What is everyone running in there diffs/manual tranny? I'm looking at switching to synthetic all around (except engine). Anyone running aftermarket covers to aid in cooling? How about manual tranny cooling systems?
I like to go with Redline for anything that I don't need to change a lot - diffs, trannys, etc. For the Allison, I'll stick with the recommended Transynd. I use Shell Rotella-T Synthetic in the D-max, all Redline in my quads, and Mobil-1 in everything else.
I got RedLine products in mine ( tranny , T/C , and diff's). I also put a F-450 Dana 80 rear finned aluminium diff cover to help disapate heat . From what I understand Spicer put the finned cover on the F-450's because they came with a 4.88 plus gear and felt the pinion speed was fast enough to warrant help in cooling - I figured it could not hurt on my 4.10 geared Dana 80 . Tom
This is just hearsay, but I heard the Redline shockproof gear oil provides so much cushion that the gears hardly mesh, they're just moving through the lube. Whether this is true or not, I'm still going to switch to that for my tranny fairly soon. I'll probably let it get broken in for another 5,000 miles or so before switching. It still shifts like an unsynchronized tranny right now. Rear lube is already synthetic so I'll just leave it be for now.
I asked the tech dept. at Red Line about the shock proof oil but they did not recomend it for prolonged driving . I think it is FANTASTIC stuff but I do not know if it will hold up at continous service levels. Tom
Yup, Shockproof is a race-only item. It does not have the modifiers required for sustained high-heat. However, Redline does have products meant for long-term street use. Their tech department is very helpful, give them a call. Any dealer can also call for you. Bay Area guys, the best price I've found out here is at Monument Auto parts in Livermore, just FYI. I use Shockproof exclusively in my quad trannys, but I change all fluids every 5-10 hours. That is one expensive oil change. The stuff is amazing, it's like freakin' glue - sticks to EVERYTHING. Plus the lightweight is a purty blue.
I don't know about the extended life problems people spoke of with Redline but I run it in my diffs in the K5. I have for 3 years now with no problems what so ever. I have done a couple gear oil changes in that time and every time it was just fine. I have logged about 40,000 miles on Redline gear oil. It has not seen any prolonged loads like heavy towing though. Just rockcrawling and light towing. I have done a couple 500+ mile trips on it and am ok sofar. Harley
I am so glad to hear you have a good report on more than race track usage. I really want to run the shock proof stuff in my Blazer since it will not see much street usage. I am still doubtful on putting it in my Dodge because of the RedLine Tech's warning not to but I plan on trying it in my K5. Tom
Yep, I have run it for awhile. I run the Redline Heavy Shockproof gear oil front and rear. 14bff welded rear and 10 bolt locked front. Redline is some great stuff. It is expensive though. The cheapest I can find it local is $9.45 per quart. Needless to say I don't change my gear oil often and if I drop my diff cover I catch it and put it back in. The stuff I run sticks to everything. It is very thick though and is a PITA to pour. If you are doing to be filling diffs I would recommend leaving the bottles out in the sun or warming them up. A fluid pump is a joy to have too otherwise it is a long slow pouring process. I run a lockright in my 10 bolt front and with this gear oil it doesn't make a single sound. Most people complain that there lockrights bang and pop. I have never heard mine utter a sound while bathed in Redline. Harley
I'm really not convinced of the value of any of the high dollar lubes. The synthetics have value in being longer lasting before breaking down, so that offsets the extra cost for the most part, depending on what you do (i.e. using the extra life AND being comfortable doing so). And the redline shock proof stuff certainly has value for racing applications where drive train shock can and does do damage. These things I can understand and see the value, so I say this to give credit where due. But I have seen a LD trucks click over 300k on regularly changed (by normal service interval) "cheap stuff" without any problems at all, or "million mile" OTR trucks that did just fine on "good stuff" before all these fancy "Slick 50" type lubes became so popular. As an example, my father in law had a 70ish Dodge with 318, TF, and 1/2 ton axles. He drove it back and forth to work something like 50 miles each way for year upon year. He also used it on the private farm he fooled with towing feed trailers, stock trailer, implements, and equipment (including a full size Ford tractor) with that 1/2 ton truck, and WAY over loaded was not uncommon. And at 300k he had the FIRST major work done to that truck with an engine rebuild because it got so bad it was burning/leaking over a quart each day on his trip to work. He is retired now but that truck is still being used to this day for the "farm work" and is now approaching 400k without ever having any diff work done. And that man would NEVER buy anything except the cheapest random oil/lube he could get at the co-op or local discount, or whatever. Not sure about the other stuff, but I know the engine oil brand changed with the weather and whatever was on sale. The only thing I can say as to why he gets such great service from everything is that he kept logs on everything and tracked the mileage/hours used on vehicles/equipment and changed lubes religiously on schedule. IMO, *THAT* is what is important. The high dollar fancy stuff doesn't seem to make that much difference other than in some extreme duty areas like drag racing and such. For normal tow rig duties, I can't see needing anything more than good quality GL5 (or whatever spec'd) changed as recommended. I run the over priced (IMO) GM synthetic in my HD due only to potential warranty issues. I may continue to run it on my next change (out of warranty) but only if I can find some supporting evidence that "tighter machining" has made the particular properties of the "grape juice" a significant value. However, I doubt that is the case since the manual, IIRC, specs GL5 compatibility, but too lazy to go double check right now... In my truggy, I run the Wal-Mart gear oil in gallon jugs, don't even remember the name at the moment. Seems like it has to get changed for one reason or another rather frequently and I sure don't see any value in the high dollar stuff. And I also see no wear issues at all in that application. My Detroit also seems to be fine with the cheap stuff, though after Harley's post, I wonder if it might have helped my front Lock-Rite live a little longer, but it was trying to turn 42" tires, so maybe not… Just my perspective, your mileage may vary.
I agree with bad dog on this. I run 80/140 in my stuff and have 2 5 gallons pails in the garage now. But I know I may have warranty problems as Eaton wants sythetic gear lube used with their axles. I change the lube in my axles every 2 years or less.
Since synthetics are supposed to resist breakdown and tolerate higher running temps better than conventional oil it will be synthetic in my rearends because it doesn't cost much more at all and I don't want to have to change the oil very often, plus I can imagine how hard the rearend works, inlcuding the oil, when dragging 18-20K gross rig down the highway at 60mph in 100* weather, it's got to be brutal on the rearend in my opinion and any extra help the syn. delivers is well worth it IMHO.
How hard can they be working, I've never had them get over 150*F. Now my 15 spd needs either sythetic and or a cooler as I've had it get to close to 250*F on a hot day running in some big hills. And its funny as the trans temps run about 5-10*F hotter going downhill against the jakes than going uphill.
Hey, if it's good enough to be used in an MD or HD, it must be GREAT for an LD, right? rotfl Actually, I'm really glad to see the temp information. I've never seen an LD with diff temp gauges, and while they may be quite different if we knew, this is likely as close as we will get unless someone else has the gauges...
