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Discussion Starter · #1 ·
When I take off slowly, no issue, but add some acceleration, even modestly, the shift into 3rd comes with a surge. I have a 1959 MX, rebuilt 10 years ago. Wondering what's going wrong. Hoping the fix is simple!
 

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First thing I would be doing is checking the fluid level. Sometimes just a little bit low can cause issues.
 

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Discussion Starter · #3 ·
First thing I would be doing is checking the fluid level. Sometimes just a little bit low can cause issues.
Thanks. What's the second thing you'd do? :unsure:
 

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When I take off slowly, no issue, but add some acceleration, even modestly, the shift into 3rd comes with a surge. I have a 1959 MX, rebuilt 10 years ago. Wondering what's going wrong. Hoping the fix is simple!
Hello puttster,

Are you sure it's the transmission causing the surge and not say the sudden loading on the engine causing the vacuum advance to cut out then back in or even some mild oscillation under the right engine loading conditions? It could even be carburetor related such that the power valve and or mixture and it could be a combination of induction and timing together.

Have you tried just keeping the transmission in second and driving up a hill with different throttle settings to see if you could reproduce the surging?

I would ascertain by diagnostics first whether it's genuinely a problem with the transmission or a problem with the engine, then go from there.

Cheers
 

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Discussion Starter · #5 ·
That would be great if the surging was in the distributor or carburetor or timing.

When I did my rebuild I had the original distributor and one from a 1974 truck but forgot which was which. One had a lot of movement with suction and one had just a little. I think I put the little movement in and have always wondered if I made the right choice :rolleyes:.

I have suspected something leaking in my carburetor because it only takes a day of sitting in the garage for the bowl to run dry. I suspect the power valve but have not been able to catch it in the act.

My timing is also suspect because I used the truck timing cover, which uses a pointer for a single pulley setup that cannot be seen by a timing light, So I would say it is not perfect tough the engine starts up and runs great ... well, maybe except for the surging.

There was no surging before I took it in to my transmission rebuilder, who replaced a leaking main seal. Could be a coincidence that this issue started a couple of weeks later but IDK enough about transmissions to make that call.

Now that I've poured my guts out o_O- what is the prime suspect?
 

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That would be great if the surging was in the distributor or carburetor or timing.

When I did my rebuild I had the original distributor and one from a 1974 truck but forgot which was which. One had a lot of movement with suction and one had just a little. I think I put the little movement in and have always wondered if I made the right choice :rolleyes:.

I have suspected something leaking in my carburetor because it only takes a day of sitting in the garage for the bowl to run dry. I suspect the power valve but have not been able to catch it in the act.

My timing is also suspect because I used the truck timing cover, which uses a pointer for a single pulley setup that cannot be seen by a timing light, So I would say it is not perfect tough the engine starts up and runs great ... well, maybe except for the surging.

There was no surging before I took it in to my transmission rebuilder, who replaced a leaking main seal. Could be a coincidence that this issue started a couple of weeks later but IDK enough about transmissions to make that call.

Now that I've poured my guts out o_O- what is the prime suspect?
Hello puttster,

Well start taking items out of the equation, for instance remove and plug off the vacuum advance on the distributor and take it for a drive and see if the problem is eradicated. There are many variables that can cause your symptom and you can make matters much worse by guessing.

The only way a transmission can cause surging is torque converter failure or binding caused by applying the wrong clutches and or bands. Some transmissions like the C6 have to release a band and apply the direct clutch for 3rd gear. If the band and the direct clutch both stay engaged the transmission can bind or if the band comes off too soon before the direct clutch applies the engine RPM's flare up before shifting to 3rd.

I am not sure what those old Borg Warner transmission (FX, MX) utilize however a sticking valve in the valve body could cause shift binding and or flare in a transmission like the C6.

I would rule out any possibilities of engine timing or carburetor problems first.

Cheers
 

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Discussion Starter · #7 ·
The third gear surging except that it does not seem to happen when cold. Drive a while and the surging begins. Most, but not every shift. And maybe a little in the 2nd shift also. Hope that adds a clue to the mystery.
Wouldn't be vacuum at the transmission because my 1959 MX does not come with a modulator. But I am suspicious of vacuum advance and timing... and of course as a last resort, the transmission:rolleyes:
 

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Discussion Starter · #9 ·
I will next time I take it out, for sure.
 

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Hey, Putts! Please define "surge", and the conditions it occurs (speed, rpm, throttle, on-shift, after-shift, one surge or cyclic, cold or hot, etc).
 

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Would this better be described as a "flare" rather than a "surge'? You say it happens on the 2 - 3 shift, when hot, and only sometimes, or less significant, when cold. What I think of as a flare is when the shift is delayed and the RPM's rise, or spike, and then the shift happens, usually as a hard shift. Has the band been adjusted? Maybe it needs tightening.
 

