5-ton no go?! - Steel Soldiers::Military Vehicles Supersite

central67 · 11-30-2008, 22:19

Hello, this is my first post, so bear with me. I have a m51a2 5-ton dump, multi fuel that has always been very reliable. The other day went to start it after sitting for about a month and started right up, went to let the clutch out and felt like it was in Hi-5th and wouldn't move. Looked into it further and output shaft on transmission doesn't turn when clutch is let out. Did some searching on the site, didn't find anything directly related to this problem, didn't know if it had something to do with the sprag clutch or air valve in transfer case? Oh, forgot to mention could only get gear shifter to move when i moved the transfer case lever in between hi and lo and rocked the truck with excavator and brakes are free. Any thoughts would be appreciated, by the way great site with lots of info, glad i finally got a chance to post.

ARMYMAN30YearsPlus · 11-30-2008, 22:31

Welcome to the site and this sounds like a shifter issue can you take the top off and look inside? It could also be the sprag if it is locked between going forward and backward. Very hard to say without a little more information.

central67 · 11-30-2008, 22:41

Thanks for the reply, i've taken the bolts out of the shifter housing it didn't want to come out freely, i assume the long bolt on the passenger side of the housing is holding it? With it running, clutch pushed in, you can go from 1st to reverse if you play with the transfer case shifter, i could get it to do that after rocking it back and forth a little, before it would not come out of 1st.

central67 · 11-30-2008, 22:46

I was going to try and find a parts break-down for the transmission, but was wondering if maybe stuck in-between gears, shift fork or rail bent or stuck due to that i can move shifter to neutral but stiil in gear? didn't know if this was a common problem or just from sitting?

Recovry4x4 · 11-30-2008, 23:48

I've had deuce trannys get stuck in 2 gears because of bent forks. Usually was able to jack them up to relieve any tension and jerk it out of gear.

ARMYMAN30YearsPlus · 11-30-2008, 23:59

Is it possible kids where playing in it and dry shifting it to play big truck driver? That could easily have bent the forks and cause a two gear contact. I just do not see it happening from sitting.

central67 · 12-01-2008, 00:03

I'm going to try and pull the shifter and top plate out tomorrow and see if they are bent, any thing to watch out for on this trans i believe it's a spicer ?

jwaller · 12-01-2008, 23:17

Quote:

Originally Posted by Recovry4x4

I've had deuce trannys get stuck in 2 gears because of bent forks. Usually was able to jack them up to relieve any tension and jerk it out of gear.

pushing in the clutch or putting the transfer in "N" should do the same thing.

rizzo · 12-02-2008, 10:58

Quote:

Originally Posted by central67

I'm going to try and pull the shifter and top plate out tomorrow and see if they are bent, any thing to watch out for on this trans i believe it's a spicer ?

you will probably have to cut out the floor cross member that the shifters are on to get the top plate out

Scrounger · 12-02-2008, 11:22

From your post I’m not quite sure I understand the problem fully. When you released the clutch it felt like it was in a high gear. Then when you looked into it the output shaft was turning when the clutch was released. So I assume that when the truck is idling there is no power transferring thru the transmission. If you have a turning engine and no output when the transmission is in gear either a fork is damaged, maybe, but unlikely transmission shaft is broken or I suspect the center of the friction disc in the clutch has let go. If you pull the inspection cover from the bell housing and look up inside with a light and have someone operate the clutch that may reveal your problem.