tranny fluid 1970 fleetwood

[Cape Cod Fleetwood]

I was told in no uncertain terms today that the AC Delco Dex6 I bought for the transmission fluid, filter change
was the wrong fluid. Period. End of issue. Its synthetic. Can not use. "They" will get the fluid.

There's no chance this is the original fluid 48 years and 96K miles later. Its pink, smells good, pan is a bit weepy.

I was told in no uncertain terms that changing the fluid at all was a bad idea, "its working, leave it alone". It wasn't until I said the pan is weepy that the fluid and filter change became authorized.

I can't get this guy mad(er) at me. He's agreed to take it into the shop in 2 weeks and just do all the engine work I want done. And I like the fact these guys only do old cars there. Who knows when the body and roof will get done at this point, I just want to DRIVE THE CAR.

<sigh>

Thoughts?



\m/
Laurie

[The Tassie Devil(le)]

Dexron III is the way to go.

I have re-used fluid that was good, having removed it from the trans to replace a filter, or fix a leak, but always strain it through a nylon stocking before returning it to the trans.

Bruce.

PS.   The secret is to drain it into a clean container first.

[64\/54Cadillacking]

That’s a load of baloney!!

I don’t care what anyone says, ATF needs to be drained and refilled with clean fluid if you want the trans to last forever. It’s like changing your motor oil, if you never change it, your engine will seize up. Even using a fluid extraction pump you can buy at the parts store just to get some of the old fluid out, can make a big difference in how the car shifts and for added protection.

Obviously dropping the pan is the best way to go, but in the mean time a simple extraction can do wonders.

I wouldn’t recommend Dex VI in older Cads either as the ATF is a thinner viscosity vs the old Dex III. What you can use instead, which has worked great for me in all of my old Caddy’s and Lincoln’s, is Valvoline Maxlife ATF. It’s a full synthetic fluid, so you gain the benefits of a full syn that’s compatible with our cars.

I’ve used it in my 78 Lincoln with the C6 trans, my 94 Caddy Fleetwood Bro, my 64 Cad, and even in some Honda’s with known tranny problems that helped with harsh shifting.

This stuff works in almost any vehicle. So I would definitely give it a shot, you can buy a 4 quart jug of it at certain Walmart’s for like $18. I do the extractions myself and saved hundreds of dollars in the process.

[The Tassie Devil(le)]

Let me clarify.

I re-use oil which I know is good, seeing as I put it in a week before, so I know it is good.

But, would I re-use 12 month-old oil, heck no.

Bruce.

[64\/54Cadillacking]

Also, I know this has nothing to do with your Cad, but it relates to the subject.

A good example of why it’s so important to change out the trans fluid is because over a short period of time, trans fluid additives break down due to heat. This is the main cause for wear. You really can’t tell if the fluid is still really good or not, until you actually drain it and see it for yourself up close through a clear plastic container. Even a little brownish hue or a dark red color in the ATF, means that the fluid is already oxidized and is breaking down.

I drained 5 quarts of ATF in my 17 Impala at around 30,000 miles. It states in the manual that a drain and refill is due at 60K.

Well to my shock, when I drained the old ATF out, it was very dark in color and smelled kinda burnt! How and why would this happen at only 30K when the manual says to drain at 60K? It goes to show that sometimes you can’t go off what the manufacturer states, it’s more like a threshold, of course changing fluids out way before the recommended intervals is always a good thing to do.

After draining the 5 quarts, the car shifted smoother, not drastically better but better than before. I decided that 5 quarts wasn’t enough, so I drained an additional 5 quarts, and the fluid still looked dark dark red. Overall I had to drain the tranny 4 times in order to remove all the old ATF where now it looks bright red like it should when it comes out.

The car shifts like butter now, like how it’s supposed too when new. A drain n refill is not enough, you might have to do it numerous times in order to get all the old fluid out of the system, but it’s worth it not only in the long run for protection, but for better performance and how well the trans responds and smooths out while driving.

[64\/54Cadillacking]

Let me clarify.

I re-use oil which I know is good, seeing as I put it in a week before, so I know it is good.

But, would I re-use 12 month-old oil, heck no.

Bruce.

My comment wasn’t directed at you Bruce! Lol

It was directed at Laurie’s mechanic.   

[The Tassie Devil(le)]

My comment wasn’t directed at you Bruce! Lol     It was directed at Laurie’s mechanic.   

That's okay, I have tough skin, except when slice it, or burn it whilst changing hot oil.

I should have clarified myself in the initial posting.

As an aside, I must point out for everyone that transmission oil gets so hot when it is being abused that the cooling tubing gets so hot that it melts plastic.

I found out that when I first used an Auto Trans in my Dragster.   The catch can (actually a catch plastic can) that was wedged in beside the cooler line had actually melted through the side of it.

