Hydro Assist:box and pump mods

[freds40]

This Thread is Featured in our Tech from our Forum Members section!
Update: Rick's info on tapping the FJ 80 series box has been added at the bottom of page #1 

This is an in depth layout of how I have drilled/tapped Toyota IFS steering boxes for Hydro assist as well as a simple mod to allow your pump to keep up. I was able to get ahold of a box (thanks toecutter) so I could show a bit more detail than my original thread on just setting up my system. This is intended to give a bit more info on the time, tools, and ability needed to do this mod. I was nervous about it the first time but once I got into it, I was upset at how difficult many people made the job sound. If you want to give me $75 to do your box, that's fine but this is not about me making money, it's to show that it can be done easily by most people. It took me about 2 hrs. from start to finish and that was with taking all the pictures. So if you have the ability, a bit of patience, and don't have the cash to have someone elso do it, try it yourself.

And this is the rest of setting up my Hydro assist system for cheap.   http://board.marlincrawler.com/index.php?topic=4699.0

[freds40]

First, all the tools I have used from start to finish. There is more or even different tools to use, but this is the system I have used and it works great for me.

Deadblow hammer
Ball Peen hammer
3/4" socket for 1/2" drive ratchet
32mm socket for 1/2" drive ratchet
Pitman arm puller
Crescent wrench
1/2" drive ratchet
3/8" drive ratchet
14mm socket for a 3/8" ratchet
Center punch
7/16" drill bit
2 smaller bits to step up in size
1/4" NPT tap
14 guage wire (about 8" long)
Brake cleaner
1/2" drive drill
Many rags.

[freds40]

If you don't have a pitman arm puller, check out Autozone. They have a free tool rental setup where you pay for the tool and they give a complete refund when it is returned. Free tool rental.    When you ask for the pitman arm puller, make sure you get this part number as both times I have gotten them, they have tried to give me a pickle fork.

[freds40]

And this is a close up of the proper tool itself.

[freds40]

Alright, first step is to pull the 32mm pitman arm nut.

[freds40]

Now to pull the arm, I have found that if you use the tool in the predetermined method of just tightening on the puller, chances are you will break it, I know, I have.    The best way I have found to pull the arm is to first tighten the puller down onto the arm. Get it tight enough that you have to put some muscle in it, but not that you are jumping on the breaker bar to turn it.

[freds40]

Next, grab your ball peen and smack the end of the puller itself. Retighten the puller. I usually get about 1/16th of a turn between blows with the hammer. Smack it again. Keep this up until the arm pops loose. First box I did it took 2 shots, this one took 5. It can take a little while but keep at it.

[freds40]

Next, turn the input shaft to about the center location.

[freds40]

Pull the 4 sector shaft bolts on the top cap.

[freds40]

Use the dead blow and tap the sector shaft up through the top of the box. A bit of fluid will come out so be ready with some absorbant.

[freds40]

Turn the input shaft to the left until it stops. Now remove the 4 input shaft housing bolts.

[freds40]

If your box has the centering valve, use the 10mm allen wrench to remove it. There is a valve, spring, and almost a cylinder that need to be removed. If you don't have one, skip this.

[freds40]

Now pull the input shaft housing, you might have to worry it a bit as the o-ring inside will stick some.

[freds40]

Now you can locate where you want your holes. The first can be moved around some. I have seen some people who have mounted it on the word TOYODA.

[freds40]

Only problem is if you ever want to move your box forward to accomodate moving the axle forward, the line coming off the box will interfere with the front body mount. I prefer the second location. Roughly 2.5" down from the top surface and 1.25" over from the casting seam. It is out of the way and allows for you to move the axle in the future without redrilling your box.

[freds40]

With this hole, if you look inside you are drilling into a large open orifice so this one is the quick and easy hole. Also note that a rag should be stuffed in to cover the bearings for the sector shaft so as not to get any chips down that direction.

[freds40]

Always center punch before drilling as walking the bit can really mess ya up on the next hole. I started with a small bit to pilot the hole, then stepped up to a middle sized bit to make the final 7/16 hole easier and more controlled.

[freds40]

Here is the pilot hole from my preditermined location.

[freds40]

Now I used to work in a machine shop and when we had to tap a hole in a free standing structure we would use a hand drill to power it in as well as to properly align it. As long as you are holding the drill with the tap in the same plane as when you drilled the hole, the tap will align properly. After starting the threads with the drill, I used a cresent wrench to finish tapping the threads. Make sure to use a good cutting oil and to back out the tap and clean the threads frequently as it only takes 1 rogue chip to strip your threads or even break off the tap in the hole.

