How often should dino gear oil be changed?

[01rangerxl]

Ford says to change the gear oil in the diff on my truck every 100K (or something crazy like that), but the factory fill was synthetic. I have already changed the gear oil before (and it needed it bad) with synthetic, but this time I am thinking about switching to Rotella T gear oil which is dino. Would I have to change the gear oil more often with dino, or would a roughly 30K mile interval still be OK? Rotella T seems like it would be a good fit for the truck considering it does get used like a truck, but I do not want to have to change the gear oil every 15K.

The truck is a 2001 Ranger with a 7.5" open rear axle.

Also, the M5OD manual transmission in the truck requires ATF. How often should dino ATF in a manual transmission be changed? Every 30K miles? The only synthetic ATF I have found in stores around here is the "one fluid fits all" Mobil. I would feel better using a Mercon/Dexron III only ATF, but I can only find it in dino.

[ May 09, 2006, 10:13 PM: Message edited by: 01rangerxl ]

 

[reyjay1]

It depends on the use. If the truck is heavily loaded all of the time the interval can be much shorter with mineral gear oil. Case in point, the SD F250-350's have a longer change interval with synthetic HD gear oil, but if in heavy use or use in which the differential can get warm, the change interval can be as little as 3000 mi with conventional lube. If you are running around unloaded all of the time you can most likely get by with longer, but to be sure you probably need to know what the max temperature of the differential is getting to regularly. For peace of mind I would switch it out early with quality syn lube in the recomended weight.

For the ATF I would have no worry putting the synthetic Mercon V products in your MT. Or even better one of Molecules MT fluids that he recommends specifically for that application. There is Full Synthetic Mercon (non V) still around, Amsoil, RP are avilable at least by order if no-one carries in your area, and valvoline does make a synthetic Mercon that I found by the drum at a local oil Valvoline oil change shop, which is not readily available OTC. Albeit it is probably GIII product, but it was straight Mercon. Again I have good confidence in the Mobil M1 Mercon/Mercon V product for any MT calling for a Mercon ATF lube.

 

[ConfederateTyrant]

I would not leave the dino gear oil in there for long, maybe 5,000 miles max. I left Castrol 80w-90 in my car's differential for 9,000 miles, and it came out discolored and was a lot thicker than when it went in (this may not mean jack-****, but it was an observation that I was not happy with). However, using a full synthetic gear oil should be able to get you 30,000-50,000 miles out of the use, probably longer. Amsoil's gear lubes are recommended for 100,000 miles in light duty trucks and passenger cars.

Amsoil and Mobil 1 ATF will not cause any issues, they are multi-vehicle formulas, and they are recommended for DexronIII/Mercon replacements. I would not hesitate to use either of them. If you want one that is not multi-vehicle, Red Line's Synthetic D4 ATF is for Dexron III, II, Mercon, and Mercon V, http://www.redlineoil.com/pdf/3.pdf Check your owner's manual for change intervals on the transmission. Synthetics can go longer than 30,000 miles, I would change dino ATF out every 15,000-20,000 miles, unless the manual states longer.

 

[sambojoho]

I've had two Rangers that I've run to 200k miles and beyond. I always changed the ATF in the manual transmission and the 80/90 differential gear oil every 30k miles, with Conventional oil. Usually used the cheapest stuff I could find that met spec (like supertech). Never had any problems.

Only problem I ever experienced is the manuals had three rubber plugs on the top of the transmission by the shifter that always leaked ATF at around 75k miles (they tended to shrink over time). Just replacing these plugs with new from the dealer every 50k or so might be good preventative maintenance.

One tip for refilling the transmission. route a length of rubber hose up through the engine compartment with the lower end stuck in the fill hole, and attach the upper end to a funnel. This made refilling a breeze.

 

[Tempest]

I have a 99' Ranger also with manual transmission. I just switched out the factory fills in both the transmission (ATF) and dif (75W-90 Severe gear) with AMSOIL products and am very happy. Shifting is much smoother than before and I would highly recommend the product.

With good quality synthetic's that will last at least twice as long as dino, why not go with the good stuff and spend more time vertical.

 

[mikeinaustin]

sorry for hijacking this thread, so ford uses synthetic diff fluid now....does anyone know what infiniti uses in its differentials? [g35 coupe with VLSD to be specific].

