Finally got the trans on my 1999 10525 all buttoned up this past weekend.
As I did with my 10323 1-speed trans overhaul ...
... I made a pan gasket and added a grease zerk so I could pump trans full of grease.
Only worn parts found in this 3-Spd trans were the output shaft and the two bushings it rides in (items 1,11 & 12 in parts diagram: 60-8770, 60-8850 & 65-4770) as well as the bushings in the 92-7746 rear height adjusters that also ride on the output shaft. Instead of replacing height adj. assy's, I just replaced the bronze bushings in both of them per this other thread I started ...
... using std. 6391K197 bushings from McMaster Carr for the outer and the special OD Toro/L-B bushing 70-9760 for the inners ($3.67 cost vs. almost $26 for new assy's each).
The output shaft & bushings were nowhere near as worn as the ones were in my 10323 1-spd trans, so I'm guessing it had a lot less hours it's 1st 10 years of life (I got it in 2009) than my same age 10323 did. But thought while I'm in there I'll replace them since they will likely be discontinued soon like the complete 92-7869 trans has been recently.
Upon disassembly, I noticed that Toro/L-B uses a cover on the RH side output shaft along with steel & felt washer on the side of the trans case (items 13-15 in parts diagram: 24-7920, 303259 & 605255). Note that these items are NOT used on 10323 / 1-speed transmissions. Toro wants almost $6 for the "cover" which is just a 61 segment long piece of 1/2" I.D. black convoluted split tubing (GARDNER # FLX-5007 - 7' for under $3) which I had a length of.
With a new length of tubing and the washers in place, the tubing acts as a spring between the RH height adjuster and the steel washer which sandwiches the felt washer to the side of the trans case ... assumed purpose is to protect bushing & shaft from dirt and possibly keep grease in the trans. But why only the one side and why not add the steel & felt washers to the other end to protect the height adjuster bushings as well ?? Space on the LH side is pretty narrow, so a length of convoluted tubing will not work, but the 65-4720 compression spring (item # 25) that is at both ends of the output shaft against the pinion gears is a perfect fit !!
So I ordered 3 extra steel & felt washers as well as a compression spring and for under $98 in parts I got it set up better than original. Output shaft ($78.76) was the bulk of the cost.
Trans took about a 1/2 cartridge of grease (Lucas Red & Tacky) ... pumped it full until it came out between case & bushings. My main concern with it being full of grease (vs. the minimal amount L-B/Toro recommends) is ... will it effect shift fork movement ?? It seems to shift just fine.