Lowering a 610 wagon

[Jgalland09]

Hey everyone, am just new to the forum as I just bought myself a180b wagon. Love the car and want to keep it generally original as poss but I HAVE to take it down a few inches. I am still kinda learning all the tech stuff when it comes to suspension but any info at all would be much appreciated.

Im guessing ill probably just put 2" blocks in the back, but the front has me a tad confused.

Ive read different ideas about it eg cut springs, coilovers etc but not sure what to do. This will br a family car as well and ideally dont want to cut springs if poss. HELP haha

[datzenmike]

Cutting springs is the worst way to lower. It can work but cutting also increases the spring rate making it stiffer. Stiffness is alright within reason but the chances of getting the height and not too stiff is unlikely.
 
 
Well if money is no object then get coil overs. If coil overs weren't so expensive I would run them also but once the ride height is set what use are they? How many times a day or week do you need to adjust your ride height, really? They are simply money going along for a ride.

 

But if money is a concern and or you like going things yourself, and if you like the same results as coil overs for about $25 then here is how I did it...
 
Remove the strut, compress and remove the spring carefully. Loosen and remove the gland nut.


 

 

Use a dental pick to remove the inner O ring. This must be removed in order to remove the damper inside. Save and clean/reuse the O ring.

 

 

This will allow you to remove the factory oil bath hydraulic dampers. If they have already been replaced with incerts, well too bad, just keep or replace if worn. If you have the factory ones you are in luck because you can replace the thin watery hydraulic fluid with thicker 20W weight motorcycle fork oil to firm them up.

 

Oil bath dampers...

 

There is about 300ml of fluid and it's messy so be ready for this.

 

With the internals out of the way, (for now) use a 6" angle grinder and trim carefully around the lower pring perch just above the weld. Just deep enough to trim it off. You can use a hacksaw.
 

 

 

 

Grind away the weld. This will allow the spring perch to now be able to slide up or down past this position.

 
 
 When assembled the bottom spring perch will be supported and held in place by a 2" split collar that can be raised or lowered to set the ride height. Mine were about $25 a pair and when tightened will support 6,000 each! that 2 1/2 610 per strut, more actually. When I finished fiddling with my ride height by trial and error I MIG welded a small spot on the strut just below the collar... you know, just in case. They have never moved.

 

 

 

But before that, the spring rate should be dealt with. A lowered ride height puts the vehicle under side at risk from bottoming out on the 'soft' factory springs. A firmer set will not only improve handling but resist suspension travel, which is a good thing. My 610 FSM rates the front springs at 96 pounds per inch. My 710 is about 100 lb/in. so very similar. I worked out the spring constant by using a simple mathematical formula and by trimming a little over one coil off increased the rate by about 50% which according to everyone is rather conservative. However better too little amount rather than too much as you can't put it back. I won't get into what's the best rate only that it can be worked out, it's easy to do and you can adjust to what YOU like.

 

Now we have the means to adjust the ride height and the means to adjust the spring rate. Next is replacing the hydraulic damper oil. I bought a liter (enough for three struts) of 20w Bellray motorcycle strut oil for under $20. Filled the dampers and bled the air out and I love the ride. All this for under $50 and the satisfaction of doing it myself. My other 710 I just used ATF auto trans fluid. It's around 12w I think and my wife drives this car, didn't want complaints.

[datzenmike]

Before

 

After

[Jgalland09]

Cheers for the accept and appreciate such a quick and detailed reply!! As far as I know all suspension is stock. Ideally I'd like to spend less on this so it can be put into other parts of the car. I've read somewhere you can put in 240zx struts in as they're shorter, better brakes too? Then could I either trim springs or purchase some new ones to suit? And quick q, blocks or reset leaves what's your opinion? Thanks heaps!

[Seansm10]

Hey mike as far as your spring rate goes from chopping, do you feel like you could chop more off and still have a somewhat comfortable ride? I'm looking to get a fairly snug fitment on some 14s that came with the car without sacrificing too much drivability (considering aftermarket springs).

 

I plan to roadtrip the wagon this summer and am trying to balance back stiffness with kickass pictures to acquire short lived internet fame. Lol.