:EDIT: Hadn't thought about it because it didn't happen to me. When tapping this hole, take your time and check the depth. I got a PM informing me that they had tapped too deep and the fitting was bottoming on the sector shaft. Quick fix if it happens is cut a couple of threads off the fitting, debur the threads, and throw it back in.

[freds40]

Now for the top hole, you are trying to catch the vein that runs front to back.

[freds40]

You can see on the top of the box, the vein is actually raised above the rest of the casting.

[freds40]

Same method, punch, pilot, step, 7/16, tap. You can see that I was a little off to the left but the bit is large enough that I still caught the vein just fine. With this hole, you need the 7/16 bit to touch the bottom of this vein in order to get enough engagement on the fitting. BE SURE NOT TO PUNCH THROUGH THE BOTTOM AS THIS WILL RUIN YOUR BOX.

[freds40]

Now make sure you clean the box THOROUGHLY. I have found that using compressed air works but can make it difficult if used too soon. If you blast air into the top vein right off the bat, it will compact the chips together and take a long time to get them all out. I have found that if you use a piece of 14 guage wire (it's what I had lying around), strip back about 1/2-3/4" and fray the wires a bit, it'll work much better. If you insert the frayed wire and twist, you can grab some chips and pull them out. Do this until the wire stops @ the other end of the vein. Then blast some brake cleaner down the vein to clean the cutting oil and small particles. Then just clean the chips from the main body of the box, pull the rag on the bearings and clean some more. A flashlight will help you find ALL the chips. Once it is %100 free of chips, you can start reassembly.

[freds40]

One thing to watch when reassembling is the teflon ring on the piston.

[freds40]

It can get cut on this sharp edge when sliding back in and cause some serious problems down the line.

[freds40]

After reassembly, throw on your lines and you are ready to go.

[freds40]

Now, some people get nervous because @ this stage, your ram will not keep up with the speed in which you are trying to turn. A simple 10 min. pump mod will take care of the problem. Some people shim the spring inside which I have heard will burn up a pump. For this part, I used a 13/64 drill bit, drill, 17mm combination wrench, and a crescent wrench. Remove the High pressure line from the pump and then the restrictor itself. When removing the restrictor, be careful that the spring inside and the plunger do not shoot out and become lost. If you are careful, they will just sit inside when you remove the restrictor.

[freds40]

Once out, turn the restrictor upside down on a hard surface and tap a couple of times. A bushing will fall out. Now drill the orifice in the restrictor out to 13/64. After drilled out, put the bushing back in and bolt it all back together.

[freds40]

Rick posted some info for working the FJ 80 boxes. Here it is borrowed (with Rick's permission) from the Tuki build:

 I wanted to abbreviate a few differences in dealing with the FJ80 box. (Its
my understanding that the FJ-80 box is also identical to the FJ55/60/62.)

STEPS:

0.) Remove and thoroughly clean outside of the steering box.

1.) Center the pitman arm.

3.) Remove the pitman arm.

4.) Remove top 4 bolts above sector shaft, 14 mm.

5.) Remove Sector Shaft.

6.) Turn input shaft so internal piston moves toward input end.

IFS box - CounterClockWise
FJ80 box - ClockWise

7.) Remove centering valve, 10mm allen. (if required)

8.) Remove 4 bolts from input shaft housing, 14 mm.

9.) Remove input shaft, don't let the internal piston spin off the input shaft.

10.) Clean the housing and stuff rags into sector shaft bearings and seals.

11.) Drill and tap housing. Typically on IFS boxes, people tap one hole in the
top and then one on opposite side of the TOYODA. But I've found that the top
hole is really difficult on the FJ-80 boxes since there appears to be less meat in
the top of some of the steering box housings plus you can't drill completely
though the box in that location. So what I've see other people do and did
myself, was I tapped a hole in the end of the box. Anywhere in the end will work
fine.

12.) Clean out the shavings and re-assembly with some lube.

13.) Plumb box to ram assist cylinder.

IFS - Top/End hole has pressure when turning left,
IFS - Side hole (TOYODA) has pressure when turning right.

FJ80 Box - Top/End hole has pressure when turning right,
FJ80 Box - Side hole (TOYODA) has pressure when turning left.



Hopefully that helps you other guys when dealing with these reverse rotation FJ80 steering boxes.

[freds40]

And heres Rick's pics from the same thread showing the work done to the 80 box.








Great info Rick. Thanks for letting me add this to my thread. I hope to be borrowing this info as I will be doing a 60 box in the coming months.