New struts? Heavier springs? or replace both?

91 hijet s83p

I have been reading alot about the whether to replace my struts with new KYB shocks from Rockauto.com which will cost $220(75$ each + 70$ shipping) or if I should just try out some heavier springs up front. I have very little knowledge with taking these trucks apart, I am just going off what I have read on the internet. When I removed both struts i was able to mash both of them down with a small amount of pressure and they did not push themselves back out. I have to put a decent mount of pressure to get the strut back fully extended. I have seen videos of people with blown struts where they could push it in and out really fast, mine are not like that but they seem pretty warn out. I have read that daihatsu struts are soft and are not that hard to mash in but I have never tested a new set, so I dont have anything to compare to.

The reason I removed the struts in the first place is because whenever I have a passenegr riding with me the front left side seems to bottom out whenever any decent sized bump is hit. Also the front end has a little bouncy ride when its just me in it and I only weigh 150lbs. Do you all think I should go ahead and replace the struts and the springs? or should I start and see if the heavier springs cure the bottoming out/clunking noise. Is there anywhere that carries these struts that wont cost me $70 in shipping? or is there another type shock that I could substitute for these?

Any advice is greatly appreciated.

Morgan

 

On my S80 the struts are shot and Rock doesn't have replacements for it so I replaced the springs with 250 lb and it made all the difference in the world.No more bottoming at all and a much better ride. If I were you I would try the springs first and see what you think.

 

That's the way I'm leaning. Thanks

 

I ordered a set last week off of speedway.... Thank you for heads up though

 

Just got done test driving with the new springs and the ride has greatly improved. I decided to keep my lift kit on and the front end is now definitely sitting a couple inches higher. The issue I am now facing is there is a very loud humming noise that I hear on the front end when I ride. I'm used to hearing the hum of the tires but this is alot louder. Do y'all think the front end is too high and its putting too much stress on my CV joints? I don't know a whole lot about these trucks but I have read people saying that lift kits can put additional stress on certain parts of your truck. My truck camer lifted and it looks to be between 2-3 inches. I think I'm gonna try taking off the lift and see if the tires rub. What do you all think is causing the humming sound?

Morgan

 

Check the cv's and also the drive shaft.On my S80 when I raised the rear the drive shaft really set up a howl and I had to drop the rear of the tranny.

 

Depending on your size and whether you typically carry a passenger, you might want to go with 300s. I started with the 259s, but this was not enough. I'm only 180 and my typical passenger is about the same. I have a 2" light in the rear and no spacers in the front. I have 25x12x8 tires, so I'm running large tires. I trimmed the body for clearance. I like the 300s much better than the 250s.

 

So the roaring sound is because my right front tire is rubbing against my new springs. Before I put these on my front tires were tilted like this ( \' '/ ). Now they sit more upright but are rubbing on the right front tire... Is it because my front end is sitting higher now which has changed the pitch of my tires? Does this mean I now need wheel spacers? Think I might try taking off my lift kit and see if this fixes the rubbing. Anyone dealt with this?

Morgan

 

It sounds like your camber or wheel lean was out before the springs.This was probably caused by the lift kit and is common with lifts. You are better off with the camber correct and dealing with the tire/wheel combination to fit the truck.

 

The 275 pound springs I put on our carry lifted the front 3 1/4 inches. That coupled with a 4 inch lift made my cv bind a little. The lift is great as long as you drop the entire front end. That's how you will fix the lean of the tires. If you just push the struts down and stretch them out and don't drop the rest of the front end......... diff......and arms....... all you have done is use all available down word movement in the arms. That will cause bump steer that will break your thumb, go ahead and ask me how I know that!! It's been a while since I read the whole thread I started called resurrecting a Suzuki carry....... but I think I have all the fun stuff from building the lift on my carry, and a bunch of great input from people a whole lot smarter than me

 

Thanks guys. I'm gonna try taking the lift off this afternoon.

 

I added a 2" lift and put 12-24x8 tires on. Then I had to add 2" wheel spacers to the front, and ground off as much of the body panels as I could because the tires were rubbing. I still had a rubbing problem when I turned, and my springs were bottoming out. I just replaced my coil springs with 250# springs. It solved most of my tire rubbing problem in the front. Now I only rub when I turn real sharp. The ride is much stiffer than with the stock springs. I also added helper springs to the rear leaf springs. It makes the bed ride a little bit higher and much stiffer! Now maybe I can carry more than air in the bed of my S83P! I'll give it a test after I replace the fan belt so my alternator and water pump work again! (I broke the belt today!)

 

My driver's side was pretty much toast at 90,000 km

 

Couple of comments, I’ll keep it simple because, quite literally this is the subject which can fill a couple of books, and be a three credit engineering class: The load your suspension sees is dynamic, and varies greatly with the speed you are moving. It increases as the square of the speed. Double the speed, and the load on the suspension from a bump in the road, is four times as great.

