Community Forums

jcgribks · 06-26-2022, 07:01 PM

I’ve got a 2003 Winnebago Adventurer 38g w/ 8.1 and the 1000 Allison trans. We just completed a 3500 mile trip and probably 90% of the times going uphill when I’d ether click off the overdrive or the trans shifts out of overdrive itself, I’ll get up back to 60-70 and no matter what I do the trans will not shift back into overdrive UNTIL I’m actually going down hill. I’ve tried to just let up on the throttle to get it back into overdrive and nothing. Stays in lower gear even though sometimes it’s just a very slight incline and I’m doing 65-70 @ 3,000+ rpm it will not go into over drive until I crest the incline and start downhill.
Is there a sensor or something that knows when I’ve started downhill?

Lowflyer1 · 06-27-2022, 04:40 AM

I don't see anything wrong here except the driver. Leave a day earlier or plan on arriving a day later if you have to.
If you want performance, you need to get a performance car.

jcgribks · 06-27-2022, 10:07 AM

I’m asking a question about my transmission. [Moderator Edit]

I didn’t ask about performance I asked if anyone had any answers why it won’t shift into overdrive. Has nothing to do with performance.

kennersonf · 06-27-2022, 10:24 AM

I believe your transmission is working properly. My transmission performs the same way. Once it downshifts because of a grade, even a small one such as an overpass, it won't shift back into overdrive until the motorhome is almost in a coasting mode and I have backed off on the accelerator. I hope this makes sense.

jcgribks · 06-27-2022, 12:56 PM

I do back off the accelerator trying to get it back into overdrive. I’ve dropped 10 mph backing off but it still won’t go into overdrive until I transition to down hill. Almost wish I have my 4L60e trans back even with the Autopark.

Arch Hoagland · 06-27-2022, 09:45 PM

Mine won't go into overdrive until I'm past 56 mph on level ground.

Have you changed the fluid and spin-on filter on a regular basis?

It came with Dexron iii, I suggest switching to Transynd.

SeaBreazer · 06-27-2022, 09:56 PM

I have the same trainy as you. When I first got my rig that is what mine did and still does. I have a buddy who has worked for allison until he retired with 40 years with them. I talked to him about the transmission doing this and he explained that the way the transmission is programmed to come out of overdrive on a grade to protect the transmission from slipping in overdrive and that is how it is supposed to work.