Author Topic: Checking Allison automatic transmission fluid - the proper way?  (Read 11581 times)

Offline plyonsMC9

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I have a 6v92 TA, Non DDEC, with the Allison transmission in my NJT MC9.  I have hot/cold levels on the dip stick.  I had always thought the way to check the fluid was hot, even idling.  Would someone please educate me on the correct way to do this?

I believe I've got the rest of the fluid checks down pretty well.  thanks all!

Best Regards, Phil
Northern Arizona / 1983 - MC9

Offline plyonsMC9

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Re: Checking Allison automatic transmission fluid - the proper way?
« Reply #1 on: May 29, 2006, 05:51:29 PM »
I should add that what I am using for "Da Book" is for the year 1989, and I have an  '83.  also, I haven't had much luck finding the proper year manual.  Even my 1989 MC9 manual seems to focus heavily on the 5 speed manual transmission.  If there's a better documentation source for things like this please let me know -

Thanks again, Phil
Northern Arizona / 1983 - MC9

Offline NJT5047

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Re: Checking Allison automatic transmission fluid - the proper way?
« Reply #2 on: May 29, 2006, 06:17:12 PM »
Check trans at normal operating temp, shift thru all the gears, place in neutral, engine idling, and the transmission oil level should be proximal to the "hot" mark.  This method is recommended over the "cold" mark check.   Don't overfill it. 
If your dipstick has a twist seal on it , be sure that the seal plug goes all the way into the dipstick tube.  If it doesn't, it will be off by the length of the rubber seal plug (about 3/4").   I assume your  dipstick is similar to mine...unscrew the "T" and the dipstick loosens...?   In any event, be sure that the dipstick is inserted all the way into the tube when checking trans oil level.   1/2" makes a big difference on oil quantity. 
You have an Allison HT740R 4 spd.  The DDEC/ATEC HT748Rs are virtually identical with exception of the electronically controlled valve body.   It may seem to shift more that 4 times, and it does, but the "extra" gears is the lockup converter . 

Cheers, JR
JR Lynch , Charlotte, NC
87 MC9, 6V92TA DDEC, HT748R ATEC

"Every government interference in the economy consists of giving an unearned benefit, extorted by force, to some men at the expense of others.”

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Offline plyonsMC9

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Re: Checking Allison automatic transmission fluid - the proper way?
« Reply #3 on: May 29, 2006, 07:57:55 PM »
Thanks JR -

That's exactly what I needed.

Kind Regards, Phil
Northern Arizona / 1983 - MC9