Acceleration Issue

[Kellenmalloy]

My wife and I just purchased a 2008 Winnebago Chalet 26ft with 20,000 miles, to drive from LA to Florida to visit my parents.

About 100 miles from Phoenix we started having an issue with the accelerator— when we get over 60-65 mph it will cut out for a second or two and and then come back in higher gear— reving up to 3500 or so. It starts out only happening occasionally and then as we drive for longer it increases in frequency to the point where it happens about every 5-10 secs and we have to stop.

The issue first happened when we hit a bumpy patch in the highway and had the generator running for the AC. I would notice it happened more often when we hit larger bumps.

The check engine light is not on and we had a computer diagnostic run on it with no returns.

Just curious if anyone knows anything about these models having issues with this or have dealt with this particular problem.

We finally found a mechanic in Phoenix that would consult us (Greulich’s) and they quoted us to replace the entire transmission! Finding mechanics that can service an RV or has availability has been impossible.

Any suggestions on where to go for service in the greater Phoenix area is welcome.

We have a 2.5 year old and are a bit stranded right now so really hoping for the best here.

Thanks in advance for any and all advice!

[ThomB]

When I read your first paragraph I went right to the transmission slipping. Then I read further. I'm not sure what chassis that rv is on. (Workhorse or Ford V10) as that's really close to when Workhorse got out of the RV chassis business. We've got a 2008 chassis V10 and haven't seen any bad transmission issues as of yet (nearly 60K miles on it).
You could try to have them just replace the transmission fluid and thicken things up a bit in there but that might just push you further into no-man's-land needing service so I'm not sure that's a real good option.


Hope you get everything sorted.

[Winterbagoal]

Transmission slippage, almost for sure. Have you checked the transmission fluid? It should be cherry red on the dip stick. Do it with the engine running, in Park. If the color is closer to brown, and/or you see any iron filings in it, it might be time to consult a transmission specialist at a Ford dealer. If it is the transmission, better to have it done right by Ford and pay a bit more.

[99dart]

You say it started after/during a rough patch of road. I would slide under the MH and inspect/push/pull on all the wire connections to the transmission. A wire may have slipped and become pinched also. I don't know if Ford is similar to a Dodge in this respect, but their older models have a TPS sensor (throttle position sensor.) When going bad it will cause the engine to rev 6-800 rpm, then be normal again for a little bit. Good luck getting back on the road.

[Kellenmalloy]

Thanks for the replies.

We sorted it out. The throttle sensors were dropping out and sending a false reading to the transmission, in turn dropping it into neutral. Replaced the entire throttle body at the mechanic and 200 miles back on the road can definitely confirm the problem isn’t happening anymore! Apparently after sitting too long without use those sensors can get wonky.

Word to the wise— the first mechanic quoted us a whole new transmission after (briefly) investigating the issue and quoted us $4k and 1 week to fix!

Note: Automotice Research in Woodland Hills (Phoenix) solved the case. These guys are super hi-tech and up front.

Greulich’s in Goodyear (also Phoenix) are the ones that gave us the terrible diagnosis. Avoid them at all costs.

[ThomB]

That had the a relief. Safe travels!

[Winterbagoal]

Thanks for posting up the resolution.
And for the service shop "reviews".
Glad I was wrong, and it was something a lot less expnsive.

[Goodspike]

I've seen worst diagnoses. Suspension and brake work for something obviously drivetrain.

My guess would have been something electrical, and to check ground points first. As noted by others, the bumps was the clue it wasn't transmission (unless something electrical with the transmission).

[99dart]

WooHoo!! I'm glad you got it. ����