Hi, I have a 72 Ranchero with shifting problems ( doesn`t shift down, once in third ) . As all other components in the gear seem to be alright ( gear has been overhauled ) , I suspected the governor to be faulty. I went to a repair shop, asking them to change the governor against another one I bought. Got the car back after four weeks with the comment. The car still shifts not back- the governor can not be blamed. I still believe that its the governor, because when I open it, I do not see the governor return spring. How can a governor regulate anything, when the piston inside is freely moving ? When I take the governor in my hand and shake it, the piston inside moves freely. In other words - Once the the main shaft turns, the piston of the governor moves by the centrifugal force. There is nothing inside the governor that pulls the spring back towards the engine shaft. This in return means that the governor does not have any function at all. The piston inside should lead the oil from one channel into another, depending on the rpm. Am I right ? Unfortunately I could not find ANY information how the governor should look correct inside. Can anyone please find me an exploded view or at least a parts list, pictures of all the parts inside ? Thank you for your help ! Ilja
My friend Joe has a teaching manual on the FMX; I can't help with the spring, but it is required. I'll see if I at least have the page photos I took for the governor on my laptop computer; if not, I'll photograph them and email them to you.
Thank you very much, that would be helpful ! I have seen these springs somewhere in the net ( 1.49$ ) but do not know if its the right one for my governor. But before I order anything, I would like to see an exploded view of the whole assembly.
The modulator was the first thing I changed, although the modulator has nothing to do with failing downshifts. For a proper downshift, the gear needs the information on the driving speed . The governor is the only item in the gear that "tells" the gear how fast I`m driving.
Yeah, I agree. Will the transmission 'downshift' when you push the accelerator to the floor? That valve controll the passing gear downshift, but it is still a downshift. Also, have you installed an online transmission fluid filter in the transmission cooler line, the one between the pump and cooler? Joe (member Landyacht) had a '76 LTD with an FMX, and while the transmission did finally lose second gear, he had installed a filter inline on the cooler, and he said that it helped for a while. I suspect the transmission was already gone, but it allowed him to drive it for a while until he was able to fix another car.
It's been a long time since I've rebuilt an FMX but I don't remember there being a spring in the location that you show. Most governors are free floating and use fluid pressure and centrifugal force to function. The governor in a hydraulic (not electronic) transmission is the most sensitive part in the trans because it floats freely with no mechanical force to return it (like a spring). Any source of debris can cause the valve to stick. Cleaning, or even replacing a governor will only work until more debris gets into the valves. The issue in these cases is to find the source of the debris. Ford tried to address this by putting a thimble screen in the governor on AOD's which uses a similar governor (the gear train in the AOD was derived from the FMX), but the screen didn't help much. BTW, In your photo I don't see the small valve inside the sleeve (it's probably there, just not disassembled in your photo). One thing you can try is to the backflush the governor while driving. This usually won't fix it permanently but it's a good test to see if your governor is sticking due to debris in the valves. 1. Find a safe area to do the test and get the vehicle up to road speed (above 45 mph). 2. Put the trans in neutral and rev the engine with quick stabs of the throttle pedal all the way to the floor several times. Be careful not to over rev the engine. 3. Be sure that the vehicle speed stays over 45 mph while doing this. That's it. If, on the next upshift/downshift sequence, the trans shifts properly, then you have debris in your governor. The only info that you can derive from this test is that if it shifts properly after the test you have debris or contamination. No change in shifting is inconclusive... either you still have the debris, or the problem is elsewhere. The next thing I would check is line pressure. If your line pressure is low (or high) the governor can't function properly. All it takes is any 0-300 psi gauge on a long hose. It's been too long and I don't remember where the line pressure port is on an FMX. You will also have to find a line pressure chart for your trans. The rule of thumb is 55 psi at idle, and 180 - 200 at WOT (wide open throttle) in D. But get a manual and follow the correct procedure for your particular transmission. If there is a governor pressure port (and I don't think there is) you can check governor pressure. It's usually equal to road speed... 5 mph= 5 psi. 60 mph= 60 psi. But like I said, I don't remember there being a gov pressure port on the FMX. On one trans that I did, I found that the governor housing was loose on the output shaft allowing a loss of governor pressure. I simply cut a small cross section of a large O-ring and placed it under the ball that locates the governor housing on the shaft which in turn pulls the housing against the shaft and seals the leak. I only found this issue once though. Also, internal leaks can cause shifting issues. Try re-torquing the valvebody and servo housings. Like I mentioned before though, most governor issues are due to contamination by particulate debris. The solution is to find the source of the debris and correct it. I hope this helps.
I would put my money on the governor...I had an AOD recently rebuilt with high dollar/HP parts (4r/70w) and brand new governor and the trans was clean as a whistle but the governor quit functioning after about 100 miles of use.
OK, I found the book I was taking about, but I am in error, it is not about the FMX specifically, it's about the valve bodies and governors of all the automatic gearboxes. So, instead of photographing the entire book, I'll just photograph the pages on the FMX, and post them here.
Nine photos, with amplifying info. As far as the 'spring holder' goes, 6mm-1.0 bolts and nuts can be substituted for the 1/4-20 SAE bolts.
Thank you for the pictures. When I understand the last picture correctly, there is no return spring. I was expecting a return spring like I showed in my first post. The pressure seems to be OK, as the workshop tested it before disassembling the gear. And I do not believe in debris, as both tested governors have been cleaned carefully , although they were clean and showed no sign of debris. I have to recheck the other governor and look for the little screw, calles "screen" in your drawing. Until now, I have never noticed this part. But if there is really no return spring and the piston is free floating, I do not understand how the whole system works. Once the governor spins, the piston moves outwards...
The piston has to be able to move freely, if the Housing isn't torqued correctly it will deform the case and the valve will not function properly. Been a issue with old fords for YEARS.
@handy_andy_cv64 do you happen to have this series of pages for the C6? The C6 in my mustang is experiencing high gear starts unless I either manually put in low or put in reverse then back to drive. The tests outlined for the FMX are the most detailed I've found.
Sadly, I no longer live with my friends Joe and Ashley. IIRC, Joe does have a C6 manual that he bought off ePay. I need to go over to their place as I have some stuff for them; I'll see if he has the C6 book, and if so, snap pics. Oh, he does have some of the 1973 Ford shop manuals, which includes the gearboxes. So I can get something, like the troubleshooting lists.
Hey Andy, don't worry about looking for those manuals. I suspect the FMX procedures are pretty close to the C6 and I'll just refer to those.
If you do the VB work, your spring/valve holder should have the same number of screws as valves. I'd also suggest mag trays for the rest of the parts.
Thanks Andy. I'm primarily interested in the troubleshooting work. I have the ford manual but it doesn't go into this level of detail on troubleshooting tests.
