Trans. Fluid Question

[Dick Simonis]

Quick question on the Allison 4000,

1)  When using the keypad should the engine be on or off?

2)  I don't know what fluid I have Transynd or ATF can I tell the difference visually?

3)  Since I am a bit low (4 qts) I would like to top it off.  I know I have transnd not sure about the ATF.  Are there compatibility issues?  I will be changing the fluid after we get home anyway, just want to be safe.

Thanks for any input...right now in Alamo, NV for the evening and will attack this as soon as I finish washing bugs off.

Dick

[Gerald Farris]

Dick,
1. By the term using the key pad, if you mean checking the fluid level with the key pad, the coach should be idling in neutral on a level surface, and at operating temperature.

2. You will not be able to visually determine what fluid you have, but a fluid analysis can tell you as well as the condition.

3. There are no compatibility issues between TranSynd and Dexron III, but if you add Dexron III to a system that is running TranSynd, you will lower the change interval to the one year Dexron III schedule.

Gerald    

[Dick Simonis]

Gerald, thanks for the info.  I with the engine running the keypad says I'm 7 qts low but the dipsitick (engine off) show overfull.  What do I believe???

Thanks again for you help.

Dick

[Gerald Farris]

Dick,
The keypad is right. To check the trans fluid with the dipstick, the engine should be idling and in neutral.

Gerald

[Dick Simonis]

Again, thanks for the help.  I strongly suspect it's not trnsynd and since I had a gallon of Dexton I went ahead and used that.  Very difficult to add fluid through a horizontal tube but luckily I had picked up a little battery powered pump that worked just fine.

How the tranny got that low on fluid and why BCS didn't catch it during the PDI is bothersome. More bothersome would be if I'm losing fluid someplace but there is no evidence of leaks so I'll just keep and eye on it for the time being.  Once I get home it's going into the shop anyway for service.

[Steve Huber Co-Admin]

Dick,
Sometimes there can be a big difference between the dipstick and keypad readings. The dipstick on my Contessa would show full but the keypad indcated a quart+ low. I chose to believe the keypad.
Steve

[Edward Buker]

The keypad check uses a sensor built into the transmission at a fixed engineered location along with temperature limits where it will or will not allow a reading based on the fluid temperature accounting for fluid expansion properties. It is always right being an engineered system built into the transmission housing.

The dipstick is an added item that is rarely properly calibrated by the RV manufacturer. You should consider remarking your own to match the keypad results if you want to use it. Similar to the need for calibrating the engine dipstick which is also rarely done.

Later Ed

[Dick Simonis]

OK, the saga continues.

Added 4 qts last night so on the road today I pulled off for a rest and checked the keypad...still 7 qts low.
Got to Kingman and it still reads 7 qts low so OK, let's look at the dipstick while it nice and hot.  Now the dipstick is WAYYY over the full mark, about twice as much as last night....i'm talking 3-4" over.

Something weird is going on and I'm wondering if the 7 low wasn't really 7 high and I just misread the info.  It showed an O, than L, than -7 which I would take to mean Oil Level 7 low.

FYI, trans temp was running 200 on the flats and up to 225 on steep pulls.  No sure but it seems to track the engine oil temp within reason although that observation may not be relevant.

[Ron Johnson]

Mine has Transynd and in 7 years my gauge has never shown over 185-190 unless it has idled too long in 1st gear.

[Steve Huber Co-Admin]

Dick,

Per the Allison Manual, "0"  "L" "7" is output for "Sump Fluid Temperature too Low"

Fluid Level read out is in following format: "O" "L" "Lo" and # for quarts low.  Overfill is same format except "Hi" instead of "Lo"


To check;
-The fluid temperature is above 60°C (140°F) and below 104°C (220°F).
-The transmission is in N (Neutral).
-The vehicle has been stationary for approximately two minutes to allow the fluid to settle.
-The engine is at idle.
-The transmission output shaft is stopped.

Steve

[George H. Wall]

It may take 3-4 min. for the cycle to complete for accurate readout.  Henry

[LaMonte Monnell]

When you first push the two arrows on the keypad with enginne running in neutral and transmission oil hot, the reading should count down from 7-6-5-4-3-2-1 then OL OK, OL -whatever or over whatever.....

[Dick Simonis]

Mine sure isn't doing any of those things.  I get the 0, than the L, than a - sign, than the number.  I know the oil is well above 140 since I'd been driving for several hours and the dash temp said about 190 when I'd stopped.  Plus the dipstick was to hot to handle.  It certainly didn't take any 3-4 minutes and certainly did not count down.

Any other thoughts??

[Edward Buker]

Dick,

Are you pushing down on the two arrows together or one after the other....needs to be together. If that is not working then you should check with an Allison dealer or a dealer familiar with that system.

Later Ed

[Dick Simonis]

Ed, I-m pushing them together.  I figure it should work the same as my PT did.  We're leaving Kingman this morning and will stop in Surprise for a couple of days and staying at Happy Trails to visit some friends.  I should have time to dig into this a bit more before the final leg to Green Valley.