Help with transmission

[Aqualung]

I’m in need of a few transmission related parts for my 72 521 but I’m not sure the exact transmission that’s in it.  I know the truck has the right l16 engine but the trans is a 5 speed which was swapped in years ago by previous owner.  Anyway to know exactly what trans is in like stamps or the case maybe?

[greenthumb]

Datzenmike is your huckleberry. He’s on here regularly and can help to identify 

[datzenmike]

 

 

 

 

 

 

 

 

 

 

Is reverse above 1st gear?

 

Is it 26" or 31.5" long?

 

 

 

[Aqualung]

I’m not 100% percent sure but it looks like it’s gonna be the trans from a 240sx.  Reverse is directly below 5th gear.  The main problem I’m having is a severe oil leak from the speedometer cable where it attaches to the trans.

[d.p]

Why would a stock l16 be mated to a KA trans? Measure it. If it’s 26” or so it’s a dogleg if it’s 31” it’s a longtail.  My reverse is right under 5th and I have a 280zx trans. 
 

if it’s leaking out the Speedo cable take it out and see why.  Maybe the housing is cracked? 

[datzenmike]

 

The small one is the seal on the pinion. The larger O ring is the seal on the speedometer sleeve to the transmission case.

 

 

 

 

The end of the cable at the transmission end has a rubber top hat that should seal any oil from traveling up the spinning inner cable.

[Aqualung]

Thanks for the reply’s and helpful info. I’m gonna get under the truck in the next few days and remove the speedo pinion gear and inspect the seals and measure the transmission length as well.

[datzenmike]

The internal seal (small) is 32709-14600

 

The O ring is 32710-14600 but take it to any NAPA and go through their O rings for a match.

[Stoffregen Motorsports]

14 hours ago, d.p said:

Why would a stock l16 be mated to a KA trans? Measure it. If it’s 26” or so it’s a dogleg if it’s 31” it’s a longtail.  My reverse is right under 5th and I have a 280zx trans. 
 

if it’s leaking out the Speedo cable take it out and see why.  Maybe the housing is cracked? 

It ain't a dogleg. He said reverse was directly below fifth gear. Doglegs have reverse up and to the left. They are easy to identify by their smooth case (no ribs).

[d.p]

Shows how much I know. Should be a long tail 5 speed then? I mean what else would somebody stab behind an l16 ?

[datzenmike]

Could be a shorty 26" 71B with an L series front swapped on. Just those two if 26".

 

The 71B (long tail 5 speed) was used in the following and very common...

 

77-79 620

80 720

77-78 280z

79-83 280zx

78-80 810

81-84 Maxima* The above are L series. *also in LD diesel

 

'81-'86.5 720*

'80-'83 S110 200sx The above are in Z series.  *also in SD diesel, and 26" and 31.5" lengths on gas engines.

 

'84-'86.5 S12 200sx in CA series

 

 

[Aqualung]

So here’s a pic of the trans from underneath 

[Aqualung]

Here’s a pic of the oil leak Im dealing with.  It’s hard to tell in the picture but the cable is blocked by the cross member making it hard to access. 

[Aqualung]

Here’s the truck, I’ve been working on it to get it road worthy.  I inherited recently and it’s been sitting in storage for the last decade or more.  So far I’ve replaced the original carb with a Weber 32/36, valve cover gasket, plugs & wires,  clutch master and slave cylinder, oil change and new battery.  I’m not a mechanic by any stretch of the imagination but I’ve done all right so far with the help of my clymer manual.

[datzenmike]

It's an FS5W71B long tail but has the 521 clutch arm, adjustable push rod and the 521 slave... which is ok. Only the 521/510 and 610 ever used this. After '72 the slave had the return spring inside, I think, but the adjustment was done away with.

 

 

Below, connect the Red/Black stripe wires to the reverse switch above just to the rear of the dust boot on the clutch arm. It's behind the torsion bar.

