1948 AV has either a clutch or brake issue, prob'ly both

ccaissie · Dec 19, 2018

I replaced clutch in this beast 2 years ago. Disc had disintegrated. After replacement it seemed to grind the gears a bit as if the pilot bushing was seizing. Found some bronze dust around the inspection cover. I did spray aero-kroil up into the splined shaft and it seemed to help at first, then got progressively worse. Rarely could get it in gear..rather, had to put in gear, then start the engine and then release the pedal.

Now clutch chatters like mad and the left brake side is really grabby and noisy. I have the replacement clutch parts to install again, but wonder if I should pull the left brake apart first to see if most of the issue is really in the brake...

I'm guessing the pilot bushing has gone to hell and the transmission shaft is no longer running true. And the brake is wonky too.

First steps? Client has given me this project for the Winter. I can't remember all the diagnostic ideas I've had in the past, so starting from scratch would be a good idea.

gene bender · Dec 20, 2018

split the tractor and fix the clutch problem. Then remove the left diff housing to fix brake

Michael Soldan · Dec 20, 2018

I had a similar situation . The tractor ground gears even with clutch in,sometimes had to put tractor in gear and then start it. My tractor had an inspection plate on the bottom and my neighbour volunteered to take a look. Almost immediately he said the bearing was sitting crooked in the yoke which appeared to be bent and so was not contacting properly. I went to Ontario Used Tractor Parts and got a yoke, bearing and clips and my neighbour put it all together and the problem was solved.We also put a new rod in that the yoke travelled on. You may have a bent rod, yoke or broken bearing , this could be a simple fix like mine.

ccaissie · Dec 20, 2018

OK guys, looks like the tractor split first. Not likely the brake has anything to do with the clutch function....

BarnyardEngineering · Dec 20, 2018

Correct. The brake has absolutely nothing to do with the clutch function.

I didn't see where you describe a brake problem but they're two different issues.

Also, probably hindsight now, but when you do a clutch you should also replace the pilot bushing and the throwout bearing.

ccaissie · Dec 20, 2018

Yeah, the chattering left brake...

Sure. When I replaced the clutch the first time, I replaced everything. Will do again. There was a question whether the pilot bushing gets lube or not. IH says NO. Some here on the forum say yes. I might lube it with some Krytox.

I'm going to really inspect the drive shaft to the tranny. i had to replace the flex joint and bolts on the transmission end once, then the clutch disintegrated.

The whole rig needs a careful look, the clutch should have lasted.

ccaissie · Mar 11, 2019

Finally split the tractor today, the pilot bushing had disintegrated and found powder and a bronze chip about the size of my thumbnail.
TO bearing good, Pressure plate good, Flywheel face good.

The bushing had disintegrated, the transmission shaft began to run out, and the off center wobble of the disk made for all kinds of binding and chattering...just like I visualized.

Since I have new disk and pressure plate and TO brg and pilot bushing, I'll replace all.
The new pilot fits easily on the pilot shaft, and it fits snugly into the crank end, so nothing has been ruined there.

Now the question...again, IH says no lube on the pilot...whaddya think?

Also replace the rear main seal while I'm in there?

BarnyardEngineering · Mar 12, 2019

Check your transmission input shaft for runout. It should spin pretty true. I had one in a cub once that had quite a bit of runout. People told me it was fine so I put it back, but it was never right. Ended up having to pay for a new input shaft.

Don't know why it was bent, don't know how it got bent, but it was bent and it was like that when I got it.

I say this because the pilot bearing does not just disintegrate. Something chewed it apart.

ccaissie · Mar 12, 2019

(quoted from post at 12:13:06 03/12/19) Check your transmission input shaft for runout. It should spin pretty true. I had one in a cub once that had quite a bit of runout. People told me it was fine so I put it back, but it was never right. Ended up having to pay for a new input shaft.

Don't know why it was bent, don't know how it got bent, but it was bent and it was like that when I got it.

I say this because the pilot bearing does not just disintegrate. Something chewed it apart.

As in my earlier description, the rear transmission coupling went bad and I replaced that, so I will have a look at the shaft...support it at the front end and check for runout.

The pilot end looks a bit worn and the bushing fits ok, but a bit loose...probably better than too tight, which it might have been last time?

Tractor is going to be sold after this, so I really want it to be right and not hand off a lemon.

1948 AV has either a clutch or brake issue, prob'ly both

ccaissie

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gene bender

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Michael Soldan

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ccaissie

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BarnyardEngineering

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ccaissie

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ccaissie

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BarnyardEngineering

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ccaissie

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