TJ's TJ

TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#1
After months of looking, my son and I went in on a TJ with frame rot. Got it cheap, due to the rot, and bought it as a project to work on it together. It will be his DD eventually when he gets his license and likely won't see more than light trail use. It is a 99 4.0L, 5 sp, 84K miles, 30/35 w/3.73s and it runs like a top.

The current plan is a 4" lift, ~33" tires, adjustable arms, SYE and DC driveshaft, adjustable track bars, Rubicon flares, aftermarket bumpers.

We were going to do safe-t-caps on the frame, but we already found a pretty clean replacement frame from an 06.

upload_2018-5-24_13-22-49.png


Here is the replacement frame.
upload_2018-5-24_13-44-52.png


The only planned mod to the frame right now is a rear spring perch re-location. Anything else that we should be considering while the frame is out?
 

EJD

TJ Overlander
Supporting Member
Ride of the Month Winner
Jul 16, 2016
1,409
1,344
Missoula, MT, USA
#3
We were going to do safe-t-caps on the frame, but we already found a pretty clean replacement frame from an 06.

View attachment 42142

Here is the replacement frame.
View attachment 42143

The only planned mod to the frame right now is a rear spring perch re-location. Anything else that we should be considering while the frame is out?
Oh man, nice score on the frame!

Coming from someone who has done safe-t-caps, I wish I could have gone that route but since you've got a clean frame I would certainly be doing a thorough undercoat job or something similar to ensure it has a long life. You may want to drill a hole in a couple strategic places for water to drain in problem areas too.

Best of luck with the switch over, can't wait to see it!
 

Mike_H

Rust Belt Heavyweight
Supporting Member
Feb 28, 2017
3,579
3,796
Grand Rapids, MI, United States
#6
There are a lot of threads...Just gotta do a google search. As far as advantages, the main one is getting the shock perpendicular to the lower control arm, where they will be most effective. You also can balance the shock mounting properly so that the shock is in the middle of its travel at ride height. Its quite involved...and frankly, I'm not sure why you would be relocating the spring perch if you don't already know about shock relocation? Not trying to be a jerk or anything, but if you are lifting enough to warrant rotating the axles and relocate spring perches, you should have already come across threads describing shock outboarding (spring perch relocation and outboarding kind of go hand in hand).
 
OP
OP
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TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#7
There are a lot of threads...Just gotta do a google search. As far as advantages, the main one is getting the shock perpendicular to the lower control arm, where they will be most effective. You also can balance the shock mounting properly so that the shock is in the middle of its travel at ride height. Its quite involved...and frankly, I'm not sure why you would be relocating the spring perch if you don't already know about shock relocation? Not trying to be a jerk or anything, but if you are lifting enough to warrant rotating the axles and relocate spring perches, you should have already come across threads describing shock outboarding (spring perch relocation and outboarding kind of go hand in hand).
Sorry, Jeeps are still very new to me. And yes, I have seen some stuff on outboarding, but nothing yet that ties spring perch relocation to outboarding shocks. My understanding of the perch relocation is that it is done to take the arc out of the rear springs when a moderate lift is added. I have seen plenty of people with a 4" lift that have done the perch relocation without outboarding.

Since everyone is building with different objectives, being new to this, it is hard to decipher what would be the correct level of modification for my intended use when scouring the internet for information. I thought that was the point of this forum, to get some opinions from you experts as to what might be right for my application? The other point is that there is alot of "wrong" ways to do things on the internet, again, being new to jeeps, again it is hard to pick out the good from the bad.
 
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Mike_H

Rust Belt Heavyweight
Supporting Member
Feb 28, 2017
3,579
3,796
Grand Rapids, MI, United States
#8
Sorry, again, I'm not trying to offend you. Just that when I looked up perch relocation for my own knowledge, outboarding the shocks seems to go right along with it (i.e. I learned about both at the same time, in the same threads). That's all.

Anyway, The springs will be ok at 4" of lift, even once you rotate the axle for the DC driveshaft. Where you might run into problems is the lower shock mount can rotate under the axle enough that the shaft will contact the tube. Then you need to extend the mount out to the shock can function. It all becomes a bit of a compromise...so relocating the perch and outboarding the shock lets you push the reset button and get things located properly again.

The more I think through it, you might not even be able to outboard the shocks, until you get the frame replaced and the jeep sitting at ride level...
 
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TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#9
Not offended, I am all ears at this point. Even if the springs will be "OK" at 4", it seems to me that moving the perches is an easy one while the frame is out that should be done to remove the arc, right?

My overall thinking is that staying closer to stock on the shocks will allow utilization of the dozens of known/proven/affordable solutions. But that being said, I should also probably emphasize that the highest priority is stability on the road with the desired 4" lift. If outboarding the shocks will offer a significant improvement, then I will definitely consider it. If it mainly gives gains off road, then I would likely pass on it for now. Does that make sense?
 

bobthetj03

vibrajeep
Supporting Member
Ride of the Month Winner
#10
There's only so far you can move the upper perches till you have interference with the track bar frame mount. My concern would be not having the axle in place to measure at full bump to make sure you're lining both sides up correctly. I can understand how having the body off and out of the way would make that chore a bunch easier, so I get the interest in doing it.
 
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TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#11
The perches have been removed. So what is the consensus before I weld these back on? From my research, it looks like the long side is typically trimmed and then the perch is centered on the holes at the top of the frame bend?
 
OP
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TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#12
For clarification to those that aren't already experts, I talked with Mr. Blaine and he verified that now is the time to relocate the perches, and that it is OK to reposition them using the hole in the top of the frame. Also, he agreed that for our intended use, not outboarding the shocks at this point was probably the correct choice...
 

cliffish

TJ Addict
Supporting Member
Oct 22, 2017
2,246
2,060
St James, NY, United States
#13
For clarification to those that aren't already experts, I talked with Mr. Blaine and he verified that now is the time to relocate the perches, and that it is OK to reposition them using the hole in the top of the frame. Also, he agreed that for our intended use, not outboarding the shocks at this point was probably the correct choice...
Well you spoke to the best so that is the route I would go...he knows his stuff!
 
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TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#15
Perches removed and relocated. I trimmed the long flange, they are not quite lined up with the frame holes, probably about 1/2" forward of them.
upload_2018-6-12_8-17-16.png


upload_2018-6-12_8-17-54.png


We also added front and rear drainage holes:
upload_2018-6-12_8-19-24.png


upload_2018-6-12_8-20-10.png
 
OP
OP
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TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#16
4' tube brush to clean the inside of the frame:
upload_2018-6-29_12-20-0.png


Cut access holes to get it in since I plan to relocate the skid plate riv nuts back to the early frame locations (ours is a late frame):
upload_2018-6-29_12-24-20.png


Propped up to give it a good cleaning and internal rinse:
upload_2018-6-29_12-25-31.png
 
Likes: JMT
OP
OP
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TJ's-TJ

TJ Enthusiast
Mar 28, 2018
147
100
MA, USA
#19
frame was washed with white vinegar, rinsed, degreased, scuffed with 180, then got a light coat of UPOL ACID#8 (never used this stuff before, but was impressed with how well it stuck to the galvy), then top coated with POR-15:

upload_2018-7-3_7-47-32.png


Hoping it should be good now for a long life in the North East salt...