Saying Hello

[StephenG]

Hello everyone,
I have just purchased a 2003 Winnebago blaze. It is in really good shape and has been in covered parking most of it's life. It has 30,000 miles on it. It has a workhorse chassis that I am trying to find information on the engine and trans. The trans. is not down shifting properly out of overdrive. When you let it down shift on it's own the engine rev's very hi and then down shifts. It sounds like it slipping and then down shifts. If I allow this to happen after 3 or 4 times it puts the engine in limp mode. If I down shift manually it try's to slip until I feather the throttle then runs normally. I am trying to find out what controls the shifting of the trans.other than that it shifts and runs fine. I just returned from a 1,000 mile trip and as long as I shifted it myself it did fine. Any help would be appreciated.
I took it to a mechanic and of course he didn't drive it far enough for it to downshift out of overdrive so he said there was nothing wrong with it.

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined us!

Congrats on the new rig! Hopefully someone will be along to help with your problem.

I would suggest that you create a signature showing the make and model of your RV. It will help folks to answer questions you may have in the future.

Good luck, happy trails, and God bless!

[Jbmsr]

Originally Posted by StephenG

Hello everyone,

I have just purchased a 2003 Winnebago blaze. It is in really good shape and has been in covered parking most of it's life. It has 30,000 miles on it. It has a workhorse chassis that I am trying to find information on the engine and trans. The trans. is not down shifting properly out of overdrive. When you let it down shift on it's own the engine rev's very hi and then down shifts. It sounds like it slipping and then down shifts. If I allow this to happen after 3 or 4 times it puts the engine in limp mode. If I down shift manually it try's to slip until I feather the throttle then runs normally. I am trying to find out what controls the shifting of the trans.other than that it shifts and runs fine. I just returned from a 1,000 mile trip and as long as I shifted it myself it did fine. Any help would be appreciated.

I took it to a mechanic and of course he didn't drive it far enough for it to downshift out of overdrive so he said there was nothing wrong with it.

https://m.youtube.com/watch?v=9yN5FzWwnRU

Jesse

[Arch Hoagland]

Is it the Allison 1000 transmission?

If so the fluid (Dexron III) was supposed to be changed every 25,000 miles or every two years.

The spin-on transmission filter should have been changed at first 5,000 miles.

Do you have any of the maintenance records?

[StephenG]

I am in the process of getting the build sheet from Workhorse now. I am not sure which trans. I have the engine is a 454 gas. I will post more information when I get it. Thanks

[StephenG]

I talked to Workhorse and found that the engine is 8.1 and transmission is 4L80E.

2002 Winnebago Blaze with Workhorse chassis

[Duner]

StephenG, send a private message (PM) to "edgray" with your email address and and the VIN #. He will email you the build sheet right away. Ed has Workhorse resources and follows that section of this forum. That's where your thread should have been posted to get the most folks knowledgeable on the Workhorse chassis. When I saw that you have a "blaze" Winnie, it brought a smile to my face .... you mean "Brave".

I was wondering if the downshifting issue is when you are using the cruise control? Most all of the early WH chassis had a 5-4-3 downshift problem when starting to pull a hill and it would over-rev the engine. I would only use the cruise on flat land or if I had a good tail wind pushing me along. There was some software changes that helped this problem a lot.

Good luck,
Bill

[GypsyR]

Kind of stretching a bit maybe but this sounds a little familiar. Sort of.
4L80E's are prone to a couple of different "AFL" problems. AFL being the Actuator Feed Limit valve. It's sort of the master fluid feeder to the various shift valves. It can develop pressure leaks in various ways. The shift valves work to control gear shifts by being held in place by springs until fluid pressure is sent to them that overpowers the springs. So when fluid pressure is lacking then whichever springs start returning valves back to their starting position. Kind not very accurately oversimplifying here probably, but anyway.

In your situation I think if the AFL is leaking in 4th then the 2-3 shift valve is the one that backs off. The result is that the transmission, at least for a few seconds tries to go to first gear. it can't actually do so at 50 mph so it "overspeeds". This sounds like neutral to us. The way to catch what it is doing is to watch the computer's info of what gear it is in via a good OBD scanner that can read the datastream. If when it seems to be in neutral during the problem the computer shows it to be 1.28 ratio then that is what's happening as 1.28 is first gear.
This is all off my memory, and may not be exact in the details as the problem I was after wasn't the same as yours. And my memory isn't that good. It stuck in my head because I couldn't wrap my head around how the 2-3 shift valve could cause it to try to shift from 4 to 1.
So basically I'm saying if it were me I would be very focused on the valve body components. Sonnax has website that lists all the fixit parts they sell to fix various transmission issues. You can look there and if any symptoms they list kind of match what you are experiencing. The listings are pretty extensive. Free info. They are some of the sharpest problem solvers in the transmission industry. No actual help though, they just make parts.
Here: https://www.sonnax.com/units/457-4l80-e

Actual pro transmission help type sites want to be paid.

(Off the top of my head above except the first gear ratio. I had to look that up. I do NOT have transmission gear ratios memorized.)

[StephenG]

Yes Duner it is a Brave.Thank you and GypsyR for your feedback.