Had to change the oil after every 4 runs as it really stunk, and the colour change was to a really dark red.   Thankfully, I was sponsored for all fuels and oils.

Bruce.

[bcroe]

Changing the filter and taking a look at things periodically is
a good idea.  A TH400 would usually not need anything for
100,000 miles, but the way they build new cars who knows. 
If a pan doesn't have a drain (to simplify the job), I add one. 

Bruce Roe

[cadillacmike68]

I recommend changing it and filling it with Dexron VI

The GM specification for Dexron VI is that it is approved for use in ALL GM vehicles using ANY PRIOR DEXRON specification.

Just don't have this mechanic do it.

You can drain it out yourself with a suction siphon through the dipstick if you want, but any decent tire shop can drop the pan, change the filter and refill with new fluid.

That leaves what is still in the torque converter, so an alternative is to disconnect the radiator cooling output line at the radiator and let the output go into a waste can and fill the system through the dipstick with fresh fluid. If you do this after dropping the pan and changing the filter, you'll get all new fluid and a new filter.

Once you get it all flushed, every 3-5 years a pan drop should be all that's needed.

[Scot Minesinger]

Probably a little of what his anger is due to resulted from customer supplied products.  Generally the mechanic shop provides everything, and usually does not welcome customer supplied repair components, especially fluids.  Right or wrong that is my guess. 

When I work on friends cars, it is great when they bring the right part to install, but it is a major bummer when it is wrong because time is lost.  However, correcting the fluid issue is a simple trip down to the auto-parts store.  Some just get mad at anything.

[bcroe]

Probably a little of what his anger is due to resulted from customer supplied products.  Generally the mechanic shop provides everything, and usually does not welcome customer supplied repair components, especially fluids.  Right or wrong that is my guess. 

Yes I found that out very early.  The mechanics want to order a bunch
of parts and charge you a huge markup.  I never did agree with that,
thought I was supposed to be paying for mechanical work.  When I saw
them destroy some nearby good parts, and charge me 5 times as much
for replacements as I had paid for them recently, I was seriously
motivated to do as much of my own repairs as possible.  Bruce Roe

["Cadillac Kid" Greg Surfas 15364]

Laurie,
It seems you have re-opened a subject that can touch us all.  We seem to forget two things.
1. Any service organization that wishes to remain in business MUST make a profit.  They are charging for their skill, experience, rent and overhead.  When we bring parts to them for their installation, it takes from that profit which, just for conversation sake includes some reserve for warrantee work.

2. When we take a project to a (reputable) they will assume they know what must be done and how to do it.  I do not know if you have informed them of your activities on the forum, but I am sure, if your mechanic has experience on cars like yours they feel they know better.

Many of us have been "disappointed" by the performance of mechanics and have the time, patience, mechanical aptitude and the money (for tools, etc.) so we do our own repairs.  I for one fall into that category, but when specialized work such as transmissions, suspension, rear end or machine shop work is required I go to a few shops that I have "felt out" over the years to be trustworthy.
When I go to these shops I ask tell them that if they are unable to reasonably secure the parts they need I have got them in reserve, and they can just add their normal mark up to my parts so they will be comfortable taking on any warrantee and they will be in business the next time i need them.  This is not a hobby to them.
I think of it this way.  If I was going to the dentist I doubt vry seriously that i would bring my own (what ever they use) filling material for the Dentist to install, or tell them how to drill and fill my teeth.

One of the other factors that we do not really appreciate is how difficult it can sometimes be to do simple tasks on these older cars.  Bolts break, things do not come apart without breaking and often things meant to be done with special tools have to be done without them because the mechanic, having done the particular task infrequently does not want to invest in something he will not use.
Just my rant for the day.
Greg Surfas

[Mike Baillargeon #15848]

Changing the filter and taking a look at things periodically is
a good idea.  A TH400 would usually not need anything for
100,000 miles, but the way they build new cars who knows. 
If a pan doesn't have a drain (to simplify the job), I add one. 

Bruce Roe

Bruce is there a drain plug kit that you prefer?  What works best for you?

Thanks, Mike

[bcroe]

Bruce is there a drain plug kit that you prefer?  What works best for you?
Thanks, Mike 

The first time I tried a drain plug kit on a TH400, it was made out
of pot metal and broke.  And it seemed to have a potential for
leaking, with a gasket.  This trouble I don't want. 

I took a piece of 1/4 inch stock a little over an inch square, and
ground one rounded edge so it fit nicely at the back, clear of any
internals.  I brazed it inside, then drilled and tapped it for a 1/8
inch pipe thread, put in a pipe plug.  It doesn't need to be low
enough to drain every drop.  It just drains enough fluid so you
are NOT taking off a pan filled to overflowing and sure to make a
mess.  I have a stack of extra pans for any rebuilds.  Bruce Roe

[Scot Minesinger]

Greg brings up a very important point - any business must earn a profit to exist and be stable.  I work on these old Cadillacs circa 1965-1976 a lot and own three 1970 Cadillacs myself.  To do the job right, it is impossible to earn a profit. 

