As many owners of the S-197 Mustang discover there is no transmission dipstick.
This presents the owner and self maintainer a few obstacles.
1. You cant check the fluid level easily.
2. The same is true for the fluid condition.
3. Adding fluid is a major task.
Ok so what can we do about this? We at RatStang Restoration have come up with the fix. Add a dipstick to the transmission. And here is how we did it too.. Aren't we just a fantastic shop? Before we begin this is not a job for the novice mechanic. It took us virtually all day and as with all hydraulics it was a mess from start to finish. This was after the components were designed and assembled in one place. So lets begin shall we?
1/2" dia high heat Stainless Steel flex hose 29" long, with a 1/2" female flare fitting on one end, and a 1/2"
to 1/2" male threaded Pipe Fitting on the other.
We had a local Hydraulic Hose shop swedge the fittings on for us.
A 3/8" female to 1/2" male adapter.
A 3/8" bulkhead fitting with two nuts.
35" length of speedometer cable.
1/2' Pipe cap (Brass).
2 each 1/2" oil resistant gaskets.
A cabinet handle of your choice (this will be used for your dipstick top).
A bottle of Lock-Tite (not shown).
A 1/8" bolt about 3" long (this will be used to make your level indicator).
Some Adel Clamps (not shown) for mounting.
Trans Filter (optional).
7 Quarts of Mercon V transmission Fluid.
Patience beyond belief.
Drill Motor 1/2"
Inch Pound Torque Wrench
Some drills and a (one for the bulkhead fitting and a small pilot drill)
Oxyacetylene welder or equivalent
Common tools and nuts and bolts for mounting
Now that you have the items together we start this by jacking the car and draining the trans pan. You do this by removing the entire level check plug assy from the pan. This is shown below...
While the trans is draining lets do some prep work.
We need to make our bulkhead fitting sealable. So what we do is thread one of the nuts all the way on against the fitting shoulder. We must first flux the threads and prepare to sweat our brass against the shoulder and nut. This is much like when you sweat copper pipe together in plumbing.
Threaded on against shoulder
Then of course sweat the nut and fitting together being extra sure we do not leave a opening to leak.
Once we are done and have cleaned the fitting looking for voids we paint it with a primer and set aside to dry.
Back to the car!!!
Next we pull the pan. Here are some notes for you:
The Pan Bolts are 8mm. In front on a tab you will find your wiring for the Cat Sensors in a plastic cover. This cover is removed by prying a tab on the top up and pulling off the plastic cover. Just insert a flat tip screwdriver under the upper plastic and gently pry up until it releases. You cannot see the tab under it. This is the cover removed. You can see the locking hole on the pan the tab locks into. Be careful unlocking it. You can also see a small clip that just pulls off the corner of the pan also in the upper right of the pic.
Next pull the pan bolts and remove the pan and gasket. The gasket is reusable. If you like after the pan is removed you can change the filter too
(2 bolts). Below is shown the Pan, Gasket, and Filter, and cigarette butt.
Now to the pan.
Clean it up. That black ring in the bottom of the pan is a magnet. Just pull it off and clean it too.
The top of the overfill tube (used to check level normally) is 2 1/4" from the top of the tube to the top of the pan lip. Mark this on your pan (Passenger side) with a sharpie or something. Mark down 3" from the top of the lip and mark again. This is where we will pilot drill for our modified bulkhead fitting.
Our pilot is shown
Now drill out the hole bigger to accept the bulkhead fitting and de-burr the hole edges.
Now we insert the bulkhead fitting with a gasket on the outside and inside under our nuts as shown below. Tighten the inner nut and use Loc-Tite on the threads. The outside of the fitting will point almost straight up, cant it about 10 degrees.
Next we preassemble the pan and tube together finger tight. We will measure the length we will nee for our dipstick later. Now the cap and stick.
First we need to drill a hole for our top retainer screw in our brass pipe cap.
Place the screw through the hole from the inside and screw on the handle you chose. Cut your screw to length if needed. Now take it off. Take your screw and with your speedo cable you will find a square end for the Speedo Drive gear. We will use this later for our dipstick cable.
Now take the screw and braze the head of the screw to the drive end (square end, not hole end) to the screw head as shown
Now reassemble the cap and handle assembly. Next we make the level indicator. I took a 1/8" X 3 bolt and chucked it in my drill press.
With a triangle file I cut several grooves in the bolt. This will hold the fluid and give me a level. What you choose to do may be different. Next I cut the head off the bolt and cut it to appx a 2" length. Then I brazed it to one end of my speedo cable. After brazing I took my file and ran it through the grooves again to take the black out of them from the brazing, and polished it up with a Scotch Brite pad. This is shown
Next Step is the determining your cable length. Take you cable/indicator setup and slide it into your tube till it bottoms. Mark the cable at the male pipe fitting edge. We will call this Mark A. Do Not cut it yet. Remove the cable and screw on your handle/cap till it is snug (Not tight) on your tube. Mark the bottom of the cap on the male fitting. Remove the cap/handle assembly. Measure the Male fitting mark and note it somewhere. We will call this Mark B. Next measure the amount your cable end extends below the cap edge. Take note.
We will call this Mark C. Next from your first mark on the cable (Mark A) add Mark B and Mark C together and mark the cable again the distance from Mark A. (We are making it shorter). Cut the cable at this mark. Now we have our length.
Next we disassemble the cap/handle and we will braze the cable into the drive end. It will go into the hole about 1/8". We can then braze the cable to the drive end/screw assembly. Clean up the screw and reassemble your handle and cap. Use Lock Tite on the screw threads. Set it aside. You have just made a flexible dipstick. Aren't you proud? Should be!!! Now disassemble you tube from your pan fitting. Reinstall your filter if you changed it and your pan and gasket on the transmission. Torque the bolts to 8 Ft/Lbs. Adjust your bands while you are down there if you like.
Next we assemble the tube. Route the tube down from the engine bay to the transmission, and to our fitting in the pan. Make sure it will not chafe anything or lay on our exhaust manifolds, or pipes. The connect it to the pan fitting and use Lock Tite on the threads. Shown installed AS SHOWN.Recheck all your work and reassemble the items removed when you took it off. Make sure your drain fitting is tight Pull your level check plug out now from the drain fitting.
Don't lose it.
Next, back to the top. I used two Adel Clamps and butterflyed them together to a harness. If you like you can mount the end wherever and however you like.
Return the car to the ground if needed and level. Next we will do initial servicing. Put a drain pan under our removed factory pan level hole. Put a funnel in our tube top. It fits right in the fitting hole. That's why we use this size fitting.
Next start pouring until a stream flows from our drain. Start the car and leave it in park. (The level is checked with engine running in Park)
Add more fluid through our dipstick until it flows from the hole again. A Steady stream, not just bursts of fluid from the hole. We will not be moving the car yet. Get in the car and cycle through all the gears several times ensuring that each gear engages. Next repeat the above until fluid flows again. Install the plug. Be careful not to burn your arm on the exhaust. Install your dipstick and screw it on snug, then remove it and check your level. Keep in mind the tube will have residual fluid in it. Let car run in park at least 5 minutes before checking the level to allow the fluid to stabilize in the tube. You should show the level about 1 to 1/12 inches from the tip of your indicator. Go Drive the car watching for slow engagement or slipping. If it is slow to engage or slips the add 1/2 quart of fluid at a time and re-drive until the slipping or slow engagement is gone.
Then add 1/2 quart to the trans and check your level mark on your dipstick.
This is where you fill it too from now on. It should be appx 1 1/2" from the tip of your indicator. No More pulling that plug, and somewhere to actually put the ATF in!!!! And here it is