JC65PARKLANE Posted July 9, 2021 Share Posted July 9, 2021 Hi The Merc-o-matic on my 65 Parklane (390-4V) has 2 main issues It won't go in third in any drive position (didn't try above 50mph for now) It has a strong oil leak at converter case when hot and in reverse ..... ? I changed the vacuum modulator and checked the kickdown linkage no issue, didn't tried yet to dial the modulator. Any help welcome ! JC Link to comment Share on other sites More sharing options...
m-mman Posted July 9, 2021 Share Posted July 9, 2021 Realistically. . . . ? Time for a full rebuild. To replace the front seal you have to pull the trans. Then what is the front bushing like? Not going into third? sludge/varnish in the valve body? How long has your car been parked? When was the fluid last changed? You could pull the valve body and soak it in solvent. . . . But by the time you do all that . . . . Its best to start from scratch with a fresh rebuild with everything fixed. In auto restoration there are few shortcuts. 😞 Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 10, 2021 Author Share Posted July 10, 2021 Hi, The trans is supposed to have been rebuild years ago before car was parked, for 5 years. I know that's what is waiting me but I wish I could tune something for the third. Fluid is clear red and don't smell burnt. Is it risky to drive in second up to 60 or 70 mph to check if third engages ? In the shop manual it's the top speed in WOT so it shouldn't hurt ? JC Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 10, 2021 Author Share Posted July 10, 2021 (edited) I read here and there a trick to 'unlock' dirty valve body by adding a small amount of DOT in the trans oil... What's your thought about that ? I've bought yet the filter and seal for the pan, what should I schedule to buy if I go for cleaning the valve body and the governor valve body and everything I will be abble to reach ? Edited July 10, 2021 by JC65PARKLANE (see edit history) Link to comment Share on other sites More sharing options...
misterc9 Posted July 10, 2021 Share Posted July 10, 2021 Do you have good manifold vacuum to the modulator? You might want to just drive around some. Something might get warm and free up. Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 10, 2021 Author Share Posted July 10, 2021 I have to check vacuum level but motor runs strong it should be OK. I drove around the block and on the street several times but didn't get above 40 mph by now as I don't know the car and don't want to make more damage.... I'll try faster next time Link to comment Share on other sites More sharing options...
rocketraider Posted July 10, 2021 Share Posted July 10, 2021 Is 65 Cruise-O-Matic/Turbo-Drive shift selector P•R•N •Drive•L or PRND21? I think, remembering my uncle's Cruise-O-Matic 64 Fairlane with P•R•N•Drive•L pattern, the WHITE (1st) dot in Drive kept the trans in 2nd gear and the GREEN (2nd) dot in Drive was for normal driving and allowed 1-2-3 shifts. If you're not in green dot Drive, try that and see how the trans works. Link to comment Share on other sites More sharing options...
Bloo Posted July 10, 2021 Share Posted July 10, 2021 (edited) Don't dump any additive in there, period. What is DOT? Brake fluid? No. Just no. No transmission additives from the parts store either. The green dot shifts 1-2-3. The white dot shifts 2-3. If you changed the modulator, you will need to adjust it. Why was it changed? Was it for this same problem or was it sucking oil? Be sure the vacuum line to the modulator has vacuum and does not leak. If there is no vacuum or low vacuum at the modulator, the transmission will assume the throttle is wide open and will not shift to third until a very high speed. Are you sure the fluid level is correct? Check the fluid with the car on a level surface and the engine running in "Park". It used Type-F fluid originally. After a rebuild, if you are sure the linings were all changed during the rebuild, a Dexron-II-III-Mercon equivalent fluid should be OK, Otherwise stick with Type-F. Upshift speeds are controlled by the governor and the vacuum modulator, The governor is a centrifugal spool valve located on the tailshaft. Edited July 10, 2021 by Bloo (see edit history) 3 2 Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 11, 2021 Author Share Posted July 11, 2021 Thanks for inputs. I know the N D2 D1 L setup. Trans in D1 makes 1-2 basta... And in D2 is stuck in two. As I mentionned I did not rev the engine above 40mph in two as I have the car since few days and don't know its condition yet. I'll gradually speed up to see if it goes in third above 60-70mph as it should regardless of throttle amount. I thought regulator didn't have to be tuned when new. I'll check for vacuum level and leaks then try to tune the screw in the inlet.JC 1 Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 12, 2021 Author Share Posted July 12, 2021 Hi. The intake vacuum supply fitting has 3 outlet.... 1 to the trans. 1 plugged same size. 1 smaller that was open decreasing vacuum supply at modulator. Plugged it and will try if better. Link to comment Share on other sites More sharing options...
m-mman Posted July 12, 2021 Share Posted July 12, 2021 8 hours ago, JC65PARKLANE said: 1 smaller that was open decreasing vacuum supply at modulator. Plugged it and will try if better. Step #1: Seal all vacuums leaks first ;-) 2 1 Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 14, 2021 Author Share Posted July 14, 2021 Hi. Trans want to catch third when cold and above 30, higher when hot. Will check the line for leak and tune the modulator. JC 2 Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 16, 2021 Author Share Posted July 16, 2021 (edited) Hi. It's realy strange that the front oil leak at the trans that exhausts at the bottom of the converter case is obviously much more important if I shut the engine down after moving in reverse and then park rather than after moving in any drive position than put the trans in park. Any idea ?? I'll check the engine to trans bolts. JC Edited July 17, 2021 by JC65PARKLANE (see edit history) Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 21, 2021 Author Share Posted July 21, 2021 I turned the inner screw in the vacuum inlet of the trans modulator 1 turn out. I assume that I need more vacuum effect in the modulator to shift in third so 1 turn out should allow more travel of the rod to the 'vacuum side' What do you think about that ? I'll try this evening and will let you know the results Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 24, 2021 Author Share Posted July 24, 2021 Hi. One turn out not enough quite no effect. Put 2 turns more out. Will try today.... Seems the Cruise o can be removed from the car whithout removing the motor, any tips ? Link to comment Share on other sites More sharing options...
Bloo Posted July 24, 2021 Share Posted July 24, 2021 Is the pushrod under the modulator present? Link to comment Share on other sites More sharing options...
m-mman Posted July 24, 2021 Share Posted July 24, 2021 17 hours ago, JC65PARKLANE said: Seems the Cruise o can be removed from the car without removing the motor, any tips ? Starting in 1965 FoMoCo used a new frame so there is no X member to impede transmission removal. Very simple. Pull converter nuts from flex plate, pull bell housing bolts from block and remove trans, bellhousing and converter. 1 Link to comment Share on other sites More sharing options...
JC65PARKLANE Posted July 25, 2021 Author Share Posted July 25, 2021 21 hours ago, Bloo said: Is the pushrod under the modulator present? Yes it is 1 Link to comment Share on other sites More sharing options...
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