Hard to shift OUT of 3rd.

[KsM715]

Hard to shift out of 3rd.

OK I've spent the whole second half of the game searching and could not find anything related to this.

One my '71 M35a2B (bobbed) it is hard to shift out of 3rd. Going into 3rd (or any other gear) is fine, well as fine as a 40 year old truck should be. When either up shifting to 4th or shifting out of 3rd to come to a stop it is very hard to get out of gear.

Anyone have any idea what the problem might be?

 

[nk14zp]

Is the oil level correct? And what oil is in it?

 

[KsM715]

Level is correct. (one knuckle down) as for whats in it? The same oil it came out of GL with.

(somehow I knew that would come into play in this thread)

 

[Torisco]

Drain and change all the oil....

Check for golddust (lfinely ground metal dust ) in the drained oil as it could indicate excessive wear of the inards.

 

[91W350]

I would be inclined to think it was in the shifted and not the transmission or oil. If you would like for me to pull a shift tower and let you try it, we can arrange that. Both of the ones I own now work very nicely. Silver or golden dust is pretty common in truck transmissions due to the low beats and reverse not being synchronized. Every time we grind first or reverse, we generate flakes or dust. If it was just the oil, why would it only bother third? I am betting on bent or rusted shifter pasts. Maybe something simple like a deposit of something on a sliding part, gasket dealer etc... Glen

 

[broman78]

is hard to shift out when you double clutch?

 

[glcaines]

I would change the oil out in any event for GL-1. In my opinion, this probably won't help, but it should be changed anyway and you can look for metal fragments in the drained oil. Then, assuming the drained oil is clean, try the shift tower offered by 91W350.

 

[KsM715]

Glen, thats whats got me confused, Why only 3rd. I will pull the top off next weekend and see if there is anything obvious. If I wasn't without brakelights right now I would driveover there and swap top plates with you to see if that's it.

I am under the impression that double clutching means clutch in and shift to neutral then let it out and clutch pedal in again and shift into the next gear. The problem is shifting out of 3rd into neutral. Doesnt matter how many times I push in the clutch pedal, it just doesn't want to come out very easily, it take a fair amount of force on the shift lever.

Edit: I will be changing the oil next weekend as well.

 

[91W350]

I am betting something is in the shift mechanism. They are on pretty tight tolerances and it would not take much. Never been into a deuce shift tower, but I know most truck towers will not tolerate much dirt or debris. I have an abundance of trucks right now, so stealing a tower for a few hours will not hurt me a bit. If that turns out to be the problem, we will see if Deuceman51 has a good used one at his compound. Glen

 

[gimpyrobb]

If your going to change the fluid in the trans, why not use what the manufacturer intended? 30wt motor oil.
Personally, it sounds like a worn syncro to me. Wouldn't the shifter be the same answer as the oil? Why only 3rd gear?

 

[TulsaME]

My tranny felt like the shifter was stuck in thick mud going into 3rd. Then it started to feel that way coming out of 3rd. Then it got worse! I took the top off the tranny and found out the shifter mechanism was working fine off of the tranny. I kept digging and now I see that the splined sleeve that the 2/3 synchro rides on is cracked and swollen. As a result, the synchro will not move freely on the splines as it is desinged to do. I think that is why mine won't shift correctly.

I think the problem began when the sleeve twisted slightly on the shaft and is now wedged in place against the keys. I think the twist and wedge caused the sleeve to swell and crack. I am in the process of trying to remove the sleeve from the shaft. It should press off. It wont. My current thought is to find a way to cut it off. End mill?

Good luck.

 

[KsM715]

Well I changed the fluid yesterday, didnt find and chunks or anything in it. The shifter acts like its shifting normally "off" of the trans. I do have one question, should the syncros slide back and forth easily? With the top cover off I pushed the clutch in and locked it down with a board holding it down from the dash to the pedal, with that done I can spin the gears and they all look fine but I can not move the shifting collars back and forth with my hand. should I be able to? I re-filled it with SAE 30 (could not find any 40 or 50 locally) took it for a drive, about 20 miles highway and 10-15 city driving. Still shifts the same.

 

[gringeltaube]

.......... but I can not move the shifting collars back and forth with my hand. should I be able to?..................

To put 2nd-3rd collar IN gear (either one) you will need some strong fingers from both hands; but you should be able to pull it OUT of gear easily just with your two little fingers and maybe a bit of wiggling...

I suspect you have a deformed or even cracked sleeve as TulsaME described, and keys about to give up, too?

G.

 

[bones1]

So 30wt motor oil is recommended for the Deuce trans?. I almost messed up and put gear oil in it. Thanks for the info.
What would we do with Gimpy to save our arses?.

 

[gimpyrobb]

Well, the military put gear oil in everything, so I think you would have been fine. Some say the oil makes it too easy to shift and they sometimes bump the reverse gear when they shift to second gear.

 

[TulsaME]

I got the sleeve removed from the main shaft today. I forgot to take any before pictures but here are a couple after pictures.
To recap… The sleeve would not press off of the main shaft so I decided I had to cut it off. My first thought was to put use a mill to cut the sleeve.
Today, I decided to keep it simple and try my Dremel tool. I chucked up an abrasive cut off disk and gave it a try. It worked great until I got about a little past halfway. Then I started to bump up against the large gear with the dremel motor. Not to worry, I installed the flexible shaft on the Dremel which gave me enough room to finish the cut. I actually didn’t finish the cut. I was about ¼ inch from the end when… SNAP… the built up internal stress in the sleeve split it apart. I took the shaft to the press and was able to press the sleeve off the shaft as described in the TM. The only trick was to cut the sleeve along one of the unused keyways.
Now I need to make my list of parts needed to put it all back together!

 

[KsM715]

Is it possible to see this type of damage without pulling the trans. and pulling the mainshaft out? What would I be looking for thru the top plate if its possible?

 

[gringeltaube]

The tranny can stay in place but the mainshaft has to come out and be completely disassembled to inspect those parts.

G.

 

[TulsaME]

You do not have to pull the transmission to get the shaft out. I took the main shaft and gears out from the top. I followed the steps I found by searching... sorry I don't have the exact link right now. It wasn't too difficult. The only specialty tool needed is a gear puller.

I did not see that the sleeve was actually cracked until I had it out of the transmission. I am not going to say it is impossible to see while it is in the tranny but you will need to look extremely closely. The TM, TM9-2520-246-34-1, has a lot of measurements you can take to see if the parts are in specification. I do not recall if there was a spec for the diameter of the sleeve. I decided mine must have been out of spec since the synchro would not move freely.

From your description, I bet you have an swollen sleeve and very possibly sheared keys. I think I have a few pictures from the dissasembly stage. I will post them if I find them.

By the way, Boyce Equipment clued me in to the fact the keys were failing or had failed. They were correct. Guess were I'll be buying some parts.

Post any questions you have... I'll try to help.

 

[KsM715]

Great. I didn't realize the main shaft could come out without pulling the trans. Time to break out the TM's and start reading.