 

Sean

[danfiveten]

Hey you need to share pics of the 610 for us to help ;) 

[datzenmike]

Cheers for the accept and appreciate such a quick and detailed reply!! As far as I know all suspension is stock. Ideally I'd like to spend less on this so it can be put into other parts of the car. I've read somewhere you can put in 240zx struts in as they're shorter, better brakes too? Then could I either trim springs or purchase some new ones to suit? And quick q, blocks or reset leaves what's your opinion? Thanks heaps!

 

On a leaf spring rear suspension, blocks are easy to make (or buy) and install needing only longer U bolts. Just like the front, any lowering endangers the underside from bottoming out on dips or bump in the road, especially at speed. Like the front the rear spring rate should be increased to limit suspension travel. Additionally the stock handling has now been compromised by firming the front. Cars are designed with a small amount of understeer as this is considered the easiest for the average driver to recover from  ..(lift off gas and apply brakes)  A stiffer front and a softer rear will naturally add extra unwanted oversteer to the handling so increasing the rear rate brings this more into balance. What I did was take a shorter leaf from a spare pack of leaf springs and add to my leaf pack. This acts as an overload spring. Combined with a set of 2" lowering blocks I got the height reduction I wanted and the firmness needed.

 

 

 

It was a longer thicker leaf that I shortened to fit in the second position. The 610 spring constant is 123lb/in and I expect the 710 is similar. You can also lower by having the springs de-arched also but extra stiffness is advised strongly.

 

Now one important thing here no matter how you lower the rear. When the body is lowered this changes the angle of the driveshaft where it leaves the back of the transmission mostly and slightly at the differential. Because of the peculiarities of driveshaft mechanics they can only turn vibration free if the two angles are equal. One angle cancels out the other so if they are mismatched it WILL vibrate proportional to the amount difference. I found a low humming sound that was not there before. I wouldn't have called it a vibration and just put up with it. But upon reflection and some research I used a compass and a string with a washer on it to make a plumb bob and found them both out. The eventual fix was a small 1/8" shim between the upper part of the lowering block and the lower spring perch on the rear side of the differential. This tilted the front of the differential downward and restored the proper front and rear angles. The difference was nothing short of amazing.

 

Hey mike as far as your spring rate goes from chopping, do you feel like you could chop more off and still have a somewhat comfortable ride? I'm looking to get a fairly snug fitment on some 14s that came with the car without sacrificing too much drivability (considering aftermarket springs).

 

I plan to roadtrip the wagon this summer and am trying to balance back stiffness with kickass pictures to acquire short lived internet fame. Lol.

 

Sean

 

Right now my 710 wagon is on '84 Maxima wagon struts with slightly shortened 710 springs. The Maxima and the 280zx are built on the same platform and very similar. (large car, inline six engine, R180 sedans and H-190 wagon) The Maxima/zx coils are way too large so 710 springs used. The rotor is a few mm smaller than the zx and vented with a huge caliper.

 

The 710 front spring is now at about 150 lb/in and it rides quite well. I do have an extra set of 710 springs and at some time in the future I plan to swap the struts side to side to place the calipers to the front to avoid clearance problems with the steering knuckle when the pads wear down. This is a long long way off in the future as I have new pads and rotors on it now . When I do, I may try a thicker fork oil and perhaps increase the spring rate to 200. I'm certainly in no hurry, and like I said, very happy with the drive ability and handling at 150. (racing 510 fronts are run at over 300lb/in!!!! can't imagine them being comfortable) I don't drive it every day, in fact mainly a few months in the summer to the Canby car show.... maybe a couple thousand miles, tops. I think a firmer spring rate would simply make the ride less comfortable on regular paved roads for minimal gain in handling. But this is just me and I realize everyone's different

[Jgalland09]

 

Hopefully that worked?! I have the car up North and the old man is driving it down next week for me so more pics then.

[Jgalland09]

My only other ATM...

[Jgalland09]

The pics are pretty poor but I'd just be happy to have tyres sitting just above the rims. Will need to get some lower profile ones but they are near new so will give them a good thrashing first.

[Jgalland09]

Lads, as I'll need this car on the road as often as poss I was thinking about getting my hands on a separate pair of front struts to work on them then chuck em straight in. As my car knowledge is average, does anyone have any tips on the struts? If I don't end up shortening the ones I have now, will 280zx ones be short enough? And are they more or less a straight swap? Any info would be great!

