1qt 75w90 1qt 85w140 in front diff 05 Silverado

[350Rocket]

I just changed my front gear oil in my 254k mile 2005 Silverado last night. The diff is quiet and fluid stays clean looking (I think the last couple changes went 30-50k miles) but it has had leaking axle seals since like 140k miles and there is a significant amount of metal shavings stuck to the drain plug, the last 2 changes. Less on the last one, but I think I went a short OCI.
Sorry I don't have an actual uoa, it was just a visual inspection and I thought to ask for opinions after doing it.
It has always run 80w90 conventional hyoid previously as that's what it calls for. This time I bought one bottle of clearance 85w140 Redline synthetic hyoid (last bottle they had) and 1 bottle of 75w90 of the same stuff. I can't imagine that with the wear this thing probably has by now that the mix of these 2 viscosities would be a problem for it, especially going from conventional to synthetic.
What do you guys think?
Next time I am ordering from amsoil because I want to use the little baggies that I can squeeze in.
Thanks.

 

[JHZR2]

Probably fine. Remember that the old 90 spec went higher, so you’ll have a 110 viscosity which is good.

How murky is that oil though? I recall from my S-10 that what came out didn’t look great for sure, just because I could tell it built up condensation.

 

[350Rocket]

Probably fine. Remember that the old 90 spec went higher, so you’ll have a 110 viscosity which is good.

How murky is that oil though? I recall from my S-10 that what came out didn’t look great for sure, just because I could tell it built up condensation.

I almost wasn't going to change it because it looked so clean but I did want to upgrade to better oil to try to extend its life. I think it was worth it just to clean all the shavings off the drain plug....but it was almost as clear as the new fluid going in. I don't leave 4wd on for very long periods of driving though, even in snowstorms.
I've seen some nasty ones in my day if changing oil in the Pennzoil express lube, but I suspect most of those had over 100k miles on the fluid. It was also common to see signs of water in front diffs on Ford's.

 

[zrxkawboy]

I would feel comfortable mixing them, since they are the same brand.

 

[fantastic]

Personally I'd of went totally to the 75-140 but your doing well by changing the fluid. The Dana 60 on the front of the F350 was quite clean while the 80k rear Dana 80 was black with a good chunk of metal on the magnet. Dana wants 75-90 in the rear but I decided after seeing that metal & the black oil I'd go to the 75-140. I'd say you've gotten a good lifespan out of your diff's at 254k though.

 

[350Rocket]

Personally I'd of went totally to the 75-140 but your doing well by changing the fluid. The Dana 60 on the front of the F350 was quite clean while the 80k rear Dana 80 was black with a good chunk of metal on the magnet. Dana wants 75-90 in the rear but I decided after seeing that metal & the black oil I'd go to the 75-140. I'd say you've gotten a good lifespan out of your diff's at 254k though.

I actually was considering running it all the 85w140, however it was the last one there, old stock on sale for like $7 off so I got it and 1qt of the 75w90. They are at least the same spec and the exact same type of redline gear oil other than the viscosity so I wasn't too worried about mixing.
I'm hoping both of my diffs make it to 400k. I thought the rear diff was gone a couple months ago, some clunking back there, but the trans shop I took it too said there was basically no metal on the magnet and everything looked in good shape. They didn't recommend replacing anything so it just got new fluid.
I assume I'll have to replace the 4L60E by 350k but maybe I'll get lucky.

 

[fantastic]

I actually was considering running it all the 85w140, however it was the last one there, old stock on sale for like $7 off so I got it and 1qt of the 75w90. They are at least the same spec and the exact same type of redline gear oil other than the viscosity so I wasn't too worried about mixing.
I'm hoping both of my diffs make it to 400k. I thought the rear diff was gone a couple months ago, some clunking back there, but the trans shop I took it too said there was basically no metal on the magnet and everything looked in good shape. They didn't recommend replacing anything so it just got new fluid.
I assume I'll have to replace the 4L60E by 350k but maybe I'll get lucky.

Yes, understood and good luck.

 

[benjy]

redline makes a 75-110, i went from nissans semi syn 75-140 to reds 75-90 real synthetic + increased my mpgs by 2-3 but only 54 thou on my 11 fronty now

 

[350Rocket]

redline makes a 75-110, i went from nissans semi syn 75-140 to reds 75-90 real synthetic + increased my mpgs by 2-3 but only 54 thou on my 11 fronty now

Yeah I noticed that but they didn't have it in stock where I bought this stuff. This mixture should be pretty close to that I guess.

My next purchase will absolutely be amsoil just for the easy squeeze baggies. It was very messy jamming the plastic gear oil bottle up into the fill port of the diff that's been leaking for many many years and I spray rustproofing under this truck like my life depends on it. So it's very messy.

Not sure what viscosity I will go with next time. So far I haven't checked gas mileage but the butt dyno didn't feel any change with the thicker viscosity.

