Reverser pops out.

[swmnCrawler]

Well my dad purchased a 420 crawler, 4 roller with a reverser, pto and blade on the front. This will be our first restoration project but that is not to say im a shy mechanic as I've being maintaining and fixing farm equipment since i was just a kid.

After a little bit of work the crawler is running, however far from good, among things still need to be worked on is the steering clutch/brake (only turns to the right) and the reverser.

With the reverser in the forward position i can't drive the thing 5 feet without it popping out into neutral. If i keep a bit of pressure forward on the reverser lever then i can drive it fine (well as fine as you can only turning left and hunched over pushing the reverser lever.) It seems to work better in reverse but i haven't used it extensively.

It's ready to get torn apart to get at the steering clutches, so what might be the problem to look for with the reverser?

[Lavoy]

My best guess is you need a reverser rebuild, could be bad bearings. Detent ball could also be missing, I have had two like that.
Lavoy

[CELSESSER]

swmnchrawler,
First, welcome to the board.

Causes of what you are describing on the reverser depends on how old your 420 is. Prior to serial number 131309 they had a gear driven reverser and after that serial number they had the clutch type reverser.

If you don't know the serial number you can tell which one you have by looking at the left side of the center tube ( the casting between the engine clutch housing and the transmission. If the reverser handle is on the left side of the instrument collumn and the linkage goed straight down the a polished rod that goes straight forward into a cast housing bolted to the left side of the center tube it has a clutch type reverser in it. There is also a "barrel bung " cap on the front of that housing also.

If it is an early gear reverser there is either gear wear, linkage wear or adjustment, worn bearings or ??? causing it.
If it is a clutch type reverser it may simply be out of adjustment or wear, damage issues. If it is a clutch type (even if not) get yourself a service and a parts manual. It will answer most of your questions (they even have pictures). If it is a clutch type don't use it till you get a manual so that you can adjust it properly, you don't want to do any further damage to very expensive parts. Once you start adjusting it you will get a better idea of if it is adjustment or if there is damage to the clutches (ears torn off or worn out disks due to slipping). One thought before going further, it is supposed to take 35lbs of force to engauge the reverser clutches either into forward or reverse. Maybe you werent pushing hard enough to get it to "click" in to the engaged position in forward. When you pulled it into reverse did it click or pop into position and stay engaged?

Again get the manuals, i'm sure Lavoy has them.

I hope this wasn't too confusing, I guess nothing is obvious.

Chuck

[swmnCrawler]

The serial number plate is missing all of the engravings so i dont know the serial number but by your description it sounds like i have the gear type. Although i'm not so sure it took 35 pounds of force to engage the reverser it does seem to pop into position like it should be there. Its just on the forward gear it manages to pop out again. I am almost positive it is engaging all the way based on how it goes into gear.

One thought on this is that when it is in forward there is not a whole lot more room to go forward before it hits the hydraulic valve so perhaps there is more adjustment to be made to how the reverser lever sits, but i really dont think this is the problem

[CELSESSER]

OK, it sounds like you have the gear reverser, only the last few thousand 420's had the clutch type. The 35lbs of force to engage is only for the clutch type, it overcenters to hold it engaged therefore the "snap" at 35 lbs. On the gear type any click felt would be from the detent balls Lavoy mentioned
I hope it is just bearings and linkage wear, good luckand keep a good supply of bandages handy!

Lavoy, anyone, Is the gear reversor shifter on the right side?? After looking at the 420 parts manual I see that the clutch type could have the shifter lever on either the right or the left side of the instrument pedistal.

Chuck

[Lavoy]

Gear type is on the RH side, clutch type is on the LH side.
My recommendation would be to pull the reverser and see what it up. Seems to me all the bearings and seals are roughly $200 if that's all it takes to clean it up. If something is bad, and you break something, $200 won't by much for parts for one.
Lavoy

[garyp]

I know it has been a while since this was originaly posted but my 420C is doing the exact same thing as described in the original post so I was wondering if there was ever a resolution. Mine is a 1958 with the older gear type reverser. Also is the earlier gear type reverser adjustable?

I just got this 420C a couple of weeks ago and I have not purchased a manual yet.

[Lavoy]

If the reverser pops out of gear, quit using the crawler and tear it down, it will only get more expensive if you continue to run it. There are no external fixes to a reverser other than one adjustment on the shift lever. You could check this first, but it would only affect the reverser when in forward.
Lavoy

[garyp]

Thanks for the info Lavoy.
At this time it does only pop out of forward so I'll try adjusting the shift lever.

[Lavoy]

Factory procedure for adjusting the shift lever for clearance is to bend it. If you are hitting the valve, make sure the bend it back some. Look on the front of the casting the lever goes into. On some, there is a bolt with a jam nut on it, this is the adjustable limit stop I mentioned.
Lavoy