I just looked at a 1994 Buick Roadmaster wagon today, jerked somewhen shifting gears (1st to 2nd I think)?

wrote:
> well it doesn't look like I'm buying the car. Love that model, I'll
> just have to look for another one.
>
> what I've been taught to do is change the fluid 3x at 1,000 mile
> intervals. That power flush stuff is crap.
>
> Technically you could change it once, periodically pull the fluid out
> the dipstick with a pump, filter that, put it back in. Then maybe
> just drop the pan and change fluid and filter 1 more time. What do
> you think? That was one thing I love about the Venture, 7.4 quarts
> spilled out when you dropped the pan. And it has a beautiful reusable
> ribbed gasket (my 2001 anyway). Other cars where 1/2 or less of the
> fluid came out when dropping the pan - I guess you have to use the
> cooler lines to change the fluid (a quart or so at a time I'm told,
> by cranking). Or what I envisioned above. Thoughts?
>
> And the question is when filling/emptying via the cooler lines, how
> much old fluid is mixing w/the new anyway. Does it really make a
> difference???

The power flus changes out all the fluid, dropping the pan doesn't. The
better solution is to drop the pan, then power flush through the return
line so the fluid goes "backwards" through the system. With the pan off
the old fluid comes out through the pump pick-up. Then you replace the
filter and enjoy the new fluid.

BUT on a trans that hasn't been serviced the entire process is a BIG
crap shoot. The reason being that the old fluid has been used up. The
additives that help it perform are gone and the mechanicals in the trans
are worn. The new fluid goes in and cleans the system, it is also
slipperier than the old fluid you usually end up with a trans that soon
starts to slip and burns itself up.

--
Steve W.

On Saturday, October 17, 2015 at 2:15:04 AM UTC+8, wrote:
>
> Technically you could change it once, periodically pull the fluid out the dipstick with a pump, filter that, put it back in. Then maybe just drop the pan and change fluid and filter 1 more time. What do you think? That was one thing I love about the Venture, 7.4 quarts spilled out when you dropped the pan. And it has a beautiful reusable ribbed gasket (my 2001 anyway). Other cars where 1/2 or less of the fluid came out when dropping the pan - I guess you have to use the cooler lines to change the fluid (a quart or so at a time I'm told, by cranking). Or what I envisioned above. Thoughts?
>
> And the question is when filling/emptying via the cooler lines, how much old fluid is mixing w/the new anyway. Does it really make a difference???

Trouble is an automatic transmission has parallel pathways, so to get the old
stuff out is not so simple.
I have a 4L60E (same as in Roadmaster). I have had it flushed a few times.
One flush used 17 litres of ATF, whereas the capactity in manuals states 11
litres. The workshop claimed you had to push about 50% extra through to
eliminate the old slops.

On Fri, 16 Oct 2015 11:15:00 -0700 (PDT),
wrote:

>well it doesn't look like I'm buying the car. Love that model, I'll just have to look for another one.
>
>what I've been taught to do is change the fluid 3x at 1,000 mile intervals. That power flush stuff is crap.
>
>Technically you could change it once, periodically pull the fluid out the dipstick with a pump, filter that, put it back in. Then maybe just drop the pan and change fluid and filter 1 more time. What do you think? That was one thing I love about the Venture, 7.4 quarts spilled out when you dropped the pan. And it has a beautiful reusable ribbed gasket (my 2001 anyway). Other cars where 1/2 or less of the fluid came out when dropping the pan - I guess you have to use the cooler lines to change the fluid (a quart or so at a time I'm told, by cranking). Or what I envisioned above. Thoughts?
>
> And the question is when filling/emptying via the cooler lines, how much old fluid is mixing w/the new anyway. Does it really make a difference???


The new fluids really can go 100K IF you don't abuse the
transmission, like with heavy towing over and over again in hot
weather. But if it's just a car driving normally they have made the
new fluids bulletproof. Old fluids gave up within 15,000 to 30,000
miles, new ones don't.

Research paper here

https://www.dropbox.com/s/jf3s818104...82674.pdf?dl=0


It compares some of the old favorites to the newer formulations with
charts and graphs showing the differences. It's from 1998 and things
would have only gotten better since then. My feeling is change the
transmission fluid at 75K intervals and you're golden.