 

[tblt44]

I just put 1.5 quarts valvoline 75w 140 and 2 o.z. of at 205 re-seal in hopes to stop my leak in my front diff of my 2003 Avalanche w/225k

 

[I<3oil]

Yeah I noticed that but they didn't have it in stock where I bought this stuff. This mixture should be pretty close to that I guess.

My next purchase will absolutely be amsoil just for the easy squeeze baggies. It was very messy jamming the plastic gear oil bottle up into the fill port of the diff that's been leaking for many many years and I spray rustproofing under this truck like my life depends on it. So it's very messy.

Not sure what viscosity I will go with next time. So far I haven't checked gas mileage but the butt dyno didn't feel any change with the thicker viscosity.

Valvoline has the flex pouches too and for sale on Amazon or at Walmart.

 

[350Rocket]

I just put 1.5 quarts valvoline 75w 140 and 2 o.z. of at 205 re-seal in hopes to stop my leak in my front diff of my 2003 Avalanche w/225k

I'm interested to hear if it helps. Won't really know if it was the change in viscosity or the at205 though. I can change to straight 75w140 at the start of summer though, since it will be more ideal when it's not below freezing all the time.

 

[350Rocket]

[QUOTE="I Valvoline has the flex pouches too and for sale on Amazon or at Walmart.
[/QUOTE]
Probably a US only thing, they don't have them at our Walmart's, but I will check amazon. In the past though I've never been able to buy oil from Amazon as they usually are charging more than list price. Sometimes double. I was wondering if they were selling drugs in these bottles or something.

 

[tblt44]

I'm interested to hear if it helps. Won't really know if it was the change in viscosity or the at205 though. I can change to straight 75w140 at the start of summer though, since it will be more ideal when it's not below freezing all the time.

Let you know in a week
I have bad leaks in both axel seals and looks like the front drive shaft pinion seal.
Put 80w 90 conventional in about 4 months ago and it got worse than with 75w 90 syn

 

[I<3oil]

Probably a US only thing, they don't have them at our Walmart's, but I will check amazon. In the past though I've never been able to buy oil from Amazon as they usually are charging more than list price. Sometimes double. I was wondering if they were selling drugs in these bottles or something.

That stinks

Valvoline Flex Fill SAE 75W-90 Full Synthetic Gear Oil 1 QT Squeeze Pouch
https://www.walmart.com/ip/329480316

 

[350Rocket]

[QUOTE="I That stinks

Valvoline Flex Fill SAE 75W-90 Full Synthetic Gear Oil 1 QT Squeeze Pouch
https://www.walmart.com/ip/329480316
[/QUOTE]
Thanks. I tried that but it's only a US option. Wants me to pick up in California (a few days drive I think lol). Also double checked Amazon and they didn't have the pouches and most of what they did have was either overpriced or a 12qt bulk package.

 

[I<3oil]

Thanks. I tried that but it's only a US option. Wants me to pick up in California (a few days drive I think lol). Also double checked Amazon and they didn't have the pouches and most of what they did have was either overpriced or a 12qt bulk package.

Dang.

Here’s the pouches on Amazon USA: Valvoline FlexFill Full Synthetic SAE 75W-140 Gear Oil 1 QT Pouch https://a.co/d/6Ko7noF

 

[350Rocket]

[QUOTE="I Dang.

Here’s the pouches on Amazon USA: Valvoline FlexFill Full Synthetic SAE 75W-140 Gear Oil 1 QT Pouch https://a.co/d/6Ko7noF
[/QUOTE]
Was able to open the page and it says currently unavailable. I don't believe they let us order from the US site anyway.
Not a big deal, for 2qts I don't mind paying a little extra for amsoil, especially since I'm hoping this diff will last another 200k. I couldn't justify amsoil price when it came to transmission fluid, but that's like 12qts do a complete fluid exchange

 

[tblt44]

Let you know in a week
I have bad leaks in both axel seals and looks like the front drive shaft pinion seal.
Put 80w 90 conventional in about 4 months ago and it got worse than with 75w 90 syn

Well 75w-140 or the seal conditioner did not work.
Looks like front axel sharft seal replacement soon. Still leaking pretty bad. The drivers sidecs leaking the worst, this looks like the easiest of the two to replace

 

[350Rocket]

Well 75w-140 or the seal conditioner did not work.
Looks like front axel sharft seal replacement soon. Still leaking pretty bad. The drivers sidecs leaking the worst, this looks like the easiest of the two to replace

Sorry to hear that. How often do you have to top yours up? My current plans are only to replace mine if the level starts to drop quicker, or the oil pickup tube O ring starts to fail (which means my first priority is to fix the oil pressure sender so I can monitor that again). Before that failed a few months ago I still had around 34 psi hot idle and plenty on colder start.