Straight 550 transmission

[RogerP70]

Well I finally had the weather and time to change fluids and filters on the “new to me” 1975 JD 555a. When I pulled the transmission screen I was happy for a moment because it didn’t look too clogged with sludge, but then came the bad news.

I pulled out a lot of crushed pieces of a long narrow spring, and a rubber seal broken into a lot of pieces. One piece of an o ring. I took pictures if it helps, I’m hoping someone with experience inside a transmission can tell me if they have a guess or know where exactly they came from. Is it common? Does it sound like this thing is about to give up the ghost?

It generally runs strong, on occasion the trans pressure drops and it slips some. Just won’t move. Let it rest a while and it’s back to normal. I’ve only operated it about 5 hours before changing all the filters and fluid today, and only spent about a half hour on it afterwards

[Lavoy]

In general, you do not read anything good about the 550 transmissions. I would say you are looking at a tear down, sorry.
Lavoy

[Stan Disbrow]

Hi,

Hmmmm. Well, oil get thinner as it gets warmer. I suspect there is an internal oil leak due to the spare parts you have found. So, the operating pressure is likely close to Not Working even at the beginning. Then, it doesn't take much to cause things to stop.

I agree with Lavoy here.

Stan

[Al Swearengen]

In general, you do not read anything good about the 550 transmissions

Boy, no kidding. How did they muff this one up so bad? Was it a complete redesign failure?

[Lavoy]

Like many other aspects of all crawler, lack of maintenance is what I often see talked about as a reason for failure, specifically not changing the trans filter because it is hard to do. This probably means that the fluid did not get changed much either.
Lavoy