Need help reversing shackle reversal (1 Viewer)

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Rick '79 FJ40

Rick '79 FJ40

Joined
Jan 28, 2005
Threads
51
Messages
411
Location
Woodstock, GA
im starting my frame-off on my '79 FJ40 and the PO put some sort of shackle reversal on it that I would like to put back like it was originally.

Has anyone done this? Does anyone have a source for the proper front spring perches/mounts?

I'd also like to get some pictures of a non-molested truck for reference.

TIA!
 
I did the same repair to my 40. I bought the perches from Specter off road, they will bolt to the old rivet holes and then weld them in place. it is a very easy repair.
 
Rick '79 FJ40 said:
im starting my frame-off on my '79 FJ40 and the PO put some sort of shackle reversal on it that I would like to put back like it was originally.

Has anyone done this? Does anyone have a source for the proper front spring perches/mounts?

I'd also like to get some pictures of a non-molested truck for reference.

TIA!
Click to expand...

Not sure how close the '77 frame is to the '79, but you are more than welcome to come by my office and snap as many photos as needed and take any dimensions.....Oh, I'm a Rick in Woodstock, GA as well. :hillbilly:
 
Cool! Im right off Hwy 140 between Canton and Alpharetta.

You can email me your contact info at rick.b.jones@att.net
 
Tysano said:
I did the same repair to my 40. I bought the perches from Specter off road, they will bolt to the old rivet holes and then weld them in place. it is a very easy repair.
Click to expand...

Ok, Thanks for the info!

I have seen some stuff on eBay and didn't know where else the mounts were available. I think I need spring perches, too. So I'm still getting info so I know what questions I need to ask.

Thanks!
 
I'm actually working on doing the same thing. I purchased my replacement hangers from BTB products. Below are some before and after pictures. The bolts were used to align the hangers in the original position. They are not fully secure at this point. I'm still trying to decide what way to position the nut.
IMG_2441.JPG

IMG_2442.JPG

IMG_4609.JPG

IMG_4610.JPG

IMG_4611.JPG
 
Just be aware that your 79 will have different spring hangers than a 78 and earlier will.

It's not a hard conversion. Post up pics!
 
jrcfj40 said:
I'm actually working on doing the same thing. I purchased my replacement hangers from BTB products. Below are some before and after pictures. The bolts were used to align the hangers in the original position. They are not fully secure at this point. I'm still trying to decide what way to position the nut.
View attachment 1187863
View attachment 1187864
View attachment 1187865
View attachment 1187866
View attachment 1187867
Click to expand...

Thanks! That helps a lot! I haven't ever looked closely at how they were on an "unmolested" truck. I mainly wanted to see what the 2 bracket types looked like so I was sure I got the right ones.

Thanks again for the help!
 
Mace said:
Just be aware that your 79 will have different spring hangers than a 78 and earlier will.

It's not a hard conversion. Post up pics!
Click to expand...

According to the info on Specter, they were the same until some time in 1980...

I'll take some pictures once I get started. I'm waiting for my buddy to get time to do it. It's sitting in his shop waiting for him to finish an 80s Camaro.
 
Damn, you're right, 8/80 was the change.

That makes life a lot easier.
 
I am looking to do the same thing on my 10/78 manu date rig. From what I can tell the front hanger/bracket is unchanged over the years but the rear one is different between some time in '77-'80. My front mounts were welded to the frame:(. But I guess this is still reversable? @jrcfj40 I noticed the frame is off your rig to switch back to stock, I assume this can be done with everything on rig by dropping the axles?? Also, why did people do this mod? Did it really improve how the front end worked, better of road, etc.....??? With the reverse shackle front end I believe my lift is 2-3 inches performed by @lcwizard aka Dave Gore, PO had dave do the work. I would either go back to original ride height and ditch the '33's or do the OME 2.5 lift. I do not want to increase my ride height from where it currently is, if anything, go lower.
 
tls3601 said:
I am looking to do the same thing on my 10/78 manu date rig. From what I can tell the front hanger/bracket is unchanged over the years but the rear one is different between some time in '77-'80. My front mounts were welded to the frame:(. But I guess this is still reversable? @jrcfj40 I noticed the frame is off your rig to switch back to stock, I assume this can be done with everything on rig by dropping the axles?? Also, why did people do this mod? Did it really improve how the front end worked, better of road, etc.....??? With the reverse shackle front end I believe my lift is 2-3 inches performed by @lcwizard aka Dave Gore, PO had dave do the work. I would either go back to original ride height and ditch the '33's or do the OME 2.5 lift. I do not want to increase my ride height from where it currently is, if anything, go lower.
Click to expand...