[datzenmike]

The zx struts are at least an inch shorter and you can easily and safely drop a couple more. You will need to remove the bottom spring perch and use your 610 perches and spring as the zx springs are way too wide to fit up into your 610 strut towers. The calipers are much larger than the stock ones and will clear a 14" rim, not so much the stock 13s. The rotor is larger and vented and the zx strut hub is off set outward by an inch? more than the 610 hubs. The shorter strut tube and any lowering will cause a positive camber issue that can't be avoided. Take note that the 610 top hat is designed with an off set so that the three studs can be positioned to move the strut in or out slightly which can help.

 

 

My 710 came with these period Moog camber plates. If you look at 710s and probably 610s also, you'll notice the front end is almost always too high compared to the back. I think Nissan screwed up on their suspension math and they are difficult to align, hence the camber plates added by alignment shops. You may need to get after market camber plates.

 

 

 

 

ANY lowering will cause toe out but this is very easy for the home mechanic to adjust himself.

 

 

 

 

The pics are pretty poor but I'd just be happy to have tyres sitting just above the rims. Will need to get some lower profile ones but they are near new so will give them a good thrashing first.

 

Well to each their own but these old Datsuns don't really look right with newer inch thick tires on them. besides you would have to increase the rim size to 16s or 17s to keep near the same diameter to.. 1/ keep near stock overall gearing and.. 2/ an accurate speedometer. Larger 15" rims and thin tires just plain look weird on old Datsuns

[Jgalland09]

Shit, well potentially the longest ever response time to a post. I've been locked out of my account and email, had kids, life etc etc, but I still have my car. It's been posted for sale reluctantly a few times due to wife pressure but I've "missed" any phone calls about it 🤣. So, update, I ended up following your advice Mike and put blocks in the back. For the front I was a bit overwhelmed so cut a coil out and haven't got around to doing anything else.

 

I've done an engine upgrade so brakes need updating too. Mike, if I was to do the 280zx strut swap, and weld on the 180b spring perches, do you know if there much else involved or is it more or less a straight swap? Any info would be very much appreciated.

Cheers!

[datzenmike]

The 610 annd 710 Goons are similar. I calculated how much coil to cut to increase the spring rate or stiffness. I think 1 and 1/4 coils raised it from 100 pounds per inch to 175. The 610 may be different but one coil will do no harm and is essential on a lowered vehicle as to are closer to the pavement now. You should be able to safely lower about 2"- 2 1/2" without bottoming out the strut but again, a stiffer spring is key to preventing this. I don't know the length of the 610 strut but likely similar to the previous 510 and the zx strut is at least 3/4" shorter to your advantage.

 

The zx calipers are massive so will use much more fluid. Your stock brake master will work but the pedal will travel farther to move more fluid giving the impression of being mushy. You probably have a 3/4" master so moving up in size will adjust this. The zx used a 15/16" master so when getting the zx struts see if you can source one too. This is what I did on my 710 with '84 Maxima struts and it works well

 

The strut angle is the same as the 610 at 10⁰ but as the body will sit lower the camber may be hard to correct. Camber plates might help.

 

The zx rotors are like dinner plates and calipers the sixe of two fists and may not clear the inside of a 14" rim. You may be able to grind some of the caliper away for clearance or go 15" rims.

 

 

All Datsun strut tubes are the same 2" so your 180b spring perches will fit perfectly however welding is permanent and cannot be adjusted for height. What I did was get a pair of 2" split collars for about $20. (which is cheaper than welding anyway) This allows you to slide the spring perch up or down and secure them in place.

 

Slit the spring perch just above the weld. A hacksaw works also. Then grind down the weld.

 

 

 

Slip the 610 perch and spring onto zx strut tube and secure split collar below it. When tightened securely each collar will support 3,000 pounds. Both collars will support the entire weight of 2 1/2 610s.

 

 

Setting your ride height is trial and error. When done I put the tiniest weld just under the collar so it could never slip down. Just in case.

 

One last thing: any raising or lowering the ride height will have some effect on what is known as bump steer. This is most noticeable when one tire travels over or down through a bump in the pavement. The steering wheel will pull to that side and on changing cross fall roads with hills and dales and add sprited driving and the steering and handling can feel squirrely. Normally at rest the steering components are horizontal and the effect in minimal but lowering will change the angle of the tie rods tilting them upwards to the strut connection point on the steering knuckle. The cure is to add a shim between the very bottom of the strut tube and the steering knuckle, effectively lowering it into that preferred horizontal placement.

 

I cut mine from 1/4" aluminum scraps...