 

 

 

 

[Crashtd420]

2 hours ago, Aqualung said:

Here’s the truck, I’ve been working on it to get it road worthy.  I inherited recently and it’s been sitting in storage for the last decade or more.  So far I’ve replaced the original carb with a Weber 32/36, valve cover gasket, plugs & wires,  clutch master and slave cylinder, oil change and new battery.  I’m not a mechanic by any stretch of the imagination but I’ve done all right so far with the help of my clymer manual.

Truck looks clean, What type of motor oil did you use?

You need something with more additives than the modern conventional oils offer...

Most seem to run a diesel oil or an oil additive... I'm sure datsunmike can clarify.. 

[Aqualung]

21 minutes ago, Crashtd420 said:

Truck looks clean, What type of motor oil did you use?

You need something with more additives than the modern conventional oils offer...

Most seem to run a diesel oil or an oil additive... I'm sure datsunmike can clarify.. 

I wasn’t really sure what to use tbh so I just went with Castrol gtx  10-30 because it was on sale.

[datzenmike]

Castrol GTX has a ZDDP level of only 800 which is a bit higher than most conventional oils sold today but if you go back to when Datsuns roamed the planet oil ZDDP levels were upwards of 1,000 ppm. Cars today do not need as much protection as our old Datsuns but skimping on the anti scuff package is maybe not a good idea when you can simply move further down the shelf and buy Shell Rotella T4 in 10w30 or 15w40 and get 1,200 ppm according to Shell. Chevron Delo 400 is similar. Most oil marked R for racing have a high ZDDP rating.

 

Next oil change switch to Rotella T4 or something in the 1,000 ppm range.

[Stoffregen Motorsports]

I always use cheap oil when I'm bringing a vehicle back to life, but then switch to something better at the first oil change. Then I install a shiny new FRAM filter and it's good to go.

[datzenmike]

The damage is slight but accumulative over a long time. Your valve train (rockers and cam lobes) are precious and almost impossible to replace. Oil makers have reduced the ZDDP levels to around 600-700 almost half what it was 30-40 years ago. They are quoted as saying that today's oils are reverse compatible and the original formula was overly high in ZDDP anyway. My opinion is that this is probably bullshit, (they really don't know or don't care or both) and just to be safe I changed to a diesel oil like Rotella T4 and sleep well at night.

[NC85ST]

Put the truck on ramps and remove the transmission mount bolts. Then put a floor jack under the transmission, near the mount  and jack it up until you have enough clearance. It shouldn’t need more than an inch or two. You’re not going to hurt anything or tear anything up as long as you don’t go crazy with the and keep an eye on things as you go up with it. Don’t forget to keep an eye on the shifter in the cab as well.

[datzenmike]

 

Oil usually runs down hill and I see that it's way up out of sight. I would first get some brake cleaner and wash that section of the transmission clean and let dry. Take for a drive and make sure it's the speedometer cable that is leaking and not the breather that are sometimes on that side.

[Aqualung]

4 hours ago, datzenmike said:

The damage is slight but accumulative over a long time. Your valve train (rockers and cam lobes) are precious and almost impossible to replace. Oil makers have reduced the ZDDP levels to around 600-700 almost half what it was 30-40 years ago. They are quoted as saying that today's oils are reverse compatible and the original formula was overly high in ZDDP anyway. My opinion is that this is probably bullshit, (they really don't know or don't care or both) and just to be safe I changed to a diesel oil like Rotella T4 and sleep well at night.

This truck won’t be a daily driver so I’ll be changing the oil annually, well before 3k miles,  I will definitely switch to the shell diesel oil next oil change.

[NC85ST]

4 hours ago, datzenmike said:

Oil usually runs down hill and I see that it's way up out of sight.

Good call. Yes, it’s well above the speedo cable.

[datzenmike]

IF... it is from the breather it could be the transmission is over filled. The fill hole and bung are usually on the left side about half way up the side. Full is when it reaches this level. It is possible to force oil in under pressure or lean the vehicle over to fill. Remove bung and see if it drains and that should do it. Other than that perhaps incorrect oil that does not have the proper anti foam package. It should have GL-4 80-90 w in it.