My tranny fluid is a purple almost black color. Allison tranny with 24,000 miles. Stealer wasn't sure what color it should be said it might have a synthetic. Says it will cost $240.00 to change all of the filters and fluids. Manual says pan filter only needs to be changed when an overhaul is done. Tranny fluid doesn't smell burnt . I have changed the spin on filter once.I do not want to pay for something that I don't have to. any advice..Jim


2003 2500HD D/A CC/SB LT Juiced Isspro Pyro/Turbo everything else stock

If you can really call these trucks stock

My dealer charged about 100 bucks to do the flush job. I provided the spin-on. Are you doing heavy pulling? I changed mine at 55,000 and the tech showed me the sight glass as he was flushing. It was a little darker than new fluid. He said it was nothing to worry about. Tranny fluid is pretty resilient stuff unless you overheat it. I know guys with their gassers that have over 150,000mi on their trannys with no fluid changes. I don't recommend going that long but it is a testimonial to the fluids longevity.

Thanks, I pull a 5ver several times a year probably in the range of 15K loaded tranny has never gotten over 200 and mostly runs between 130 and 150 degrees. Tranny seems fine shifts smooth even with the Juice on. Just don't want to burn it up. All other tranny fluid is red even after thousands and thousands of miles...Jim<TABLE class=tborder cellSpacing=0 cellPadding=6 width="100%" align=center border=0><TBODY><TR vAlign=top><TD class=alt1>2003 2500HD D/A CC/SB LT Juiced Isspro Pyro/Turbo everything else stock

If you can really call these trucks stock
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Ii I were you, I would change fluid every 25,000, just like the manual says. I pull a 5000 bass boat mainly during the summer months. I don't feel that is a heavy load for my monster. That is why I go by the 50,000mi interval.

:grd: Drain and refill the transmission. Also change the external filter. I put Transynd in mine.
The OEM fluid that Allison intended in all of there automatic transmissions. Allison testing has shown this fluid to provide superior protection and extended drain intervals. It is a full synthetic.
Price: $ 35.00 a gallon at - http://www.gmdieseltech.com/store2/
Will take 2 gallons.

<HR width=\"100%\" src="skins/default/en/images/spacer.gif">2004 GMC 2500HD Ext. Cab Long Box ; Duramax (LB7)/Allison; GMC bed liner; Air Lift Super Duty air bags; Michelin LT265/75-R16 LTX M/S ; Luverne Running boards; Bilsteinshocks; Isspro gauges; Racor frame mount fuel pre-filter.

Towing a 2004 Everest 291L 5<SUP>th wheel </SUP><SUP>
</SUP> <!--AFTER PRICE-->

On the tranny forum you can find complete instructions for flushing the tranny yourself. I did mine last weekend. Was quite simple. You will need atleast 1 person to help start the truck while you are underneath measuring fluid coming out of the cooler line. I drained it, dropped the pan, replaced the internal filter, replaced the external filter, cleaned the pan and gasket, replaced the pan and gasket, added 2 gallons of transynd, disconnected the tranny cooler return line (very easy to do with a screwdriver), had the wife start the truck, flowed 1/2 gallon out, added 1/2 gallon, repeated this 3 times, replaced the tranny cooler line, checked the level, done in 3 hours or less. Cost of transynd (5 gallons) and 2 filters....$180. Not a mechanic, never touched a tranny before, easy. SPICER

I changed the filter my self at 5K and the dealer did the transmission at 30K for $125. I got no problems and don't want any. I have pulled a 1200lbs trailer around 11,000 in the last year and a half.

I also use transynd. I change mine at 50,000 miles and again at 150,000 miles. I do not change the internal filter, unless the pan would need to come off for repair, which has not happened yet. 75% of my miles are towing hard.

I got the following from the Allison web site in the frequently asked question area GM pickups with Allison transmissions.

http://www.allisontransmission.com/service/faq/index.jsp?CategoryID=11

Q. Automatic Transmission Fluid (ATF) - Can I use TranSynd fluid?
A. TranSynd is a fully synthetic transmission fluid available from Allison Distributors/Dealers or at GM dealers. TranSynd is a licensed DEXRON III product and has been extensively tested by Allison Engineering in a broad range of Allison products. While TranSynd was developed mainly to meet the harsh operating conditions of heavy-duty transmissions in severe operating conditions like transit buses, its benefits translate to the pickup truck market.

Q. Automatic Transmission Fluid (ATF) - Can I use synthetic fluid?
A. Any fluid that meets DEXRON III requirements is suitable for use in the Allison 1000 Series™. Always verify that the container reads DEXRON III, regardless of whether it is mineral-based or synthetic.

