76 710 wagon rear shocks suggestion

[Johnny76710]

I’m wondering if I should go with KYB shocks ? Also the front end  are struts they need to be redone I’ve heard of changing out at cartridge ? 

[banzai510(hainz)]

stock are kyb gr2S

"Gas A Just "is their high pressure version

 

if you want just stock all the manfufactures are OK but i do prefer gas.unless its the old KONI orange shocks which I love

[datzenmike]

The front shocks (or dampers) come from the factory in an oil bath. The strut tubes are filled with oil and the valves and pistons are inside. If you have the original struts you have two choices. You can empty them out and replace with a smaller cartridge shock absorber. But make no mistake it's not made for the 710 and is likely a generic shock made for something else. They work, but aren't cheap. The other is to empty out the old, watery, thin hydraulic fluid and refill with thicker viscosity motorcycle fork oil. You get to keep the factory compression and rebound rate and ratio valving for a 710 but the thicker oil is harder to push through them and this makes them firmer. I used 20W Belray fork oil that costs about $17 for a liter, enough to fill three struts.

 

Old oil

 

 

 

 

[Johnny76710]

I’m going to try and work on them sometime soon I have the fork oil already. How much are the cartridge?  Whitch is better ?@datzenmike

[datzenmike]

I've never bought then or used them. A quick check showed $50 for cheap ones to maybe 3 times this? EACH! Maybe someone else can say more?

 

Suspension and ride quality is very personal and what fits one person or the rest of the herd isn't always what you may like. You almost have to try things yourself and sort out what doesn't work. In very general terms some stiffening of the springs will improve handling and absolutely essential if lowering to prevent bottoming out. If stiffer springs... then firmer or new shocks/dampers. Only you can say what works for you. For example on the 510 the stock spring rate is about 89 lb/in. (Race prepared can exceed 300 lb/in) The average increase is 175 to 225 lb/in. Or double at least but how does this translate to ride stiffness? Is it twice as stiff??? What is stiffness? Is it measured in un-comfortableness???  How do you compare the resulting ride quality?? Well you can't as it's all subjective and we are all different in our tastes. If going stiffer, err on the lower side and work your way upward is my advice. Don't just select 200 lb/in because that's what everyone else did.

 

I was happy calculating and adjusting my spring rate, lowering with a few hand tools (it's adjustable, but like I mentioned who ever adjusts coil overs once you get the ride height where you like it???) and refreshing my dampers. Cost me under $50 and best of all I did it myself and learned a lot about how things work on a suspension. Like introduced bump steer and how to correct it. I'm happy with the ride quality around town and on 2k road trips. Not every one will be in my position to do it this way and it may be easier (but certainly not cheaper) in the long run to just buy coil overs and inserts.

[DatsSully]

Not to hijack the thread but I'll be doing a 280zx strut swap on my 710 soon. They didn't come with the inserts, would the oil inserts from my original struts swap in or will I need to purchase gas shocks? 

 

Also I recently replaced my rear shocks with basic KYB's, they seem to have improved the ride quality a small amount compared to the 45 year old shocks. Just don't try to tighten the bottom bolt too much, or better yet replace it with a new grade 8 bolt. Otherwise you might be spending some time with your good friends drill and tap.

[Johnny76710]

Hey How did the swap go on the 710? @DatsSully I haven't done anything yet to my suspension. 

 

[Johnny76710]

@datzenmike I asked my mechanic about draining the fluid for me and refilling it but he doubted me and said hes tried that before and it ends up leaking. If you can please send me a link on the Cartridge/inserts or a suggestions on how I can stop it from leaking when replacing oil. Thanks 

[datzenmike]

 

 

Gland nut top. Underside of gland nut is a seal that keeps the oil in.

 

 

Below the gland nut threads is another seal or O ring. 

 

 

I do all my own work. The O ring was carefully removed cleaned and replaced when assembling. Maybe he forgot these or damaged them when removing. I used a dental pick to remove them.

 

I have no links because I didn't want to replace the oil bath ones. Replaceable inserts are OK, but they are not for a 710. They are like shock absorbers, often one size fits many different vehicles and just the mounting ends are different. By keeping the oil bath dampers you keep the stock compression and rebound valving. KYB may be nice and all but they're made for a VW Rabbit or something else and not for a 710. Sure it will work but...   ... and I can say I 'did it myself'.

 

[Johnny76710]

Thanks mike I definitely have hope whenever I decide to do work on this project  that I can make it work without leaking . I also have a different question do I have  1976 datsun 710 wagon 4 door 4 cylinder Manual transmission original carburetor. What should be my  temperature ? I use 20w 50 convention  Motor oil. The guy I bought it from said he ran the car on 160 degrees and it’s not running at that anymore so I’m assuming I need to replace the  thermostat but I’m wondering what  temperature is the best 160,170,180? @datzenmike

[datzenmike]

It's designed to run at 185 F ish so a 180F should be perfect. If you have to run a 160 thermostat to keep it from over heating then there is a problem that needs fixing. Fuel efficiency, power, and wear suffer when an engine runs cooler than it should. Cars today are designed to run between 195F and 220F for a reason... efficiency.

