M51a2 won't downshift

[metalman99]

I just took my project M51a2 dump for it's first drive since buying it and it won't downshift while moving. I may have gotten lucky once or twice, but if i'm in 3rd, 4th or 5th and slow and try to downshift, it just grinds. Upshifting seems fine and clutch seems fine.

I'm new to these trucks, any comments would be appreciated. I'm getting ready to tear it down to the chassis and want to be sure my trans is not shot.

I've only driven one other 5 ton, a 73' M52 and it seemed to downshift fine, but not to first, I was told 1st is not syncroed.

I searched and all I found was a comment on 800 series that rpm's need to be very low to downshift.

Can anyone share their experience with this please.

 

[doghead]

It should downshift fairly easily. (except into 1st)

Is your oil up?

Is your clutch adjusted and working properly?

 

[73m819]

It should downshift fairly easily. (except into 1st)

Is your oil up?

Is your clutch adjusted and working properly?

Is your clutch draging

 

[metalman99]

Not sure about the trans fluid level (I know I should be), I'll get the materials to change that this week.

I don't think the clutch is dragging, seems to work fine.

I know a local guy with a couple of these, I'm going to call him and see if he can take a look at it.

Thanks for letting me know it should downshift easily, that's what I thought, needed to be sure.

 

[vtdeucedriver]

Get the trans oil warmed up, drain it and refill it. I had a deuce that would not down shift well (not that you really should in a multi) but doing a oil change took care of some quirky shifing problems.

 

[metalman99]

Will do.

 

[hummerjohn]

It sounds like the PTO is engaged. When you are driving with the PTO engaged it heats up slightly and creates a gear bind.

 

[metalman99]

It sounds like the PTO is engaged. When you are driving with the PTO engaged it heats up slightly and creates a gear bind.

That could very well be, it has a winch and dump bed PTO, I'll check this.