Diff Fluids
07-23-2003, 09:41 AM
#1
Registered User
Thread Starter
Join Date: Jul 2003
Location: Grass Valley, California
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
Diff Fluids
The dealer wants $75/diff to change the fluid...pretty steep! Is there anything special about the fluid? I have a standard Dana 60F in front and a limited slip Dana 80 in the rear. <br><br>Please help me save some money here.<br><br>John
07-23-2003, 09:54 AM
#2
Registered User
Join Date: Feb 2002
Location: Sturbridge, Taxachusetts
Posts: 1,424
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
John, the diffs are easy to do, even for this amateur wrench turner. You'll need a thin putty knife to tap into the cover joint to break the seal, and a tube of blue RTV gasket maker. Go for it!
07-23-2003, 10:02 AM
#4
Registered User
Join Date: Feb 2002
Location: Sturbridge, Taxachusetts
Posts: 1,424
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
I have an '02 and there was no fiber gasket, just lots of silicone. Use a single edge razor to clean the surfaces, and protect the gears with newspaper or a rag while you're scraping the old stuff off. Might want to use some acetone or brake cleaner to degrease the mating surfaces before applying the RTV.
07-23-2003, 10:06 AM
#5
Registered User
Join Date: Aug 2002
Location: El Dorado Hills, CA
Posts: 138
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
The first time I did it, I didn't even remove the cover. I just used a suction gun to pull it out. The second time, I had to remove the cover because it got hit by a brake drum traveling at about 60 MPH (I was doing about the same speed, do the math)
Anyway, the parts guy recommended some Permatex Hypalon (or something like that), which DOES NOT WORK. It stays in a jelly-like consistency. Good for gasket dressing I suppose, but not good for "gasket-making". The stuff that was originally on there was gray silicone, and heavier than usual. I believe I found what they use, and it is "Permatex Ultra Gray" it is much thicker in consistency than the usual RTV, and it worked great even with my dinged up cover.
I don't want to start an "oil war", I am not passionate about one brand over the other. I used Valvoline Dura-Blend 85W-140 and that is some pretty amazing stuff, judging by the spot in the driveway that remained shiny and wet after detergent, simple green, pressure washing, and even cat litter and paint thinner and even lacquer thinner. I finally got it up using naptha and cat litter twice. In my experience with gear oil (a lot), I've never seen anything so tenacious. Not that pouring oil on concrete is anything like scientific testing
Anyway, the parts guy recommended some Permatex Hypalon (or something like that), which DOES NOT WORK. It stays in a jelly-like consistency. Good for gasket dressing I suppose, but not good for "gasket-making". The stuff that was originally on there was gray silicone, and heavier than usual. I believe I found what they use, and it is "Permatex Ultra Gray" it is much thicker in consistency than the usual RTV, and it worked great even with my dinged up cover.
I don't want to start an "oil war", I am not passionate about one brand over the other. I used Valvoline Dura-Blend 85W-140 and that is some pretty amazing stuff, judging by the spot in the driveway that remained shiny and wet after detergent, simple green, pressure washing, and even cat litter and paint thinner and even lacquer thinner. I finally got it up using naptha and cat litter twice. In my experience with gear oil (a lot), I've never seen anything so tenacious. Not that pouring oil on concrete is anything like scientific testing
07-23-2003, 10:12 AM
#6
Registered User
Join Date: Aug 2002
Location: El Dorado Hills, CA
Posts: 138
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
Oh yeah, also what Commatoze said, anytime you're using RTV, the mating surfaces must be completely clean and oil-free to get decent adhesion.<br>
07-23-2003, 10:17 AM
#7
Registered User
Join Date: Feb 2002
Location: Sturbridge, Taxachusetts
Posts: 1,424
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
Good point about leaving the cover on for one change. I found a big magnet mounted to my cover that was really doing its job. It probably wouldn't hurt to suck out the old lube instead of breaking the cover off.
Trending Topics
07-23-2003, 10:33 AM
#8
Registered User
Join Date: Aug 2001
Location: Kathleen, GA
Posts: 269
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
But if you are going to take the covers off, you may want to change to synthetics. Go 75W-140 for towing. Regular driving, go with the 75W-90. I switched to Valvoline Synthetic. No friction modifier required and the LSD works great.
