Got it to pass smog, the work begins now... 1986 Nissan 720 project

[A guy named Rick]

How hard is it to rebuild a 5-speed in a 720? I am going to try replacing the fluid first and see if I have any positive results, but this thing is suffering in agony. It will confuse me and make it sound as if the engine is pinging sometimes. Pretty sure some bearings are going. It's most notable under load, definitely 4th and 5th but 3rd is starting too. I'm thinking the new sound I'm hearing that sounds like pinging could be the input shaft. 

Edited September 12, 2021 by A guy named Rick

[datzenmike]

Pinging is also classic dry seized U joint under load. Sounds like ball peen hammer tapping the drive shaft.

 

Drain the old oil and look at it ans what falls out plus the drain has a magnet on it. This is not a good sign...

 

 

I've drained transmissions in the wrecking yard and ball bearings from the counter shaft fell out. Another the oil looked like silver paint. I stopped right there.

 

[A guy named Rick]

7 minutes ago, datzenmike said:

Pinging is also classic dry seized U joint under load. Sounds like ball peen hammer tapping the drive shaft.

 

Drain the old oil and look at it ans what falls out plus the drain has a magnet on it. This is not a good sign...

 

 

I've drained transmissions in the wrecking yard and ball bearings from the counter shaft fell out. Another the oil looked like silver paint. I stopped right there.

 

 

Lol 😆 well my u-joints are ok. Plus I have new ones ready, but when I had taken the front half of the shaft to get the support bearing replaced, the guy said the u-joints were fine. 

 

It's been awhile since putting fluid in this transmission. What's the trick to filling it without making a mess or have it running down my arm. Gear oil is disgusting stuff 😒 

[datzenmike]

Couple of feet of garden hose...

 

 

Kitchen funnel from a dollar store...

 

 

Holds about 2 liters so when you get close let the hose drain. It's full when it leaks out around hose. Some will dribble out so have newspapers under. Yank the hose and pop your bung in quickly. Spray down with carb/brake cleaner and dry so you can see any future leaks.

 

In cold weather warm the oil in hot water, it will pour faster.

[A guy named Rick]

4 hours ago, datzenmike said:

Couple of feet of garden hose...

 

 

Kitchen funnel from a dollar store...

 

 

Holds about 2 liters so when you get close let the hose drain. It's full when it leaks out around hose. Some will dribble out so have newspapers under. Yank the hose and pop your bung in quickly. Spray down with carb/brake cleaner and dry so you can see any future leaks.

 

In cold weather warm the oil in hot water, it will pour faster.

 

Brilliant 👏 

 

Edit: I just read this again and noticed you said liters. My American mind remembered reading quarts instead, which is ok because 2 quarts is less than 2 liters anyways. 

Edited September 13, 2021 by A guy named Rick

[A guy named Rick]

On 1/6/2017 at 2:14 PM, datzenmike said:

80w90 GL4 is the same thickness as 80w90 GL5 and would shift the same. However differentials need extra scuff protection on the tooth faces that transmissions do not. This anti scuff additive contains a sulphur compound (you may have noticed the smell when changing the oil?) that in GL4 is in an amount (about 4%) that does not bother the copper/brass.bronze synchronizer rings. GL-5 oil contains it in about 6% concentration, which is 50% stronger and will over time tarnish and erode the copper.

 

GL4 is more than enough protection. GL5 is not good for Datsun transmissions.

 

Even GL4 should be changed at the recommended intervals. About 5 years 30K miles

 

Well, shit... this is what I used back then...

And must have drove 10,000 miles on it... 😬😬

 

[A guy named Rick]

Needed about a 4 foot bar to get this off. I wonder if previous owners ever changed it. Probably not, since it was designated a junk vehicle.

 

When I "changed" it, I let it drain out the tail and replaced.

 

Edited September 13, 2021 by A guy named Rick

[A guy named Rick]

So I ran into the problem of finding GL-4. I got some Lucas 80-90, but it says it meets or exceeds gl4 and gl5. So I went to Chevy because they had some GM GL-4 75-85. @datzenmike will this be ok? 

[datzenmike]

 

This is no problem. It takes a long long time for this stuff to do any damage.

 

 

Completely normal, but not so much if this was cleaned 10K ago and this is the wear since.

 

2 hours ago, A guy named Rick said:

So I ran into the problem of finding GL-4. I got some Lucas 80-90, but it says it meets or exceeds gl4 and gl5. So I went to Chevy because they had some GM GL-4 75-85. @datzenmike will this be ok? 

 

The Lucas may nbe alright because it may be synthetic and it may not have the GL-5 anti scuff content. If it says 'yellow metal safe' or 'okay for brass synchro rings' then ok. The GM oil will be fine.

 

[A guy named Rick]

1 minute ago, datzenmike said:

 

This is no problem. It takes a long long time for this stuff to do any damage.

 

 

Completely normal, but not so much if this was cleaned 10K ago and this is the wear since.

