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FMX problems
#1
Okay, not too sure how to describe this exactly since I know nothing about transmissions, but I'll give it a try. I've been noticing that while driving around town slow, it feels like the transmission gets hung up between second and third. It'll go to shift, sound like it went into neutral because of the rpm increase, and then go into gear. I don't remember for sure, but this was either a new or a rebuilt transmission about 15 years ago that had a few hundred miles put on it before the car was parked. When I had the engine out, the torque converter had a date on it for sometime in the late 1990's, so at least that is "new". Could it just need a band adjustment and filter change? It only does it putting around. If I take off at a decent speed or really get into it, it will not do this. I don't know if this could be called slipping, it feel like it goes 2-N-3 while driving it. 1973 Grandé, and like I said, I believe this to be a rebuilt trans, but it might've been new, but that was 15 years ago. I've put maybe 1000 miles on it and this is really the only issue it's given me beyond the fact the car is very slow and is turning about 3000 rpm for 70. I'd like to put an OD trans in it, but that's beyond my capabilities right now. Any and all help is greatly appreciated as this is currently a daily and my only running vehicle since I took my truck apart to rebuild the engine.
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#2
Sounds like it may be a fluid pressure problem at low speeds. I'd start with changing fluid and filter.



“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
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#3
could be build up of clutch material in the fluid gumming up the speed governor or valve body.

what color is the fluid on the dip stick? is it red, dark red, brown, black?

follow Don C's advice first, fluid and filter change. you might want to open up the fittings on the radiator transmission cooler lines and when you have the pan dropped for the fluid and filter change blow air through the lines and trans cooler in the rad to get some junk out. with the pan down, scrap all the junk out and clean it really well.

after that you would need to drive the car and see if there was an improvement.

if the fluid and filter do not have an effect then you have to go deeper into the transmission possible rebuild.
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#4
72HCODE;241313 Wrote:could be build up of clutch material in the fluid gumming up the speed governor or valve body.

what color is the fluid on the dip stick? is it red, dark red, brown, black?

follow Don C's advice first, fluid and filter change. you might want to open up the fittings on the radiator transmission cooler lines and when you have the pan dropped for the fluid and filter change blow air through the lines and trans cooler in the rad to get some junk out. with the pan down, scrap all the junk out and clean it really well.

after that you would need to drive the car and see if there was an improvement.

if the fluid and filter do not have an effect then you have to go deeper into the transmission possible rebuild.

When I first pulled the engine I had to remove the torque converter with it and when I drained the fluid it was very dark red almost black. When I put it back together I put fresh type F fluid in the converter. I'll be sure to blow out the lines while I have it apart and also blow out the cooler praying I don't break it because this does need a new radiator because it's leaking due to old age. I guess the next question is should I bother with trying to adjust to the band while I'm in there?
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#5
if the fluid was dark almost black during that first time into the trans, pretty much the trans was marginal at that point.

smell the fluid you have in it now, does it smell burnt.

if i remember the FMX rear band requires a special spacer to set the torque specs.

chances are 15 years ago somebody lied to somebody about the rebuild on the transmission and its been on borrowed time since.
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#6
72HCODE;241335 Wrote:if the fluid was dark almost black during that first time into the trans, pretty much the trans was marginal at that point.

smell the fluid you have in it now, does it smell burnt.

if i remember the FMX rear band requires a special spacer to set the torque specs.

chances are 15 years ago somebody lied to somebody about the rebuild on the transmission and its been on borrowed time since.

That's a very good possibility. From the little that I've read, it said that a 1/4" spacer is needed for the one in the pan. I don't know if that would be the rear band or not. I also don't know if it's a special tool or anything that's 1/4" would work. Either way, I'll give it a filter change and see what happens. It doesn't smell burnt, it just seems to be dirty. Being this car has a 2.75 gear in it, I don't think anyone ever tried to race it, but you never know. I had an offer from a coworker today, and I'm gonna take it if he can get the money. But until then, I'll see what I can do. Thanks for the help.
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