Transmission reverse gear grind

[Cav Trooper]

Last fall at Veterans day I took the Mutt out to a local event in about 50 deg. weather. About 10 mile drive. I parked and was asked to move the Mutt up to the front of the restaurant. When I went to back out, I could not get the trans into reverse, it would grind trying to go in. I tried a couple of times then turned off the engine and put trans in reverse and started. I moved to the new spot which would require using reverse again. When I left about 2 hours later, the trans shifted into reverse with not problem. I have since had this issue a couple of times, sometimes after I do the turn off trick and shift, the next time reverse works ok, sometime with a little grind. I was told it could the detent balls and springs in the top cover. Another comment was the syncro for reverse. I didn't know that reverse has a syncro. I am about the pull the top cover on the trans and notice that there are "freeze" plugs for the three detent balls. Where can I get new ones if I remove the old ones?

[Mr. Recovery]

They are listed in TM9-2320-218-34P they are part# 172530 as "part of kit" part# 5702253 NSN 2520-00-887-1352 I would think NAPA or O'Reilly's could get them if you take an old one to them.

dan-2beers.jpg

[raymond]

1st gear and reverse are not synchronized gears.

[rickf]

If it is grinding while sitting still then you have a clutch issue. The mainshaft is turning while you are trying to put it in gear. That is a symptom of the clutch not fully disengaging. Where does the clutch engage when you are letting off of it in first gear? If very close to the floor then it probably just needs adjustment.
As far as the reverse lock out detent ball. The balls do not go bad. The reverse lockout spring does go bad but the symptom of his issue is grinding into reverse while trying to shift into third gear going down the road. It has nothing at all to do with shifting into reverse while sitting still. Check the free play on your clutch pedal and if there is a lot of free play then adjust your clutch and the problem should be resolved. If it is not then the clutch disk is probably swelled. But this would also give you a problem with first gear. Second gear is synchronized so it would not be noticed as much there but if you are also getting grinding in first then definitely clutch.

[Cav Trooper]

Thanks guys, as usual, very good information. I never thought about the clutch since the other gears act normal. Learn something new every day, even at 75.

[rupert's]

This same thing has happened to me many times, in my car the problem was what rickf says.
In my case I had other symptoms that the clutch does not separate completely:
-When putting the car in 2nd gear, it made a small movement forward, and when it went into reverse, too. A little tug.

The next time this happens to you, put it in second gear and then put it in reverse. If in this way the reverse gear does not scratch you, it is surely that the clutch is too close.
All the best

[Cav Trooper]

I followed the responses I received about the clutch adjustment to remedy the reverse gear grinding. I check with the manual and adjusted accordingly. I still get the grind, funny, it seems to be mostly after driving and the tranny is warm. I don't get any gear issues with the 1-4. I was told to try adjusting the clutch linkage out a little more which I did today. I'll have to test drive tomorrow to see if it helped. If that doesn't fix it, what next?
I really don't want to pull the engine/trans if I can help it. Right now, if it grinds, I shut off the engine and shift into reverse and restart, no problem. I do get some bucking as I back up, is that different issue?

Thanks,
CT

[Horst]

everything you describe still points towards a clutch issue.

I have never done it (always pulled the power pack) but I think you can remove the lower sheet metal clutch cover with the power pack in the truck. This way you can at least visually inspect the clutch for wear.

[svramselaar]

hi

look also if you have adjust the clutch
wen you push the pedal i bit if the rod from the pedal to the lever is direct go
i had one`s a mutt at my shop the lever at the pedal has a square and it was worn a bit round
so if you push the pedal it moved at and the clutch was not coming free
at the bottom you can see the square at the rod

[rickf]

Not quite sure what George means but it could have something to do with the bushings in the pedal assemble or also the bushings on the cross shaft between the frame and the engine. But, if any of those bushings were that bad you would also be having issues with first gear and a dragging clutch in other gears. It is sounding like maybe you have a contaminated clutch disc. Your description of it starting to happen once hot leads me to believe the disc is swelling up once it gets hot. This is usually caused by oil on the disc from a bad transmission input seal. Engine rear main seals will possibly do it but most oil from a main seal is on the back side of the flywheel and inside the bell housing, it does not get on the disc unless you are fording and water gets in there and spreads the oil around.

[svramselaar]

hi

at my older answer you can see the square at the bottom of the picture
below the you can see the square at the lever nr 29 if the bolt nr 27 gets looser there can be a play if the square gets a bit round
i had this at a mutt ones

[svramselaar]

hi
the drawing is not from a A2 bud the only difference is the stoplight switch

[rickf]

Now I see, you are talking about the small plate that keys onto the shaft and is bolted on. If the bolt comes loose the hole and key on the shaft wear and you end up with play in the clutch. I was thinking you meant the Number 14 bushings. Most of these things that create play in the system can be compensated for by the clutch adjustment up to a point. After that you need to start replacing worn parts. But as long as the clutch is not engaging right as soon as you start to come off the floor with the pedal then grinding should not be a clutch issue. When you push in on the clutch you will be taking up all of the play in all of the loose points so you may and up with a lot of free play at the top of the clutch pedal and almost no travel from the floor at engagement. If you are getting that and you cannot adjust it out then it is time to start looking at those bushings on the pedal shaft, the arm that George talked about, and the bushings on the Z-bar from the engine to the frame. In addition to all those points you also need to look at the hooks on the ends of the adjusting rods to make sure they are not wearing through. This is a spot that needs an occasional drop of oil.

[Cav Trooper]

Thanks all, I have the clutch adjusted so that it engages about 1" from the top of the stroke. I still get the grind issue. I have tried the second gear first then reverse and it seems to help. Am I to assume that the whole engine/trans pack needs to be removed from the vehicle to service the clutch? With what Rick suggested about trans front oil seal, it's looking like I will need to pull it. Can the oil seal be accessed without taking the trans apart?
Thanks,
CT

[rickf]

The powerpak does have to come out to get the transmission and clutch out. And yes, the seal can be replaced without disassembling the transmission but you need to be sure the front bearing in the transmission is not bad and could have contributed to the bad seal. If you pull the seal and it is hard and brittle then that was the issue, simply an old hard seal. Replace it and be sure the pilot bearing in the flywheel is good and reassemble. I am betting you will find a problem of some sort with the clutch disc.