 

 

The Lucas may nbe alright because it may be synthetic and it may not have the GL-5 anti scuff content. If it says 'yellow metal safe' or 'okay for brass synchro rings' then ok. The GM oil will be fine.

 

 

I had never removed the plug.

 

So I have a dilemma. My fill plug is seized. I'm assuming it is a 18mm, since 17mm is too small and I do not have an 18mm wrench. Also, the corners are rounded. I'm a little screwed. Unless there is another way. I don't have a welder to welder a socket to the fill nut. I wonder if JB Weld could work.

[datzenmike]

Use a monkey wrench, a pipe wrench it never fails. Put a foot and a half of pipe over the handle to increase leverage. If you can drive it around for half an hour to get the transmission hot. Aluminum expands from heat about twice as much as steel making the hole larger than when cold.

[A guy named Rick]

2 hours ago, datzenmike said:

Use a monkey wrench, a pipe wrench it never fails. Put a foot and a half of pipe over the handle to increase leverage. If you can drive it around for half an hour to get the transmission hot. Aluminum expands from heat about twice as much as steel making the hole larger than when cold.

 

I think the monkey wrench i got is too big (14 inch). Probably need a 10inch. There's an electrical thing screwed into the side (neutral safety switch? Idk) that's not even hooked up to anything that gets in the way when attempting to use the monkey wrench.

[Charlie69]

GL 4 on Amazon

https://www.amazon.com/CRC-Sta-Lube-SL24239-Multi-Purpose-Hypoid/dp/B000M8RYMC/ref=sr_1_5?dchild=1&keywords=gl4+gear+oil&qid=1587304422&sr=8-5

 

[captain720]

If you buy a cheap little hand pump for a few bucks the gallon is really the way to go

[A guy named Rick]

Now that I think about it, I don't remember if I was able to get the fill plug off before. I think I may have refilled it through the sensor that's screwed in next to it. Is that possible to do? A deepwell socket will remove that. Is this possible to do? I'm not sure if it is the reverse or neutral safety. Either way, it's not hooked up to anything. I'll take a pic later.

Edited September 14, 2021 by A guy named Rick

[Charlie69]

The plug is a larger diameter hole.  Like mike said use a pipe wrench and get the plug out.  I usually try to tighten a stuck plug or bolt a little, just enough to get some movement, then loosen and remove.  When you get the plug out buy a new one to put back in.

[A guy named Rick]

1 hour ago, Charlie69 said:

The plug is a larger diameter hole.  Like mike said use a pipe wrench and get the plug out.  I usually try to tighten a stuck plug or bolt a little, just enough to get some movement, then loosen and remove.  When you get the plug out buy a new one to put back in.

 

Problem is, the pipe wrench i have is too big it seems. I might try a smaller one. If all else fails, hypothetically, I can fill through there right?

Just trying to get it filled back up. I have some stuff to haul off still. Once winter comes, I won't be driving this much at all and that might be the time I start getting some stuff done on it. Figuring out if I'm keeping the napz, or going with a KA, and doing a lot of other stuff.

[datzenmike]

My pipe wrench is 14-16 inches long with about a foot of pipe extending the leverage length. As there isn't a lot of positioning choices with a square, I once had to dig a hole in the drive way. The bung doesn't really need a lot of torque to fit and be leak proof. Snug it up good, spray degrease  and dry it and check in a few days. Over tightening is usually why they are a bitch to get off... and the steel tends to grip tighter to aluminum over time. An anti seize paste helps.

[A guy named Rick]

5 minutes ago, datzenmike said:

My pipe wrench is 14-16 inches long with about a foot of pipe extending the leverage length. As there isn't a lot of positioning choices with a square, I once had to dig a hole in the drive way. The bung doesn't really need a lot of torque to fit and be leak proof. Snug it up good, spray degrease  and dry it and check in a few days. Over tightening is usually why they are a bitch to get off... and the steel tends to grip tighter to aluminum over time. An anti seize paste helps.

 

I could always use a dead blow hammer to the end of the pipe wrench haha.

 

But seriously, could I fill through the reverse sensor right next to the fill plug? I think, but am not sure, that I did this before. 

[datzenmike]

It's a form of electrolysis corrosion and grips like it's welded. You want something that shocks it suddenly from that aluminum grip. Heat around the bung with a propane torch. Use a 6 lb sledge hammer. I pull downwards with 30-40 pounds and smack the pipe over the handle. Makes a snap sound then pretty much spins off by hand.

 

Better to fix this problem rather than going around it.

[A guy named Rick]

12 hours ago, datzenmike said:

It's a form of electrolysis corrosion and grips like it's welded. You want something that shocks it suddenly from that aluminum grip. Heat around the bung with a propane torch. Use a 6 lb sledge hammer. I pull downwards with 30-40 pounds and smack the pipe over the handle. Makes a snap sound then pretty much spins off by hand.

 

Better to fix this problem rather than going around it.

 

I understand. I know this transmission will be coming out eventually.