Q. Automatic Transmission Fluid (ATF) - What type of Transmission fluid can I use?
A. Transmission fluids licensed by General Motors to use the trademark DEXRON III are required in the Allison 1000 Series™ transmission.

I have called the Amsoil technical assistance line and they advised against using their TranSynd replacement fluid called Torque Drive in the pickup applications. From the above statement it looks like it would be acceptable, but not necessary. The standard Amsoil ATF would do the job.

Thanks for the help. I will drain it and refill it utilizing Transynd replacing the external filter only..Can someone tell me what color transynd is? I am still puzzled by the purple/Black looking fluid in it now...Jim



2003 2500HD D/A CC/SB LT Juiced Isspro Gauges Stock Everything else

If you can really call these trucks stock

Thanks for the help. I will drain it and refill it utilizing Transynd replacing the external filter only..Can someone tell me what color transynd is? I am still puzzled by the purple/Black looking fluid in it now...Jim



2003 2500HD D/A CC/SB LT Juiced Isspro Gauges Stock Everything else

If you can really call these trucks stock
I put 2 super powerful rare earth magnets on the outside of my external filter. Combined with the donut magnet in the external filter, my stock tranny fluid was crystal clear red at 38,000 miles. Not a lot of towing. I believe the magnets do help keep the fluid clean. Make sure your donut magnet is in your external filter and did not get thrown out. And clean it before replacing it.

The transynd was a little darker and less clear than the stock dexron III. SPICER

Thanks for the help. I will drain it and refill it utilizing Transynd replacing the external filter only..Can someone tell me what color transynd is? I am still puzzled by the purple/Black looking fluid in it now...Jim



2003 2500HD D/A CC/SB LT Juiced Isspro Gauges Stock Everything else

If you can really call these trucks stock
I changed my spin-on filter out at 8,000 miles and noticed that my tranny fluid was also purple in color. I posted a note in the Allison thread and was assured by one of the tranny vendors that the fluid was fine...just a difference in the color of the dye. I haven't towed anything yet, have no power add-ons and have never limped the tranny. My temp has never gone above 150 and the fluid does not smell burnt. It is just purple instead of red!

Know an independent mechanic. Says to service auto transmission every 25,000 no matter what make or model. Never done business with him, met him at wife's high school reunion. Lives 1000 miles from here so he wasn't trying to drum up any business from me so feel the advice is honest.

Is everyone having them change the main pan filter? Manual says to do this only when an overhaul is being completed. Seems to me just remove all of the old fluid including that in the TC and refill and replacing the external spin on filter..JIm

2003 2500HD D/A CC/SB LT Juiced Isspro Pyro/Turbo everything else stock

If you can really call these trucks stock

Is everyone having them change the main pan filter? Manual says to do this only when an overhaul is being completed. Seems to me just remove all of the old fluid including that in the TC and refill and replacing the external spin on filter..JIm

2003 2500HD D/A CC/SB LT Juiced Isspro Pyro/Turbo everything else stock

If you can really call these trucks stock
You will not get as "complete" of a flush this way. The bottom of the pan is designed such that probablt 1/2 gallon still sits in there after the oi is drained. Add to that the fluid in the filter and in the TC........To drop the pan and replace the filter is VERY easy. Never touched a tranny in my life and I found it very simple. Even a flusk like I did is only a 90% fluid change. A drain and fill is maybe a 60% fluid replacemant. SPICER

I am having it serviced today. I let the stealer do it as to have a record of it being done. I have about 12,000 left on the warranty. A little pricey at $200 but I will know if there is something wrong. Will most likely change it myself next time around..Thanks for everyones reply...Jim2003 2500HD D/A CC/SB LT Juiced Isspro Pyro/Turbo everything else stock

If you can really call these trucks stock

Guys I appreciate the information. Got the truck back last night. Tranny fluid is now bright pink. Service tech told me that the tranny was fine no metal or anything in the pan and that the dark fluid was something not to worry about as Allison puts a dye in some of the tranny's as well as synthetic fluids. Fluid was fine not burn't but discolored. I put the juice back in and am ready to :ro) ..Jim<TABLE class=tborder cellSpacing=0 cellPadding=6 width="100%" align=center border=0><TBODY><TR vAlign=top><TD class=alt1>2003 2500HD D/A CC/SB LT Juiced Isspro Pyro/Turbo everything else stock

If you can really call these trucks stock
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I just talked to the Allison shop here in town, they told me the Transynd change only increases the change recomendation to 50K instead of 25K. He also told me it does not extend the warranty from Allison but if the change and Maint. has been done by an authorized service center he has seen them cover repairs on Trans with over 100k on them.


They want $350 to do the complete flush and changeover to the Transynd. He also said changing the internal filter is a waste of money but they would do it if it was requested.