Yet another Transynd flush ?

[LA DMAX]

I've read the posts up and down and I think I can do this transynd fulsh myself thanks to all you guys posting. My questions are:

1. Does the torque converter get flushed out or not?

2. If no how can we flush it?

Now this is where my lack of knowledge makes me post yet another question. When you are draining through the from cooler line with the truck running(I presume the tranny is in park), what would happen if you put it in drive or reverse while keeping your foot on the brake? Would this engage the TC and force more of the Dex III out giving you a more complete transynd flush or am I totally off here? Thanks for your input.

LA DMAX

[DmaxMaverick]

LA DMAX

Don't go out of P while you flush. You will certainly start throwing codes with the lower fluid level, and it will not accomplish anything more. It will surely leave air bubbles in the system that could take a long time to purge, and continue to generate DTC's.

The converter will flush. It is not "engaged" when you shift into a gear. It is "engaged" all the time (the converter, not the converter clutch). It is a pump, afterall.

If you flush the tranny like it is explained on the forum, you will replace more than 95% of the old fluid. What remains is negligible.

Don't forget to replace the magnet when you change the filter. Can't say that too many times.

[LA DMAX]

DmaxMaverick, thanks for the explanation, makes sense now. I know this is one of those beat to death threads. Thanks again.
Later

LA DMAX

[56Nomad]

LA DMAX,

Tomorrow, my bro in law and I are going to
flush both our trucks together........ I'm glad you asked
and thanks DmaxMaverick for your reply.

I thought I beat this topic to death first!

[TraceF]

In the last few weeks someone posted that the flushing systems only flushed out the cooler.

My dealer tells me this is wrong.

It works like this:

By tapping into the cooler line, the old fluid coming through it via the trans pump is returned from a seperate reservoir as new, fresh fluid.

This is a lot more effective than the old way of dropping the pan and only adding a fraction of the capacity back new.

Remember, our manuals tell us to change the Allison spin on at 7500 to get the initial wear metals out. Then change the tranny at 25k.

Good luck!

[hoot]

Cleaned up my flush notes some.

See signature "Collected NOTES"

[ 02-08-2003: Message edited by: hoot ]</p>

[56Nomad]

Hello Hoot..... here is the "Reader Digest" summary of what you and
others have posted previously.

Both my brother in law's and my truck were approaching 25,000 miles so
we flushed both trucks today! It really was not all that difficult, however
I will say it was a bit messy, even with two of us working together. Plan on
using lots of newspaper..... better yet, big pieces of cardboard under your
working area. Have lots of clean rags handy too. Also, we used 2.5 gallon
plastic jugs to measure out the amount of ATF removed. We stayed with
the stock pans and here is our summary. (Almost all of this information
is from Hoot's summary and previous postings) Keep in mind that both
my brother in law and myself are just basic amateur mechanics...... that
means anyone should be able to do it.

+Drained pan - about 7-8 qts came out.

+Reinstalled pan plug and removed pan - 12 bolts, very easy to loosen & remove.

+Gasket was in great shape and slid off pan upon removal.

+Removed black plastic, pressed in, screen holder - more ATF came out from
the resultant opening. Wiped it with clean rag.

+Cleaned pan - Wiping bottom of pan with clean rag and came up black with
what was assumed to be particulate metals, etc. Cleaned the pan magnet.
Very glad I did this!

+Removed filter - Magnet was firmly attached to filter and would be
difficult to note if you weren't looking for it

+Cleaned magnet - used clean rag and took some time to "pull" any material
off of it as it wants to stay and is so small, it is hard to note. Comes off
as black film on paper towel, very tiny particles.

+Installed magnet on new filter and installed filter - filled filter with new fluid,
assuming this would help "prime" and was easy to do.

+Positioned gasket and reinstalled pan - We used the original gasket
The tranny pan gasket IS REUSABLE and should survive many on/off cycles

+Tightened bolts in star pattern. Each torqued (20 ft/lb.) Tightened pan plug (25 ft lb.)

+Refilled Pan - from dipstick opening, using funnel, used 9-10 quarts....

+There are two lines on the passenger's side of the transmission up front
near the converter; the lower one is the "To Cooler" line and the upper one
is the "From Cooler" line. Disconnect the "From Cooler" Line - much easier than
expected. Slide plastic cap back, carefully remove the snap ring. Pull the line
out of the fitting.. don't remove the fitting from the tranny - just slide
the plastic cover back. More ATF came out of hole and cooler line. Draining is
from "From Cooler" line, now hooked up to a 2 ft clear tubing into a EMPTY plastic jug.
Start engine which causes fluid to drain. Plastic jug is filled in about 30 seconds
(about 6 quarts). Some of the new ATF will be sacrificed..... but you will know that
your system is flushed. This procedure required the two of us. One person to (START)
the engine (keep in NEUTRAL) and the other person under the truck to scream (STOP)
when the plastic jug was filled to 6 quarts of flushed out ATV.

+Reinstalled "From Cooler" line - used same clip, hard to believe that little clip
keeps line sealed! Don't forget to push line as far as it will go before clipping.

+Filled transmission - with another 6 quarts of ATF, drove truck in each gear,
checked Hot, may need to add more so check later...

+All said - about 1.5 hours for each truck and we each used just a tad over
4 gallons of Transynd per truck. The 5 gallon pail of Transynd is Allison
p/n 27101-CTPL) $136.50 in our area.

[REC06]

Nice step by step lay out, with that and hoots photos and directions I will be flushing mine soon. Thanks for taking the extra time to educate the rest of us

[SteveO]

Trace F,

I'm pretty sure your refering to me and another member talking about a Cooler Flusher that Allison has put on the Essential tools list for Authorized Service/Rebuild facilities... That flusher does exactly what it says, flushes the "COOLER" only..
Your dealer is presumably talking about another type of flusher..

Manual should state (unless it's changed for 03) to replace the spin-on at 5K then every 25k for Short Trip Schedule, 50k for Long Trip Schedule..

56Nomad,

I do not think it's necessary to remove the pan to wipe the stuff out... It's up to the individual.. If your installing a deep pan then this is a given..

Thanks, Hoot, DmaxMaverick you are making it easy on me..


LA DMAX,

Keep it in Park with the Park Brake set [img]smile.gif[/img]
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Please guys, Don't waste your money on a new pan gasket.. I have never ever seen one leak that the bolts were tightened down properly.. If you do take the pan down, remember 20-22 Ftlbs is not very tight..

[HESS101]

Boys I just made a 7 page copy of this thread. Looks like everything in a nut shell. Great stuff thanks.