John Deere 350 B

m and d

New User
I am a retired mechanic that just bought a JD 350B crawler loader. I overhauled the engine, did the undercarriage, steering clutches and brakes. The machine has a loud 'whine' in reverse. The reverser doesn't slip and shifts smooth. Looking for any advise on what parts is failing in the reverser or if they all made noise. Thanks Dave
 
I've driven 350's with & without reverser. With the reverser & backing up a steep hill, the engine bogged way down tho it keep on backing. Noisy & I thought something was wrong but was told they all acted that way in reverse. In the 350 without the reverser & backing up the same hill, the engine never changed pitch.
 
Thanks for the reply. My 350B is loud enough that I have to wear hearing protection. I heard that the reverse idler gears are straight cut, not helical and that is the reason for the noise. I wonder if the straight cut gear is wore out making the noise worse. I have all winter to quiet this machine down but don't want pull it apart for nothing.Dave
 
Whine in which reverse? Reverse in the reverser or reverse in the transmission? As far as the reverser goes - yes - the reverse countershaft has straight-cut gears. When the filter cover if off the reverser, you can put your hand on the shaft and check for looseness.

Keep in mind that a weak spot in the reverser if the little counter-bearing between the input shaft and output shaft. When that starts to go it will also whine something awful when in hydraulic reverse. For the many reversers that I've rebuilt, having that bearing fail was the #1 reason. When in forward - the input and output are locked together and it does not turn.
 
Wow, that is the info I was looking for! Yes it is the reverser reverse making noise. I don't have a reverse slot in the manual trans. I would assume that there is no reverse in the manual trans then. Right? The main shaft bearing failure make a lot of sense. Yesterday's Tractor website is awesome. I was planning on testing the pressure before and after changing the reverser fluid today. To all that use this site, Have A Great Day!!!! Dave
 
Note that like others said - those reversers whine in reverse when all if fine due to the straight-cut gears. It is a matter of how much whine. Many 350Bs came with reverse in the gear trans and also with the reverser since the hydraulic reverser was still an option with the B series. When the C came out, it had to be standard equipment since it powered the steering clutches too.

If that center-bearing fails, the reverser will either seize, or spring a huge oil leak. I've seen those center-bearings get so hot they melted. Early 350s and 1010s had a smaller bearing. I think somewhere along the B series is when Deere (or Twin Disc) made it bigger. Still failed at times though. I had to fix a lot of Cs. Funny because as far as I know, the reverser in my 1960 1010 is still original. 56 years is a pretty good. If it ever blew - not sure I'd try to fix it. Parts are hard to find and also very expensive.
 
If my 350B Serial number 1477611 had reverse in the manual trans wouldn't the shift lever have a slot for reverse? Should I unbolt the slotted gear plate and see if there is a reverse? I did change the filter and fluid today and it is at least 40 percent quieter. The filter had some crud on the bottom side so I am sure it was plugged too. The pressure was 120 psi at high idle in both fwd and rev. I felt the reverse idler gears and tried to move the shaft and everything checked good. The fluid was clean with no metal in it. If anything I will bet the center bearing that spins only in reverse may be my noise. Thanks again for your reply. Dave
 

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