Strange metallic scraping sound

[duecedodger]

Hey y'all I've been having a problem with my M35A2 and can't really figure out what is going on. When I shift on to 3rd high and let off the clutch it sounds like it's scraping or grinding kinda 4th gear is quite but 5th makes the most noise. It's ok if I have a little throttle depressed but if I let off at all it just gets louder. Any info would be great! Thanks in advance frank.

 

[gimpyrobb]

Hard to say, but I think its time to pull the top off and look inside the trans. Post up pics of anything your not sure about.

 

[duecedodger]

Ok will do, thanks for the quick reply!

 

[Floridianson]

Could it be the Throw out bearing? Take off the inspection cover on the bottom of the flywheel housing. With motor running the TB should not be spinning.

 

[duecedodger]

Ok so I took the top of the transmission off and the gears are fine. The sound now is kinda the sound of a vacuum cleaner and sometimes I can't get any of the gears to engage.

 

[m-35tom]

pull the drain plug and catch all the metal!!

 

[duecedodger]

Ok I'm planing on draining the transmission gear oil. But does the bell housing need to be drained as well?

 

[armytruck63]

The bell housing should not have the drain plug installed. The drain should be open and the drain plug is stored in a threaded hole near the drain hole. Make sure the drain is open. I know on at least some trucks the bell housing is pressurized for fording when the drain plug is installed.

 

[ATPTac]

From the odd description of the sound that you're giving, and a total stab in the dark, I would guess it sounds like a bearing(s). I'm still lost between metallic scraping and vacuum though...

 

[welldigger]

It almost sounds like the common drivetrain scream. Has it always done this or is this a new problem?

 

[duecedodger]

When I bought it, it did make some noise but not like it is now it got louder. Also the gears not engaging sometimes is new. I just let the clutch out a little and push it back in and fight to get it in gear.

 

[m-35tom]

When I bought it, it did make some noise but not like it is now it got louder. Also the gears not engaging sometimes is new. I just let the clutch out a little and push it back in and fight to get it in gear.

if you are talking about 2nd at a stop, that is normal. sounds like bad bearings, oil drain will tell.

 

[SCSG-G4]

The bell housing should not have the drain plug installed. The drain should be open and the drain plug is stored in a threaded hole near the drain hole. Make sure the drain is open. I know on at least some trucks the bell housing is pressurized for fording when the drain plug is installed.

If it's a Marine/Seabee vehicle, there may not be a place to put the drain plug. My M-36 is that way - it was factory built with the deep water fording kit installed.

 

[duecedodger]

Well I lost all gears in hi and low range. I was in 4th hi going up a hill it popped out of gear and that was it I had to coast down the hill to get off the road and now I'm waiting for a tow truck.

 

[hndrsonj]

Well I lost all gears in hi and low range. I was in 4th hi going up a hill it popped out of gear and that was it I had to coast down the hill to get off the road and now I'm waiting for a tow truck.

Why did you keep driving it?

 

[armytruck63]

If it's a Marine/Seabee vehicle, there may not be a place to put the drain plug. My M-36 is that way - it was factory built with the deep water fording kit installed.

Good to know. Thanks!

 

[FMJ]

Why did you keep driving it?

Because he wanted to buy a new transmission. . . .

 

[doghead]

It was only partially broke before today!

 

[duecedodger]

Actually it was my only vehicle at the time that's why I had to drive it. But I'm replacing the clutch parts. The gears them self are fine no broken or missing teeth so I guess I just blew the clutch.