07-23-2003, 12:23 PM
#9
Guest
Posts: n/a
Re:Diff Fluids
[quote author=emjay link=board=5;threadid=17433;start=#163139 date=1058973170]
Oh yeah, also what Commatoze said, anytime you're using RTV, the mating surfaces must be completely clean and oil-free to get decent adhesion.
[/quote]
A possible exception to that is a silicon material sold at Suzuki shops - it is their 1216 silicon, and sells for about $25 a tube - demos with this stuff show it will seal mating surfaces even when it is applied SUBMERGED in oil!
One tube goes a long ways, and I've NEVER had a hint of a leak with it... I've done a couple of differential covers and a couple of lawnmower engine cases with it...
Oh yeah, also what Commatoze said, anytime you're using RTV, the mating surfaces must be completely clean and oil-free to get decent adhesion.
[/quote]
A possible exception to that is a silicon material sold at Suzuki shops - it is their 1216 silicon, and sells for about $25 a tube - demos with this stuff show it will seal mating surfaces even when it is applied SUBMERGED in oil!
One tube goes a long ways, and I've NEVER had a hint of a leak with it... I've done a couple of differential covers and a couple of lawnmower engine cases with it...
07-23-2003, 12:44 PM
#10
Registered User
Join Date: Aug 2002
Location: El Dorado Hills, CA
Posts: 138
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
That sounds impressive! Good tip. I always use Permatex #2 on anything that holds gear oil with a gasket. That stuff will seal oily surfaces well, too.<br>
07-23-2003, 03:50 PM
#11
Registered User
Join Date: Aug 2002
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Re:Diff Fluids
[quote author=Smoke Dog link=board=5;threadid=17433;start=0#163149 date=1058974385]<br>But if you are going to take the covers off, you may want to change to synthetics. Go 75W-140 for towing. Regular driving, go with the 75W-90. I switched to Valvoline Synthetic. No friction modifier required and the LSD works great.<br>[/quote]<br><br><br>What about Friction modifiers for Limited Slip?? Is it necessary or does synthetic gear oil not require it ???
07-23-2003, 04:23 PM
#12
Guest
Posts: n/a
Re:Diff Fluids
[quote author=rschaer link=board=5;threadid=17433;start=#163275 date=1058993439]
[quote author=Smoke Dog link=board=5;threadid=17433;start=0#163149 date=1058974385]
But if you are going to take the covers off, you may want to change to synthetics. Go 75W-140 for towing. Regular driving, go with the 75W-90. I switched to Valvoline Synthetic. No friction modifier required and the LSD works great.
[/quote]
What about Friction modifiers for Limited Slip?? Is it necessary or does synthetic gear oil not require it ???
[/quote]
I use Valvoline "synthetic blend" 75/140 in my differential too, because a pure synthetic I had tried previously rendered my LSD worthless - the Valvoline stuff SHOULD give me added protection in towing service, and my LSD functions just as I like it once again, and no, no friction modifier was required in my case - but clutch packs in these differentials DO vary in operation... A fair number of guys trying the synthetics have reported poor-to-no LSD action after switching due to the added slipperyness of the synthetic that causes the LS clutches to lose their grip...
So far, the "synthetic blend", or mix of synthetic/dino lube seems to work for me...
[quote author=Smoke Dog link=board=5;threadid=17433;start=0#163149 date=1058974385]
But if you are going to take the covers off, you may want to change to synthetics. Go 75W-140 for towing. Regular driving, go with the 75W-90. I switched to Valvoline Synthetic. No friction modifier required and the LSD works great.
[/quote]
What about Friction modifiers for Limited Slip?? Is it necessary or does synthetic gear oil not require it ???
[/quote]
I use Valvoline "synthetic blend" 75/140 in my differential too, because a pure synthetic I had tried previously rendered my LSD worthless - the Valvoline stuff SHOULD give me added protection in towing service, and my LSD functions just as I like it once again, and no, no friction modifier was required in my case - but clutch packs in these differentials DO vary in operation... A fair number of guys trying the synthetics have reported poor-to-no LSD action after switching due to the added slipperyness of the synthetic that causes the LS clutches to lose their grip...
So far, the "synthetic blend", or mix of synthetic/dino lube seems to work for me...
