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vettenuts · 08-12-2019, 01:35 PM

Drained my fluid yesterday and refilled with the same amount. A cold check showed overfull. Drained 2 quarts and showed low so started adding 1 pint at a time until I replaced approximately 1 quart. Unfortunately, engine and transmission were getting warm and the fluid level was rising so I called it a day and checked cold this morning. Showed about 1/8” below cold band lower line so I added another pint and rechecked a while later. Noting the coolant level was still up due to running motor earlier, I now found the fluid 3/8” above the upper cold band line.

Kind of feel like I am chasing my tail here. Does anyone know how long you can run the system before a cold check becomes inaccurate?

I have now called it a day and will recheck in the morning when I know it’s truly cold.

Arch Hoagland · 08-12-2019, 02:49 PM

I never check my transmission fluid when cold. Allison says check it when it is hot.

I'd suggest getting it hot and then check it. Go from there.

lwmcguire · 08-12-2019, 04:10 PM

Don't know your model but most check warm with the control console per instructions

vettenuts · 08-12-2019, 05:30 PM

Manual is very specific, it must fall within the cold range when checked cold before it can be driven after a fluid change. Then it can be checked hot. So I am trying to get that correct level before driving the coach.

CJ7365 · 08-12-2019, 05:47 PM

Although I am not an Allison mechanic I would hardly think that if the cold level is 1/8" low or 3/8 high would cause any damage, I would run it, and get that trans fluid hot and do a hot check

Ted Lambert · 08-12-2019, 06:03 PM

Quote:

Originally Posted by CJ7365

Although I am not an Allison mechanic I would hardly think that if the cold level is 1/8" low or 3/8 high would cause any damage, I would run it, and get that trans fluid hot and do a hot check

Yes I worked on Allison's stall it out at fairly high RPM and get the temp out in the operating range than check it.

When you stall it out you do no damage if your clutch packs don't slip all is fine.
Stall it out in increments such as
In gear.......half of running rpm for about 2 min
In neutral...Half of running RPM for about 10-15 seconds
Repeat the above till in operating range.

If you are unfamiliar with a stall test that is the safe way.
If you are still uncomfortable than take it to a dealer.

Note
Make sure you run it through all the gears if possible first in order to insure all components are charged with oil.

Arch Hoagland · 08-12-2019, 09:56 PM

Is that an Allison 1000 transmission?

vettenuts · 08-13-2019, 05:49 AM

Quote:

Originally Posted by Arch Hoagland

Is that an Allison 1000 transmission?

No, 2100MH although the 1000 follows the same procedure after a fluid change.

vettenuts · 08-13-2019, 07:43 AM

Got the cold level squared away this morning. Once the weather clears out tomorrow hopefully I can run the coach and do my hot check.

bowpulpit · 08-13-2019, 02:11 PM

When doing a hot level check.....can you start the engine, leave the transmission in neutral and check level after 10-15 minutes or do you have to drive the coach for a few miles then check the level?

Arch Hoagland · 08-13-2019, 03:49 PM

Quote:

Originally Posted by bowpulpit

When doing a hot level check.....can you start the engine, leave the transmission in neutral and check level after 10-15 minutes or do you have to drive the coach for a few miles then check the level?

I've done it both ways and it is the same.

vettenuts · 08-14-2019, 06:35 AM

The manual says to run for an hour and provides a temperature range in the sump and at a location I can’t access internally. I have a laser temperature gauge so I plan to run for about 25 miles (coach needs a run anyhow) and then get the sump temperature. We went for a ride yesterday in the car and the local elementary school has an area that looks to be very level. I am hoping to check it there rather than driving up on top of the wood ramps I used to get it level for the fluid change and cold check.

Dougsee3 · 08-14-2019, 09:16 AM

Quote:

Originally Posted by vettenuts

The manual says to run for an hour and provides a temperature range in the sump and at a location I can’t access internally. I have a laser temperature gauge so I plan to run for about 25 miles (coach needs a run anyhow) and then get the sump temperature. We went for a ride yesterday in the car and the local elementary school has an area that looks to be very level. I am hoping to check it there rather than driving up on top of the wood ramps I used to get it level for the fluid change and cold check.

I just use the motorhome level system. I check it once in a while on trips at rest stops just leave running and use auto level on the motor home. It makes checking it consistent always.

vettenuts · 08-14-2019, 11:16 AM

Quote:

Originally Posted by Dougsee3

I just use the motorhome level system. I check it once in a while on trips at rest stops just leave running and use auto level on the motor home. It makes checking it consistent always.

Doesn’t it alarm the whole time? Mine sets off the jacks down alarm when the engine is running.