FMX gearbox rebuild

[Spider69 16]

I will start shortly to rebuild my FMX gearbox.

I have my car, 69 mach 1,  since 3 years now and have no idea about any maintenance made on the gearbox previously.

I can hear a strange noise when I drive the car during the 500 first meters and after this everything works fine.

And it doesn't happened every time.

 

I wonder if I should replace the converter?

 

 

 

[SA69mach 39]

Good luck with the rebuild.  I would like to see how you go.  Please post your progress and pics as you get into it. 

 

If you are not changing the engine specs, the stock converter is worth keeping, but also highly recommended to have it cut open and inspected/overhauled.  The original converters manufacturing process did not braze the fins in place, and that would be worth doing now.  Quite often the fins have moved, or loosened over time.  The furnace brazing takes care of all that, permanently.  It is how they should have been made in the first place.

And you know your converter will fit your transmission.

You wont know the condition of the converter unless, and until, it is cut open for this work.

 

Most common signs of bad seals in your FMX is some minor leaking, (caused by fluid overflowing the vent tube, as if drains out of the converter) and difficulty shifting into gear, from neutral, when cold.  Gear engagement is harsh and often severe, and will not change gear reliably, either up or down the range.

Bad seals is a pretty straight forward rebuild.  The FMX is not well loved, but usually the internals are fine.  They were made with good steels in those days. 

[Spider69 16]

Thanks for your reply, obviously I will post pics.

I have some other things to do, like u-joint, harmonic balancer, fuel pump, ...

Gearbox rebuild will start end feb or early march.

Good tip "braze the fins" I will have a deep look on this.

I never opened a converter, do you have some pics related to the fins?

 

The rebuild is preventive, I have just a leakage at the shifter o-ring and this strange noise during the 500 first meters when engine is cold and not every time.

Apart from that it works fine and the car is driving very well.

 

I see that we have quiet the same car with FMX gearbox.

Mine was also  black jade, It's now Acapulco blue, but I don't have A/C.

[SA69mach 39]

Nice car.  Very similar cars.

 

The noise and minor leaking is just the first signs of worn seals.  It takes a long time from first signs to final death with the FMX.  But it wont drive nice for much longer.  I think your preventative rebuild is just the right time.

 

I have never done a converter.  I would not recommend this as a home job. 

 

check youtube for plenty of videos showing the internals and operations of torque converters.  I tried to link for you but something not working today - I cant 'paste the link that I wanted to show you.  "Torque converters explained - Eric the car guy"

 

You can also check TCI's website for video of them building and rebuilding converters - skilled work with high levels of machining involved.  Very hard for home garage guy like me.......

[Spider69 16]

I think so too, it's the right time for a rebuild.

I will not do the job by myself but with a friend who has the right skills.

I could find the YouTube videos, helpful and nice.

 

TCI website is nice but there are not a lot of info for FMX gearbox

[Spider69 16]

OK, order has been send, new torque converter will be Hughes Performance HUP-3825.

Work will be done early March.

 

I think originally the gearbox was not painted, can you advice?

I would like to paint the gearbox in blue corporate blue would be nice!

[SA69mach 39]

I cant find that HUP-3825 converter on the Hughes website, or anywhere else.  Can you tell me some more about it?  Stall speed, construction, and is it FMX specific?

 

The casing can be whatever color that you like.  Blue is as good as any.

The shops will usually blast and clean your case during an overhaul job, and they paint some variation of silver if you dont care.  Sort of a stock color for transmissions.

 

I am only concerned with the quality of the parts and the workmanship on assembly.  Mine is 'some variation of silver'  haha....

 

One last thing, something I sort of assumed you would know - there is a very detailed video produced by Badshoe Productions - for many or all of the early Ford  transmissions, engines, diffs - step by step teardown and rebuild, very detailed.  Definitely worth a look for you....

 

www.badshoeproductions.com/

[Rsmach1 71]

Here is the converter at Summit. http://m.summitracing.com/parts/hup-38-25

[SA69mach 39]

thanks RSmach1.

