3-Point Hitch 3320 3pt hitch not lifting

[GreatWhitehunter]

This will be a FYI to others so you guys can benefit from my findings. About
3yrs back I added a 448 hoe to my 3320. The dealer did all the install and added the Power Beyond. About a month later I was having rockshaft issues. While loaded with an implement it would constantly slowly lower and then try to recover. It was under warranty so I let the dealer handle the repairs.

When it returned the dealer said they replaced the rockshaft valve itself.
I didn't ask anymore questions. Shortly after the warranty expired I was harley raking and couldn't seem to get the grade I was after. Again the 3 pt hitch was falling and raising. What I found was the sintered filter in the PB circuit had failed and broke in pieces. I ended up pulling the rockshaft valve apart and found nothing but after reassembling everything worked. I've since done 3 Hygard changes and replaced all three filters.

Which brings me to today, I head out to do some boxblading and raise the hitch control handle. No movement of the hitch what so ever. So I check all the usual suspects. Linkages,oil level etc and find nothing. I pulled the PB sintered filter to make sure it was intact. It was but the filter chamber was not filled with hygard. So I knew the issue was before it in the rockshaft assembly. So after the disassembly I find a small piece of the sintered filter jammed in a port of the valve. It was blocking the shuttling of the spool itself. I was relieved to find no damage to the shuttle itself. This piece of debris was obviously floating around in the circuit all this time since the current filter is intact. I'll post some pics in the am. If anyone has details on cutting and pasting from the JD parts site please PM with the instructions.

Matt

[CinderSchnauzer]

FWIW - Don't know if this info will help in the future. I had an O/S 3320 with 447 BH, all factory ordered. As installed when using the 3 pth the heavy power beyond hose is looped and plugs into the fitting on the curbside rear of the tractor. For BH operation the heavy hose is removed from the Quick Coupler, left dangling and one BH line goes on the curbside and the other is plugged into the male fitting on the roadside rear of the tractor.

I recently upgraded to 3320 CAB and had to add Power Beyond. Despite a decal on the PB frame that seems to indicate not to plug into the end of the heavy hose, I was advised by the shop foreman that JD has issued a bulletin saying to connect one BH line to the curbside rear of the PB (where the heavy hose was originally) and connect the other hose to the end of the heavy hose - and do not use the fitting on the roadside of the bracket.

They tell me this way the flow returning from the BH goes through "the filter" whereas if returned via the roadside fitting "the filter" is bypassed and any debris ends up in the sump.

[GreatWhitehunter]

I've snapped a not so great pic of the debris. It's part of the sintered filter, part #27 on the part diaghram. Cinder, are you saying deere is recommending not using the PB filter? I talked to my dealer about the issue and he swears he's never seen on of those filters come apart. Since this all started after the PB install I'm thinking a piece of debris got into the sump during the install and then made it's way through the loop back to the filter and destroyed it. There's not much to the Rockshaft valve itself so if your mechanically inclined I wouldn't hesitate to do the work youself. I'm betting this would be of 1k of shop time at the dealership. I've placed a penny next to the debris for size reference.

Matt

[GreatWhitehunter]

Here's a pic of the valve assembly itself. If you notice a large bolt head on the upper right side of the valve. That hold a small relief in the valve body. The piece of debris was lodged in the valve itself.

[kennyd]

I have never heard of that filter coming apart either except in your case GWH, I have to suspect your theory is correct, the guy installing it damaged it somehow (dropping it maybe?), or it was just a defective filter from the start.

Glad you got it fixed, hopefully for the last time!

[GreatWhitehunter]

The filter itself is quite brittle so if it was dropped I could see it failing. I believe this was the last piece but you never know.

Matt