Community Forums

racer65 · 04-11-2017, 07:07 PM

ok so I have a 97 Monaco Windsor with 8.3 cummins 3060 Allison 22,000 original miles. can someone tell me why it won't go into over drive now till I'm at 75 mph and before it was like 65 and it doesn't always down shift I have sence changed fluid and filters with transyn any help will be great not sure tranny is giving any codes but don't really know how to check. and I am awsuming the economy mode is simply turned on and off by the push button.

UncleBilly · 04-11-2017, 11:13 PM

Look up videos on YT on the transmission. A few I've seen explain how the Allison works. A few on here are Allison techs, so they may leave info...

1996 Country Coach Intrigue 😜

deandec · 04-12-2017, 09:41 PM

I have the same transmission installed in 1995 and have driven it about 80,000 miles.

Overdrive is both the 5th and 6th gears as I understand.

My rig will shift to 6th gear at about 55 mph on flat land.

You may need to visit an Allison repair shop.

**CountryFit** · 04-13-2017, 10:53 AM

mine is a variant model - md3066.
i don't know or see "overdrive", just the gear 1 to 6.
same as dean's, at about 55 mph or up, it stays in 6.
matter of fact, once i choose "d", the gear pad always shows 6. it will down shift on climbing hills but it does not show what the actual gear is. the only time it shows lower than 6, is when i turn the pacbrake on it drops to gear 4. (another time is when i press arrow down to any gear).

are you experiencing or expecting that it behaves differently?

Mr_D · 04-13-2017, 10:58 AM

Quote:

Originally Posted by CountryFit

mine is a variant model - md3066.
i don't know or see "overdrive", just the gear 1 to 6.
same as dean's, at about 55 mph or up, it stays in 6.
matter of fact, once i choose "d", the gear pad always shows 6. it will down shift on climbing hills but it does not show what the actual gear is. the only time it shows lower than 6, is when i turn the pacbrake on it drops to gear 4. (another time is when i press arrow down to any gear).

are you experiencing or expecting that it behaves differently?

The single window transmission control that you have only shows the "preselected" gear not the attained gear. The two window control unit shows both. Yours is acting correctly.

Skip426 · 04-13-2017, 11:15 AM

Welcome to iRV2.

5th and 6th gears in the trans are both O/D.
You mentioned changing filters , have you changed the engine fuel filters ?
Here is why I ask.
The transmission control module , uses a program to compare the throttle position sensor ( TPS ) info , to actual engine RPM. If the TPS doesn't see the RPM it wants, compared to the TPS ; it assumes the engine is under load ( e.g. climbing a hill) and delays the up shift .
So any problem with engine power ; partially plugged fuel filter ; or bad TPS readings can cause your issue.
FYI: Here's info on the codes , your Allison can produce.

**CountryFit** · 04-13-2017, 10:29 PM

Quote:

Originally Posted by Mr_D

The single window transmission control that you have only shows the "preselected" gear not the attained gear. The two window control unit shows both. Yours is acting correctly.

thanks for assuring me on this.

Mr_D · 04-13-2017, 10:41 PM

I like to know what gear I'm in so I set my VMSpc up to show the attained gear on the '02 DSDP. The present rig has the two window control but I still set the VMS 400 CL to show it.

LPerry · 04-13-2017, 11:09 PM

Quote:

Originally Posted by Skip426

Welcome to iRV2.

5th and 6th gears in the trans are both O/D.
You mentioned changing filters , have you changed the engine fuel filters ?
Here is why I ask.
The transmission control module , uses a program to compare the throttle position sensor ( TPS ) info , to actual engine RPM. If the TPS doesn't see the RPM it wants, compared to the TPS ; it assumes the engine is under load ( e.g. climbing a hill) and delays the up shift .
So any problem with engine power ; partially plugged fuel filter ; or bad TPS readings can cause your issue.
FYI: Here's info on the codes , your Allison can produce.

I'll second this. We have all diesel vehicles and have had "transmission" issues a couple times that turned out to be low power for one reason or another.

Skip426 · 04-14-2017, 10:17 AM

Quote:

Originally Posted by Skip426

Welcome to iRV2.

If the TPS doesn't see the RPM it wants, compared to the TPS ; it assumes the engine is under load ( e.g. climbing a hill) and delays the up shift .

I didn't do a great job of re-reading this before I posted.

Should read : If the TCM ( Transmission Control Module ) doesn't see the RPM it wants, compared to the TPS;....

EDIT: I'll add I've seen plugged air filters cause this same issue too.

racer65 · 04-15-2017, 01:37 PM

can anyone let me know of location on all fuel filter to change to try and get problem resolved

MnTom · 04-15-2017, 06:56 PM

Quote:

Originally Posted by racer65

can anyone let me know of location on all fuel filter to change to try and get problem resolved

You will have one or two filters right by the engine and there is also a possibility of another filter somewhere between the tank and engine that might be an inline type filter. Unless you look hard you may miss the inline filter.