Trailing arms touching chassis

[roofingbloke]

Got the bed off my long fleet, i am going to do a small notch, got the measurements, with the air bag in the spring location fully aired out the trailing arm is the limiting point of how low i can go,

Question if i want to go lower what is the next step,

I see porterbuild sell a crossmember for the front trailing arm location, but how much lower ?

[Hottrucks]

the next drop is going to require you to spend some $$$$...relocate your bag mounts shocks,...its at the point to start thinking a 4 link

[fleetsidelarry]

Originally Posted by roofingbloke

I see porterbuild sell a crossmember for the front trailing arm location, but how much lower ?

there was a recent thread about flipping the front trailing arm mounts rather than replace the crossmember but I don't see how that changes the eventual interference problem.

[SCOTI]

Originally Posted by fleetsidelarry

there was a recent thread about flipping the front trailing arm mounts rather than replace the crossmember but I don't see how that changes the eventual interference problem.

It changes the pinion & slightly alters when the interference would occur.

Roofingbloke, what notch & bag set-up are you using? I've done more than 1 6x-72 w/the air bag in the stock coil location. With the bag deflated, I've yet to have interference issues w/the T/A hitting the frame. I'm curious about what might be different.

[roofingbloke]

All rear end is stock at the moment, using slam 6" bags, 3.5" when aired out, 2" lowering blocks,

When i have done some measurements it works out that the upper edge of the axle will be 1" down from the top edge of the chassis, so no point in a step notch, so will be going for a small step notch, but i dont think i will get any lower without modifications to the crossmember that holds the front of the trailing arms, cannot afford new tubular arms so need to think some more,

Thanks for the replys, Darron

[PGSigns]

The trailing arms will not hit the frame. The rear end will be the limiting factor and it will bottom out in the notch or the top of the housing will hit the bed floor first. With mine fully deflated I hit both about the same time.
Jimmy

[roofingbloke]

Originally Posted by PGSigns

The trailing arms will not hit the frame. The rear end will be the limiting factor and it will bottom out in the notch or the top of the housing will hit the bed floor first. With mine fully deflated I hit both about the same time.
Jimmy

I think you have got this all wrong, The biggest problem is trailing arms hitting the frame, the axle will only hit the bump stops on a notch if you built it wrong.

Dont want to go to the expence of a four bar.

[SCOTI]

Originally Posted by roofingbloke

I think you have got this all wrong, The biggest problem is trailing arms hitting the frame, the axle will only hit the bump stops on a notch if you built it wrong.
Dont want to go to the expence of a four bar.

Depending on how big the 'notch' is, PGsigns is correct based on my experiences w/the trucks I've worked on. The limiting factor is the bag in the factory coil position. It limits the amount of drop regardless of how big the notch is.

If the bag is in the factory placement between the frame & T/A, the T/A should not contact the frame (even w/the bag fully compressed @ 2.8" min height).

[PGSigns]

Here is a pic from when I was doing mine and it shows the bag with no air in it. I did not want to raise my bed floor so I don't have any blocks on mine. I need to put bump stops in the notches to stop the rear from hitting the wood in the bed. You have 2 inches between the arm and the frame as it sits in the picture.
Jimmy

[roofingbloke]

My bags wont be in the origional coil spring location, therefore i will get more drop, hence the trailing arms hitting the frame will be a problem,

Anyone come across this problem also,

[SCOTI]

Originally Posted by roofingbloke

My bags wont be in the origional coil spring location, therefore i will get more drop, hence the trailing arms hitting the frame will be a problem,

Anyone come across this problem also,

Your original statement is confusing....

Originally Posted by roofingbloke

Got the bed off my long fleet, i am going to do a small notch, got the measurements, with the air bag in the spring location fully aired out the trailing arm is the limiting point of how low i can go,

I thought you were stating the problem existed w/the bags in the stock coil spring location. Trim the frame where the interference occurs.

