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JohnnyDiesel

Lowering blocks / Rear leaf spring improvements?

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Hi Guys/Gals,

 

I have a lowered 73' Datsun 1200 truck with a nice and low rear-end.  The leaf springs are lowered on some lowering blocks / 7" U-Bolts with rear struts replaced. MY question for all of you is do people make custom leaf springs that will lower my car and improve the pogo-stick like driving the lowering blocks have?

 

I like my car the way it sits, but I'm looking for something a little more comfortable to drive, any tips / tricks / website links you can provide me to help educate me would be very appreciated!

 

IMG-0014.jpg

IMG-0014.jpg

 

thanks,

Johnny

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IM not a suspension expert but lowering block just move the axle up otherwise everything else it the same. So Im not getting what you really want. If one want softer some people revove the leaf but you can get axle wrap under hard acceleration or stopping where the axle willstarting rolling..

Get springs that are stiffer with out the block but will be same hard ride.

 

be honest its a 73 dinky car not a caddilac

 

try some different shocks????

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Yup, pogo-sticking is due to too soft of dampening on the shocks.

Another thing you are dealing with is the 46 year old leaf springs, that are rusted on the surfaces where they slide against each other when they compress.

Take them apart, sand them lengthways to remove as much of the scale as you can, then go to Speedway motors, and buy a roll of Leaf Spring Liner.

It is a plastic strip that comes in a roll, with a lip on each side to keep it between the leafs of the spring, and stops the high friction that makes the springs ride rougher than they should.

I don't remember what width I bought for mine (the stuff comes in 3 different sizes).

Buy a tube of the thickest damn grease you can find, and lube the springs when you assemble them.

 

91033038_L_1cdc9d23-d376-4bae-b38d-91ea8

 

 

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That new looking bump stop looks like it is almost touching the axle, I am not familiar with that bump stop either, is it hard rubber or something else?

Also that is a lot of drop block, when one goes that low you have to make sacrifices, mainly the ride suffers unless one starts modifying stuff, and I have no idea what one has to do to a 1200 ute to have a nice ride that low.

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Springs simply store energy and release it. You can go stiffer so you don't bottom out or softer and you will. Shock absorbers resist compression and rebound turning energy into heat just like the brakes turn motion into heat, making the ride smoother. For the shock absorbers to work they have to have some travel to work through. You are on the bump stops which are solid rubber springs. This leaves the air filled tires. Basically you are riding on beach balls. No wonder it's bouncy.

 

Does this car have a frame? You will need to cut away and reinforce areas where the axle will make contact with the body when the suspension is fully compressed. This will give you the necessary travel room for the shock absorbers to act. You may need to reposition the mounts to extend the shock. There's no sense having a stock shock location that is just short of bottoming out. 

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20 hours ago, G-Duax said:

Yup, pogo-sticking is due to too soft of dampening on the shocks.

Another thing you are dealing with is the 46 year old leaf springs, that are rusted on the surfaces where they slide against each other when they compress.

Take them apart, sand them lengthways to remove as much of the scale as you can, then go to Speedway motors, and buy a roll of Leaf Spring Liner.

It is a plastic strip that comes in a roll, with a lip on each side to keep it between the leafs of the spring, and stops the high friction that makes the springs ride rougher than they should.

I don't remember what width I bought for mine (the stuff comes in 3 different sizes).

Buy a tube of the thickest damn grease you can find, and lube the springs when you assemble them.

 

91033038_L_1cdc9d23-d376-4bae-b38d-91ea8

THIS is helpful!I was hoping someone could at least give me a slight improvement or something to try at home. Thanks for the reply bud ! 

Cheers,

J. Diesel

 

 

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15 hours ago, datzenmike said:

Springs simply store energy and release it. You can go stiffer so you don't bottom out or softer and you will. Shock absorbers resist compression and rebound turning energy into heat just like the brakes turn motion into heat, making the ride smoother. For the shock absorbers to work they have to have some travel to work through. You are on the bump stops which are solid rubber springs. This leaves the air filled tires. Basically you are riding on beach balls. No wonder it's bouncy.

 

Does this car have a frame? You will need to cut away and reinforce areas where the axle will make contact with the body when the suspension is fully compressed. This will give you the necessary travel room for the shock absorbers to act. You may need to reposition the mounts to extend the shock. There's no sense having a stock shock location that is just short of bottoming out. 

I'm not going for a 2019 show car ride experience.

 

This car is something I just want to drive on weekends to cars and coffee events maybe a half hour away? I think I either sugger through it OR maybe I raise it up an inch or so to allow for some travel in the front and rear.. hmmmmm

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I am surprised no one here has suggested composite springs.