 

2500 stall....hmm.  that will be interesting to see how it suits a stock 351.

 

Could be great.  You never can tell for sure until it is in.  The blurb says it is set for 2500 stall on BBF engines, and may vary 500-700 lower for SBF, which would make it about perfect for a daily driver. 

I like it... 

[Rsmach1 71]

Might be a little big for a stock replacement, have to keep in mind if you're doing any extended highway driving you'll want your cruse rpm above the 2000-2300 sm blk stall. Depends on cam, gears tire sz.

[Spider69 16]

Hi,

I got the converter today.

Really, the shipping costs and custom duty are so expensive and the parts provider in the US are not really keen to lower this extra costs.

Thx for your replys.

Here pic enclosed.

I talked with the guys from summit, got good feedback about this converter and they said he will fit to my fmx gearbox with stock car and 351 engine.

Hope it will.

 

Overhaul will start in March.

 

Thx for the link SA69mach, nice and useful.

 

I'll post news soon.

 

 

[SA69mach 39]

Looks good.  Is it stock stall?

Are you doing all or part of the rebuild on the transmission?

What rebuild/overhaul kit are you going to use?

[Spider69 16]

What do you mean with stock stall?

Planned is a total rebuild, I don't want to do it again in the next months or years.

 

I don't know which rebuild kit we will use, I don't do it by myself but I will ask.

[Rsmach1 71]

He was asking about the stall of the converter, by the looks of it you got the Hughes from Summit, so 2200-2500?

[SA69mach 39]

Yes, my apologies, I checked that converter out before.  2200-2500, but rated at 500-700 les for Small Block ford .  so that is right about stock stall speed.

[Spider69 16]

yes it's from Summit.

 

Rebuild kit could be found on this website

http://transpartsonline.com/

 

I think master overhaul kit but I will know more when we'll start working on it.

[LindenBruce 27]

The FMX is a really good transmission.  They are simple and reliable transmissions.  The main thing with it is that its very heavy since it has a cast iron center case.  I believe you can get a shift kit for it and if that is still correct I would do that.  Use good quality steels and clutches.  B.     

[Spider69 16]

Hi Lindenbruce,

For sure I will use good quality stuff, I'm not an expert but the guy who buy the rebuild kit is.

What do you mean with a shift kit?

 

I this an internal part of the gearbox?

[Rsmach1 71]

They make the trans shift faster, so less slippage between shifts, done thru the valve body. Here is the kit. http://m.summitracing.com/parts/trg-37-1

 

They are actually "good" for an automatic trans, by eliminating some of the slipping it reduces heat, and lengthens band and friction life.

[1969_Mach1 333]

A shift kit setup for mild firm shifts and an additional external trans cooler will greatly increase the transmission life.  Heat and clutch slippage are the biggest factors that wear out automatic transmissions.

[Mach1 Driver 560]

One last thing, something I sort of assumed you would know - there is a very detailed video produced by Badshoe Productions - for many or all of the early Ford  transmissions, engines, diffs - step by step teardown and rebuild, very detailed.  Definitely worth a look for you....

 

www.badshoeproductions.com/

 

great stuff, thanks!

[Spider69 16]

Hi,

I will check the shift kit and certainly order, thx for the advice.

 

1969_Mach1

I have already an external cooling system for the trans and happy with :-)

 

Rebuild will certainly be postponed to May because we have in France a nice meeting in April with the 'mustang club France'.

And this will take place at the race track 'Le Mans' you obviously know.

I cannot miss this meeting because my car will not be ready, so I decided to postpone a little bit.

[Spider69 16]

I'm back.

Work has started.

transmission is out of the car and loaded into my pickup.

 

 

 

 and I will peint the exhaust intakes.

 

Other pics will come soon

 

By the way I changed the spark plugs wires

 

[LindenBruce 27]

Yep, that's an FMX alright.  LOL.  I hope it turns out to be a tire burner.  B.

[Spider69 16]

Correct it's an FMX.

Not easy to fins the right tires at a correct price so I'm not really a burn fan :-)

 

The black central part of the trans will be painted in blue.