fluid change

[longtops]

OK guys,I know you all have talked about this somewhere on here but I need a step by step on how to change the fluid on a gyromatic.Can I access the fluid drive through the hole in the floor board? I remember someone saying to be careful about droping the bolt from the drive,if this happens does the bolt go into the bellhousing?Help me out here.What do I need to do to accomplish this. Will it help to do this? and do I refill with 90wt hydro from tractor supply? Almost time to enjoy our OLE MOPARS!!!!

[Tom Skinner]

Longtops,

I have a C-38 1948 Chrysler Royal Fluid Drive. I use 10wt Oil to top off

the fluid coupler. Move the Carpet back on the Passenger's side front. Open the Side Door on the Passengers front towards the front of the car (that is

to say on the "Hump") Remove Fill Here Tab. Tap your starter until a fill bolt stops at your Fill Here hole. Stuff a good sized Shop Towel around the plug neatly to prevent dropping into the Bell Housing as you remove it. Use 2 Towels if need be. Fill with 10 wt oil to top do not spill any into the Bell Housing, re-install the plug tightly, and then re-install the Fill Here Tab, Carpet Etc. To drain this is to risk saturating your Clutch Disk, by tapping it around open and throwing 10 wt Oil everywhere. Also if you drop that plug into the Bell Housing the only way to retrieve it is to remove the Bell Housing Lower Pan to fish it out. (A real pain in the petutie). Now when you service/replace your Clutch Disk if you want drain it then and then refill it, when all that crap is assessable and clean out the Bell Housing thru out with

some Brake Cleaner. Use in a well ventilated area.

Tom

[48mirage]

Do not confuse the fluid drive with the gyromatic transmission they are two seperate things. The fluid drive is in simplistic terms a torque converter that is in front of the clutch. There is an access panel on the passenger side hump. (The front one, for removing the plug) Many of us have drained and refilled the drive with universal tractor fluid.

The gyromatic transmission should have 2 plugs on the side of the transmission, 1 higher than the other. remove the top one to vent and remove the bottom 1 to drain. Refill the transmission with 10w non-detergent oil. This oil can sometimes be difficult to find but I've seen both the right tractor fluid and the 10w non-detergent oil at my local Napa.

P.S. The fluid drive unit will take almost 2 gallons to refill.

Go here:

http://www.merc583.addr.com/mopar/framesets/techtipframeset.html

Near the bottom of this web page is a section on fluid drive.

[Fluid drive]

Hey Tom:

It really isn't a good idea to use motor oil in a fluid drive unit. 10 WT non detergent is specified in the M-5 transmission but ATF should be used in the fluid drive unit.

[Tom Skinner]

Fluid Drive,

Thanks! I only added a Pint once in 5,000 miles, I have only owned the car 2 years now. I will go to 10 wt ATF next top off. I wouldn't atempt to drain this unit and soil up the Bell Housing unless I was in there for other work.

I put a clutch in Feb, '08. everything is dry and clean in there as should be.

No Damper Seal Leak.

Tom

[Dodgeb4ya]

I would NOT change the fluid in the fluid coupling. The bellows seal and graphite ring could start leaking!!! Have seen that happen a couple times after draining the fluid drive coupling and then refilling with Dextron II. The units never leaked before. Universal tractor fluid is probably the best to refill with. I have several Fluid Drive and Fluid Torque drive cars. If they don't leak leave em alone! I agree with Mr Thomas 100%!

Bob

[Fluid drive]

You will have to forgive me but Chrysler Corp. used to tell us specifically not to use motor oil in those couplers. It may be that I am starting to loose some of my memory but I am sure of that. The engineers that came up with that fluid drive idea did so around 1939. I remember because I graduated from high school in 1936 and went to work as a trained chrysler mechanic in 1938. When they were developing the "buttermilk drive" units as we used to call them they tried everything imaginable for fluid including vegetable oil and finally came up with a special product for use in them . The factory guys told us that motor oil had a detrimental effect on the seal.(carbon build up I think?) Most of the engine rebuilds I've done since the Mopar Fluid drive oil became extinct I have installed new seals and seal rings in the units and used the universal type ATF without any problems. In fact, I still have my Miller fluid drive seal installation tool kit. It has a fitting and line with a gauge on it so the unit can be pressurized and checked for leaks - we used to put them under water like you do an inner tube or tire. Can't say that I have ever had any problem with any that I installed new seals in .

There are so many really swell contributors on this forum that I have really enjoyed reading it. I wonder if it might be time for me to let the younger sharper guys do the talking.

Will

[Don Coatney]

I wonder if it might be time for me to let the younger sharper guys do the talking.

Will

Will;

Keep talking. Otherwise your experiance with these old cars will be lost. Tell it like it is.

[Frank Elder]

Mr. Will,

Don't you dare stop educating us, I either write down your replies or subscribe to your threads depending on the time involved. Ditto what Don said!

[48mirage]

Mr. Thomas says he "cannot believe any damage or dirt buildup can occur."

I believe differently, age and heat would be my concerns. Yes the units are sealed but over time and through many heat cycles oils will breakdown into smaller molecules.

[PatS....]

Will;

Keep talking. Otherwise your experiance with these old cars will be lost. Tell it like it is.

I agree 100%!!!

PLEASE tell us more!!!!!

It's fantastic to have someone here who actually made a living working on the FD's when they were new.

Please Please share your experiences with us "younger" guys!!!