was called sorry). I have tested Engine for if it pulls pressure properly and it does but half lines are a mess other than what i made a makeshift solution for

[datzenmike]

The Vacuum advance and the EGR are two separate ported vacuum sources. You can just leave the hose off the EGR to disable it but you want the distributor advance working.

 

Do you have two wing nuts holding the air filter housing on? or only one?

[Syphious]

Aah mkay, that simplifies it quite a bit then. And my filter uses 6 little clips to hold the filter itself on, and the housing uses four bolts that go into the carb, why?

[Syphious]

Mkay so its to a dying topic now but i just wanted to thank you guys for the help, running just that vacuum line and t-ing it to one other line into the carb, works so much better and is so nice to get a straight up answer on the vac. Lines, mechanically she runs near perfect now! New dist cap should fix the rest, it has a very slight misfire, new plugs and wires, coil packs seem fine but ive not checked.

[Syphious]

K well your reply didnt show up mike, But I read it in my email but yeah, I said earlier that I installed a 32/36 DGEV. Works great, I just need my next paycheck in order to get the minor stuff it needs. May just get new plugs and wires anyways.. My wires were cheap 20$ wires anyway but i need the dist. for sure, It could be stock possibly..

[datzenmike]

I posted something but then found the reference to having  a weber.

[Syphious]

Ah, mkay. Thatd explain it

[Syphious]

Mm, are there any other plugs we can run through the Z24 other than copper? Any platinum plugs? Or would it be pointless?

[datzenmike]

NGK is what they come with and run best with. I have run L series on NGK iridium? (the ones with the fine needle point) they ran good but the motor was in excellent shape.

[Syphious]

Well i know you dont run anything other than NGK in jap vehicles, especially nissans, ive just got the normal plugs and was wondering if there was anything else. And I dunno, I probably wouldnt want to run those then unless I rebuilt my engine then just to be safe although it seems to be very well kept. Ive kindof wanted to swap a ka24e into it sometime but thats just an idea since the z24 still runs so well