 

 

I measures the distance down needed to place the tie rod horizontal and it was about 1/2" so two spacers and longer bolts corrected it. It all depends on the amount of lowering.

 

 

 

[Jgalland09]

8 hours ago, datzenmike said:

The 610 annd 710 Goons are similar. I calculated how much coil to cut to increase the spring rate or stiffness. I think 1 and 1/4 coils raised it from 100 pounds per inch to 175. The 610 may be different but one coil will do no harm and is essential on a lowered vehicle as to are closer to the pavement now. You should be able to safely lower about 2"- 2 1/2" without bottoming out the strut but again, a stiffer spring is key to preventing this. I don't know the length of the 610 strut but likely similar to the previous 510 and the zx strut is at least 3/4" shorter to your advantage.

 

The zx calipers are massive so will use much more fluid. Your stock brake master will work but the pedal will travel farther to move more fluid giving the impression of being mushy. You probably have a 3/4" master so moving up in size will adjust this. The zx used a 15/16" master so when getting the zx struts see if you can source one too. This is what I did on my 710 with '84 Maxima struts and it works well

 

The strut angle is the same as the 610 at 10⁰ but as the body will sit lower the camber may be hard to correct. Camber plates might help.

 

The zx rotors are like dinner plates and calipers the sixe of two fists and may not clear the inside of a 14" rim. You may be able to grind some of the caliper away for clearance or go 15" rims.

 

 

All Datsun strut tubes are the same 2" so your 180b spring perches will fit perfectly however welding is permanent and cannot be adjusted for height. What I did was get a pair of 2" split collars for about $20. (which is cheaper than welding anyway) This allows you to slide the spring perch up or down and secure them in place.

 

Slit the spring perch just above the weld. A hacksaw works also. Then grind down the weld.

 

 

 

Slip the 610 perch and spring onto zx strut tube and secure split collar below it. When tightened securely each collar will support 3,000 pounds. Both collars will support the entire weight of 2 1/2 610s.

 

 

Setting your ride height is trial and error. When done I put the tiniest weld just under the collar so it could never slip down. Just in case.

 

One last thing: any raising or lowering the ride height will have some effect on what is known as bump steer. This is most noticeable when one tire travels over or down through a bump in the pavement. The steering wheel will pull to that side and on changing cross fall roads with hills and dales and add sprited driving and the steering and handling can feel squirrely. Normally at rest the steering components are horizontal and the effect in minimal but lowering will change the angle of the tie rods tilting them upwards to the strut connection point on the steering knuckle. The cure is to add a shim between the very bottom of the strut tube and the steering knuckle, effectively lowering it into that preferred horizontal placement.

 

I cut mine from 1/4" aluminum scraps...

 

 

I measures the distance down needed to place the tie rod horizontal and it was about 1/2" so two spacers and longer bolts corrected it. It all depends on the amount of lowering.

 

 

 

Man that's why I had come back here because that's exactly the info I was looking for. I think I'll get the 280zx struts for the brakes, and do just what you've mentioned above. I was just worried about having extend controls arms and the like. Can someone remind me how to post up pics again into comments?? Cheers for all the info.

[datzenmike]

 

Hard to see but I used a spirit level from the idler arm out to the steering knuckle to estimate the shims thickness needed to get that tie rod level. Looked like 1/2" so I tried it and bump steer all gone on first try. As you can see the tie rods tilt upward now from the lowered body. That needs to be horizontal. Doesn't take much.

 

Any raising or lowering past stock effectively shortens the tie rod length pulling the rears of the front tires inward (fronts outward) causing toe out that needs to be corrected. I had already re aligned the steering so when I added the bump steer spacers it brought it back to stock but toed in and had to align the front again. It was all good in the end.

 

 

 

 

A similar odd thing happens on the differential when lowered. A drive shaft with any bend will speed up and slow down to turn that corner, just look at the right side. This would vibrate like hell in a vehicle so what is done is the second U joint is 180 to this one and the two effects cancel out IF the two angles are the same!!!! So the rule is the angle between the transmission center line and the drive shaft center line MUST equal the drive shaft center line and the differential.

 

Lowering the body will upset one of these angles. Now I didn't know this when I lowered my Goon and indeed there was a low hum when driving. Later, I measured both angles and (in my case) adjusted the pinion on the differential slightly downward with a shim on the back side of the lowering block. Hum gone.