 

I got it filled, drove it a bit. Still noisy, I wasn't expecting any miracles. In my 240z (in another city) I have an engine and transmission from a 1976 280z. I can't remember if it is a 5-speed or not (never have driven it with that engine and transmission combo; it was an automatic originally I was converting when it started to sit) I know the 5-speed was an option, and was a wide range up until 78 or 80. 

Would i be able to just swap bell housings or entire case and run it on my truck. Forgive me, I know it's been covered before, and have read about this, just want to be sure. I know the l-series tits to the passenger side, z-series is more straight, so z bellhousing needs to be used. 

[datzenmike]

240z and 260z 4 speeds were wide ratio giving a small advantage to the lower displacement engines but 4 and later 5 speeds in the larger L28 powered 280z were a mid ratio including the first year '79 280zx. The 4 speed was discontinued for the '80 280zx model year.

 

Build dates from August '76 and on, the beginning of the '77 model year, cars had an optional 5 speed. A '76 would only have the mid ratio 4 speed unless swapped in. After 50 years of keeping a Z car on the road anything could be in it.

 

L series transmissions

Wide ratio first gear..... 3.549 used in early 4 speed z cars and the 620 truck as well as 5 speed trucks

Mid ratio first gear....... 3.321 used in 280z, 810, Maxima and trucks.

Close ratio first gear.... 3.062 only used in the '80 and up non turbo 280zx

[A guy named Rick]

12 hours ago, datzenmike said:

240z and 260z 4 speeds were wide ratio giving a small advantage to the lower displacement engines but 4 and later 5 speeds in the larger L28 powered 280z were a mid ratio including the first year '79 280zx. The 4 speed was discontinued for the '80 280zx model year.

 

Build dates from August '76 and on, the beginning of the '77 model year, cars had an optional 5 speed. A '76 would only have the mid ratio 4 speed unless swapped in. After 50 years of keeping a Z car on the road anything could be in it.

 

L series transmissions

Wide ratio first gear..... 3.549 used in early 4 speed z cars and the 620 truck as well as 5 speed trucks

Mid ratio first gear....... 3.321 used in 280z, 810, Maxima and trucks.

Close ratio first gear.... 3.062 only used in the '80 and up non turbo 280zx

 

Sooooo probably not a good idea then

[A guy named Rick]

On 10/20/2010 at 6:50 PM, datzenmike said:

 

FS5W71B

 

 

 

2wd Z22 motor reg, long wheelbase and KC.

 

1st... 3.321

2nd... 2.077

3rd... 1.308

4th... 1.000

5th... 0.833

 

2wd SD22 motor reg, long wheelbase and King Cab.

 

1st... 3.592

2nd... 2.246

3rd... 1.415

4th... 1.000

5th... 0.813

 

4wd Z22 motor King cab only

 

1st... 3.592

2nd... 2.246

3rd... 1.415

4th... 1.000

5th... 0.813

 

 

 

1..3..5

2..4..R

 

 

The 4X4 and diesel gears are identical but the speedometer is driven off the transfer case in the 4X4 so the tailstock of the 4X4 will not have the hole for the speedo drive pinion. The diesel starter is on the driver's side so the transmission will not bolt to the gas motors. Generally the transmissions are 31.5" long but there are short 26" 5 speeds, I have one from a 4X4. The shortness is all in the tailstock. Front and rear case halves will swap as well as internal gears (in sets). An L series front case can be swapped onto any of the '81 5 speeds from a 720.

 

Man, I know how to search. From 2010! 

 

Is the Z24 ratios the same? If so, and if the 5-speed i have is actually the original one from 1976, this site lists the ratios for the 1970-73 4 speed 1974-75 1/2 4 speed 1976-78 5 speed as being:

 

1st gear 3.54, 3.592, 3.321
2nd gear 2.197, 2.246, 2.077
3rd gear 1.42, 1.415, 1.308
4th gear 1.00, 1.00, 1.00
5th gear - - .864

 

The 76-78 5-speed would be the same ratios as the Z22. Is Z24 same??

[datzenmike]

First the '76 wouldn't have a 5 speed unless swapped. So first things first.... do you have a 5 speed or not.

 

This is the 71B 4 speed they all have that rectangular plate with 6 bolts and a round flat breather. The 71B 5 speed does not.

 

 

If you have confirmed you do have a 5 speed, to determine if wide or mid ratio, mark the input and the output spline at say 12:00 and place in first gear. Have someone turn the input 20 times while you count the output turns. 

 

20/3.592= 5.56 turns.... Wide ratio

20/3.321= 6.02 turns..... Mid ratio

20/3.062= 6,53 turns.... Close ratio. This will work for a 4 speed also.

 

The '71 71B 4 speed was used all years of the 240/260/280z with wide ratio through '74 and mid ratio for the '75 and up 280z. I think I said this earlier.

 

720 trucks.

All 4x4 were wide ratio 4 and 5 speeds. Not good because there is no provision for a speedometer in them. Speedometer is in the transfer case.

 

1980 2wd were wide ratio because small L20B engines

1981-'82 Z22 were all mid ratio except Cab/Chassis, diesel and KC/long bed trucks

1983 Z24 were all mid ratio except diesel.