GENTLEMEN, GENTLEMEN, GENTLEMEN!!!
In regard to running 30 weight engine oil in a Cub Cadet transmission, here is the "distillation" of what I have heard so far:
1) We all know that REAL men can remember a shift pattern and so they buy GEAR DRIVE machines; not hydro's. Consequently, I bought an old 122 (gear drive) to tinker with. I probably should have been more clear on that. One of you figured that out by looking at my profile ... he gets an "A" for diligence!
2) I had never even considered -mixing- engine oil with transmission fluid or hydraulic oil. Doing that would be like asking your transmission lubricant to instantly turn into swamp slop. Note however that adding a quart of transmission fluid to your car engine oil and idling the engine for a while is the fastest way to de-sludge a dirty engine that I know of!!!
3) Virtually all 30 weight engine oils today are detergent. Try to find one that isn't; you'll have a very hard time.
4) I also have a Farmall Super "A" (note again, NOT a hydro!!!). It, per the manual, runs 90 weight in the transmission. One of you spoke about having to let Farmall H's and M's with 90 weight in the transmission warm up a bit before ripping down buildings with them. I always do that ... out of kindness to the 57 year old Super "A". I have heard old guys say that they have seen old Farmalls with so much water in the transmissions that they froze in cold weather and had to be warmed up -externally- in order to melt the ice in the transmission so that the warmed up engine could move the tractor at all.
5) If you look at the history of the REAL (gear drive) Cub Cadets you find that the transmission was taken directly out of a Farmall Cub when the market for small farm tractors began to dwindle. If you don't believe that, just look at the gear shift lever on a Farmall Cub sometime. It looks like it was stolen off a Cub Cadet! How many Farmall Cubs do you think are running around with Hy-Tran in their transmissions? Well, OK. -MAYBE- the "Keeper Of The Holy Hy-Tran" has one, but I'll bet there aren't many others. I'll bet there are a whole bunch of Farmall Cubs running around with 90 weight in their "Cub Cadet Transmissions".
6) The real reason for considering using 30 weght engine oil in the transmission, and yes, in the creeper planetary GEAR drive also, was not cost. The cost difference doesn't amount to a hill of beans in the grand scheme of things. The real reason for doing this is S-I-M-P-L-I-C-I-T-Y!!! Think about it ..... three places on the Cub Cadet that use oil (engine, transmission and creeper drive), and they all use the same oil: 30 weight engine oil. Wouldn't that be simple!?
7) About now you are undoubtedly saying, "Gee, this guy says he can remember a shifting pattern, but, now he says he can't remember which oil to put where on the Cub Cadet. He must be a real bone head". I -DO- wish you would stop thinking about my grandsons like that! Need I say any more?
Thanks for ALL of the discussion on the subject. I think I know what I'm going to do when I get to cleaning out and refilling the transmission and the creeper drive.
Len Siebert
P.S. The sissy Cub Cadets should all use Hy-Tran in their transmissions; just like I do in the hydraulic system on the Farmall Super "A"! (That should make the KOTHH happy!)