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From France to USA : help please!


oukippy

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On 9/29/2018 at 7:19 PM, wayno said:

Take them stupid clamps off that are holding the 2 upper leafs to the straight bottom leaf, the ride quality will likely dramatically improve and the rear of the truck will likely raise a little, them clamps do not belong there and are there for only one reason, to lower the truck.

 

I'll work on the lowering problem tomorrow (should I say raising?). I want to raise it by 5 cm in a first try (in order not to have the wheel under the wing at all) and I hope that removing the clamps will be enough.

I suppose that the leafs will be under tension while removing the clamps. Should I remove them completely or put them only on the 2 main leafs by sliding them (it seems to me that there was a clamp on both of them before) ?

Newbie question but I must ask: do I remove the clamps after using a jack or I leave the car on the ground ?

 

Thanx for all !!!

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I believe they are under tension with the truck just sitting on the ground, if you lift the back end they will be under more tension.

I believe they are like a clamped down spring, releasing the spring can be dangerous if under enough tension, so be careful, I believe I used a "C" clamp to  compress mine to put them type of clamps on my rig, I removed the "C" clamps after the clamps were in place, I then took it for a drive and took the clamps off as the ride was terrible, I went a different route after that, I notched the frame and other such things and now it is really low.

I would take all the clamps on the leafs completely off and take it for a drive, then look at it from the side a ways away and see if it raised it enough for your liking, also to see if you need to raise the front.

The back might raise the 5 cm by just removing them clamps.

Now keep in mind that I am not there to see what all was done to this truck to lower it, I believe the backend will raise some and I believe you will have a much smoother ride in the rear, but I do not know it for sure.

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I moved the clamp in order to let the flat leaf alone but it didn't change anything. It seems that all 3 are flat.

Do I need to ride the car to make the leaf take their new heigh ?

Is it better to remove the clamps completely or to let them where I put them ?

 

1538823904-dscf3498.jpg

 

 

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As I said, I do not know what all has been done to lower this truck, I would have removed all the clamps, if nothing changed I would assume that the leafs have had the arched removed or flatter leafs were installed, if nothing happened when you took them clamps off then you may need new leafs to raise it.

I cannot see the photos you post anymore, so if you already have lowering blocks you can remove them to raise the back up.

I am not going to be much help being I cannot see the photos anymore, good luck with your project.

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20 hours ago, wayno said:

As I said, I do not know what all has been done to lower this truck, I would have removed all the clamps, if nothing changed I would assume that the leafs have had the arched removed or flatter leafs were installed, if nothing happened when you took them clamps off then you may need new leafs to raise it.

I cannot see the photos you post anymore, so if you already have lowering blocks you can remove them to raise the back up.

I am not going to be much help being I cannot see the photos anymore, good luck with your project.

 

Thank you very much for your help. I agree that it's probably 3 flat leafs.

Yes I have 3" blocks that I'll remove. Obviously the u-bolt thread is too short to just remove the block and keep the bolts.

I'm trying to find shorter u-bolt but it's not easy here. If I searched well, it should be 3.6" from center of the bolt to center of the bolt and 0.5" for bolt thread width.

 

Another solution would be to replace the block with a 1 inch. I could have found it on ebay.co.uk but I don't know if it will work with the Datsun leaf springs as it is sold for Ford cars:

https://www.ebay.co.uk/itm/1-or-25mm-Ford-Leafspring-Lowering-Block-Kit-GE20-GRAYSTON-QUALITY/391890413419?epid=621558699&hash=item5b3e7d276b:g:ML0AAOSwicZZv9of

 

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I know it's not ideal to buy from the US, but these guys have everything leaf spring related - https://www.stengelbros.net/Round-Bend-U-bolts_c_562.html

 

If you are only searching the web for lowering blocks, your results may be limited. Try searching for lift blocks too.

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2 hours ago, Stoffregen Motorsports said:

I know it's not ideal to buy from the US, but these guys have everything leaf spring related - https://www.stengelbros.net/Round-Bend-U-bolts_c_562.html

 

If you are only searching the web for lowering blocks, your results may be limited. Try searching for lift blocks too.

