OK oil gurus, I'm planning on changing my transmission and transfer case fluid soon and wanted some opinions. I have Motorcraft fluid in there now but am planning on changing with Mobil1 synthetic. Is there anything else I should consider? Amsoil is not an option, so please don't suggest that. Oh ya, it's a 1997 F250 with a ZF-5.

 

I can't belive it. John Diesel, one of the Gurus of FTE asking a question. Amazing. I thought he was one of our diesel gods. Oh well, it's good to have you on our side of the fence for a change John..Welcome.. ................
FWIW, my '97 F-350 , E4od is due for a fluid change and the manual says that the right type is Mercon but it isn't stocked anymore. I called the Ford dealer today, fwiw, and he told me Mercon/Dextron III was ok. to use. I'll call another dealer for his input tomorrow but was wondering any input from the group. My truck leads a sheltered life so I don't think synthetic is necessary.

 

Thanks for the kind words. Although I am biased towards particular engine oils I am open to suggestions for transmission and transfer case fluids. FTE is a great resource. Although I feel very comfortable with what works behind my PSD the rest of the the truck is a little less black and white in my head.

 

Johnsdiesel: I would run Redline tranny fluid. It has more antiwear additives. The Redline D4 (Dextron III/Mercon) has GL-4 level of antiwear. I called Mobil and they don't even rate their ATF by the GL rating (normally for gear lube), but the tech said if it were rated likely it probably would be GL-3 at best. They ship in 3 days Fed Ex (but will make you sign for the package unless you request otherwise).

I switched my Mazda 5 speed from M1 to Redline D4 and while I really can't say it shifts any better, I like the extra antiwear adds. Also it is compatable with the yellow metal in the tranny.

 

I am also switching my tranny and transfer case lubricant to a synthetic product. I have a '98 Expy with the E4OD and Control-Trac. I will probably use M1 ATF as it seems to be the cheapest. I can get it almost anywhere for $5/qt, and with the E4OD taking 16+ qts and the TC 2 qts, well, you see where I'm coming from. The Royal Purple ATF is about $6.50/qt, the Amsoil ATF about $8/qt, and the Redline D4 ATF about $10/qt. It is simply a question of economics and the fact that M1 ATF can hardly be considered inferior to the other products.

 

Unless you use 4wd a lot, the transfer case is real easy on oil, any ATF is going to work. The ZF is another story. I agree with Paul on the Redline. Although, since you are in TX, not MI, Redline MTL might even be better, mainly because it is friction modified specifically for synchros instead of automatic trans clutches and bands.

Pennzoil and others also make sychromesh transmission fluids, if you dont want to do mail order.

Jim

 

Should I be OK using this instead of ATF? The owner's manual says to use ATF but at almost 168K I care about what works best since the warranty is long gone.

 

Thanks to those of you who responded already. Very good information. Anyone else? Where are all the "usual" members posts?

 

Hrm. This is an interesting question. I'm going to take a slightly different approach to this.

I say just run the Motorcraft. Do you have any reason to think it's not working good? When you move to synthetic, there is an increased chance of leakage. And with a manual transmission, that doesn't get checked often, a little leakage can turn into a big problem. If you want the additives, throw a quart of the redline in there with the motorcraft to save some money.

 

Thanks for the input rusty70f100.

 

hey i did not know that syn. has better chance of leaking. is this true.

 

The change of synthetic leaking appears to be more a case to case thing. It was more common back in the day..but as today's dino oil has become so fantastic, the chance of synthetics finding a place to leak is severely diminished. This is the way things have been painted for me from our oil guys on the board. If your engine doesn't leak today with dino, it shouldn't leak with synthetic either. But there are cases. Same with Differential and Transfer Cases as well.

Rusty does bring up a very good idea. It'd also be very good from the economics perspective.

You can't go wrong by switching over to Mobil 1 or another quality synthetic lube. Redline would definately have to be the pinnacle as far as your fluids are concerned. With something new like that, I'd want the added comfort of Mobil 1 or better in there. My F150 is doing just fine on its diet of Orielly's generic ATF though, so *shrug* its up to you. If it weren't for me not wanting to open the transmission again...I'd probably switch it over to Mobil 1 or something (even B&M Trickshift, anything lol).

With manual transmissions, wouldn't a Type F ATF be the best ATF to use, as opposed to Mercon-spec fluids?

With my Mazda..I didn't think it'd care what it had - and I didn't care what it had as long as it wasn't gear oil. It's got Mercon/Dexron crap in it, and it does fine. I ought to switch over..but I'll give her some time.

 

Go with Motorcraft Mercon Synthetic. Good product, good value, OEM spec.

 

I'm not a big fan of Valvoline...but I like the transmission fluid. I have the MaxLife ATF in my transfer case. At 120K miles, I figure a seal conditioner or two couldnt hurt.

 

The only problem with that is limited availability.