Checking/adjusting bands at every fluid change?

Turbo301

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I was reading the manual for my '73 Fury and saw that they recommend (require?) that the transmission's bands be checked/adjusted whenever the fluid is changed. I'm not familiar with old Mopars, but I don't remember seeing such a requirement for other cars (at least older Fords). Is it bad for the transmission to change the fluid without doing bands, i.e. could the new fluid cause slippage or something where the old fluid would have otherwise worked (perhaps due to debris in the fluid)? I don't really like horsing-around with transmissions, so if a drain/refill requires other work I'll probably just take it to a pro, but I was curious.
 
If your transmission is shifting properly and the fluid is pretty and doesn't smell like burnt toast, don't do ANYTHING.

If you have no symptoms as listed in the Service Diagnosis chart, don't do ANYTHING.

If anything, make sure your "kickdown" adjustment (apologies to Big_John :poke:) is set exactly according to the FSM and go drive the car, enjoy life. Don't go looking for trouble!

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If your transmission is shifting properly and the fluid is pretty and doesn't smell like burnt toast, don't do ANYTHING.

If you have no symptoms as listed in the Service Diagnosis chart, don't do ANYTHING.

If anything, make sure your "kickdown" adjustment (apologies to Big_John) is set exactly according to the FSM and go drive the car, enjoy life. Don't go looking for trouble!

That works for me :).
 
Changing fluid is a good thing. It is a lubricant, coolant, and hydraulic fluid. If you don't know how old it is then I like to change it, and see what's in the bottom of the pan. If the converter has a drain plug then do that also.

Yes old dirty stinky fluid can keep the trans working and new fluid can make it inoperable. Way more common on a late model Automatic Od trans than a 727.
 
Changing fluid is a good thing.
Well, I'll certainly agree that it's not a BAD thing. But unless there's something giving symptoms of unruly shifting behavior or the fluid looks/smells burnt it's just not needed. As an added plus....if the friggin' pan isn't leaking I would leave it alone!

As for the bottom of the pan, every one I've ever had off shows friction material and assorted shiny shards of clutches, always. Guaranteed that stuff is there. So what you gonna do, rebuild the trans? Drive it. :thumbsup:
 
I saw those FSM comments way back when our '66 Newport was a used car. I asked the local old-line Chrysler product service manager about adjusting the band as a normal situation.

His reply was "I've run them tight. I've run them loose. No difference". End result, don't do anything UNLESS there is a slippage issue, or some other shift quality concern. So we just changed fluid every so often and all was well. With over 150K on that particular transmission before the car went into storage.

In a situation where there are lots of upshifts and downshifts (think NYC taxi) AND there gets to be softer shifts, or slower shifts, THEN a fluid change and possible adjustment might be warranted. Possibly similar with trailer towing in the mountains? "Normal" use? As long as everything works well, don't worry about it.

CBODY67
 
All im saying is that I just want to know the fluid is new, the filter is new, and what's in the bottom of the pan. You ever found half of a thrust washer in the pan? That's something I'd want to know.

Funny thing about the fluid, it doesn't last forever and not a good policy to wait for it to smell bad or be burnt.
 
So I guess the next question: since Dexron is up to VI, will that still be okay in these old transmissions? I used it in my '80 T/A and it works great...
 
I pump out about 5 quarts every 20k miles or so through the fill tube and refill to the mark with synthetic. Never removed a pan.
I've NEVER had a trans problem. Ever. Dozens of cars, all the old American makes.
The 93 Dakota 318 I bought in 92 has 300k on it. Lots of hard 60 mph towing miles on it in big heat too.
I'm 67.
 
I pump out about 5 quarts every 20k miles or so through the fill tube and refill to the mark with synthetic. Never removed a pan.
I've NEVER had a trans problem. Ever. Dozens of cars, all the old American makes.
The 93 Dakota 318 I bought in 92 has 300k on it. Lots of hard 60 mph towing miles on it in big heat too.
I'm 67.
That's what I've traditionally done, too; that's why I find it so annoying that new cars don't have transmission dipsticks :(.
 
For new cars an online car guy that speaks common sense says just recover and measure what you take out and put that amount back in. As long as it's not leaking it will have the right amount. And if you do this when low miles and no leaks then write down the refill amount in the owners manual so you will have it.

