350 B Reverser

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Jason37756
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350 B Reverser

Post by Jason37756 » Sun May 19, 2019 7:02 am

I have a 1972 350 B crawler that I am getting ready to tear into. The dozer will not pull under it's own power but can be towed. It also steers when being towed.

I have read thru a lot of posts here on the website and have come to this point.

I think the issue rest within the reverser. When the reverser is placed into reverse and the clutch pedal is released a wineing noise occurs then the motor bogs and then dies. When the reverser is placed into forward and the clutch pedal is released the motor just bogs then dies. When the reverser is placed into neutral it functions normally...motor idles like a dream. Wineing and bogging exist no matter what gear the tranny is in. I do not believe the issue is in the tranny because when the tranny is placed into neutral I can physically move the rack and pin in the tranny...it becomes free when placed into neutral. Also I can tow it, so the finals are turning.

The previous owner said it made a big snapping noise and hasn't moved under its own power since. Under the current circumstances I feel like it is an internal mechanical issue...broken tooth or bearing jammed inside the reverser, but if not then I don't want to disassemble the dozer. Am I missing anything externally that could cause this issue?

I have no experience with the reverser, so I am learning how to check its function, pressure requirements, check points, etc...

I haver the service manuals and will be referencing them.

What are your thoughts?

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jsal
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Re: 350 B Reverser

Post by jsal » Sun May 19, 2019 3:32 pm

possible problem there is a splined coupling between the reverser and trans that wears out only way to check is take apart may have other problems seeing that it stalls engine

JIM

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Re: 350 B Reverser

Post by 350B$Pit » Sun May 19, 2019 5:41 pm

I just bought a 350-B a few weeks ago and will be watching this thread....the reverser in this model seems to be a weak point. Well for a 40 something old machine. :)

Jason37756
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Re: 350 B Reverser

Post by Jason37756 » Sun May 19, 2019 6:42 pm

I bought the crawler for the winch, but was told the coupler could be the issue. I have replaced these before and might get lucky and this be the problem.

The fact that I can tow it seems to conclude that the coupler isn't an issue. I know a sheared coupler could be turned, but it wouldn't create the stall issue...under normal circumstances.

Either way still looks like a tractor split.

Jason

original possum
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Re: 350 B Reverser

Post by original possum » Mon May 20, 2019 7:59 pm

You may have spun out a bearing in the transmission. Remove the transmission cover and see if there is any movement in the shafts. You can bend a hook in a welding rod to try to wiggle the lower shaft.
Early 40C w/Yakima toolbar and homebuilt ripper: 350 w/6-way

Jason37756
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Re: 350 B Reverser

Post by Jason37756 » Mon May 20, 2019 8:25 pm

I had the rear plate off the dozer to switch the pto and winch drive out from another dozer...while in there I had a normal amount of play when in neutral and no play with the transmission in gear. The gears also turn freely when the dozer is towed with the tranny in neutral. I didnt place it in gear when towing...I would assume it would engage the tracks.

Still sounds like a split to repair a potential spun bearing.

Jason37756
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Re: 350 B Reverser

Post by Jason37756 » Tue May 21, 2019 7:45 pm

I pulled the dozer into my shop today and while doing so I placed the transmission into 2nd gear. Both tracks locked up and would not turn... Slipped the tranny into neutral and it rolled smooth.

I should have it torn apart this weekend. I suppose I'll pull the motor and reverser together. Or the motor then the reverser...either way I'll pull the front apart.

Jason

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gregjo1948
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Re: 350 B Reverser

Post by gregjo1948 » Wed May 22, 2019 4:01 am

I don't think it is the coupler between the reverser and the trans.. If it is the coupler it probably wouldn't lug and stall the engine. Sounds more like something binding in the trans. to me.
JD 350B diesel w/rops & 6way blade, Case 580B Loader/backhoe, Farmall 504 highcrop, International 404 utility, International 284 diesel w/belly mower, 1972 Ford F600 dump truck, Galion 3-5 roller

Jason37756
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Re: 350 B Reverser

Post by Jason37756 » Wed May 22, 2019 5:59 am

as original possum said i need to remove the transmission cover and take a look. makes sense that something in there could have it bound gregjo. i'll know more in a few days.

the previous owner did do some work in there before, so his work could have failed. seems like he said he had to machine a part of some sort.

thanks

jason

Jason37756
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Re: 350 B Reverser

Post by Jason37756 » Thu May 23, 2019 7:26 am

Here are a couple of pictures on pintrest.

https://pin.it/7rezqlhml4plsu

I have a few questions

What could have caused the bearing to be bent like this and could this be enough to seize up the shaft?

