Dropped Chain Coupler on Oliver 1855 Again! What Gives ???

I have put the larger bolts in the front left and right rear mounts to straighten the engine, and even shimmed the rear mounts. Adjusted the bolt under the over/under to take up tention.

I slid the sprockets together before I put the chain coupler on, and make sure it is 100% aligned, and still falls off.

I checked the play in both the over/under and the transmission and they are tight and no bearings going bad. Even put the long stainless cotter pin in and it still breaks.

Looked and checked the bolts to the main frame and trans for tightness or cracks. Everything checks out. Coupler looks good as do the sprockets.

At first, the transmission was 1/32 inch below the trans shaft, and thought I got that fixed with shims. I might try putting the trans shaft 1/32 above the trans shaft this time ???

This time it came off with a loud clunk, and the pin hit the front trans lubrication line, which I now have to replace. What a Pain getting to that one. Can't seem to break it loose.

What am I missing with the coupler falling off ????? ??

Thanks for that idea!

Planning on getting a die grinder and cut it off and use a socket to get it off. Then make a new line.

The Old mechanic (Real Wizz at these Olivers) didn't think that this was the problem, but suggested setting the output shaft slightly higher than the transmission shaft this time.

Says that the torque from the engine may lower it slightly when it is loaded? But I thought that the bolt under the Over/Under was suppose to stop that?

But I am giving it a try anyway. I rechecked it this time before I moved or changed anything, and it looks very straight. Who Knows, Maybe it is the chain itself inside the rollers giving way?

And if you had proper schooling you would know to say it is an Oliver, not a Oliver. Have a nice day now knowing you learned something!

COWBOY, did you get the coupler chain from AGCO? If not, it should have the two center bar links like the OEM coupler chain does. Also, there are two sizes of coupler sprockets used on the Olivers of this era. If you replaced them, make sure you got the right size and not ones for a 1650 or similar. Good luck.

But now I think I found the problem,... I called the last owner and he said he replaced the sprocket on the transmission, then sold it. This is where i came into the picture. I looked at it closely, and found that the sprocket on the over/under is worn where the chain rides. It is worn wider than the newer sprocket.

So everytime the power is transfered form engine driving wheels, to wheels driving engine, the chain must be twisting, and makes the cotter pins shear off.

Will have to get another sprocket and new chain and replace it in the spring. Winter is no time to pull the engine when have to work outside. Thanks for the advice everyone.

The chain that you should have in there is not a double chain, it is the width of 2 rollers without the center bars.

As a oliver/white dealer, we have been putting a washer that is slightly smaller than where the chain rides and large enough to clear the over/under nut. This takes up the extra endplay in the chain from front to back and helps to keep the chain from moving and possibly twisting. We do not ever put the gear on the over/under above the transmission gear. It needs to be level or slightly lower.

Thanks again

Led

Other than that, I'm not really sure. Hopefully once I get this fixed, dropped coupler chains will be a thing of the past.

Now my 1855 Cummins has had its chain for right at a year now sence the new engine and I havent touched it. So it seems if everything is in alignment and the sprockets are working that these chains will last a long time, even with a lot more power than they were designed for. But if one thing is wrong it will tear up everything, including sprockets and transmission shafts.

I still like the trunion mount of the 2150 and 2255 best of all, wish there was a way to adapt that trunion to the other olivers.

Good luck with that 1855 Cowboy....

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