[kev2809]

did you offset the bag on the side of the frame and ta rather than bolting it in between?

[roofingbloke]

Just measuring at the moment,

I have a 63 long fleet.

With 2" lowering blocks & bagi in spring location, when aired out the trailing arms are very close to the chassis (half inch)

So if i want to go lower whats the next option, I dont want to go to the expence of tubular trailing arms,

Anyone come across this situation.

[kev2809]

you can move the bags on the side of the frame or put them over the axle, but the arm will still hit the frame. the only option from there is a link setup...then you have to move your bag.

or step the frame where the arm contacs the frame...then you can keep your original ta's. if you havent done your step notch yet you start the step from there...instead of just over the axle. check out puropedo's build..he did this same thing.

[Twiztid_66c10]

my plan on fixing this when i do my rear setup is to move where the trailing arms connect. i am going to do this buy disconecting the crossmember for the arms strighten the arms out so they dont go out at such a angle and mount new brackets to the rearend and and re mount the cross member. for mounting the bags i am going to mount them on the outer rear frame and on top of the axle hope this makes sense

[slimneverdies]

Originally Posted by Twiztid_66c10

my plan on fixing this when i do my rear setup is to move where the trailing arms connect. i am going to do this buy disconecting the crossmember for the arms strighten the arms out so they dont go out at such a angle and mount new brackets to the rearend and and re mount the cross member. for mounting the bags i am going to mount them on the outer rear frame and on top of the axle hope this makes sense

I'm not sure you want to mess with the geometry that's built into the triangulation of the trailing arms. It's hard enough to just duplicate the original angles. I would think you could just do a two link if youre gonna change the angles. I could be wrong tho
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[Twiztid_66c10]

a guy i know has built and lowered these trucks for many years and has a big company in portland or. and he was the one who gave me this idea said he does this kinda thing all the time just gotta take your time and do it right

[tubbedII]

Originally Posted by roofingbloke

Just measuring at the moment,

I have a 63 long fleet.

With 2" lowering blocks & bagi in spring location, when aired out the trailing arms are very close to the chassis (half inch)

So if i want to go lower whats the next option, I dont want to go to the expence of tubular trailing arms,

Anyone come across this situation.

Like everyone has said, unless you move the bag location, you won't run into interference with the t/a and frame. You can run a bigger block in the rear (pay attention to scrub lines, so wheel size determines this) to get lower, but with a bolt in notch, a 2" block and bags in stock location you're as low as you can get.

I saw a rat rod type 65 at a show laying frame with stock t/a's and bags in the stock location. They z'd the rear frame right before where the t/a would contact the frame. I say "z" because it was done almost just like one where it was just cut, moved up and welded back together...not a typical step notch or custom back half. I don't know if this was safe, but he said he'd been driving for over a year and had no issues.

[kev2809]

if you plan to make new brackets to bolt the ta's too, why not build a 4 link? just curious, seems like it could save you the headache.

also, if you reposition the ta's where are you mounting your bags?

[Twiztid_66c10]

Originally Posted by kev2809

if you plan to make new brackets to bolt the ta's too, why not build a 4 link? just curious, seems like it could save you the headache.

also, if you reposition the ta's where are you mounting your bags?

cheaper moving ta's then 4 link already have all stuff there just need to make a couple brackets. i plan on mounting the bags on the outer side of the frame rail right above the axle. so one mount will be on axle and other on out side of frame on the c-notch

[kev2809]

ah, i see. i kept thinking you were mounting your bags on the sides of the ta's. be sure to post some pics..i would like to see how it turns out.

[slimneverdies]

Twizid, what did you end up with? I'm trying this same thing on a 73-87 frame
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[roofingbloke]

my bags are in the post at the moment so wont know for a week or so,


also held up with my front end, i done a crossmember section, 1.25" and steering now hits crossmember so i am concentrating on the front whilst i am waiting for the post.