 

Nice website, prices seems interesting and it's the first time I see a logical way to classify the products by size. Thank you.

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All 520/521/620 and 720 rear leaf springs are 1,200mm long and 60mm (2 1/3") wide leaves.

 

The '78  are stacked thus...

 

Top 1,200mm X 60mm X 7mm thick

2nd   60mm X 7mm thick*

Bottom 60mm X 13mm thick*

 

The FSM says 1,200mm long but that's not right.

 

Free camber (unladen) is 161mm or 6.34".

Spring constant is 1.9 to 5.5 Kg/mm or 106 to 308 lb/in. In other words the spring rate increases as the spring deflects.

 

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Toyotas, Mazdas, all small trucks used the same basic size rear axles, you could look into any small truck with leaf springs in the rear for the "U" bolts to see if they will work, also spring places make them for you but generally they are kind of expensive.

I have what you need, but I am positive you can get what you need cheaper where you live than having it shipped from over here in the USA.

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There are hundreds on eBay. Why not take the blocks out and see how the truck sits. If it's fine then use a ruler and measure the size of u bolt you need.

 

It you need a 1" block then buy of of those ford ones you linked to before or even take one of your blocks to a machine shop and cut it in half!

Edited by frank88
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2 hours ago, frank88 said:

There are hundreds on eBay. Why not take the blocks out and see how the truck sits. If it's fine then use a ruler and measure the size of u bolt you need.

 

It you need a 1" block then buy of of those ford ones you linked to before or even take one of your blocks to a machine shop and cut it in half!

 

Are you saying that there's no difference between lowering blocks ? It is allways the same thing ? It doesn't depend of the car brand or model ?

 

I've found this : 5U-159R 1/2 X 3-1/8 X 8-3/4R 20 Round U-bolt with nuts and washers

Edited by oukippy
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Drop blocks(lowering blocks) are mostly all the same, over here they are generic, meaning the same blocks will fit Mazda, Toyota, Nissan/Datsun, anything with basically the same size rear leafs, most small trucks over here use the same size rear leafs so the auto parts stores just carry 1, 2, 3, or 4 inch drop blocks with the correct size "U" bolts as a kit.

I am using an old browser so I cannot see the link you posted in the last post, but my other computer is at the shop right now, so maybe in a few days I will be able to see everything again.

Here are a few 2" drop block kits for our older small trucks, I could not find 1" drop blocks.

https://www.ebay.com/itm/rear-axle-drop-kit-2-aluminum-lowering-blocks-u-bolts-1998-older-import-trucks/201507150828?hash=item2eeac31bec:g:lIsAAOxydyxSPKx8:rk:1:pf:0

https://www.ebay.com/itm/2-lowering-blocks-fab-steel-rear-axle-ubolts-drop-kit-1998-older-import-trucks/372430744544?hash=item56b69a2be0:g:vA0AAOSw3hJblGi3:rk:5:pf:0

https://www.ebay.com/itm/Rear-Axle-Drop-Kit-2-aluminum-lowering-blocks-u-bolts-1998-older-import-trucks/232948162957?hash=item363ccae18d:g:46oAAOSwRL5bcdxT:rk:6:pf:0

https://www.ebay.com/itm/2-lowering-blocks-cast-steel-rear-axle-ubolts-drop-kit-1998-older-import-trucks/201538434867?hash=item2eeca07733:g:ylAAAOSw1x1UNCck:rk:7:pf:0

There were 15 results when I searched 2" Nissan drop blocks on ebay in the USA, you will notice most say for "1998 and older import trucks", I still think you could find stock sized "U" bolts with no drop blocks if you searched a wrecking yard over there and looked at all the small trucks, but maybe you do not have wrecking yards.

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Blocks are not model specific, but there are differences that matter.

 

The pin diameter - the hole and corresponding pin on the block need to be roughly the same is the center bolt/nut diameter in the spring.

