What made the "Datsun 1 Ton" trucks, 1 tons?

[68Datsun510]

Was it just rear springs?

[RadioRedline]

6 Leafs Baby!

 

Radio

[kaoss]

8 pain in the ass bed bolts that suck to get off 30 years later. Really? 8? 8 fugging bed bolts??? C'mon!!!!

[merlin]

Good advertising

[68Datsun510]

Anyone have these springs and not want them?

[kaoss]

I have a set of springs from a 77 620. Not sure how many there are in the pack. I'll look tonight.

[68Datsun510]

My springs are fine, i just want the heavy sprung suspension

[datzenmike]

The 520 and the first year L521 ('69) were rated to carry 2,200 lb. The '70 an on PL521 were rated for 1,100 lb.

 

The 620 were all rated for 1,100 lb except the Cab Chassis model starting in Jan '78. I don't have that info but it is likely higher.

 

All 720 2 and 4 wd were rated at 1,100 lb except the Heavy Duty models which were 1,700 lb until mid '82 when they were downgraded to 1,550 lb and the Cab Chassis dual wheel continued at 1,700 lb.

 

All 521/620/720 2 and 4X4 springs are the same length.

[68Datsun510]

Capable of holding, yes, but how fast and how well can it stop? HAHAHA! THey dont mention that in the old ads :P

[datsunaholic]

The number of springs in the original spring pack didn't have a real effect on weight capacity. For instance, most 73-74 620s have 3 main springs plus a massive untapered, straight-cut overload. That's the same spring pack that rates as a 1-tonne (metric ton, over 2200 lbs) everywhere else in the world, but in the US it was rated as a half-ton. My folks were sold theirs as a "3/4 Ton" even though the dataplate doesn't reflect that. I've seen a couple "light" '72-73 trucks, and in addition to the lighter 5-spring pack they also had 4.38 rear gears whereas the "heavy" 3-leaf pack 72-73 had 4.88s.

 

The 1972-74 3-leaf pack:

 

 

'76 Longbed 5-leaf pack with ADDED upper overload: (not stock)

 

 

And there's the rub- the original 3-leaf pack is actually HEAVIER than the later 5-spring pack. Each leaf is a lot stiffer, thicker, and the 3-leaf heavies are back killers with the original bench seat.

 

Starting in '75 you couldn't find the heavy overloads, instead switching to a thinner, tapered and rounded overload but the spring packs still varied as to how many leafs they had. In '78-79 the springs had gotten significantly softer, and those springs were likely true "half ton" springs.

 

The variants I've seen, some have one leaf above the "long leaf", and some have all the leaves below it.

 

I've had well over the "rated" 1100 lbs in my '74, very close to a full 2000 lbs. Stopping is fine... you have to give it distance. It actually rides a lot better with 500# plus in back.

[oldskoolvws]

All 521/620/720 2 and 4X4 springs are the same length.

 

Mike, does this mean we can use 720/HB rear leaf springs from Belltech on the 521?

[wayno]

8 pain in the ass bed bolts that suck to get off 30 years later. Really? 8? 8 fugging bed bolts??? C'mon!!!!

 

I'll tell you kaoss, I would rather have 8 bolts holding on my box that actually function, rather than the 4 pathetic jokes that are used on the full size dodges of the late 90s and early 2000s, my friend has a dodge cummings diesel that had to be repaired because the mounting surfaces of the dodge box were designed for light duty at best, they were certainatly not for heavy loads on any type of regular basis. The dealership told him that he must have somehow caused the problem and nobody else had the problem, but he kept complaining till they agreed to fix it under warranty, he delivered the truck to where they told him to, and there were almost a dozen dodges in there with the same problem, on that day!!!

[wayno]

Mike, does this mean we can use 720/HB rear leaf springs from Belltech on the 521?

 

As Datzenmike said, they are the same length, but the bushings and hardware are differant depending on the year/series, but I have been able to figure out how to put whatever year rear leafs I want on whatever year I have, I actually like the earlier stuff the best myself because of the front bushings on the rear leafs.

[albyneau]

The number of springs in the original spring pack didn't have a real effect on weight capacity. For instance, most 73-74 620s have 3 main springs plus a massive untapered, straight-cut overload. That's the same spring pack that rates as a 1-tonne (metric ton, over 2200 lbs) everywhere else in the world, but in the US it was rated as a half-ton. My folks were sold theirs as a "3/4 Ton" even though the dataplate doesn't reflect that. I've seen a couple "light" '72-73 trucks, and in addition to the lighter 5-spring pack they also had 4.38 rear gears whereas the "heavy" 3-leaf pack 72-73 had 4.88s.

 

The 1972-74 3-leaf pack:

 

 

 

My 71's ridin on the 3-pack w/ the monster overload~ are they not the originals?

[reinCARnate]

8 pain in the ass bed bolts that suck to get off 30 years later. Really? 8? 8 fugging bed bolts??? C'mon!!!!

 

LOL...try 40 years, those were a pain in the arse.

 

[albyneau]

LOL...try 40 years, those were a pain in the arse.

 

 

 

:lol:My 71's got ten bed bolts~ must be 25% tougher! :lol:

 

Again I ask~ My 71's ridin on the 3-pack w/ the monster overload~ are they not the originals? Or just the funky rating for US bound rigs that DatzenMike posted..?

Point of trivia: a metric tonne is 32#'s less tan a long (US) ton, which doesn't sound like much, bit given the lack of international standardization at that time maybe~ just MAYBE~ that was the rating's "straw that loaded the camel's back...? Or maybe that was Detroit's lobbyists' trying not to have a dent put in big fat gas-guzzlin American truck sales?