transmission and differental fluid

[ET]

I wanted to ask everyone on what fluid they use for the manual transmission and diffs. Would you suggest synthetic or 80w90-140?<br><br>

 

[JTCamp]

I use 80w-90 in the diffs and trans case.

 

[76Broncofromhell]

I use 80W-90 in both, but I was thinking of switching to 75W-140 in the transmission to have a little bit better shifting.

 

[ford67bronco]

80W-90 here too.

 

[67halfcab]

[quote author=jtcamp link=board=5;threadid=12631;start=0#94331 date=1040926883]<br>I use 80w-90 in the diffs and trans case. <br>[/quote]<br><br>I use the same in my diffs and before I pulled the 4spd for the C4 that's what I used in the 4spd.

 

[Explore74]

I would go with synthetic, no matter what weight you choose to go with. I was pulling a trailer(about 4500 lbs) up the pass into Albuquerque and boiled the grease in a fresh rear end. I went into town with a guy we were travelling with and got some mobil 1 rear end grease, put it in, and have never had another problem. I am a BELIEVER in synthetic ever since.

 

[BwoncoHowie]

[quote author=76Broncofromhell link=board=5;threadid=12631;start=0#94434 date=1040951139]<br>I use 80W-90 in both, but I was thinking of switching to 75W-140 in the transmission to have a little bit better shifting.<br>[/quote]<br><br>Bingo,<br>The author here says it right. 80-90 in the diffs. and if you have trouble shifting in colder climates, that 75 weight works very well. If you wanted to pay the extra dough for synthetics, I've heard that it makes the gears run cooler.<br><br>BH

 

[rulebreaker]

[quote author=Explore74 link=board=5;threadid=12631;start=0#94675 date=1041047418]<br>I would go with synthetic, no matter what weight you choose to go with. I was pulling a trailer(about 4500 lbs) up the pass into Albuquerque and boiled the grease in a fresh rear end. I went into town with a guy we were travelling with and got some mobil 1 rear end grease, put it in, and have never had another problem. I am a BELIEVER in synthetic ever since.<br>[/quote]I would go broke using synthetic! It would take 2 gallons to change everything and I HAVE to do this 3 to 4 times a year. Dang mud/water!

 

[SCOTT]

I run Mobil 1 in the engine, Valvoline sythetic dexron III in the C-4 , Mobil 1 75-90w in the differentials and transfer case. The synthetics cost more, but I figure they are worth it in the long run. <br><br>Scott

 

[semprbronc]

[quote author=SCOTT link=board=5;threadid=12631;start=0#94865 date=1041122943]<br>I run Mobil 1 in the engine, Valvoline sythetic dexron III in the C-4 , Mobil 1 75-90w in the differentials and transfer case. The synthetics cost more, but I figure they are worth it in the long run. <br><br>Scott<br>You can run DexronIII? It doesn't have to be type F? I wanted to use Dexron III and the parts store guy said I couldn't do it.[/quote]

 

[Explore74]

dexronIII will just make the trans shift a little softer. It is actually a more stable fluid.

 

[67halfcab]

[quote author=rulebreaker link=board=5;threadid=12631;start=0#94737 date=1041088804]<br>[quote author=Explore74 link=board=5;threadid=12631;start=0#94675 date=1041047418]<br>I would go with synthetic, no matter what weight you choose to go with. I was pulling a trailer(about 4500 lbs) up the pass into Albuquerque and boiled the grease in a fresh rear end. I went into town with a guy we were travelling with and got some mobil 1 rear end grease, put it in, and have never had another problem. I am a BELIEVER in synthetic ever since.<br>[/quote]I would go broke using synthetic! It would take 2 gallons to change everything and I HAVE to do this 3 to 4 times a year. Dang mud/water!<br>[/quote]<br><br>I thought you were intentionally using Mud/Water in your diffs instead of 80-90w ;D ;D ;D

 

[Explore74]

Go broke maintaining it, or go broke fixin it. Whats the difference? My wife still gets torqued up, and I'm still broke. ;D

 

[SCOTT]

Semprbronc,<br>I did quite a bit of research before using the current ATF I am using. The Valvoline synthetic is suitable for Mercon III (GM) Mercon and Mercon V (FORD). Even though all my manuals say I should be running Type F. I went with the Mercon/DexronIII blend because it flows well in very low temperatures (common where i live), especially in a synthetic blend. I found information stating - do not substitute Type F for Mercon, but I have not seen anything saying I cannot substitute Mercon for Type F. I have been running this for several years now and have not had a problem yet. <br><br><br>Scott<br><br>

 

[semprbronc]

Thank-you. Tomorrow I will be heading back to the store...cha-ching.

 

[rulebreaker]

[quote author=Explore74 link=board=5;threadid=12631;start=0#94876 date=1041126342]<br>Go broke maintaining it, or go broke fixin it. Whats the difference? My wife still gets torqued up, and I'm still broke. ;D<br>[/quote]On the other hand how can non synthetic go bad in 3 months?