Fordomatic Ring Gear Balancing

[croslinb]

I had the Fordomatic in my '56 Thunderbird rebuilt and now need to replace the ring gear on the flywheel. It has 8 spot welds from the factory. Grinding the welds and then putting the new ring gear isn't a problem. I have a welder guy who is beyond belief but when he's done with the welds, I want to balance the entire flywheel assembly.

Any thoughts?

[miker98038]

My thought is to post this over at yblocksforever. Ted Eaton of Eaton Balancing is there frequently, and would probably have the most reliable answer.

[croslinb]

Thanks. I just sent him an email with photos in it. I haven't yet removed the worn ring gear so if it's something he can do, I'll ship it off to him.

Bob

[miker98038]

Let us know what you find out. I’ve never thought to balance a ring gear before. Done a lot of flywheels, clutch’s, etc. But it hasn’t been often (if ever) I’ve changed just the gear on a previously balanced assembly.

[1930artdeco]

I asked about that when Tim McMaster did my engine and he said you cant because it is a fluid coupler. However, I may be wrong in the way I heard it.

[rotorwrench]

Sponsored Links (Register now to hide all advertisements)

The fluid drive set up balances itself for the most part but the whole torque converter could be balanced by itself with no fluid in it. It would be easy to static roll balance. Spin balance might be problematic. There isn't much to the drive plates on the later units.

[scicala]

I hate to be a stick in the mud, but it sounds unesesary to me.
just my opinion, since the assembly was probably balanced close enough as is, and the only change with be the ring gear.

Sal

[KULTULZ]

Well, what I want to know is what type of trans is in this BIRD.

The RG is attached to the torque convertor cover on the pre-1958 F/M, not the flex-plate. FORD did not offer a separate RG for an AT, only MT and they are not machined alike. Where was this RG sourced?

And yes, you do balance a convertor the same as you do any rotating part.

- https://go4trans.com/technical-torqu...waste-of-time/

- CONFUSED IN W (BY GOD) V -

[dmsfrr]

Originally Posted by KULTULZ

Well, what I want to know is what type of trans is in this BIRD.
. . .

In a '56 the Fordomatic could be the air-cooled version or the improved fluid cooled version.
It was a mid-year change.

Air-cooled has a finned torque converter and a pair of air vents in the lower half of the bellhousing.

Fluid cooled has a pair of steel lines from the trans to the cooler in the lower tank of the radiator.
.

[KULTULZ]

The question is not whether a 1956 F/M is air or water cooled.

What TRANS does he have that has the RG on the flex-plate? Did he do some type of conversion/update?

[5851a]

I thought the ring gear was replaced with the front of the torque convertor? If you needed a ring gear Ford sold you the ring gear attached to the front cover and it came with a large o ring. You had to take the row of bolts out to separate the cover and convertor. Maybe that was just a 6 cylinder sedan thing.

[rotorwrench]

The ring is part of the torque converter cover on the air cooled and water cooled versions. It seems like 1955 was the first year for the medium case Ford-O-Matics with the 292 engine and the second year for the 1956 only with the 312. The earlier ones in 56 had the big air cooled torque converter and the later ones were more conventional types with a smaller torque converter and bell housing. Mercury 312 cars also had the medium case transmissions and likely used the same torque converters for the similar types. Ford cars with the option of a 312 would also have the medium case transmissions but I don't see a lot of them out there.

I've seen NOS torque converter covers on flea-pay now and then but I've not seen separate starter rings. They really were never intended to be replaced separately. A person had to find the whole cover and the big o-ring seal. A different ring might fit it as long as it is the same dimensions and tooth count but it would have to be welded up to the converter cover after cutting off the old one.

[dmsfrr]

Example Fordomatic flexplates. The 3rd example is (obviously) attached to a torque converter.
.

[croslinb]

I sourced the new RG from Concours parts in Nevada. If it were just a press fit RG, no problem. But, this has eight spot welds between the plate and ring gear so when I grind down the welds, remove the old RG, then heat the new RG and put it on, I need to redo the spot welds. That's where the problem lies. Ted Eaton suggested I balance it with the TC cover bolted on but I still have the problem of being unable to mount the assembly on some sort of shaft to check the balance.

[croslinb]

I seem to remember that being the case with a six cylinder, but apparently not with the V8 FM. When my welding guy redoes the spot welds, they likely won't be all the same size and weight as the factory ones.

[Lanny]

Take a small hand held grinder, and grind a little off each weld
till they all look somewhat close.





.

[KULTULZ]

Originally Posted by croslinb

I sourced the new RG from Concours parts in Nevada. If it were just a press fit RG, no problem. But, this has eight spot welds between the plate and ring gear so when I grind down the welds, remove the old RG, then heat the new RG and put it on, I need to redo the spot welds.

I had no idea it was available (aftermarket only) as OEM was one piece (1P 7950-A)

That's where the problem lies. Ted Eaton suggested I balance it with the TC cover bolted on but I still have the problem of being unable to mount the assembly on some sort of shaft to check the balance.

The actual balancing will have to b done through a professional shop.

[Daves55Sedan]

If you have the early ('51 thru mid '56) Fordomatic with air-cooled converter, the whole converter assembly is balanced at the factory.
Any time somebody takes one of these converters apart needs to be aware that there are balancing marks (an "0" stamped on front cover and matching "0" stamped in side of impeller housing) that need to be mated in re-assembly to maintain balance integrity.
Yes, fluid does play a role in helping to balance the revolving converter but it cannot overcome a converter assembly imbalance.
You can even see the spot welds on the front of the ring gear in KULTULZ picture, so yes, the ring gear is spot welded on to the front cover plate.
Originally, if your ring gear lost some teeth, you had to get the front cover/ring-gear as an assembly from the Fomoco parts department along with a new front cover O-ring seal.
Yes the ring gear needs to be heated to expand the metal to permit placement on the front cover and needs to be welded onto the front cover in the same way as it was originally. How the Ford service department balanced the new front cover/ring-gear with the old impeller housing is beyond me. Whatever they used probably became obsolete and thrown out in the mid '60's.
Note: 6-cylinder cars with Fordomatic still used the air cooled transmissions thru at least 1959.
If you tried to match the method and volume of weld used to the original, you might be okay, but I would try to find some service establishment that can insure a good balance.

[KULTULZ]

As far as I know ... ...

FORD did not offer a service replacement RG for an AT. You either replaced the cover or flex-plate.

Whether air-cooled or water cooled has no bearing.

[KULTULZ]

Originally Posted by croslinb

i seem to remember that being the case with a six cylinder, but apparently not with the v8 fm. when my welding guy redoes the spot welds, they likely won't be all the same size and weight as the factory ones.

!!! Bingo !!!