Does anyone ever just check diff fluid?

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Jun 25, 2009
Just wondering on this, say recommended interval was 30k. At 15k does anyone ever just check the level(assuming you have a fill plug)? If its not leaking, is it just crazy? We all here on BITOG are known to be a little crazy time to time. I was asked to check the rear diff fluid level on a friend's truck and I couldn't understand why he thought it was a normal thing. Granted i dont deal with RWD/AWD vehicles often, i didn't know if it was normal. I check trans fluid often but its a dipstick in the engine bay. No need to crawl under to check a fill plug.
I don't. But I do palm-touch a differential housing 'sensing' temperature once in a year of two, after a >30 minute drive at >60 mph .
I change the diff oil in my 03 V8 4Runner every 60K or so and always check the level before draining. It gets a lot of towing and bumpy unmaintained roads. In 165K+ miles I've never noticed a change in the level that I could measure by sticking my finger in the fill hole. One of these days if I can remember I'm going to check the temperature after some heavy towing in the summer with an IR gun and then after just driving around on good roads with no load.
I do now and again. In automotive vehicles i suppose its not common for the fluid to just be low, but on on larger vehicles semi's etc you'd be surprised how the levels can just be low for not apparent reason. Often the axles aren't fully filled from the factory or because of high load situation and excessive heat some oil will be lost out the vents, or because of the different hub setups wheel seals will go out at random or bearings will wear out and cause wheel seal issues and oil will be lost out the end of the axle. I usually just look for leaks or check for oil at the vent hose, but I will try to check it once or twice a year.
Not only do I check the fluid, I change it and check the breather(bobble head) at the top of the diff to make sure it's still working. Same with the TC & tranny.
I topped off my rear diff (7.625) because of a pinion seal leak and kept an eye on it throughout the summer if that counts. As far as I can tell, the seal is no longer leaking too which is nice. Maybe just enough dirt and oil caked on the seal to slow the leak? Who knows.
I've had a transfer case get immensely low, and the synthetic ATF end up nearly purple with absolutely no sign of leaks. So yes, sort of. I'll check the diff oil after a week of running usually after I change it.
With a very minor pinion dribble, I check level once a year and a small top off every few years. I never do a drain and refill on a diff.
Yes; but only because I have a Mag-Hytec cover on the front and rear differentials and they have a magnetic dipstick making it a 2 minute job.
I used to check differential oil level when I was younger and then a light can on. If I fill it properly and there is no sign of leakage then by definition it must still be OK. That's called modern maturity or laziness-your call. Ed
Don't forget you can lose it through the wheel bearings seals. Keep an eye on the inside of your tire rims in the back. I came across an incident where the guy obviously lost his fluid. The bearing on the driver side heated up and seized, probably due to a lack of lubrication. The C clip failed and the axle and wheel came flying over the median toward my lane. The bearing assembly was so hot it set fire to the grass on the median. SF
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Originally Posted By: Dobbie
Ditto on the -- no leak -- no check. Just drain & refill at the miles interval needed on specific vehicle.
The owners manuals on the new trucks do not suggest ever changing the fluid for the first 150,000 miles. Shameful!
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It really depends. I only do it on customers' cars if there appears to be a leak or if I'm giving it a thorough once-over. I check mine periodically but that could be every 10-15,000 mi. As many diff's as go several hundred thousand miles without being opened up even once, any maintenance is better than most get. Amsoil Severe Gear FTW!
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