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Topic: allison leaks when RPM's above 3200 ? (Read 586 times) previous topic - next topic
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allison leaks when RPM's above 3200 ?

Yahoo Message Number: 8340
Hello all,
Just finished a trip this weekend up north, lots of big hills. Going up on I had the transmission down into 3rd and it was cranking about 4200 RPM's. Got to the top of the hill and leveled off and noticed lots of smoke coming from the pass. side. Pulled over and thought I had blown a tire. Smoke was from transmission fluid hitting the hot exaust. So I continued on and noticed that as long as the RPM's were below 3K I didn't see any smoke. I topped off the transmission with 2 qts. and drove home yesterday. Only noticed smoke once, checked and I'm down about 1/2 qt. now. Anyone else have this issue ?
Thanks

Re: allison leaks when RPM's above 3200 ?

Reply #1 –
Yahoo Message Number: 8342
You must have a gas model to get those RPM's. I do the best I can to keep RPM's below 3,000.
Best
Ron Hall

Re: allison leaks when RPM's above 3200 ?

Reply #2 –
Yahoo Message Number: 8343
Yup 8.1 gasser, I left that out.
also the first time it was leaking fluid from above the back of the pan and making a small pool. On the way back it wasn't leaking that bad.. The rig only has 8K miles total, so maybe a dried out gasket ?

Re: allison leaks when RPM's above 3200 ?

Reply #3 –
Yahoo Message Number: 8344
4200 is pretty high - You might have just got it to hot / boiled over?...I'm at about 3300 RPM when pulling a 24ft 6k trailer up a grade doing about 45 or so.


From: deputybubba2
To: KodiakChassisClassC@yahoogroups.com
Sent: Wednesday, January 18, 2012 3:15 PM
Subject: [KodiakChassisClassC] Re: allison leaks when RPM's above 3200 ?


Yup 8.1 gasser, I left that out.
also the first time it was leaking fluid from above the back of the pan and making a small pool. On the way back it wasn't leaking that bad.. The rig only has 8K miles total, so maybe a dried out gasket ?

Re: allison leaks when RPM's above 3200 ?

Reply #4 –
Yahoo Message Number: 8345
Had the same thing happen, it would only leak under higher rpms. Turned out to be when gm put the shift lever in, they didn't get a good seal. Depending on when you bought it, Allison will warrant the fix. Took mine to a truck shop that did warranty work on Allison trans.

Re: allison leaks when RPM's above 3200 ?

Reply #5 –
Yahoo Message Number: 8346
Had the same thing happen, it would only leak under higher rpms. Turned out to be when gm put the shift lever in, they didn't get a good seal. Depending on when you bought it, Allison will warrant the fix. Took mine to a truck shop that did warranty work on Allison trans.

Re: allison leaks when RPM's above 3200 ?

Reply #7 –
Yahoo Message Number: 8395
Dropped of at allison dealer last night.
They say GM has a directive that on the 8.1 gasser they have to drill a 'vent' hole in the dipstick tube above and below the gasket.
so looks like about a $500 repair.

Anyone know if this was still under GM warranty would this be repaired for free ? Just curious if I should write to GM about it.

Thanks, glad it wasn't more serious.

Re: allison leaks when RPM's above 3200 ?

Reply #8 –
Yahoo Message Number: 8396
Quote
Quote

Dropped of at allison dealer last night.
They say GM has a directive that on the 8.1 gasser they have to drill a 'vent' hole in the dipstick tube above and below the gasket.


What year is yours? Mine is a late 2007 and have never seen it do that.

Take care,
Greg

Quote

 

Re: allison leaks when RPM's above 3200 ?

Reply #9 –
Yahoo Message Number: 8397
Mine is a 06, it was a bulletin from GM techs not a directive if that makes a difference. I had an allison in my pickup but it was diesel and never got up in the RPM's like the gasser can. When it happened I was down into 3rd gear climbing a long hill, doing about 50 MPH or so.
Hope this helps.