Also should the shaft be able to free spool in its current condition? I have removed both fuel and hydraulic tanks, the seat, etc.. I would imagine that the clutch in the reverser is locked down preventing the shaft from turning??

Thanks

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Stan Disbrow
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Re: 350 B Reverser

Post by Stan Disbrow » Fri May 24, 2019 4:49 am

Hi,

Link isn't working for me. Might be that I am not on Pintrest, or that sight might not like this tablet browser. I can't really tell.

Reverser is all in neutral with power off. No hyd pressure to make the clutches in there up with the engine off.

You do need to have both sticks tied back to turn the output shaft of the trans on a B. They have pressure plates making up the dry steering clutches (the C and D have wet clutches and need the hyd pressure from the reverser pump to make up).

Stan
There's No Such Thing As A Cheap Crawler!

Have: '58 JD 420c 5-roller w/62 inside manual blade
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Jason37756
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Re: 350 B Reverser

Post by Jason37756 » Fri May 24, 2019 5:46 am

Thanks Stan,

Here is another link

https://knoxville.craigslist.org/grd/d/ ... 64604.html

My iPad wont access the pinterest link either but my computer will... Technology :roll:

If the reverser clutches are free then I think I've found the problem. The input shaft won't turn when being towed in any gear or by hand with a pry bar. The rear bearing, on the input shaft, is severely bent and the gear next to it seems too close to the housing to me.

Just to clarify I towed the dozer and watched the output shaft turn...didnt even think to disengage the clutches via the sticks.

Thanks

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Lavoy
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Re: 350 B Reverser

Post by Lavoy » Fri May 24, 2019 8:41 am

That is only the roller cage, highly unlikely that it can have any effect on the trans in and of itself. Now, if it is bent because the bearing has piled up, yes, but the cage itself is not the issue.
To me, there is some pretty severe gear wear on the one gear, most likely from grinding the gears when shifting, but maybe it is only the pic. If the input shaft won't turn, you are looking at a rebuild unfortunately. As long as the reverser is out, I would tear it down as well and check bearings, replace seals and O-rings.
Lavoy
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Jason37756
430 crawler
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Joined: Thu Dec 15, 2016 8:23 am
Location: Tennessee

Re: 350 B Reverser

Post by Jason37756 » Fri May 24, 2019 9:33 am

Yeah that's severe wear...another issue all together.

Yeah it's tore down so it's pretty simple to pull the reverser now. I have located an entire clutch assembly and may switch it back to a straight 350...


Thanks

Jason

Jason37756
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Location: Tennessee

Re: 350 B Reverser

Post by Jason37756 » Sat May 25, 2019 6:59 pm

I got the transmission split off the rest of the crawler today...had to hook my winch to the front of the dozer while I lifted and pulled the transmission and final drives off. Otherwise the entire machine was sliding when I attempted to remove the rearend. The service manual recommends removing the finals, but I've yet to see anyone do that.

The reverser turned smooth with a nice amount of resistance, so I believe that's a good indication. The coupler was intact with a bit of rust. I assumed wrong when I first decided what the problem was. Gregjo and original possum were correct in their assessment. Thanks! I would have been barking up the wrong tree.

That bearing was an absolute mess...some rollers broken or worn in half, bearing cage was in three pieces. After removing the input shaft, the pto shaft turned smooth as well as the output shaft. I'll need to pull the inner race from the shaft and I should be back in business with a new bearing.

I'll get some pictures up soon.
Last edited by Jason37756 on Sun May 26, 2019 2:53 pm, edited 2 times in total.

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