8N 3PT not raising high enough?

[EdGooding]

If you overhaul your top cover, I highly recommend using a piston from the later NAA model instead of the 8N piston. It's been proven to last much longer and scar the cylinder up less. If you watch that video, Rachel talks about it.
Also, before you start on the job, buy a cam follower pin. They are usually pretty worn. If you can't find a new one, and the existing one has a flat worn on it, you can extract it and insert the crappy end into the hole and have a whole cam again.

It looks like Steiner Tractors has them in stock for $5: https://www.steinertractor.com/FDS3403-Inner-Hydraulic-Lift-Control-Rod-Pin#checkFitScroll

 

[John0829]

Or you can use the shank of a proper sized drill bit for the cam follower pin, I do. But many do not like it for they think it will wear out the cam more quickly, and I guess it might, so far I have had no issues doing it. If the cam is found to be worn it can be built up by someone using a torch and bronze rods.

 

[BossofBBQ]

Thanks for the photos Ed! I have them saved off and stored with my service records. I'll pull the top cover next weekend when I have some spare time. What am I looking for once the cover is off? Bent linkages I assume? I watched Rachel's video and will most likely end up rebuilding the top cover with a NAA piston. I will order a cam follower pin accordingly.

 

[EdGooding]

Thanks for the photos Ed! I have them saved off and stored with my service records. I'll pull the top cover next weekend when I have some spare time. What am I looking for once the cover is off? Bent linkages I assume? I watched Rachel's video and will most likely end up rebuilding the top cover with a NAA piston. I will order a cam follower pin accordingly.

Once you get the cover off, replacing the piston/cylinder and cam follower pin are often the only parts you need to replace. Look for any other parts that look broken or not right. The former owner clearly abused the draft control system, so you may find some linkage damage. After that, it comes down to making the proper adjustments for both the draft and position control functions. That's why I pointed out the jig for this. You can buy it, use it, and then sell it on eBay and get most of your money back. I have a variation of this jig that I got years ago from Zane Sherman. I've attached the instructions for it because they have some good inside-baseball tips for this task.

 

[BossofBBQ]

I'll plan on getting the jig too- I can imagine that it would save a lot of time/effort in getting the adjustments right the first time.

Another thing I noticed- when lifting heavy implements, the pump makes a "clunking" noise. It seems to be strong, and has no problem lifting disc harrows and boxblades. It just can't get them very high off the ground because the range of motion is so limited. Is the clunking/knocking normal, or should I plan on a pump rebuild as well?

I'll pull the top cover off this weekend and report back with my findings.

 

[EdGooding]

I'll plan on getting the jig too- I can imagine that it would save a lot of time/effort in getting the adjustments right the first time.

Another thing I noticed- when lifting heavy implements, the pump makes a "clunking" noise. It seems to be strong, and has no problem lifting disc harrows and boxblades. It just can't get them very high off the ground because the range of motion is so limited. Is the clunking/knocking normal, or should I plan on a pump rebuild as well?

I'll pull the top cover off this weekend and report back with my findings.

The clunking noise is coming from your pump and does indicate wear in the scotch yokes. However, folks have used them for years with that noise. Once you get your top cover right, and if the lift works as it should, I would probably put up with the noise. The true test of your pump is to pressure test it. There is a port on the right side of the pump where you can attach a pressure gauge. After you deal with your top cover, and if you want to do this, I can share some instructions.