From: Dave Ball (vought@msn.com)
Date: Tue Nov 19 2002 - 11:00:29 PST
Fred if it shifts normally and there is no grinding or jumping out of gear
while decelerating the transmission is probably fine.
Are you sure it is the Transmission and not the Transfercase the 201
transfercase can be loud if the output bearing is shot or if the drive
flanges are lose.
M37's use a flange bolt that has a knurled shoulder it is a press fit and if
regular bolts are used they tend to become loose with time and cause the u
joints to fail and the flanges to egg shape there holes so look close it
could be the u joints or flanges as well.
Also if the bellhousing is mounted metal on metal and missing the rubber
isolators there can be a lot more noise than normal.
You need to crawl under and give things a tighten and then change the fluids
in both gear boxes fill them will 90 wt and drive and listen again.
Gear whine is a different sound than bearing or countershaft slop.
There is a lot of gear whine in the M37 but it is mostly at 40 to 55 MPH in
direct 4th gear it should build in loudness as you accelerate until it
becomes a constant reverberating whine that oscillates at speed not a
grinding rough sound that's the same pitch at all speeds.
Try coasting and shifting to neutral does the sound change? go away? try
coasting in gear push the clutch pedal to the floor release it does the
sound change? go away?
Let us know what you find the M37 is a good truck but some times you need to
get under and talk to them face tot face.
Dave Ball
----- Original Message -----
From: <FredWC1@aol.com>
To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
Sent: Tuesday, November 19, 2002 9:45 AM
Subject: [MV] M37 trans noise
> I have a '52 M37 with the later type transmission. I would like to get
some
> idea how LOUD this transmission should be. At any speed it is really
noisey
> "growl" ect but NOT at idle. Acceleration or deceleration equally loud. It
> shifts fine up and down, the oil is clear and the magnetic drain plug is
> clear no pieces and no suspended metal in the oil. I know straight cut
gears
> are loud, BUT THIS! Some M37 people have stated that if it is under 160
> decibles it is parked! I just don't want to ruin the gearbox if something
> isin't right, but I have no point of reference. Any ideas, suggestions?
> Thanx, Fred
>
> ===Mil-Veh is a member-supported mailing list===
> To unsubscribe, send e-mail to: <mil-veh-off@mil-veh.org>
> To switch to the DIGEST mode, send e-mail to <mil-veh-digest@mil-veh.org>
> To reach a human, contact <ack@mil-veh.org>
>
This archive was generated by hypermail 2.1.4 : Wed Apr 23 2003 - 13:37:52 PDT