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Discussion Starter · #12 ·
I took it out today, 5 miles in city, with wife taking notes. Cold, 2-3 shifting was good @1200-1500rom, vacuum in drive 15#. At 150 degrees I got my first bad shift, what 70XL calls a flare. In the 1200-1500 rpm range the flares were minor, but increasing in duration at 1800-2000 and as the car warmed over 180 degrees. Occasionally the 1-2 shift flared and occasionally there was no flaring on the 2-3, at low rpm.

Dropped wife at her Tesla store and halfway back smoke started surrounding the car. Tranny was chugging, finally quit entirely a mile from home. I had a can of fluid, poured it in and she started shifting again, enough to get home and leave a trail of fluid up the driveway. Underneath, I saw it was pouring out from the bellhousing.

200 miles ago I had brought the car to my shady tree mechanic (who had put the 1959 MX in) because it was leaking from the bellhousing. He "replaced" the front seal which fixed the leak, though, obviously, not permanently.

Dang. I think I will give up on my mechanic and the $1,300 I gave him, he is 20 miles away and I probably can't get the car there anyway. Suggestions for my next move?
 
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Had you checked the fluid level when the flaring first started? Does the fluid now look dark and does it smell burnt? It may be time for rebuild, or replacement transmission, if you've cooked the internals. It doesn't sound good for your current unit.
 

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Discussion Starter · #14 ·
Fluid was good before the bust. Where can I get a rebuild kit for a 1959 MX? I read here once that rebuilders will sub C6 wheels because MX are unavailable. They are close but dont quite work. So I was thinking of getting a correct kit and giving it to a rebuilder.
 

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Maybe you don't need a complete rebuild, maybe it just needs new seals and band adjustment? Now, finding that out is the real hard part. :unsure:
 

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Fluid was good before the bust. Where can I get a rebuild kit for a 1959 MX? I read here once that rebuilders will sub C6 wheels because MX are unavailable. They are close but dont quite work. So I was thinking of getting a correct kit and giving it to a rebuilder.
Hello puttster,

They do sell generic kits for the MX still, however it looks like there are no bands available and you'll have to send out your old bands for relining which could take some time. Plus if your transmission needs hard parts it might take some searching before a good used one is found. These old Borg Warner MX, FX and Fords version FMX are a dying breed of transmission. I rebuilt an FMX and it required stealing parts from an FX and machining them. Plus the bands had to be sent out for relining and that was before global meltdown 2.0 and it took several weeks to get them. Personally I'll never do one of these Borg Warner transmissions again.

Have you thought about the possibility of just converting to a C6 instead? I know the initial installation would take some doing, but at least after that servicing the C6 will be much easier as parts are still aplenty.

Just thoughts.

Cheers
 

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Call Fatsco for parts. They actually have some stuff that they don't list on their website. I was able to get bands from them for my '65 within the past year. They had me send my old ones in as a core. They seem to be the only retailer that understands the unique features of the MX.
 

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JMO of course.... but I think you took a major step backwards having that 1959 MX installed in your 65.

What was wrong with your original trans and do you still have it?

The 59 MX needs that "kickdown" linkage set properly or trans damage WILL occur.
I can't emphasize this enough!!!!
It's EXTREMELY IMPORTANT!!!!!!
That "kickdown" linkage is actually Throttle Pressure control and determines trans proper mainline pressures during all operating conditions.
Kickdown is actually a secondary function of that linkage.
If there is some hacked up, cobbled together "kickdown" linkage on that 59, you will sooner-or-later have the same problems all over again.

The 65 trans with vacuum modulator is a much better setup.
The Vac Mod is almost foolproof as it determines trans pressures,
and default condition (vac disconnected) the trans goes to high line pressure and avoids the trans "burning up".

The kickdown on the 65 trans is just that... kickdown function only.
Again NOT SO with the 59 trans, it's NOT "just a kick down".
 

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Discussion Starter · #19 ·
Good info Galaxiex, thanks! I have been pretty casual adjusting the linkage. I wonder if that was causing the surfing in 2-3? Do you know if I can use the instructions from my 65 shop manual to set the linkage?
 

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JMO of course.... but I think you took a major step backwards having that 1959 MX installed in your 65.

What was wrong with your original trans and do you still have it?

The 59 MX needs that "kickdown" linkage set properly or trans damage WILL occur.
I can't emphasize this enough!!!!
It's EXTREMELY IMPORTANT!!!!!!
That "kickdown" linkage is actually Throttle Pressure control and determines trans proper mainline pressures during all operating conditions.
Kickdown is actually a secondary function of that linkage.
If there is some hacked up, cobbled together "kickdown" linkage on that 59, you will sooner-or-later have the same problems all over again.

The 65 trans with vacuum modulator is a much better setup.
The Vac Mod is almost foolproof as it determines trans pressures,
and default condition (vac disconnected) the trans goes to high line pressure and avoids the trans "burning up".

The kickdown on the 65 trans is just that... kickdown function only.
Again NOT SO with the 59 trans, it's NOT "just a kick down".
+1

Howdy galaxiex,

I was wondering does the older MX with the Throttle Pressure Control have a safety like the GM TH700R4 where if the TPV is set to low or becomes disconnected it fail safes in the high pressure/dragged out shifts region?

Cheers
 
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