differential backlash reset

[riverbend]

1940 H
Here are the results-
Locked up the pinion shaft.

These are kind of blurry because it is hard to hold the ring gear and the camera steady.

The tooth pattern on the ring gear.

It sure isn't a one time thing. I had it apart 6-7 times.

 

[rustred]

explain what u have done her so far. yes as i said its trial and error. and is that the backlash of .010 you are showing? this pattern is no different than from before u took it apart. have u moved the crown gear to the left as i said?

 

[caterpillar guy]

I thought the consensus Was since they were used gear not to change it due to the current wear pattern on them from years past and it not being a good idea to change them. I guess it is up to the owner to do as they see best for their tractor. I would probably unless it was really bad noise wise left it alone just because of the work to change it. they are a mostly trial and error effort to set them.

 

[rustred]

you are right, but we type info for the heck of it , then the opposite is done. then it gets them in more hot water.it got me baffled why remove the pinion? if was not out before, that pattern is a crown gear adjustment if he wants it with a better pattern.

 

[rustred]

i just took a look at that pattern on the unpainted teeth there in that dark image and if i am seeing right that pattern dont look all that bad the way it is worn in. and you dont need to be locking up any gears to check backlash. its just a small forward and backward movement and watch the dial. no real force involved there. also thinking if you started the engine and used low gear to rotate the pinion. but no dont do that , too much could happen.

 

[Janicholson]

I like it. there is more wiping toward the mid tooth area and the backlash is OK. They are a pain to get close enough!!! Jim

 

[riverbend]

Well, long story short, I broke the differential and since it was summer I replaced it and reinstalled the original gears. I put the shims back where they were and reassembled it. The tractor was much noisier afterwards and the differential gears obviously needed to be reset. Now it is winter and I have time to reset them. Not to mention that the counter shaft third gear had a broken tooth and grease was starting to leak out from under the brake cover. In the process I found both of the bull pinions were worn on the bearing side and a failed inner axle bearing on the left side.

I really appreciate all the experience and advice I get from everyone on this site. There are some remarkably knowledgeable and helpful people here. Having said that, I'm the guy buying the parts, doing the work, and counting on this tractor so I tend to listen to everyone and then chart my own course.

I'm well north of $1000 worth of parts in an 80 year old tractor that still proudly wears it's work clothes. And I know that once I'm all done I could get maybe $1500 for it since it does have good tires...

 

[riverbend]

I moved the shims from the left side to the right side so it seems that would move the ring gear to the right, away from the pinion gear. This is the first time I have really dug into a differential. I'll be calling on you guys when I put 4.11 gears in my '67 Volvo (Dana 30). The original 4.56 set makes it kind of busy at 75 mph.

 

[Duner Wi]

You are headed in the right direction.
if you get the tooth pattern correct the noise should be minimal. With used gears it can be difficult to get backlash and tooth pattern. I aim for correct tooth pattern over backlash.

 

[rustred]

That is totally opposite of what it needed. I said the crown gear had to be moved to the left into the pinion to get the pattern to move towards the centre of the tooth. But u gave no shim number measurements so a person could make a decision on the thicknesses you had to work with. I am still curious and will ask again how much did you move the crown out to the right ? .003? And is the pinion in the same place ?

 

[riverbend]

That's interesting. My manual says:

 

[rustred]

my mistake, i was thinking automotive diff in my mind which my advise would have been correct. dug out a photo of that unit and yes your book is correct. if i had my eyes and hands on your unit it would not have happened as would have seen where the shims are. dang me.

 

[riverbend]

Not a problem. If I was right all the time...

 

[the tractor vet]

Well guess you will learn soon enough that one does not go messing with and tryen to reset old gears . Once they set a pattern just leave them alone . But what do i know only been doing them for the last 60 years . If ya want it like new then find NEW gear SET and then do the set up .

 

[BarnyardEngineering]

(quoted from post at 21:28:06 12/29/22) Well guess you will learn soon enough that one does not go messing with and tryen to reset old gears . Once they set a pattern just leave them alone . But what do i know only been doing them for the last 60 years . If ya want it like new then find NEW gear SET and then do the set up .

To be fair I don't think he had much choice in the matter. The new diff changed the spacing so now he has to chase it back as close to the old pattern as he can get, and then put up with whatever noise results.