Gear noise

[wilco]

We just got the new exhaust manifold gasket on the CCKW 352 and it is much quieter.
We now can hear a lot of gear noise in the tranny and Xfer case.
Is ths normal for a CCKW?
They both have new 80w90 gear lube in them..

Thanks, Wilco

 

[paulfarber]

To some gear noise is loud, to other not so much. There are some insulated mounts that may have failed and may be shorting the vibrations to the frame/cab.

The TM9 shows them.

Personally I notice the gear noise.. much worse in 6x6.... esp when I have the bed off. In the jeep I don't hear it so much, but the CCKW, yeah.

 

[greasemog]

My '42 was very loud when I bought it and I kept wondering if it was normal. Then I found the front transfer case idler shaft bearing had exploded and the shaft was jumping around and cracked the housing. The oil wouldn't drain out of my case because there was so much metal inside of it so it was pretty obvious. Put a new used transfer case in it and the drivetrain is much quieter. Try running it through its gears with the transfer case in neutral, maybe you can pinpoint the noise between the two assemblies and fix it or live with it. I'm guessing if you are concerned enough to post it it isn't normal.

 

[paulfarber]

Gear noise can increase as the gears wear, bearing wear, shafts get worn. At best your truck has 20 years on the gearbox (depending on what type of reconditioning it went through while in storage or use).

Worse is that you have a gearbox with 60+ years on it, and its simply worn out.

Nothing about the gear box is specific to CCKWs... look at the oil, does it smell funny? Are there bits of metal in it? You know, general mechanical stuff.

Used gearboxes are plentiful. I have 2 (I don't know how I got them... they were just there one day, and a transfer case). But they are still used and the owner most likely has no way of knowing how much life is left in them.

Most of the gears are available from Rex Ward (UK) if you wish to do a proper rebuild, but it will be spendy. He does rebuild gearboxes but charges 550£ plus a core charge.

Thats about a grand all said and done.

You could get a used gearbox for approx $250 and refurbish it... but I can still see $250-500 in parts (bearings, shafts, normal wear parts) or plop it in and hope for the best.

I know of no one who has posted than they rebuilt a gear box either.... you think at some point it would have come up.

 

[paulfarber]

Here's what the TM9 has to say about it:

63. TRANSMISSION.
a. Excessive Noise.
(1) Noise which seemingly comes from the transmission may be
caused by another assembly such as axle, transfer case, propeller
shaft universal joint, or clutch; therefore, before replacing the transmission
due to noise, make sure that difficulty does not exist elsewhere.
(2) Improper or insufficient lubricant may cause transmission
noise. Change or add lubricant as directed in Section VIII.
(3) Transmission noise may be caused by gears or bearings being
worn, broken, or loose on shafts. These causes require replacing the
transmission with a new or rebuilt unit (pars. 154 and 155).
(4) A noisy condition in the power take-off will reflect through
the transmission. Check power take-off mounting nuts and tighten
as necessary. Incorrect number of gaskets between power take-off
and transmission will cause noise. Install correct number of gaskets
(par. 157 or 15. Excessively worn power take-off gears necessitate
replacing the power take-off assembly (par.,'157 or 15.

If you ever need a quick TM9-801 fix I have a simple search on line
Online TM9 Search

The entire TM9-801 is available online from my site:

www.tm9-801.com TM9-801 Truck 2 1/2 TON 6x6 GMC CCKW-352 & 353