You start a job and discover other issues, keep the precious classic taking up a bay in a climate controlled (a/c and dehumidification in addition to just heat - you leave raw steel in it for a year and no rust) for a week awaiting further parts, they are wrong and another week passes by.  I do this for the love of the hobby.  Sometimes it takes 6 hours to do a 1 hour job, but at least it is done correctly.  Example; a bolt broke off in the crank hub that secures the pulley to it and rather than just install the three bolts, I drilled the broken bolt and extracted it properly - most other shops would leave it and install the other three bolts.

Since it really is almost impossible to earn a profit working on these old cars from a shop that generally works on modern cars, I just do it myself.

The other side is if people knew what it takes to keep a classic car in proper repair to drive across Country, very few would ever buy a classic and jump in.

[bcroe]

Here are pics of my trans drain.  Since I do maintenance, mods to
make it quick and clean are worth while over decades. 

I found a lot of jobs were just a matter of some study and some
more tools.  Rule here is, a tool pays for itself the first time you
use it (instead of paying someone else to use theirs).  Just a
couple of trans overhauls probably justified the lift.  Some things
like trans and suspension work can be messy, but not really all
that difficult.  It helps if you only work on similar models, which
you then can become more familiar with.  Maybe even better than
a pro, who must deal with most of the stuff on the road.  Bruce Roe

[Mike Baillargeon #15848]

Here are pics of my trans drain.  Since I do maintenance, mods to
make it quick and clean are worth while over decades. 

I found a lot of jobs were just a matter of some study and some
more tools.  Rule here is, a tool pays for itself the first time you
use it (instead of paying someone else to use theirs).  Just a
couple of trans overhauls probably justified the lift.  Some things
like trans and suspension work can be messy, but not really all
that difficult.  It helps if you only work on similar models, which
you then can become more familiar with.  Maybe even better than
a pro, who must deal with most of the stuff on the road.  Bruce Roe

Thanks Bruce......there a boat load of kits on eBay and your right they look like leakers or easily broken.

Yours is straight forward and pretty easy to do.

Thanks again,  Mike

[76eldo]

Leaving in old fluid is not only an old wive's tale it's moronic.  My 76 Eldo has almost 100K on it.  The 1-2 shift started getting a little rough on it about 5 years ago and like 90,000 miles.  I have service records on the car and I think the trans was serviced periodically during the first owner's 25 years he spent with the car.

When I serviced it I replaced the modulator with a new one, and dumped the fluid and changed the filter.  The car shifted much better and has performed flawlessly since.

Trans fluid loses it's properties over time just like engine oil or coolant.  It needs to be refreshed.  Actually if you want to do it right you should change it twice to get out all of the old crud.  The wive's tale is that the new fluid being so high detergent will wash out some kind of magic crud that's been keeping your car shifting up to that point.  A load of crap.

If changing your trans fluid and refilling with the right fluid makes your trans malfunction then it needed to be rebuilt anyway and you were on borrowed time with it.

Brian

[bcroe]

Leaving in old fluid is not only an old wive's tale it's moronic.  My 76 Eldo has almost 100K on it.  The 1-2 shift started getting a little rough on it about 5 years ago and like 90,000 miles.  I have service records on the car and I think the trans was serviced periodically during the first owner's 25 years he spent with the car.

When I serviced it I replaced the modulator with a new one, and dumped the fluid and changed the filter.  The car shifted much better and has performed flawlessly since.
If changing your trans fluid and refilling with the right fluid makes your trans malfunction then it needed to be rebuilt anyway and you were on borrowed time with it.    Brian 

I have had apart lots of transmissions from the 60s and 70s.  If the
metal, friction, etc parts are OK, it might continue for a long time. 
But there are rubber seals that keep clutches from slipping, etc. 
Those seals may shred or fail at any time at this age.  Replace them
now with a $30 kit, keeping your good hard parts.  Or risk blowing
away the whole trans later.  Easy for me to say who can do it myself. 
Bruce Roe

[Cape Cod Fleetwood]

The wive's tale is that the new fluid being so high detergent will wash out some kind of magic crud that's been keeping your car shifting up to that point.

Those were his exact words.

I received NO mntx records with this car, I'm doing a 24K mile service a la 1970.
I want my own parts, all AC Delco. I don't want to fight a mech over parts.
Just use mine, they're correct for the car. They knew what they were doing in 1970.
The only thing I changed was the oil, using a higher zinc infused product.

I'm a contractor. I would *LOVE* to show up at my jobs with client supplied, windows, wood, shingles,
misc... a dream come true. Think of the hours that saved me having to shop for them, time I don't get paid for.
If their window doesn't work, or its the wrong size, its on them, not me. You're just renting my body.

\m/
Laurie