2018 Subaru wife's car has a trans pan with a drain plug and a fill plug in the side. Trick is to have the rpm above 1800 to get all the fluid back in or it's running out the fill plug.

They are making us work for it now! Lazy folks will just drive until it fails, which is what they want you to do. At that point you have to buy a trans or buy a car, either way they win, we spend money.
 
All im saying is that I just want to know the fluid is new, the filter is new, and what's in the bottom of the pan. You ever found half of a thrust washer in the pan? That's something I'd want to know.

Funny thing about the fluid, it doesn't last forever and not a good policy to wait for it to smell bad or be burnt.
Yes sir, I can absolutely dig what you're saying. Totally get it because I've been there, too, but with drag racing situations (high-stall converters and ClutchFlight stuff). It's the curiosity of "half a thrust washer" thing.

OTOH, when I took possession of my Hurst, I knew the trans was rebuilt in 1998, the car had 20K on it since then, shifted perfectly (once I tweaked the kickdown adjustment, that is) and it didn't leak, fluid looked good.....never touched it.
 
On the other hand, guess who took his C8 to the dealer for the First Filter Change and Trans Flush at EXACTLY the mandated 7500 miles? :rofl:
 
I had a 727 fail to engage in reverse on a very cold morning. The problem was a very dirty filter. I replaced the filter, adjusted the bands and filled with new fluid and ran the trans for seven more years with no problem. None of this is difficult and IMHO is worth the effort. As a side note, on a couple of 904's, I have squeezed a couple years out of a tired (slipping) transmission by adjusting the throttle rod to give more pressure. Not a proper repair- just a "band-aid"! Lindsay
 
Dexron III can still be had as "Type III" atf in ACDelco and "Multi-Make" in other brands. Just read the container to see that the main application is for cars that needed GM Dexron III fluid/Ford Mercon V atf.

Dex VI is at least part-syn or now either full-syn. It's fully compatible back to the first HydraMatics, which used Type A Suffix A atf, according to GM. Your choice on that part.

CBODY67
 
I agree on the fill tube point. With that, they want you to go to 100k to change fluid. I bought a C5 vette couple years back with just under the 100k. Lifted and pulled the pan. Filter clean, and then the fun begins. Fill up the the horizontal plug, run the engine until it hits the specified temp around 130F and then fill with it running. Fun under the car, I can tell you. But, on my current 66, the odo says 68k but who knows, prob correct based on pedals, the engine and so on. So, I pulled the pan. It was also shifting a bit hinky, not bad. The pan was pristine....clean, no layer of crap whatever. Filter also OK from the outside. And, I adjusted bands. One, I now forget which, was just over a turn looser than spec....the other was just a taste loose. Afterward, it did shift a taste better. One note on oil. Some of the racers will run hydraulic oil....hmm. And, many of the later chryslers had to have the friction mod as in AT4 or you would get shudder. But our 727 seems immune.....might run on H2O??
 
I probably shouldn't say anything because I may jinx my transmission but the 727 in my '67 Fury III convertible has gone just under 500,000. ( the car has 647,000, miles to date). This trans was attached to the 2nd 318 engine I put in in 1983 and I have changed the filter and fluid several times along with a front seal once and the small seal where the shifter pivot is. I have never adjusted the bands but I do baby this car and treat it with respect. The year after I put in said engine and transmission. I pulled the engine to replace all the freeze/core plugs and I changed the front seal where the converter goes in for preventive maintenance.
These old 727s are pretty durable and a transmission mechanic once told me that he had very little problems with these units. I hope after saying all this it doesn't die.:eek:
John
 
I was educated and worked around machines for my lifetime, as well as work on cars and bikes for fun. And, it is always interesting to consider some of the interactions going on that just amaze us. And for this issue, it is a balance of friction and lubrication that is still interesting. When you consider the bands and the clutches in these things, you have to ask how in the heck can they survive this punishment. They are designed as friction surfaces, and the new stuff is lubricated....or some of it is. Inside our transmissions is a lubricant that tries to keep the surfaces from contact with a hydrodynamic film, and yet, you cannot operate without lockup for these parts. So, how does wear come in with said friction, fluid film, heat and lock. It is crazy. And I think one comment above can relate, and that is if it aint broke, dont worry about it, as in if it is still shifting, nada mas.
 
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