fullchoke 22 #1 Posted May 27, 2023 I have a GT-14 that I got the engine running, and decided to change the transmission oil. The Napa Gold filter has a 2018 date on it so it needed to be changed. The oil I drained out of the trans is clear. Clear like water not a yellow tint like motor oil. The info under the seat says to use Type A fluid in the trans. I've read that Ford type F and Dexron mixed 50/50 duplicate type A. Was Type A clear? I have a lift truck that takes straight 30wt non-detergent. That is the only auto trans I have that takes motor oil. I have seen it said that Type A and Dexron are the same, but I don't think that is true, as Type A had some Whale oil in it. I have moved my machine around without knowing about the tow valve. It never was moved far, or fast. so I'm hoping nothing was harmed. I'm concerned about using the proper oil, and would appreciate some advice. I've had this machine a couple years, but aside from starting it it has not moved on it's own power yet. I bought it from an estate so I know nothing about it's history. It came with a tiller. I have a use for the tiller so I'm now trying to get everything to work. The tiller oil is low also. If someone knows what oil it requires, I would appreciate that info too! Many Thanks Share this post Link to post Share on other sites
WHX?? 49,135 #2 Posted May 27, 2023 @19richie66 is our GT 14 expert ... perhaps he will chime in. Share this post Link to post Share on other sites
Sailman 1,294 #3 Posted May 27, 2023 Most of the GT 14's, to my knowledge, came with the red ATF fluid. Some folks have changed them over to straight 30 weight oil but its important to make sure the whole system is purged. Don't want to mix the 2. Maybe the clear is a particular brand of ATF fluid? That's about the most I can suggest. Not sure but I think the tiller might take heavier gear oil. Experts on here will chime in.... 1 Share this post Link to post Share on other sites
19richie66 17,522 #4 Posted May 27, 2023 No expert here. I would bet someone put hydraulic oil in it like Nuto 68. I would flush it and replace with the proper ATF as in the manual and a new wix 51410 filter. The tiller gearbox I believe takes gear oil. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,090 #5 Posted May 27, 2023 Operator manual for one of the GT-14 tillers 1 Share this post Link to post Share on other sites
Wheel-N-It 2,969 #6 Posted May 27, 2023 Expect the seals on the tiller to leak oil. Throw some 90-140w gear oil and some oil stop leak (like Lucas) in it to see if you can save the seals. If it still leaks, then you'll have to replace the seals. I have had to replace mine once. Share this post Link to post Share on other sites
fullchoke 22 #7 Posted May 27, 2023 The oil that was in the transmission is thin, I would say atf or maybe a bit thinner. While the filter was dated 2018, the owner did write the hours on the filter, and according to that it was only used 4 hours. Does this transmission need the friction modifiers that are in ATF? I forgot about my John Deere with it's Hydro-static Transmission. It takes that clear JD HY Trans oil. Would that be good to use? Since this transmission doesn't have clutch plates that require a friction modifier that is in all red atf, ATF may not be the best oil? I don't know the specs of the obsolete Type A. The tiller hasn't been used much. I don't think it leaks. It did tip over and oil ran out the breather, so it's low. Does the tiller have any brass in it that would be harmed by G-4 or G-5 gear oil? G-1 is not too common anymore. I might find some G-1 just in case. Thanks Share this post Link to post Share on other sites
squonk 41,291 #8 Posted May 27, 2023 Proper replacement for type A is Dexron/Mercon. No mixing. 2 Share this post Link to post Share on other sites
fullchoke 22 #9 Posted May 27, 2023 Well, I have everything on hand from ATF+4, Ford Type F, 30wt HD, HY Gard, HY Trans, Transcend, 10/40, 5/20, but no Dexron VI as luck has it. I will need to get some. When this transmission was designed, and made in the late 60's Type A transmission fluid was the best oil for it. So that is what's called for, but if those engineers had the oil formulations we have today, Type A probably would not be the best choice. Aside from Type A being obsolete that is why I asked what to use. The filter on the transmission was a Napa Gold 1521, is that a good replacement? Does anyone know if there is any yellow metal in the tiller? Thanks Share this post Link to post Share on other sites
squonk 41,291 #10 Posted May 27, 2023 That filter is wrong. You need a Napa 1410. Also use Dexron/Mercon if you don't want to use synthetic. Share this post Link to post Share on other sites
fullchoke 22 #11 Posted May 27, 2023 If I do see synthetic on sale, is it called Dexron/Mercon Synthetic, or is there a certain name and weight I should look for? 1521 being the wrong filter, did it cause problems? Thanks Share this post Link to post Share on other sites
squonk 41,291 #12 Posted May 27, 2023 1521 is an automotive engine oil filter. Same threads and gasket just different internals and it would do very little damage if any. Dexron/ Mercon is a dino oil trans fluid. Dex Vi is synthetic. Personally I used Dex Merc on a Hydrogear I had. Share this post Link to post Share on other sites
fullchoke 22 #13 Posted May 27, 2023 I looked up the differences between the 1410 & 1521. The both had the same filtering material at 21 micron. They both flowed the same rate, but the 1521 had a anti-drain back valve, and a by-pass valve. With those extras it costs less. Is it wrong because it could hold oil in the filter and be over the full level in the transmission? Probably the 1410 costs more because it's use is more limited, and maybe it can hold more pressure, being industrial rated. Just guessing. Share this post Link to post Share on other sites
19richie66 17,522 #14 Posted May 27, 2023 (edited) I believe the 1410 is designated a hydraulic filter. The wheelhorse filters cross over to this one. Never had an issue using them. Edited May 27, 2023 by 19richie66 Share this post Link to post Share on other sites
fullchoke 22 #15 Posted May 27, 2023 I bought the napa 1410, and Dexron VI. Now I just need to start feeling better to get some ambition up. As far as Tiller gear oil, I bought a full synthetic thinking it wouldn't have the additives that harm yellow metal like Dino GL5 gear oil, They did have GL1 but only by the gallon. If anyone has been into a wheelhorse tiller, I would like to know if there are any concerns with GL5, as I think by the 70's the tiller gearbox would have been considered modern. Once I get everything working (fingers crossed, as I bought this machine as a non-runner) I'll post up a picture of it. Thanks 1 1 Share this post Link to post Share on other sites
oliver2-44 9,848 #16 Posted May 28, 2023 We used GL5 in many old 1940-50 gearboxes with brass worm and pinion back at my work before I retired. The Conoco/Phillips lube engineer I worked with said GL5 was only a concern with brass gears that operated heavily loaded and at high temperatures. 1 Share this post Link to post Share on other sites
fullchoke 22 #17 Posted May 30, 2023 I got all of the fluids and filters changed. Removed the sickle bar mower, as I don't have any use for that. Mounted the tiller. Just drove it around to my back yard, but haven't done any work with it yet. The engine seems strong...no smoke, but it only has 826 hours on it so it should have quite a bit of life left. Thinking about how much use I'm going to get out of it makes me think I probably should consider selling it. This is the only GT-14 I have seen so I don't know how much it's worth out here in Oregon. Liking vintage equipment was my only real reason for buying it in the 1st place. I promised a photo or 2, so here they are. Thanks for the help in getting this little tractor going again. 1 2 Share this post Link to post Share on other sites