 

Conventional oil? I wouldn't run today's oil formula. Look up the ZDDP controversy. It basically says that today's oils will not adequately protect our  rocker arm to cam lobe wear. This is because in the last few decades oil makers have been constantly reducing the amount if zinc, and anti scuff additive called ZDDP. It's at least half what was around when out Datsuns were new. It not needed in new cars and not good for the catalytic converters so slowly being reduced. 'THEY' (oil makers) say it's reverse compatible. That the levels in the past were way too high anyway so there is no danger using half the amount. See what you think about it. Myself, I switched years ago to an oil that still has the same levels. Diesel oils are exempt from this and still have full strength ZDDP in them. So I ran Shell Rotella T4 15w40 but this last oil change I 'm trying 10w30. Chevron Delo 400 is the same and there are any amount of others. 20w50 is needlessly thick even for California winters.   

[Johnny76710]

I bought my 76 datsun from a older man in YuCampa,CA and he drove it free way miles from work and back  for 15 plus years 40miles a day . and he said that he had it running on a 160 because he heard a knock in the engine sonthat why he decided to put and 160. Now thought I know that it’s not good to run the car at a colder  temperature I won’t do it. I’ve  noticed it runs fine at the normal temperature, I just need to get that 160  thermostat out and replace it with a 180. The man said only to put 20w 50 in it I don’t know why but I still do . I’ve had the car for two year now I’m the 3rd owner. So far I’ve only had minor issues like fuel pump, clutch slave cylinder and just got the radiator replaced . It was running on 160 until the thermostat failed it runs forsure on 180 now on regular road and 160 on the freeway . I haven’t had time to replace the thermostat but I  plan to before I go to Vegas in the 3rd of July  . I haven’t had any problems like hearing engine knocks . I live in the South Bay of California and  I drive my datsun to Vegas once in a blue moon but I will be making my 5th trip soon . Thank god Datsuns are reliable @datzenmike

[DatsSully]

On 6/8/2020 at 5:10 AM, Johnny76710 said:

Hey How did the swap go on the 710? @DatsSully I haven't done anything yet to my suspension. 

 

 

It was straight forward and would have only took me about two days if I hadn't gone through everything and made it all pretty. I found it was a good time to replace my LCA bushing, Ball joints, and T/C bushings. If I was to do it over again, after seeing the condition of everything down there, I'd have replaced my idler arms and bushings. I didn't take too many pics of the install though.

I compiled all the info I found researching this(mostly from mike) and made it into a google doc, doing this for all the other stuff I'm doing to my car. When I get to a point I'm happy with I'll make a build thread and post them for people to use. This way any images used won't end up missing or with the photobucket watermark over them in the future.

EDIT: Also I just used KYB shocks for the 280ZX since I didn't have the original oil filled ones. I used KYB gas shocks for the rear too, super easy to do unless you snap a bolt head like I did.

Edited June 14, 2020 by DatsSully

[datzenmike]

On 6/11/2020 at 4:01 AM, Johnny76710 said:

I bought my 76 datsun from a older man in YuCampa,CA and he drove it free way miles from work and back  for 15 plus years 40miles a day . and he said that he had it running on a 160 because he heard a knock in the engine sonthat why he decided to put and 160. Now thought I know that it’s not good to run the car at a colder  temperature I won’t do it. I’ve  noticed it runs fine at the normal temperature, I just need to get that 160  thermostat out and replace it with a 180. The man said only to put 20w 50 in it I don’t know why but I still do . I’ve had the car for two year now I’m the 3rd owner. So far I’ve only had minor issues like fuel pump, clutch slave cylinder and just got the radiator replaced . It was running on 160 until the thermostat failed it runs forsure on 180 now on regular road and 160 on the freeway . I haven’t had time to replace the thermostat but I  plan to before I go to Vegas in the 3rd of July  . I haven’t had any problems like hearing engine knocks . I live in the South Bay of California and  I drive my datsun to Vegas once in a blue moon but I will be making my 5th trip soon . Thank god Datsuns are reliable @datzenmike

 

20w50 will work no problem but try 15w40 Rotella T4. You need higher ZDDP levels. All oils are about the same thickness when hot. Thick oil doesn't flow as well when cold. I can't imaging how running a 160F is a cure for and engine knock.

[Johnny76710]

@datzenmike I just bought the 15w40 Rotella T4 is it meant for Diesel engines and gas ? I’m gonna do a oil change today. 

[Lockleaf]

Its marketed as diesel oil.  That is the correct oil. Many of us run that exact oil in our cars.  If you run standard motor oil you need to "race" or "vintage car" oils, or add a ZDDP additive to every standard oil change.  The rotella already has the high zddp.

[datzenmike]

It does have a higher detergent additive. Diesels are inherently sooty.  If your engine is dirty (most carbed engines are) it will get cleaner  You might find that the oil gets 'dirty' faster at first but the oil is still good. After a couple of changes this should settle down.