 

[Kestas]

Unless somebody on this site knows, you may get your answer here:
Infinity forum

 

[01rangerxl]

quote:

---

Originally posted by sambojoho:
I've had two Rangers that I've run to 200k miles and beyond. I always changed the ATF in the manual transmission and the 80/90 differential gear oil every 30k miles, with Conventional oil. Usually used the cheapest stuff I could find that met spec (like supertech). Never had any problems.

Only problem I ever experienced is the manuals had three rubber plugs on the top of the transmission by the shifter that always leaked ATF at around 75k miles (they tended to shrink over time). Just replacing these plugs with new from the dealer every 50k or so might be good preventative maintenance.

One tip for refilling the transmission. route a length of rubber hose up through the engine compartment with the lower end stuck in the fill hole, and attach the upper end to a funnel. This made refilling a breeze.

---

That's a good tip for filling the transmission. Thanks.

Do you remember what the part number is for the plugs? I know which ones you are talking about and have heard about them leaking, but I didn't know how long they usually lasted. The truck has 72K miles on it, so I should probably get some replacements soon.

Thanks for all the advice everyone.

 

[mechtech]

You can't be MolaKule's expert advice, but my two cents are to change it every couple of years.
If you somehow get water in the vent hole [not uncommon], change it immediately.

 

[MolaKule]

For the most diffys, I recommend changing the fluid at 5,000 miles when new, and then using a good synthetic with 30,000 mile OCI's.

Since about 1998, Ford has been using a very good factory fill synthetic, but I would never let the diffy fluid go with a 100,000 k OCI.

 

[sambojoho]

quote:

---

Originally posted by 01rangerxl:

quote:

---

Originally posted by sambojoho:
I've had two Rangers that I've run to 200k miles and beyond. I always changed the ATF in the manual transmission and the 80/90 differential gear oil every 30k miles, with Conventional oil. Usually used the cheapest stuff I could find that met spec (like supertech). Never had any problems.

Only problem I ever experienced is the manuals had three rubber plugs on the top of the transmission by the shifter that always leaked ATF at around 75k miles (they tended to shrink over time). Just replacing these plugs with new from the dealer every 50k or so might be good preventative maintenance.

One tip for refilling the transmission. route a length of rubber hose up through the engine compartment with the lower end stuck in the fill hole, and attach the upper end to a funnel. This made refilling a breeze.

---

That's a good tip for filling the transmission. Thanks.

Do you remember what the part number is for the plugs? I know which ones you are talking about and have heard about them leaking, but I didn't know how long they usually lasted. The truck has 72K miles on it, so I should probably get some replacements soon.

Thanks for all the advice everyone.

---

No, I don't remember the part number for the plugs, but my dealer was able to find them pretty quickly in their system. They were around $2-$3 each.

 

[Titan]

To answer your question: How often should a dino fluid be changed? The answer is: drum-roll

ONCE, to a synthetic put together my Molakule. At least, that's what I'm doing.

 

[therealdeal770]

man i didnt even know you were supposed to change rearend or manual transmission fluid.i bet mines in bad shape with 127***miles on both.

 

[Titan]

trd770, you'd be nauseated by the junk in there if you saw it!

 

[01rangerxl]

I just looked at the recommended maintenence schedule for my truck - printed directly from Ford's web site. It looks like I was 50K miles off with the differential fluid change interval. It's 150K miles! I don't think so! I don't trust any oil to last that long.

 

[ConfederateTyrant]

150,000 miles? That's pretty crazy, you want to get all of those break-in wetals out of there and put in fresh fluid before attempting to go long drains with the differential. I ran the original gear oil in my Grand Marquis (during Ford's recommendation for 100,000 mile service) for 90,000 miles and it was filthy looking.

 

[Dave Hess]

I wonder how hot does the gear oil get inside a differential?

Anybody know?

 

[TheLoneRanger]

quote:

---

Only problem I ever experienced is the manuals had three rubber plugs on the top of the transmission by the shifter that always leaked ATF at around 75k miles (they tended to shrink over time). Just replacing these plugs with new from the dealer every 50k or so might be good preventative maintenance.

---

There's a common retrofit that replaces the rubber plugs with metal plugs (freeze or casting plugs), for a more permanent fix.

 

[oilyriser]

change often if you launch boats with it, and water might get into the diff

 

[bruce381]

when total wear metals exceed 100ppm.
bruce