727 shift probs

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GTS Dave

GTS Dave

You're born free, then you're taxed to death.
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I was working on a 340 Duster overheating problem (fixed by replacing water pump and new fan clutch) and in the process I replaced my radiator, thinking it was clogged. The new replacement radiator looks identical, has the same locations for the transmission lines, so I swapped the fittings, hooked the tranny lines back up, topped of the trans fluid. However, I used Dexron III / Mercon, instead of the type F that was originally in the 727 (called prev owner, found out about the type F, too late)

Before working on the overheating prob, transmission shifted perfectly.

Now, the transmission at times revs up a lot higher in 1st before shifting to second and slips when shifting to second. I sometimes have to let off the gas pedal to get it to shift.

So far I have pulled the trans cooling lines of the new radiator, blew air through the radiator to verify it wasn't plugged, dropped the trans pan, blew air back through the lines back to the tranny to verify the lines were not plugged. I went a head and replaced the filter, put on a new pan with a drain plug. I have since drained all the fluid (converter has no drain plug) and replenished w type F, still have intermittent slippage. 727 does have a shift kit in it. When working right it does shift hard. There was very little, fine metal accumulated on the magnet on the pan, 'normal wear' according to those I have talked to. I have driven the car several miles, making sure there are no air pockets and the fluid level is correct.

I am planning on one or two more 'flushes' with type F.

Anyone have any suggestions?
 
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d55dave said:
Did you disturb the trottle valve (kickdown) linkage at all? Is it still hoomed up and rigged properly?
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Nope, never got near the linkage. I did check it though, it is moving freely and kicks down all the way.

I was also wondering if due to mixing the fluid that maybe a valve is sticking possibly? Has anyone tried something like the hotshot secret transmission stiction eleminator ?

Would that in effect ruin the hard shift the tranny shift kit?

Thanks.
 
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GTS Dave said:
Nope, never got near the linkage. I did check it though, it is moving freely and kicks down all the way.

I was also wondering if due to mixing the fluid that maybe a valve is sticking possibly? Has anyone tried something like the hotshot secret transmission stiction eleminator ?

Would that in effect ruin the hard shift the tranny shift kit?

Thanks.
Click to expand...
Unless it's changed over the past few years, the #1 transmission additive used in transmission shops was a product called LUBE-GARD. There are different types available, but in your case I think the RED bottle product would best suit you. Google the name LUBE-GARD and go to their website to see the additives they make for automatic transmissions and the various NEW oils currently being sold/used by the OEMS. I've heard that TYPE F is no longer being made and is very hard to find.
 
transman said:
Unless it's changed over the past few years, the #1 transmission additive used in transmission shops was a product called LUBE-GARD. There are different types available, but in your case I think the RED bottle product would best suit you. Google the name LUBE-GARD and go to their website to see the additives they make for automatic transmissions and the various NEW oils currently being sold/used by the OEMS. I've heard that TYPE F is no longer being made and is very hard to find.
Click to expand...

I haven't heard anyone know what Lube Guard is for quite awhile. :D
Aamco carries it last I knew.
Red is the one.

I agree it kind of sounds like a sticky valve or governor on the upshifts, but that wouldn't explain second slipping would it?
Almost sounds like fluid aeration symptoms to me, but where?
Or half way between gears? (linkage adjustment?)
 
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fishy68 said:
I'd check the front band adjustment also. It can cause that exact problem if it's too loose
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Would/could that also explain the late 1-2 shift?
In my experience it skips right from first to third if the band is too far out of adjustment.
 
TrailBeast said:
Would/could that also explain the late 1-2 shift?
In my experience it skips right from first to third if the band is too far out of adjustment.
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I have had it happen. Whether it skips right into 3rd depends on how loose the band is. Somewhat loose can cause late/sloppy shifts. Real loose and it skips 2nd all together
 
fishy68 said:
I have had it happen. Whether it skips right into 3rd depends on how loose the band is. Somewhat loose can cause late/sloppy shifts. Real loose and it skips 2nd all together
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I didn't adjust the bands while I had the pan off, didn't think just dropping the pan would affect the bands. So next time I drop it, I will do it anyway.

The replacement pan is same depth as the factory pan. I did add a couple super magnets to the bottom of the new pan.

As to type F, I have no problem finding here locally.
 
Dropping the pan doesn't affect the bands. You have a problem that could be front band related so that's why I suggested it. The front band adjustment is located on the driver's side of the trans right above the shift linkage so you can do it without taking the pan off. By your description I think it'd behove you to check it cause if it's loose it could smoke the band and that'd mean a trans rebuild.

btw: when doing a trans service i.e. replace fluid and filter, it's common place to check/adjust the bands on a torqueflite since their not self adjusting.
 
fishy68 said:
Dropping the pan doesn't affect the bands. You have a problem that could be front band related so that's why I suggested it. The front band adjustment is located on the driver's side of the trans right above the shift linkage so you can do it without taking the pan off. By your description I think it'd behove you to check it cause if it's loose it could smoke the band and that'd mean a trans rebuild.

btw: when doing a trans service i.e. replace fluid and filter, it's common place to check/adjust the bands on a torqueflite since their not self adjusting.
Click to expand...

Thanks for your directions, I've only had the car since last fall and little if any experience with the 727. In my investigation, you and others recommendation of doing the band adjustments each time the pan is dropped is 'standard practice' and is now on my to do list.

Update: I did my first 'flush' today using type F fluid, and did a test drive, went home and topped of the fluid level, and drove it most of the afternoon, and everything's back to normal. No slipping, and romping on it from a dead stop, she's chirping the tires when it shifts, etc.

Hard to say if flushing it made any difference, poss air in the lines, who knows..

I will have it out again tomorrow just to say 'all is ok'. I appreciate everyone's input, I've learned a lot.

On to my next project, new fender-top turn signals.. but that's another thread.

Thanks guys.
 
Type F is the wrong fluid for a Torqueflite. While it can be used, it is not the Chrysler preferred fluid. Dexron is.

That said, I don't think what you have is fluid related. Sounds like it was going to happen anyway and the fluid is simply a coincidence.

Type F has been used for years to make a Dexron fluid type transmission shift harder......and it will, but it is still not the correct fluid. I have always said people looking for a harder shift in a Dexron transmission with Type F were doing it the wrong way. I still maintain that.

If it slips with Type F, it will slip with Dexron. Slipping is an indication of a mechanical failure, or of a needed adjustment. Hopefully, the latter will fix it.
 
GTS Dave said:
Thanks for your directions, I've only had the car since last fall and little if any experience with the 727. In my investigation, you and others recommendation of doing the band adjustments each time the pan is dropped is 'standard practice' and is now on my to do list.

Update: I did my first 'flush' today using type F fluid, and did a test drive, went home and topped of the fluid level, and drove it most of the afternoon, and everything's back to normal. No slipping, and romping on it from a dead stop, she's chirping the tires when it shifts, etc.

Hard to say if flushing it made any difference, poss air in the lines, who knows..

I will have it out again tomorrow just to say 'all is ok'. I appreciate everyone's input, I've learned a lot.

On to my next project, new fender-top turn signals.. but that's another thread.

Thanks guys.
Click to expand...

Well as RRR says type F will generally make a TF shift more solid. Would have never expected it to do that much but as long as it works run it and enjoy.
 
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