 

Width - some springs are wider than others, but mostly springs are in the 2.25 to 2.50" wide category.

 

Pinion angle - some blocks are cut with an angle to compensate for the change in ride height. This may work for you, or not.

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On 10/9/2018 at 1:18 PM, oukippy said:

Ok, I'm tired of searching u-bolts in France (few available and never the good size). I'm ready to buy in USA.

Could someone give me the stock size of 620's u-bolts or a 1" lowering kit suitable for my 77 620 (part number 55247-B9800) ?

Try that link I supplied earlier. That should give you the information you need about your u-bolt size.

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Neither of them auctions show or say that they come with "U" bolts, so you are still without "U" bolts.

Here are a set of re-plated "U" bolts, they are kinda expensive but I suspect they will work for you as they are from a 620.

https://www.ebay.com/itm/73-DATSUN-620-TRUCK-REAR-LEAF-SPRING-U-BOLTS-REPLATED-NICE-OEM-PARTS/323320371761?epid=10020916303&hash=item4b47655a31:g:RV8AAOSwKVVbM7LT:rk:8:pf:0

I look at your situation this way, if your truck leafs have no arch in them after removing them stupid clamps(changed nothing), then you do not need lowering blocks the way it is, you just need to get proper "U" bolts so you can remove the lowering/drop blocks unless you want to keep it lowered.

I do not know what was done to the leafs you have, they could have been de-arched, leafs could have been removed, or maybe there is a way to heat them and make them sag, professionally de-arching is the only way I would keep them, the other two ways I mentioned to lower the truck would necessitate replacing them with another set of leafs that are complete/unmodified.

Measure your U bolts, how wide apart are the ends of the "U" bolts where the nuts are, measure front to back, are they 3 1/2" center of nut to center of nut?

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Yes I know there's no u-bolt. I was planning to use the one I already have.

But you're right, 2" less will probably not be enough. I'll measure my u bolts tomorrow and I will order some u-bolts from stengelbros.net.

The only question is which length should I take? I'll measure my u bolts and probably remove the block length and the extra-length that should have been cut by the previous owner. It should give me the correct length or a little bit more.

 

Thank you again for taking time to help me.

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If you were to set a stock "U" bolt on a flat surface and measure from the flat surface to the top of the "U" blot it should be around 6 1/2 inches(around 165.1mm), the threads go up the "U" bolt shaft 1 1/2 inches(about 38mm).

I have another "U" bolt that measures out to 8 inches on a flat surface that has 2 1/4 inches of threads going up the "U" bolt shaft.

I have no idea what these "U" bolts are off of anymore, they are just in a bucket, but they might give you an idea what your "U" bolts are supposed to be when you get your measuring tape out, I believe these "U" bolts I have are stock lengths that are used to hold axles on the leaf springs with no drop/lowering blocks.

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On 10/13/2018 at 3:20 AM, wayno said:

If you were to set a stock "U" bolt on a flat surface and measure from the flat surface to the top of the "U" blot it should be around 6 1/2 inches(around 165.1mm), the threads go up the "U" bolt shaft 1 1/2 inches(about 38mm).

I have another "U" bolt that measures out to 8 inches on a flat surface that has 2 1/4 inches of threads going up the "U" bolt shaft.

I have no idea what these "U" bolts are off of anymore, they are just in a bucket, but they might give you an idea what your "U" bolts are supposed to be when you get your measuring tape out, I believe these "U" bolts I have are stock lengths that are used to hold axles on the leaf springs with no drop/lowering blocks.

 

RoundBend.jpg

I have measured :

A = 0.5"

B = 3-1/8" (measured under the axle but if I measure at the ending of the bolt, it's more 3,54", probably because they are bended)

C = 10"

 

My blocks are 3" so I only need C = 7" or 6-1/2 if I consider the useless thread that should have been cut.

 

Consequently I have to choose between:

1/2 X 3-1/8 X 6-3/4R 16 Round U-bolt

and

1/2 X 3-1/8 X 7-3/4R 18 Round U-bolt

 

 

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