The springs provide no dampening. They provide resistance. The resistance to the deflection increases linearly, unless you have special variable rate springs. If you have 150-lbs/in rated springs and put a 75-lb load on them they compress half an inch. Put 300-lbs on them they compress 2-inches.

The struts dampen the load. They have a resistance which is velocity dependent, the faster the load is applied the more they resist. So if you have the spring-strut assembly, the spring resists the load, and the strut resists how fast the load can move the assembly.

Creep over the bump in teh road, and the load on the suspension is close to what it would be if you were parked on the bump, and the suspension doesn’t deflect much, with the load taken by the spring. Go faster, and the strut, slows down how fast the suspension moves in response to the load caused by the speed.

So, as the struts wear out, they resist less, and when you hit a bump at teh same speed you always have the suspension bottoms out because the strut has worn. If you put a 200-lb load in teh front seat and the truck sags, more than it used to the spring is wearing out.

Typically struts wear out long before the springs do, and that lets things move faster in response to loads, and the suspension will start hitting the rubber bumpers.

All that said, on the mini trucks it makes sense to do both struts and springs at teh same time. Your in there and already have teh spring out, and have to take the spring off the lid strut to put the new one on. So, it is a good time to replace the spring.

Most of the mini trucks have springs with an interior diameter (id) of 2.5-inches. Which means you can install the springs designed for coil over shocks, which come in a huge array of rates fro 75 to 500-lbs/inch.

I run a plow on the front of my Hijet half the year, so I opted for 15- to 450-lbs variable rate springs. Mine are designed for coil over shocks, ( which is what the spring/strut assembly is), which are 12-inch free length, with a 2.5-inch id.

I got mine through Summit Racing’s site, for less than half of what the minitruck dealers charge for new springs.

Here are a couple of videos: ; ;

 

The struts are not nitrogen charged. The are very basic oil bath with valving

 

The S80 series and S100 series, springs have a free length of 11.6-inches, and an ID of 2.5. So, the 12X2.5-inch coil over springs are very close and work well. A tiny bit more effort to get them installed initially.

The S8?, left hand drives= “Off-road” version which was imported to the US as landscape and campus maintenance vehicle had a front spring rate of 200-lb/in.

 

Hello to all!
Jigs and fixtures, I want to do the same similar situation (w/plow) on my 89 Daihatsu hijet s81 front end! what were the parts #'s from summit racing you used for struts and springs?
Thanks, Limestone!

 

Sorry about the delayed response, the carb on my truck screwed up, and I’ve been fighting with it for a while now. I think I got it tuned up this weekend. Need to get some pictures, and post a how to, on how to adjust the carb on the S110 series.

I checked and Summit no longer lists the springs I have. They do have a couple of choices with variable rate winding with a rate of 175 to 350-lbs/inch. https://www.summitracing.com/search...350-lbs-in&SortBy=Default&SortOrder=Ascending

The struts I got are KYB 633117 (right), and KYB 633118 (left). they are correct for my S110, and probably fit the 80-series. I got them off eBay, out of England. Search eBay, with the string KYB (633118, 633117), and set the location filter to worldwide.
Check with the seller before buying to make sure they ship to the US.
I’d also check one of the parts sites in Japan, Which have the parts diagrams to double check the part numbers are the same for the S80 series, and the S110s.

 

Bolt pattern and shape where different then the struts on my 110

 

Jigs,
Thanks for the reply and info! I greatly appreciate it!
Limestone

 

Hey Jigs,
I was wondering, when you did your struts and springs. What did you use for adjusting the tension on your adjustable springs? I'm not referring to the spanner wrench or any specific tool, but the adjustment collar, so to speak, at the top of the strut, below the lift kit! Did you purchase additional hardware from KYB? Did you use a thrust bearing kit? Thanks,
Limestone

 

Limestone, the springs are variable rate, and not adjustable. We just put them on the new struts with the parts provided. I don’t think we reused anything from the ones which were on it.

 

Jigs,
Gotchya, Thanks again!
Limestone

 

Jigs,
Got the KYB struts out of UK. Got the progressive rate 175/350 springs from summit racing. Built the 2" lift for the struts. Thanks for the great Info!
Limestone

 

Hi there, I wonder if Hijet struts are compatible with Atrai 7 (S221E/G)? Am looking for a relatively economical replacement...

Reference: https://autoparts.beforward.jp/detail/Suspension---Components/Suspension-Assemblies/PA01083056/

Cheers.

 

Buy it, and Try it, and let us know! Cheerios!

 

if you are on beforward you should be able to find ones for your truck

 

Yes, but it seems a bit overpriced, asking >USD200 for one used strut...

 

Have you looked on eBay with filter set world wide?