 

http://www.flex-form.com/Default.asp

 

There are several wagons with them among forum members or that I saw at Powerland this past year.

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Wayno and Mike mentioned this above but you didn't really reply to it so I'll say it again. In your pics it looks like your sitting on your bump stops. With a 3 or 4 inch set of blocks like yours you really need to completely remove your bump stops or you will constantly be hitting the axle on them....that is if it's not actually already sitting on them. Remove your bump stops and test out how it feels, should be totally different.

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I would suggest shorter bump stops rather than removing them, but it likely would not hurt to remove them and take it for a test drive.

I have removed my bump stops on a couple of my trucks, but I don't load them trucks up with a lot of weight because I don't want the frame hitting the axle, the 520 I eventually notched the frame because I went even lower(7" total in the back), but I also used Roadster rear leaf shackles, again not made for weight, it's just a truck built to look good.

As I said before, them bump stops you have may be hollow, that is why I asked if it was hard rubber or something else.

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23 hours ago, datzenmike said:

 

 

Does this car have a frame? 

 

This is why I asked this. Looks like it doesn't but hope I'm wrong. If a frame, it can be notched and reinforced for axle clearance when it compresses the shocks on a bump. 

 

Doesn't matter if only driving 1/2 hour away from home. The tires need to be in constant and controlled contact with the ground. 

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1 hour ago, wayno said:

I would suggest shorter bump stops rather than removing them, but it likely would not hurt to remove them and take it for a test drive.

I have removed my bump stops on a couple of my trucks, but I don't load them trucks up with a lot of weight because I don't want the frame hitting the axle, the 520 I eventually notched the frame because I went even lower(7" total in the back), but I also used Roadster rear leaf shackles, again not made for weight, it's just a truck built to look good.

As I said before, them bump stops you have may be hollow, that is why I asked if it was hard rubber or something else.

It appears the bump stops weren’t always in there before, as the paint is chipped away. I think I will try and find some bump stops that are smaller. How are they attached? 

 

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1 hour ago, datzenmike said:

 

This is why I asked this. Looks like it doesn't but hope I'm wrong. If a frame, it can be notched and reinforced for axle clearance when it compresses the shocks on a bump. 

 

Doesn't matter if only driving 1/2 hour away from home. The tires need to be in constant and controlled contact with the ground. 

It appears notched, I can take pics tomorrow in better detail tho 

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This is what a notched frame looks like.

DSCN1509.jpg

 

I suspect yours is a uni-body type vehicle, it has body strengtheners added to the body where it needs it like over the rear axle and in the engine bay/front suspension area, this was/is a common way to build vehicles now.

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1200 Utes are still a unibody/monoqueue same as a coupe & sedan.

 

Along with the other guys it looks to me like you are probably hitting the bumps stops with as low as the car sits. When I first raced my coupe, we used lower blocks and I ended up cutting the bump stops quite a bit.

 

Stock 1200 springs come with material in between the leaves to cut down on stiction but  even if they are totally gone they are not going to cause severe harshness. They will contribute to it but it's not a pogo stick to Cadillac difference.

 

Part of the issue with radically lowering the car is the damper/shocks are not operating in their optimum range.

 

Here is what I would do:

 

1. Put a big smear of grease on the bump stop and see if it's hitting the axle in normal driving. If it is cut the stop until it stops hitting.

 

2. If the bump stop isn't hitting the axle tube put a 150lb load in the bed and see if the ride improves (you need to check the bumps stops aren't hitting after adding the load). If the ride does improve then take the small leaf out of the spring pack (see datsun1200.com and look for the race suspension manual it talks about this)

 

3. Go to the aforementioned suspension manual and see the modification for lower/extending the shock mount stud in the mounting plate. This will get the shocks in the proper range of travel.

 

4. If all else fails just raise it back up. If you currently have the rear lower than the front, get it back to the standard rake (read front and rear near level)

 

 

Edited by Tom1200
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Maybe find a Gas A Just KYB shock and that might slightly raise it.plus remove the bump stop
They are a stout high pressure shock that has a strap and you but the bushings on then cut the satrap and shoot it up to where it needs to go. As they are hard to compress when fully extended under the car

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a ratsun fix for dead leaf spring liners is crazy carpets. buy one at your favorite winter store for 5 bucks and cut it into strips for your springs. It works well!

 

as for pogoing, cut down your bump stops and get rid of those 5 dollar shocks and put on some that are worth a damn. you can go to a gas shock if you want but a high quality oil filled shock works great for leaf sprung vehicles.

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