Date: Wed, 14 Jan 2009 21:26:50 -0800
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Transmission Noise ?
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Well !
How kind, considerate, and helpful that you've answered my questions so
thoroughly - what a pleasure !
ok.......a cyclic donning......cyclic any time the rear wheels are turning.
Does the frequency of the cyclic sound speed up with more road speed ? -
probably I'd guess.
my hunch is towards either rear wheel bearings or the Ring and Pinion, or
the side bearings .........the large side bearings that support the ring
gear......or ring gear holder.
I would tend to lean away from thinking it's the rear wheel bearings if both
sides have been done, and both sides checked.
Seems unlikely there would be a problem with both sides. I suppose faulty
new parts or workmanship is possible. Fwiw......I've never had a problem
with them after doing them.........but I also wonder if the quality of parts
has gone down from say, 8 years ago.
another thing making me lean toward the transmission is the high miles on
it. And worn side bearings in the ring and pinion area matches the symptom.
Be nice if you had another trans to try.
oh.............all right.........here is a listening test you can do in
flight. Have someone else drive so it's doing the noise.........and put
your ear right on the shift knob......
or your listening stick.
If the cyclic droning sound is there at the shift knob, from sounds coming
up the shift linkage..........again, my vote is 'trans' .....especially the
side bearings at the R & P......or the R & P gears.
there's no way you can reach much to listen to while driving with the engine
cover removed.....plus engine noise and road noise would be a lot.
I suppose you could get a thin listening stick onto the top of the
trans..........that might work.
if it does it at say 40 mph 'in the air' .......jacked up and
running.........if it makes the noise under those circumstances, you should
be able to isolate it.
it's really fun to put your listening stick on various things......
and a baseball bat, if that's what you used, is too big. You can hear
injectors clicking, listen to the alternator bearings, listen to the
distributor turning......
listen to the fuel pump internally ...........anything you can think of that
moves or flows......you can listen to it very nicely this way. I happen to
have some long slender teak wooden rods.........they work great. I'd think
the denser the wood the better it might be at transmitting noises.
And ..........there are some things that you just can not identify until
taking them apart.
I'm leaning toward the trans...........and if it'll do it running at 40 mph
or even faster in the air..........you should be able to find it.
try that listening to the shift linkage going down the road too.
The shift linkage makes a great noise transmitter for transmission noises
sometimes.
Awaiting your next report.
Tanks again for the comprehensive answers.........Sometimes it feels like .I
don't see all that much intelligent expression and cooperation on internet
groups .......
some for sure, but it's not like it's 'the normal thing' . Like you
know...........someone that interacts and writes with enough information for
the other party or members to actually understand them easily ! Soooo nice
when that happens. Pleasure to read your intelligent and well-written
responses.
I'm thinking trans right now.
Scott
----- Original Message -----
From: "Walter Houle" <whoule@ECSCONTROLS.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, January 14, 2009 8:11 PM
Subject: Re: Transmission Noise ?
Sorry, the original thread got really long so I clipped off a lot of it.
Here's some quick answers. Scott's questions are in quotes:
"describe the noise and WHEN it does it" - It's a steady droning that occurs
at 30 mph and over. Its as loud as the motor is between 30 to 45 mph.
"And how old or new is the transmission?" - It's the original one from 1985.
210,000 miles on it. No service was ever done on it except for infrequent
oil changes. Now using Redline MT-90 for the last 3,000 miles.
"why are you sure it's in the rear, and not the front?" - It just sounds
like it is. The shop also says its in the rear. We spun the front wheels in
the air and they felt fine. Those bearings were just repacked, not replaced.
"type of noise..........whirring, rumbling, high pitched whine, etc?" - It's
a steady drone, no rumbling. At speeds over 55 mph it resonates with the
engine noise and goes wah wah wah.
"if you have not actually seen inside your CV joints" - I installed 4 new
Lobros a week or so and 150 miles before the rear wheel bearings were
replaced. I used a 90G grease tube from Van-Café in each, plus I shot some
more in with a needle afterwards.
"WHEN did this noise start?" - On a 200 mile trip immediately after the
bearings were installed.
"did it gradually develop, or did it start more suddenly?" - Gradually. I
noticed the wah wah sound after the first 50 miles on the freeway and its
gotten slightly louder over time.
"after what work or changes to the van?" - The new CVs were in for approx.
150 miles and they were always quiet. Then the front wheel bearings were
repacked and new rears were installed. The noise started 50 miles after the
bearing work.
"Does it make the noise coasting down the road, engine off, trans in
neutral?" - Absolutely, In neutral, clutch in, clutch out, engine off,
swerving side to side all have no effect on it.
I have a hard time suspecting the transmission or the CVs because it started
right after the rear wheel bearings were installed but I can't be sure. Is
it safe to do the listening stick test sitting on the back seat with the
engine cover off and someone driving??
Thanks for your interest in this.
Walter
85 Vanagon
-----Original Message-----
From: Scott Daniel - Turbovans [mailto:scottdaniel@turbovans.com]
Sent: Wednesday, January 14, 2009 1:16 PM
To: Walter Houle; vanagon@GERRY.VANAGON.COM
Subject: Re: Transmission Noise ?
hi there,
sure, try some ordinary cheaper gear oil as a test. I don't see how that
could hurt.
It's been a while......... describe the noise and WHEN it does it, again,
please.
And how old or new is the transmission ?
and why are you sure it's in the rear, and not the front, this noise ?
also the type of noise..........whirring, rumbling, high pitched whine, etc.
on listening to rear wheel bearings.....'in the air' .
first I do it with the tires and wheels on,
then with those removed,
and finally with the rear drums removed.
also.....if you have not actually seen inside your CV joints.....all 4 of
them......
you really need to know that those are not dry, or excessively loose.
I've seen many, many dry CV joints.
Not saying I think that's where the issue is.........just that you need to
be sure that's where it is not.
oh yes........WHEN did this noise start ?
did it gradually develop, or did it start more suddenly, and if so, after
what work or changes to the van ?
Does it make the noise coasting down the road , engine off, trans in neutral
?
Answers to those questions would help us help you.
thanks, Scott
----- Original Message -----
From: "Walter Houle" <whoule@ecscontrols.com>
To: <vanagon@GERRY.VANAGON.COM>
Cc: "Scott Daniel - Turbovans" <scottdaniel@turbovans.com>
Sent: Tuesday, January 13, 2009 5:49 PM
Subject: RE: Transmission Noise ?
Here's the latest: I did the stethoscope trick last week using a
Louisville Slugger for an earpiece. It worked great, but I didn't hear
anything unusual. I heard what I thought were normal mechanical gear
meshing sounds. Maybe they sounded a tiny bit rough or gravelly but they
didn't get louder or worse with increasing axle rpm. They were
consistent on either side of the van, too. So, nothing conclusive.
Next I visited the shop that installed the new rear wheel bearings. They
were nice enough to tear both sides down and re-inspect everything. They
didn't find anything there either. The bearings looked fine, no scoring
or bluing, and the grease was very clean. So again, nothing conclusive.
However, the noise is still there. One thought is the bearings
themselves. They're SKF. Is there any reason to believe this brand runs
noisier than the original OEM ones? If so, we could try a different
brand of bearing, like FAG.
One other recommendation I heard is to temporarily swap out the Redline
MT90 with some heavy Valvoline stuff and to see if that damps out the
noise. If it does, then I can suspect a worn transmission. Is this a
safe test to do?
Thanks,
Walter
1985 Vanagon MT
