Fairlady Engine, Transmission, and Differential Servicing

Replaced engine, transmission, and differential oil two days ago. I used Castrol Magnatec 10W-40 for the engine...as usual (1 Gallon + 1 liter). As for the tranny and differential, I switched from Mobil to Conoco since I wanted to try it out if it would make a difference. Price wise, the Conoco is a bit more expensive than the Mobil oils so I hope it's worth it. For the transmission, I used Conoco 80W-90 gear oil (API-GL5) and for the differential I used Conoco SAE 140 (API-GL4) oil. The mechanic at the auto shop as well as several Datsun Fairlady roadster owners recommended that I use SAE 140 oil for the differential to lessen the gear noise and to better protect the differential gears during high speed operation. But in the www.311s.org website, the recommended differential oil is 90W. I'll have to evaluate the performance of the SAE 140. The good thing is that it's really hot here in the Philippines, so the 140 weight wouldn't "freeze-up."

Driving impressions: For the engine, I've been using Magnatec since I bought the Fairlady and I'm really impressed in its performance. So far no smoke from the exhaust, start-ups are much easier even during the mornings, and oil consumption isn't an issue, but there's a small leak in the engine. For the tranny, the Conoco 80W-90 is the same with Mobil's 80W-90. Shifting is still light without much noise. I'll have to evaluate this in the long-run. For the differential, the SAE 140 will be much thicker than the 90W and 80W-90 I used previously. I haven't noticed any difference during standing starts. I'll have to see what happens when I'm driving down the highway at high speed. Hopefully the thicker 140 weight will better protect the gears during long operations. In the future I might switch to a 85W-140 differential oil...that might be better.

Caltex Extended Life Coolant

Today, I decided to replace the coolant in the roadster. It's been a year since the coolant was last drained and replaced. I used Caltex's Extended Life Coolant, which seems an ok choice, since it's also used by Ford, Jaguar, Mercedes-Benz, Volkswagen, Audi, etc plus it's also affordable at P240 a liter. Based from the specification chart at the back, the maximum service interval for this coolant is five years for passenger cars...not bad at all.

So I drained the old coolant, which was, by the way, alreay brownish in color - must be from the rust and other crud in the cooling system. The old greenish color of the coolant wasn't as visible as it used to be...it's already been dilluted. Then I poured water into the filler neck to wash out some of the left over crud in the system. Next is I mixed Caltex's Extended Life Coolant with water - about 30% coolant concentrate and 70% water. After which I started the engine and checked for leaks. I'll test drive the roadster later to check whether the coolant is doing it's duty...I hope!

I also replaced the fuel line from the fuel filter to the carburetor...the old one has started cracking...must be due to the heat and vibration. The other day I also cleaned the fuel filter using carburetor cleaner. So far engine start-ups and idle are much better. My next mission is to have the tranny and differential fluid checked and if the budget permits...replaced.

Restoration Update:

Finally I'm back home after a two month stint in film school.

I started the roadster this morning... after two or three engine revolutions the R16 started with no fuzz or hesitation. There wasn't any blue smoke from the exhaust, which is a good sign indeed. I adjusted the engine idle to lower RPM. Also had to bleed the clutch system. The clutch pedal bottoms out, but it still disengages the tranny. I'll have it checked one of these days.

Then I took her for a ride after lunch. Brakes were also ok, but with a hint of stuck-up on the right front caliper. I had a blast driving with the top down...the air was cool and it was windy. Had a great time with my Fairlady.

Will have to replace the transmission and differential fluid soon. Tranny still has this whine. Engine oil change is also due.

Well at least the roadster is driveable and the engine is still strong. I was tempted to open up the throttle :)