Noise need help diagnosing!

[david1]

On our trip and when I slow down I hear a click clack clack clack clack clack clack the coach has been driving great strong 65 miles an hour. When I
put it in neutral and the coach slows down, the noise comes back, when I accelerate even a little bit the clacking goes away. I checked to make sure I
didn't have a lug nut floating around in the hubcap, and I've taken a temperature on the bearings and they are fine. I'm thinking a CV joint or
transmission is about to explode!? I got underneath no grease no split boots pulled out all of the joints everything seemed fine wondering if it's a
governor gear? What are your suggestions If? If you guys could cross post this on the other GMC groups that be great thanks,again not sure any
thoughts?

Update 1- not the hub caps
Update 2 - I disconnected the intermediate speedometer cable from the transmission because the needle was bouncing under 15-20 mph, didn't impact the
issue.
Update 3 - at Cherry Hill Park campground in Maryland outside DC
Update 3.5 - coach idles fine no noise and the noise doesn't seem to be related to engine RPM at rest.

Dave
(David Martin on Facebook)
--
'78 Palm Beach. car nut new to RV'ing 26 ft. 403 rebuilt in 2018, rebuilt tranny in 2014, Dave Lenzi knuckles & hubs, yada yada yada OEM chromed
wheels,Green Brady Bunch stock

 

[Matt Colie]

> On our trip and when I slow down I hear a click clack clack clack clack clack clack the coach has been driving great strong 65 miles an hour. When
> I put it in neutral and the coach slows down, the noise comes back, when I accelerate even a little bit the clacking goes away. I checked to make
> sure I didn't have a lug nut floating around in the hubcap, and I've taken a temperature on the bearings and they are fine. I'm thinking a CV joint
> or transmission is about to explode!? I got underneath no grease no split boots pulled out all of the joints everything seemed fine wondering if
> it's a governor gear? What are your suggestions If? If you guys could cross post this on the other GMC groups that be great thanks,again not sure
> any thoughts?
>
> Update 1- not the hub caps
> Update 2 - I disconnected the intermediate speedometer cable from the transmission because the needle was bouncing under 15-20 mph, didn't impact
> the issue.
> Update 3 - at Cherry Hill Park campground in Maryland outside DC
> Update 3.5 - coach idles fine no noise and the noise doesn't seem to be related to engine RPM at rest.
>
> Dave
> (David Martin on Facebook)

Dave,

Silversnort has a good start, but without hearing it, I could also sort of fit that to a loose torque converter or flex plate. Update 3.5 makes this
less much likely.

Fortunately, there is a lower cover than can come off easily so you can put a wrench on the converters fasteners. Now that two are possibly
eliminated, if you didn't find a good bet, try shaking the torque converter. It should not move at all. If the flex plate screws are loose, that is
a Big Issue. Let's hope you found it before this.

If you did not, come on back, there are ways the flex plate can be managed. It will not be fun or easy.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

 

[david1]

So I spoke to Ken Frey who as you all know is retiring,and he suggested getting the front end up in the air and have some at the driver seat try to
recreate the issue while I was under the coach, and we were able to do that. The noise was coming from the final drive. And there is about 1/4" play
up and down on the driver's side output shaft. When moved up and down a clunk and excessive play was evident. So I stopped there.. Ken suggested I
don't drive it as I could cause damage to the transmission. A local GMC'er back home has a used unit and my son is driving it down. Ken Frey has a
rebuilt one when he's back at his shop on Monday so I can have my son pick one up from Ken as back up plan. So we have a plan A and Plan B.
Fingers crossed.
- Dave

--
'78 Palm Beach. car nut new to RV'ing 26 ft. 403 rebuilt in 2018, rebuilt tranny in 2014, Dave Lenzi knuckles & hubs, yada yada yada OEM chromed
wheels,Green Brady Bunch stock

 

[Richard RV]

It's good to have friends and family. Glad you caught it in time.
Good luck, Dave!

Richard
--
'77 Birchaven TZE...777;
'76 Palm Beach with 18,477 verified miles;
‘76 Edgemonte

 

[john r. lebetski]

You can have Cinnabar ship you a pre loaded and setup 3.42 final and get a core charge back for your old one
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[jim kanomata1]

Check your inner constant vel connection at the final drive. 6 bolts on
each side of final drive.

On Sun, Mar 28, 2021 at 7:03 AM John R. Lebetski
wrote:

> You can have Cinnabar ship you a pre loaded and setup 3.42 final and get a
> core charge back for your old one
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[jim kanomata1]

It is standard for the driver side of final to have slop as there is no
load on the spider gear.
The noise is not coming from there,

> Check your inner constant vel connection at the final drive. 6 bolts on
> each side of final drive.
>
> On Sun, Mar 28, 2021 at 7:03 AM John R. Lebetski

>
>> You can have Cinnabar ship you a pre loaded and setup 3.42 final and get
>> a core charge back for your old one
>> --
>> John Lebetski
>> Woodstock, IL
>> 77 Eleganza II
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk
> http://www.gmcrvparts.com
> 1-800-752-7502
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[Tom Katzenberger]

Dave,

I am 1 hour to the north, in Baltimore. If you need to rebuild the CV, I have new boots I just bought from Jim K. that came in this week. I can pick
you up after work and we can use my new parts to rebuild the CV at my Shop. I have 3 GMC's at the shop in various conditions.

Let me know if I can be of assistance?

Take care,
Tom
--
Tom & Oki Katzenberger,
Kingsville, Maryland,
1977 23' Birchaven, 455 C.I.D.

 

[david1]

Well with the help of my awesome Son Sam Servati who drove over 7 hours and brought his mobile GMC Repair Truck packed with His whole tool chest,
bench grinder, power tools, chemicals, and more. Plus two final drives, which we had the pick of so we picked the one that we thought had a little
more life left in it. We.pulled the final drive and found that the pinion gear had lost several teeth and chunks where in the Pan. So the diagnosis of
the final drive was correct. We gotthe replacemenr in on the second try! Never hurt the new gasket as we took the advice of many in the community. My
son even had a spare tranny and torque converter, stub axle, cv axle, two gaskets, and assortment of axle bolts all from the gracious mister Ernest
Dankert a member of the Heritage Cruisers. I was tempted to take that transmission and keep it in the back as a spare for the rest of the trip!! - but
it's going back to Rochester. Thanks also to Ken Frey for the diagnosis advice, and Jonathan Roche, Ray Erspamer, and others who offered advice and
assistance. We are back on the road again!

Dave
--
'78 Palm Beach. car nut new to RV'ing 26 ft. 403 rebuilt in 2018, rebuilt tranny in 2014, Dave Lenzi knuckles & hubs, yada yada yada OEM chromed
wheels,Green Brady Bunch stock

 

[david1]

Thanks Tom. The replacement final drive got us to South Carolina and I'm hoping back home to Western New York. But if I have any issues as I pass
through the Maryland area on Sunday or Monday I will reach out to you.
--
'78 Palm Beach. car nut new to RV'ing 26 ft. 403 rebuilt in 2018, rebuilt tranny in 2014, Dave Lenzi knuckles & hubs, yada yada yada OEM chromed
wheels,Green Brady Bunch stock