Community Forums

linjerr · 04-30-2014, 09:17 AM

I have a 2008 Gulfstream FRED MH with a 6 speed Allison Transmission. It sounds like a howl coming from the transmission when I let up on the accelerator or when it is coasting. Any experience this?

stuhly · 04-30-2014, 09:28 AM

Sounds like a U joint going south.

rhusak · 04-30-2014, 09:38 AM

Quote:

Originally Posted by linjerr

I have a 2008 Gulfstream FRED MH with a 6 speed Allison Transmission. It sounds like a howl coming from the transmission when I let up on the accelerator or when it is coasting. Any experience this?

Hi..
Sorry to hear of your issues..
I would be much more inclined to look at the rear axle.. Those kind of noises are indicative of a pinion bearing or ring and pinion issues.. Check the axle grease asap!
Ron

Skip426 · 04-30-2014, 09:45 AM

Is this a new problem , or something that's on a coach that's new to you?

Do you know the trans model number? 1000, 2500 ?
Noticeable in all forward gears or just , lower gears, 3rd and lower?
All speeds? Any noticeable vibration ?
How many miles on the RV ?

mel s · 04-30-2014, 10:13 AM

Quote:

Originally Posted by rhusak

Hi..
Sorry to hear of your issues..
I would be much more inclined to look at the rear axle.. Those kind of noises are indicative of a pinion bearing or ring and pinion issues.. Check the axle grease asap!
Ron

X2!
Seems more like a rear axle, (aka: differential), noise.

My differential has been humming loudly, (not howling), for 13 years,
(105 k miles), anytime the the accelerator is applied.

However, since the OP hears a "howl" when he "lets up on the accelerator or when it is coasting" he might have a different problem.

Mel
'96 Safari, 132k miles

**TonyDi** · 04-30-2014, 10:34 AM

When was the last time the tranny was serviced?

Muddypaws · 04-30-2014, 10:42 AM

Never having crawled under your FRED I'm only guessing: but it's possible that you have a split driveshaft. If so there may be a carrier and bearing between the two driveshaft sections. As well as 2 more U-Joints. The bearings have been known to fail. U-Joints fail all the time.

You might also have a Cardan or Double-Cardan joint in the driveshaft. If you see a rubber boot anywhere on the shaft check it for cracks or leaks. Cardan joints are a type of CV joint, they are prone to contamination related failure.

Good luck!