Allison Trans Flush?

[local392-496]

Do I need to have my Allison flushed or just change the fluid and filter regularly? I heard that your not suppose to have them flushed, but how can you get all the old fluid out it you dont?

[GMCWAYNE]

Do I need to have my Allison flushed or just change the fluid and filter regularly? I heard that your not suppose to have them flushed, but how can you get all the old fluid out it you dont?

 

<{POST_SNAPBACK}>

 

 

 

You should not power flush the allison.

You can pump out the old fluid by doing the following. Drop the pan and change the internal filter, clean pan and magnet. Change the spin on filter, don't forget to clean and replace the donut magnet on the spin on. Refill the pan with fresh fluid. Remove the return line from the tranny cooler. Attach a piece of hose or tubing the the return line and route it into a drain pan. Start the truck and Let the tranny draw new fluid out of the tranny pan while pumping old fluid from the return line. Only pump out about 4 quarts. Kill the engine. Refill trans and repeat 2 more times. Replace the return line, top off the trans, run the tranny up to at least 160 degrees and check level. You should have 5 gallons of fluid on hand for this method.

You can also do what I did. Drop the pan, change the internal filter, clean the magnet and pan, replace, change the spin on. Fill the trans with new fluid and check. This will use about 9 quarts. Then down the road, Drain the pan and change the spin on. This will use about 6.5 quarts. Do that again and you will be at least 90% new fluid while still using almost 5 gallons.

[dewfpo]

Do I need to have my Allison flushed or just change the fluid and filter regularly? I heard that your not suppose to have them flushed, but how can you get all the old fluid out it you dont?

 

<{POST_SNAPBACK}>

 

 

 

You should not power flush the allison.

You can pump out the old fluid by doing the following. Drop the pan and change the internal filter, clean pan and magnet. Change the spin on filter, don't forget to clean and replace the donut magnet on the spin on. Refill the pan with fresh fluid. Remove the return line from the tranny cooler. Attach a piece of hose or tubing the the return line and route it into a drain pan. Start the truck and Let the tranny draw new fluid out of the tranny pan while pumping old fluid from the return line. Only pump out about 4 quarts. Kill the engine. Refill trans and repeat 2 more times. Replace the return line, top off the trans, run the tranny up to at least 160 degrees and check level. You should have 5 gallons of fluid on hand for this method.

You can also do what I did. Drop the pan, change the internal filter, clean the magnet and pan, replace, change the spin on. Fill the trans with new fluid and check. This will use about 9 quarts. Then down the road, Drain the pan and change the spin on. This will use about 6.5 quarts. Do that again and you will be at least 90% new fluid while still using almost 5 gallons.

 

<{POST_SNAPBACK}>

 

 

 

 

X2

 

Drain and refill or home flush as described above. No power flush. Suggest synthetic DexIII or Transynd.

 

DEWFPO

[Black02Silverado]

Do I need to have my Allison flushed or just change the fluid and filter regularly? I heard that your not suppose to have them flushed, but how can you get all the old fluid out it you dont?

 

 

 

 

 

You should not power flush the allison.

You can pump out the old fluid by doing the following. Drop the pan and change the internal filter, clean pan and magnet. Change the spin on filter, don't forget to clean and replace the donut magnet on the spin on. Refill the pan with fresh fluid. Remove the return line from the tranny cooler. Attach a piece of hose or tubing the the return line and route it into a drain pan. Start the truck and Let the tranny draw new fluid out of the tranny pan while pumping old fluid from the return line. Only pump out about 4 quarts. Kill the engine. Refill trans and repeat 2 more times. Replace the return line, top off the trans, run the tranny up to at least 160 degrees and check level. You should have 5 gallons of fluid on hand for this method.

You can also do what I did. Drop the pan, change the internal filter, clean the magnet and pan, replace, change the spin on. Fill the trans with new fluid and check. This will use about 9 quarts. Then down the road, Drain the pan and change the spin on. This will use about 6.5 quarts. Do that again and you will be at least 90% new fluid while still using almost 5 gallons.

 

 

 

 

 

 

X2

 

Drain and refill or home flush as described above. No power flush. Suggest synthetic DexIII or Transynd.

 

DEWFPO

 

 

 

 

 

 

Above method works great. I also suggest to those that can't afford the major investment in 5 gallons of fluid to do the pan and filter change and just change out the fluid at your next 3 regular scheduled engine oil changes. It helps keep the cost down as well as does not put a shock to the transmission with the new fluid if it has high miles on it.

 

The spin on filter rocks, to bad they don't include one for all auto transmissions.

[ThorsHD]

thanks

[Paulie G]

Do I need to have my Allison flushed or just change the fluid and filter regularly? I heard that your not suppose to have them flushed, but how can you get all the old fluid out it you dont?

 

<{POST_SNAPBACK}>

 

 

 

You should not power flush the allison.

You can pump out the old fluid by doing the following. Drop the pan and change the internal filter, clean pan and magnet. Change the spin on filter, don't forget to clean and replace the donut magnet on the spin on. Refill the pan with fresh fluid. Remove the return line from the tranny cooler. Attach a piece of hose or tubing the the return line and route it into a drain pan. Start the truck and Let the tranny draw new fluid out of the tranny pan while pumping old fluid from the return line. Only pump out about 4 quarts. Kill the engine. Refill trans and repeat 2 more times. Replace the return line, top off the trans, run the tranny up to at least 160 degrees and check level. You should have 5 gallons of fluid on hand for this method.

You can also do what I did. Drop the pan, change the internal filter, clean the magnet and pan, replace, change the spin on. Fill the trans with new fluid and check. This will use about 9 quarts. Then down the road, Drain the pan and change the spin on. This will use about 6.5 quarts. Do that again and you will be at least 90% new fluid while still using almost 5 gallons.

 

 

Why does this take so much fluid?

 

I'm going to change to mobile-1 this weekend and I'm wondering why you wouldn't just need a few extra quarts around.

 

also is it important to change the internal filter when doing a fluid swap? I would rather not drop the pan if I don't have to.

 

(2001 allison 5 speed 66k)