M817 Transmission Grinding

[kcsav]

I am new to this site and just purchased a M817. It is rather hard shifting while rolling without grinding and vertually impossible to downshift without coming to a complete stop. Additionally, 3rd and 5th gears will slip out of gear while underway. 3rd will go back in but 5th will not. Would this be a transmission problem or clutch. I have downloaded all available manuals and it appears the the clutch is not udjustable other than the pedal linkage. I can't find anything related transmission adjustment. Thanks in advance for any information that someone may have to correct these issues.

 

[EMD567]

Transmission. Sounds like the syncro's are badly worn. You should be able to match speed with the engine and the driveline(no clutch) and shift it that way. It just takes time to let the speeds match. As for coming out of gear, for right now, get a short rubber strap to hold the gear shift in position

 

[Maverick1701]

Transmission. Sounds like the syncro's are badly worn. You should be able to match speed with the engine and the driveline(no clutch) and shift it that way. It just takes time to let the speeds match. As for coming out of gear, for right now, get a short rubber strap to hold the gear shift in position

yup syncros are failing going out

 

[Capt.Marion]

Transmission. Sounds like the syncro's are badly worn. You should be able to match speed with the engine and the driveline(no clutch) and shift it that way. It just takes time to let the speeds match. As for coming out of gear, for right now, get a short rubber strap to hold the gear shift in position

Floating and/or double-clutching will be your best bet until you can get your trans rebuilt or get a replacement one.

 

[clinto]

Assuming you have the correct amount of clutch disc departure (there is a spec for how much of a gap there should be in between the flywheel and the disc with the pedal pushed in), then the transmission sounds well worn-synchros and probably thrust washers as well.

Rebuild or replace.

Also, welcome to the site. We're having a big rally next week, see link for more info. We'd love to have you come out.

http://www.steelsoldiers.com/ga-rally/53347-official-2010-ss-ga-rally-info-thread.html

 

[Capt.Marion]

Assuming you have the correct amount of clutch disc departure (there is a spec for how much of a gap there should be in between the flywheel and the disc with the pedal pushed in), then the transmission sounds well worn-synchros and probably thrust washers as well.

Rebuild or replace.

Also, welcome to the site. We're having a big rally next week, see link for more info. We'd love to have you come out.

http://www.steelsoldiers.com/ga-rally/53347-official-2010-ss-ga-rally-info-thread.html

That's a good point--your clutch could just be not disengaging fully.

 

[kcsav]

Thanks guys. Do you know what manual the specs are in. I think I have them all and am getting dizzy just looking at all of the information. Is this the reason for the inspection plate in the side of the clutch housing assembly.

Man I really wish I could make the rally but have another commitment on Saturday and thought Sunday would not be worth coming for in that everyone would be leaving. The guy that I bought the m-817 from is going and looking for a few items I need.

 

[clinto]

Thanks guys. Do you know what manual the specs are in. I think I have them all and am getting dizzy just looking at all of the information. Is this the reason for the inspection plate in the side of the clutch housing assembly.

I don't know which one it's in. Some kind of maintenance manual.

Inspection plate is not only for measuring plate departure but also for greasing the zerk on the throwout bearing.

Man I really wish I could make the rally but have another commitment on Saturday and thought Sunday would not be worth coming for in that everyone would be leaving. The guy that I bought the m-817 from is going and looking for a few items I need.

Sorry you can't make it. Maybe next year. The rally will be running Thursday and Friday as well. Friday should have a pretty good turnout.

 

[badgmc56]

Sounds to me like there may be a broken snap ring on the mainshaft. The gears are sliding on the shaft and not meshing properly. That will make it pop out of gear and not be able to down shift. Yes, the syncros could be worn a bit but unless they are toast ,you should be able to down shift with worn syncros by matching rpms.

 

[kcsav]

Clinto, Are you sure there is a zirk on the throwout bearing. I cant find it ans the parts manual does not show one Also, on the outside of the hoising where the shaft goes through housing there are two threaded "hose" caps and upon removing them they are full of dried grease. Is this normal in the manual says there should be zirk fittings. I plan to replace with zirks.

As for shifting I am sure I need some proctice in that it appears these truck are not comparable to civilian type vehicles or are they in regards to shifting. i dont think I'm that bad though.

Can the gears shaft be removed without removing the entire transmission?

Thanks again guys.

 

[Floridianson]

Clinto, Are you sure there is a zirk on the throwout bearing. I cant find it ans the parts manual does not show one Also, on the outside of the hoising where the shaft goes through housing there are two threaded "hose" caps and upon removing them they are full of dried grease. Is this normal in the manual says there should be zirk fittings. I plan to replace with zirks.

As for shifting I am sure I need some proctice in that it appears these truck are not comparable to civilian type vehicles or are they in regards to shifting. i dont think I'm that bad though.

Can the gears shaft be removed without removing the entire transmission?

Thanks again guys.

The zert just puts grease on the shaft that the bearing rides on not the bearing.

 

[EMD567]

RThe best thing is to drop the tranny, and while the tranny is down, replace the clutch. Trust me, no sooner then you get the tranny back up, the clutch WILL fail. It's a murphy's law.

 

[kcsav]

Thanks guys. EDM 567 that makes sense. Why do all of the work only to have another problem. Any idea as to the Manufacturer & make of this transmission.

 

[jcappeljr]

Double clutch it....

 

[jasonpolk]

kcsav,
I had the same symtoms when I picked up my M817, the truck was very hard to shift as if it was not syncronized and it was impossible to downshift. I realized that the shift lever to raise and lower the dump bed was not fully disengaged. I disengaged the lever and put the safety lever down in the lock postion ( follow the directions in the operators manual) and the truck shifts perfect. This may not work for you but it would be worth checking, it might be a quick fix.

Jason

 

[bigjuice69]

just like Jason said my M51A2 did the same until i disengaged the pto

 

[Rgdl]

I just read all the posts in this thread.

Several people mention rebuilding the transmission. Who sells rebuild kits for these.

 

[doghead]

Thanks guys. EDM 567 that makes sense. Why do all of the work only to have another problem. Any idea as to the Manufacturer & make of this transmission.

The make and model are on the tag on the side of the transmission(just above and to the right of the oil fill plug).

Have you checked your oil level? Have you changed it?

 

[BKubu]

I have purchased new, unused transmissions for anywhere from $700-1,000. Call the dealers. Start with John Winslow, Dave Newman, and White Owl...then move to TNJ Murray, Clark, Memphis, etc. Many came out surplus about a year ago. You should be able to find one. If you do a complete rebuild, that is going to cost you some serious $$$ just in the parts (go price out one of the synchros to see), never mind your time rebuilding it. Another option is to find a good take-out. However, you never know with take-out parts. I have had some good luck and also some misses. I have purchased what was supposed to be a good part, but I think the seller sold it as a means of testing it out (in other words, if it comes back, it was no good). Be careful if you go the take-out route. Most reputable dealers will take the transmission back within a reasonable period of time, but you are still out your time and labor. Good luck.