# Allison 3000 series trans. Models B300, B400 & T



## milford57 (Dec 1, 2009)

Has anyone experienced water intrusion and or damage to their Allison 3000 series Trans. Models B300, B400 & T?  If so - what seemed to be the problem and how did you fix it?


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## LEN (Dec 1, 2009)

Re: Allison 3000 series trans. Models B300, B400 & T

Welcome,

The only problem I have heard of is coolant in the trans, and that came from the radiator/trans cooler combo that developed crack between the two and allow coolant into the trans-fluid. The cure is to replace the cooler. Some sealed the radiator and then put a separate trans cooler on to keep the cost down. Radiator trans cooler is very pricey.

LEN


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## dbarton291 (Dec 1, 2009)

RE: Allison 3000 series trans. Models B300, B400 & T



> milford57 - 12/1/2009  2:14 PM
> 
> Has anyone experienced water intrusion and or damage to their Allison 3000 series Trans. Models B300, B400 & T?  If so - what seemed to be the problem and how did you fix it?



Are you experiencing water in the trans, or engine coolant?  The two have very different causes and remedies.  My experience is the same as Len's.  Most of the time, it's a problem in the cooler in which anti-freeze is bleeding over from the engine cooling system into the trans.

Glycol attacks the bonding of the friction material in the transmission clutch plates that holds the friction material to the steel core.  Once glycol enters the trans, the best remedy is to fix the leak, then have all the friction clutch plates, seals and gaskets in the trans replaced.

I did see one tour coach in which the rear restroom had a leak and poured water over the transmission breather and into the trans.  

There have been a few vehicles made where the top of the dipstick tube is in a place which exposes this area to melting snow, rain, etc.  If the dipstick is loose, water gets in.

Water or engine coolant in the trans will turn the normally red trans fluid a pinkish color once enough gets in there.

There are test kits that will detect glycol and help diagnose the difference between water intrusion and engine coolant.

I hope this helps.


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## H2H1 (Dec 1, 2009)

Re: Allison 3000 series trans. Models B300, B400 & T

that is great news, where does one find the kit to test the fluid with


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## dbarton291 (Dec 2, 2009)

Re: Allison 3000 series trans. Models B300, B400 & T



> H2H1 - 12/1/2009  11:14 PM
> 
> that is great news, where does one find the kit to test the fluid with



http://www.aviceda.com/nelco/

http://www.espchemicals.com/product...5358335&ObjectGroup_ID=4796&Category_ID2=1200

Oil analysis also detects the presence and level of water and glycol.  For those you have to take an oil sample and send it to the lab.  Google oil analysis services and you'll get a bunch of them.


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## milford57 (Dec 18, 2009)

Re: Allison 3000 series trans. Models B300, B400 & T

LEN, DBARTON291 & HSH1 - Thank you so much for taking the time to reply with excellent information.  Most Kind Regards / milford57


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## dbarton291 (Dec 18, 2009)

Re: Allison 3000 series trans. Models B300, B400 & T



> milford57 - 12/18/2009  1:39 PM
> 
> LEN, DBARTON291 & HSH1 - Thank you so much for taking the time to reply with excellent information.  Most Kind Regards / milford57



My pleasure.  Doing something for somebody else helps keep me outta the pool hall!  Merry Christmas and Happy New Year!


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