I still prefer a shackle reversal although this kit here has some major flaws. It was a design that Advance Handling marketed in the late 90's.
My kit looks like you took those front hangers and reversed the rake so they swing rearward instead of out. The Advance units got the reputation of being rock hangers. With my design the front spring was flipped front to rear. The front leaf in stock setup the front half is ~24" long and the rear in ~20 long. Using a rear raked hanger we can spin the spring leaving the axle in the same place. Based on a stock front spring this improved approach angle by 11 degrees. The Advance Handling design loses about 6. Caster was changed from 0~1/2 positive to 2~3 deg positive which was a vast improvement in straight line line road manners. The A/H rear shackle hanger also had some flaws. The front to back symmetry made manufacturing easy but created a problem if you retained a stock shackle. The spring eye would contact the back of the hanger before full compression and limit up travel. forcing up travel once the shackle is locked can bend a spring. Champfering the back allows the eyelet to swing clear. If you use a spring with the large eyes, which most are now, I prefer building around the larger 18mm pin like the 60 series and 1980 and later 40
I don't sell them anymore but I do build them for in house builds. There are too many issues that can cause problems to just pass them out on the internet without having a long consultation with someone familiar with the possible issues. For one, spring manufacturers are
terribly inconsistent. I tried a set of springs from a very well known manufacturer we'll call "S" that required an 8 deg caster shim to bring the
axle to stock caster. When I sold them through Man-A-Fre, they sold them with springs that had been tested to work with them so the results could be controlled. Without knowing the characteristics of the spring the installer has chosen, it's hard to make recommendations for
specific fixes.
When you reverse the shackles, the axle now swings away from the t-case. If the installer uses the wrong shock, the stock 40 drive shaft slip yoke, at 2 3/4" , isn't long enough and the driveshaft pulls apart in droop. If the this much droop is allowed you are probably
binding the u-joint at the t-case. The stock drivetrain tilts downward at the back. If you have 20 degs at the rear d/s, the front is seeing about 25ish. The stock u-joint is only good for 25~27 degrees of angle. The fix is to use the slip yoke and ujoint assembly from the FRONT of an 80
series. They are also found on Tacomas and 4runners. They have a 6" slip yoke and a ujoint with 45deg of articulation. Builders in the know are familiar with this piece as it can also be bought new in the 8" version from Georg (Valley Hybrids) and Kurt ( Cruiser Outfitters). This will require
a pinion flange that can be redrilled for the 80 pattern. The round flanges work great.
With a 4" or better lift the potential is there to go beyond the limits of what Toyota designed. Lots of wheel travel looks great on paper
but the whole package has to be assessed or you'll be doing some trail repairs as these things don't generally reveal themselves on the pavement.
Best you can do after any serious suspension mod is elevate the truck with all the running gear hanging and turn the driveshafts by hand.
Look carefully at each ujoint through full rotation. If yo have slight interference you can relieve the contact areas with a flap wheel or some kind of abrasive. If the interference is heavy or completely binding you will either need to replace those ujoint assemblies or limit down travel with a shorter shock. Before someone says " never limit travel with your shock" ,since forever, down travel has been limited by manufacturers with a shock. It's up travel that should never be limited by shocks.

OH, and there should be a cut out for the frame number.....

IMG_3135.JPG


IMG_3136.JPG


IMG_3578.JPG
 
Excellent write up Dave!!! Mine was before the cutouts sadly...........
 
I can post up pics of my setup
 
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