On Fri, 16 Oct 2015 20:13:49 -0400, "Steve W." >
wrote:

wrote:
>> well it doesn't look like I'm buying the car. Love that model, I'll
>> just have to look for another one.
>>
>> what I've been taught to do is change the fluid 3x at 1,000 mile
>> intervals. That power flush stuff is crap.
>>
>> Technically you could change it once, periodically pull the fluid out
>> the dipstick with a pump, filter that, put it back in. Then maybe
>> just drop the pan and change fluid and filter 1 more time. What do
>> you think? That was one thing I love about the Venture, 7.4 quarts
>> spilled out when you dropped the pan. And it has a beautiful reusable
>> ribbed gasket (my 2001 anyway). Other cars where 1/2 or less of the
>> fluid came out when dropping the pan - I guess you have to use the
>> cooler lines to change the fluid (a quart or so at a time I'm told,
>> by cranking). Or what I envisioned above. Thoughts?
>>
>> And the question is when filling/emptying via the cooler lines, how
>> much old fluid is mixing w/the new anyway. Does it really make a
>> difference???
>
>The power flus changes out all the fluid, dropping the pan doesn't. The
>better solution is to drop the pan, then power flush through the return
>line so the fluid goes "backwards" through the system. With the pan off
>the old fluid comes out through the pump pick-up. Then you replace the
>filter and enjoy the new fluid.
>
>BUT on a trans that hasn't been serviced the entire process is a BIG
>crap shoot. The reason being that the old fluid has been used up. The
>additives that help it perform are gone and the mechanicals in the trans
>are worn. The new fluid goes in and cleans the system, it is also
>slipperier than the old fluid you usually end up with a trans that soon
>starts to slip and burns itself up.

Another theory is that the reverse flush forces debris back into
little openings it was lucky to get thru the first time and now you
are jamming it back in there. The same issue has been raised with the
common practice of pushing disk brake pistons back into the bore -
that it forces dirty fluid back up into the delicate ABS valve block
and mucks it up. New advice is to crack the bleeder when pushing the
pistons back to avoid that. I see no reason to flush a transmission..
For the cost of the flush you could just have a regular pan drop and
filter done twice as often and not run the risk.

for clarity what I meant above was pull it out through the dipstick a few times before the 2nd change. Whatever. 60$ 3x isn't horrible if it keeps it running.

I knew a guy who had a Freestar w/black tranny fluid driven in the metro NY area, around 100k. He changed the fluid 3x in 100 mile intervals. It lasted a few years. He junked the van eventually, but it's a Ford, so what can you expect (I know, some Fords last 300k, but that one didn't). It probably died (what specifically I don't know) at 160k about.

Usually it's the clutch packs that go in a tranny. They need slippery oil. I don't understand that being the issue. I do know of A LOT of (GM) cars though that never had their fluid changed and last upwards of 200k or more. This issue seemingly will never be resolved. If it's a new car, I guess the best thing is to change it every 30k just to be safe.

On Monday, October 19, 2015 at 3:49:34 PM UTC-5, wrote:
> for clarity what I meant above was pull it out through the dipstick a few times before the 2nd change. Whatever. 60$ 3x isn't horrible if it keeps it running.
>
> I knew a guy who had a Freestar w/black tranny fluid driven in the metro NY area, around 100k. He changed the fluid 3x in 100 mile intervals. It lasted a few years. He junked the van eventually, but it's a Ford, so what can you expect (I know, some Fords last 300k, but that one didn't). It probably died (what specifically I don't know) at 160k about.
>
> Usually it's the clutch packs that go in a tranny. They need slippery oil.. I don't understand that being the issue. I do know of A LOT of (GM) cars though that never had their fluid changed and last upwards of 200k or more. This issue seemingly will never be resolved. If it's a new car, I guess the best thing is to change it every 30k just to be safe.

I once had the automatic transmission in my 1973 full size Dodge van rebuilt. One of the things that was worn out was one of the synchronizer rings. It cost me over $800.00 to have the transmission rebuilt at the Dr. Transmission shop near me.

On 10/19/2015 5:02 PM, JR wrote:
>
> I once had the automatic transmission in my 1973 full size
Dodge van rebuilt. One of the things that was worn out was
one of the synchronizer rings. It cost me over $800.00 to
have the transmission rebuilt at the Dr. Transmission shop
near me.

Synchro ring in a 747? Just more and continuing evidence that
you're clearly out of your mind.