 

It's littler things like the bump steer spacer and correcting the drive shaft angles that make it a better driving car.

[Jgalland09]

Zx struts acquired! I've removed the springs and the perches and actually have some coilover sleeves that fit these struts. What have people done for strut inserts? Gone with updated ones or stuck with the original and refilled them? I've also tracked down some camber plates so that should hopefully solve one of my issues. With regards to the 15/16 master cylinder, any ideas what i can pinch one of those off?

[datzenmike]

I substituted 20w BelRay motorcycle fork oil in my '84 Maxima struts for my 710. I also increased my stock spring to 150 pounds per inch spring rate.

 

 The 280zx up to Aug '81 has one that will bolt to a 610 booster.

[fiveoneO]

I just built some ZX struts for my 510. My struts had some cheap no name inserts in them, so I replaced them with some Koni's. I've always thought I would be fun to play around with the original struts. See what can be done with thicker oil and different shims.

[datzenmike]

Shims?

 

 

Maxima struts, vented rotor and monster caliper. I think the rotor diameter is just a mm or two less than the 280zx.

 

The trouble with inserts is they are not specific to a 510. They are for something else. An improvement in ride though.

 

My other 710 I kept the original struts so lowering has it's limits. Two-three inches but must include some spring stiffening to reduce travel and bottoming out the body on the pavement. Springs are too soft anyway so adding spring rate itself improves the handling and with lowering really improves the handling. For this one I used ATF which doesn't really have a universal viscosity. It's somewhere between 8-12w. 

 

Lowering (and also raising) will upset the steering geometry and add bump steer. This is an annoying pull of the steering wheel to the tire that drops into a dip or goes over a bump not shared with the other front wheel. This can be measured and corrected for with bump steer spacers mounted between the steering knuckle and the bottom of the strut tube. Most of the time it's fine but under 'canyon carving' performance driving it's very unwanted steering input upsetting your control.

 

Measured how much the outer end of the tie rod needed to come down to be horizontal.

 

 

 

Made a half dozen 'spacers'.

 

Turned out two 1/4" were the ticket and longer bolts. Cost was $8 for the bolts.

 

It was a small thing but paid off in much better driving 'feel'.

 

 

Rear end lowering.

 

Basically I added an extra second leaf, which may have added ride height but counteracted this with 2" lowering blocks to match the front height. Again when lowering you really should increase spring stiffness. Just like the front raising or lowering alters the drive shaft angles and introduces vibration. The rule here is the transmission to drive shaft angle MUST equal the drive shaft to differential pinion angle for the vibration to cancel out. I had to add a 1/8" shim to the back of the lowering block to tilt the front of the differential down for the correct geometry. Again a small thing but improved the ride and driving comfort removing a low frequency hum.

 

[rosso]

Although DMike's solution of homemade spacers will work (and are very inexpensive to make and well done), I would suggest buying a true bump steer spacer. These spacers are machined to fit into the recesses cast in the struts and lower control arms.

 

Here's a photo of mine mounted to 280ZX struts (with T3 coil over kit) and the stock 510 suspension.

 

[Jgalland09]

BTW does anyone know the height difference between stock 610/180b front struts and the 280zx versions of the same? Do you guys think I should shorten the 280zx struts or will they be fine as is.

[datzenmike]

I think the 280zx struts are 3/4 to 1 inch shorter than the 510... and the 610 uses pretty much the same strut. If lowering 2-3 inches and proper stiffer springs are used you should have no problems.

 

Lowering has it's own problems. It affects bump steer, camber and toes in the steering. Correcting the bump steer will also correct the toe problems.

[fiveoneO]

@datzenmike I've never actually seen what the internals of a stock 280zx strut are like, but every damper I'm familiar with has a piston at the bottom of the shaft with holes in it that the shock oil flows through. By placing shims of different sizes and thicknesses over these holes, you restrict the amount of oil that flows through these holes and that changes how stiff or soft the damper is. This is a picture I found, its of a mono tube damper, but it should be similar.

[datzenmike]

280zx looks just like all other Nissan dampers and nothing like the picture above. 

 

This is what came out from my '84 Maxima wagon struts...

 

 

 

The rod fits inside that tube and everything slides down into the strut tube filled with oil. If you manage to have the original oil bath dampers just drain out the watery hydraulic oil and fill with 20w motorcycle fork oil.