Differences in Tacoma leaf spring rates

[AlpineAccess]

I put leafs from a 2016, regular cab SR on my trailer when I was building it, figured I could mock it up and change it later. They were soft so I did a cheapo add a leaf. Pretty close but I'd but I need another hundred pounds of load for dealing with the bigger and higher speed hits on the highway.

Does anyone know what 2nd or 3rd gens come with the stiffest spring rate stock? I'm assuming TRD Sport Crew Cab would be the ticket?

 

[DaveInDenver]

All the leaf springs on Taco are soft. The only option was if you could convince your dealer to give you "TSB" springs, which meant an extra leaf in the pack. There was a second TSB that corrected corrosion issues with Tacoma springs and if you had those installed there was a chance that your original "TSB" springs were replaced with standard issue packs.

The way to tell is if you have 2 main leafs then you have regular USA springs. They'll have one overload spring that looks like a diving board. If your pack has 3 main leafs and one overload spring then you have "TSB" springs. Those are essentially Canadian or Mexican commercial packs for work trucks. Toyota would install them if you complained about excessive sag from towing or having a camper under TSB SU006-007/305-08/350-10 (Harsh Ride). The original issue in that case being you were always riding on the super stiff overload and the CA/MX commercial pack being 3+1 were increased rate.

The 3rd gen AFAIK have no differentiation. You always get soft pavement friendly packs. The geometry is the same just no TSB to get commercial packs like a Mexican or Canadian work truck got. At least for free under TSB.

So uprated springs are Old Man Emu or those you build yourself. I got a set of corrosion-free (so to speak) replacement TSB packs for my 2008 and they are sssoooffftt like stock packs. I'd run 'em but only with 3-leaf add-a-leaf packs you might find from standard outlets. Stock they are uber soft in my experience. Even aftermarket, I run OME Dakar with an extra leaf, seven (seven) total to support the weight of a WilderNest. No swing out or anything.

Also don't discount that 2005 and newer Taco have tension shackles so putting the leaf pack in a standard compression shackle arrangement changes things. What used to be maybe acceptable could no longer be. This is something people who do shackle flips on 05+ find. Even heavy duty OME become no good after that. Either too much uptravel or no droop or whatever.

 

[AlpineAccess]

Thanks Dave!

I went with Taco springs specifically because they are soft; my trailer is around 1000 lbs with around 1000 lbs of load capacity, probably quite a bit lighter unloaded than the tail on a 4 door tacoma, but around what I think the regular cab SR would weigh (hence why I used this set).

The regular cab SR springs are 2 leafs with an overload that look to be the lightest ones on the market (from Tacoma World discussions), so I'm wondering if just getting the third leaf in there would help with when the trailer is lightly loaded and at higher speeds.

I am using compression shackles on them, seeing that they use a tension system is something I did not factor in. Overall, I'd say it is performing very closely to how my initial calculation suggested it would, but if I could find a spring with even an extra 50lbs of dampening in the initial 10% of the compression cycle it would be a really nice improvement in handling. On washboard it is a dream to tow - it just floats along. A bigger hit causes more compression and I'd like to control rebound a little more.

I just ordered a set of older VW Bug shocks which I am going to weld in hangers in for.

At the end of the day its a trailer, so I'm just trying to get JUST a bit stiffer Tacoma spring and the stock springs are so cheap to buy and test out that I may grab a set of TSB springs and give them a shot. I had the TSB done on my 2013 Tacoma and it definitely tightened things up a bit - thanks for pointing that out, it might be just what's needed.

Apologies as this response isn't very well organized, just paint on the wall for the moment.