1941Dodge
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I apologize in advance if this is nothing new, but I have searched the past couple of nights every which way I know to find a similar situation. I will attempt...poorly...to make it short. Ive lurked around here for more than 10 years but have never really posted much so please consider me a noob.
I "maintain" two 813 5 tons for a county Fire Department. Last year I lost front drive on one of them and found out while trying to drive up a rather steep incline after extinguishing a pole fire. I believe it was working when I drove in since there was a similar slope I had to climb when going in to reach the fire. No bang, pop, or any other indicator that something had failed, just couldnt make it up coming out and the Chief told me the front wheels werent turning.
Long story short, everything I know about these trucks, Ive learned the hard way...because something broke or isnt working. Im a volunteer with acceptable mechanical knowledge and understanding but by no means am I a mechanic. Im a Land Surveyor by trade.
After calling around to find out that none of the reasonably local heavy truck centers would even touch working on this transfer case, I did some searching and found the write up on how to test the sprag engagement. We jacked up a wheel and ran the test. The wheel locked on one direction while in reverse gear, and freewheeled in the other. When switched to 1st, it frewheeled in both directions. Apparently the forward sprag was out. I would like to mention that we did pull both air lines and shot some PB into them before we did the teat. I ordered a sprag and race from Boyce along with an air seal kit and got to work. Even though id never done the work before, i had the ouput housing out in about 4 hours before realizing I didnt have the necessary tools to #1 remove the front output nut, and #2 press off the race. Chief did some calling and we got tied up with a mechanic who had knowledge and experience with the T138 and he took the unit and swapped out the parts. No chunks in the oil or heavy grey to the oil. This is where, in hindsight, I should have figured out what he was asking about. On the back end of the front output shaft, there was what appeared to be a "snout" that went into the transfer case, it looked like it was splined but it was perfectly smooth and almost poloshed, so was the inside where it seated...kind of like a pilot bushing-transmission input shaft arrangement. In my untrained eye, it would have made sense that the splines were there to catch oil to feed the un-bushed arrangement. I put it all back together. We did the one wheel test and got different resistance from position to position which I took as having a new sprag that hadnt had gear oil on it to break up the cosmoline and let it grab. WRONG. Went on a grass fire about 6 weeks ago and nearly got stuck on the barely thawed slimey ground. Apparently not fixed.
We put our heads together and got a friend with a heavy wrecker to jack up both rears. Not so much as a hint of front driveshaft engagement. Our mechanic that put the new sprag on was there to help us trouble shoot and that is when the lights started to go off...pulled the output section off to confirm...which only took about an hour and a half this time....absolutely...the "bushing arrangement" was actually the splines which arent terribly deep to begin with, had worn down...or something...and it was all shiney metal. I figure that there was just enough grab left in the splines when we did original the test that we would get some feedback....Im ordering a whole reman case from Boyce this week.
My question is this: Has anyone seen the inner splines on the front output shaft shear or wear off smooth before? I would like to figure out if there is something else I need to add to our training to help prevent this from happening again.
PM, email, throw rocks, or smoke signals even kind of work. Im trying to learn as much as I can and the TM's really leave a lot of gaps in coverage without one having all of the background experience that comes with learning these teucks through military service. I do have a couple pictures of the damage as well, just dont have the energy to figure out how to post tonight.
I "maintain" two 813 5 tons for a county Fire Department. Last year I lost front drive on one of them and found out while trying to drive up a rather steep incline after extinguishing a pole fire. I believe it was working when I drove in since there was a similar slope I had to climb when going in to reach the fire. No bang, pop, or any other indicator that something had failed, just couldnt make it up coming out and the Chief told me the front wheels werent turning.
Long story short, everything I know about these trucks, Ive learned the hard way...because something broke or isnt working. Im a volunteer with acceptable mechanical knowledge and understanding but by no means am I a mechanic. Im a Land Surveyor by trade.
After calling around to find out that none of the reasonably local heavy truck centers would even touch working on this transfer case, I did some searching and found the write up on how to test the sprag engagement. We jacked up a wheel and ran the test. The wheel locked on one direction while in reverse gear, and freewheeled in the other. When switched to 1st, it frewheeled in both directions. Apparently the forward sprag was out. I would like to mention that we did pull both air lines and shot some PB into them before we did the teat. I ordered a sprag and race from Boyce along with an air seal kit and got to work. Even though id never done the work before, i had the ouput housing out in about 4 hours before realizing I didnt have the necessary tools to #1 remove the front output nut, and #2 press off the race. Chief did some calling and we got tied up with a mechanic who had knowledge and experience with the T138 and he took the unit and swapped out the parts. No chunks in the oil or heavy grey to the oil. This is where, in hindsight, I should have figured out what he was asking about. On the back end of the front output shaft, there was what appeared to be a "snout" that went into the transfer case, it looked like it was splined but it was perfectly smooth and almost poloshed, so was the inside where it seated...kind of like a pilot bushing-transmission input shaft arrangement. In my untrained eye, it would have made sense that the splines were there to catch oil to feed the un-bushed arrangement. I put it all back together. We did the one wheel test and got different resistance from position to position which I took as having a new sprag that hadnt had gear oil on it to break up the cosmoline and let it grab. WRONG. Went on a grass fire about 6 weeks ago and nearly got stuck on the barely thawed slimey ground. Apparently not fixed.
We put our heads together and got a friend with a heavy wrecker to jack up both rears. Not so much as a hint of front driveshaft engagement. Our mechanic that put the new sprag on was there to help us trouble shoot and that is when the lights started to go off...pulled the output section off to confirm...which only took about an hour and a half this time....absolutely...the "bushing arrangement" was actually the splines which arent terribly deep to begin with, had worn down...or something...and it was all shiney metal. I figure that there was just enough grab left in the splines when we did original the test that we would get some feedback....Im ordering a whole reman case from Boyce this week.
My question is this: Has anyone seen the inner splines on the front output shaft shear or wear off smooth before? I would like to figure out if there is something else I need to add to our training to help prevent this from happening again.
PM, email, throw rocks, or smoke signals even kind of work. Im trying to learn as much as I can and the TM's really leave a lot of gaps in coverage without one having all of the background experience that comes with learning these teucks through military service. I do have a couple pictures of the damage as well, just dont have the energy to figure out how to post tonight.
