Profile Picture

Synthetic oil in 9" rear end

Posted By slumlord444 Last Week
You don't have permission to rate!
Author
Message
slumlord444
Posted Last Week
View Quick Profile
Supercharged

Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)

Group: Forum Members
Last Active: 6 hours ago
Posts: 1.1K, Visits: 110.5K
It's been discussed before but I''m having trouble with the search function. Currie says don't use it. Been running it in my T Bird with no problems and planning on using it in another car. What are your thoughts?
55blacktie
Posted Last Week
View Quick Profile
Supercharged

Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)

Group: Forum Members
Last Active: 8 hours ago
Posts: 142, Visits: 211
I have an Auburn limited-slip in my 55 Dana 44. It came with an additive, but I was told not to use synthetic. I don't know that it would be a concern with an open differential. there are synthetics that are safe for hypoid and non-hypoid. 
Ted
Posted Last Week
View Quick Profile
Co-Administrator

Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)Co-Administrator (10.3K reputation)

Group: Administrators
Last Active: 2 days ago
Posts: 6.4K, Visits: 165.5K
My issue with synthetic oil in rear differentials are oil leaks at the pinion seals.  While not every rear will leak oil with synthetic oil, I’ve had enough of them to do so that I’ll not use synthetic oil there.  In those instances where the rears leaked using synthetic oil, switching back to conventional oil stopped the leaks.  Only after replacing several pinion seals in rears that leaked synthetic oil was it finally figured out that the synthetic oil was the problem and not the pinion seals themselves.


Lorena, Texas (South of Waco)


57RancheroJim
Posted Last Week
View Quick Profile
Supercharged

Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)

Group: Forum Members
Last Active: Last Week
Posts: 650, Visits: 96.3K
I'm thinking they must have newer seal materials that can handle synthetic. The old seals don't like it. When I took my 9" in to have new gears, bearings etc I was told there was no problem using it. This was by Hoopers who build tons of rear ends. So this was the first time I used synthetic and I'm reaching the 10,000 mile mark with no leaks.
55blacktie
Posted Last Week
View Quick Profile
Supercharged

Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)Supercharged (345 reputation)

Group: Forum Members
Last Active: 8 hours ago
Posts: 142, Visits: 211
One of the reasons for my restoring my 55 T-bird is that it leaked from every possible location-engine, transmission, rear end, and steering box. So far, I find no signs of leaking from the rear end, but I'm still working on the restoration. What advantage to you expect to get from using synthetic gear oil, and how often/how hard do you intend to drive it?
57RancheroJim
Posted Last Week
View Quick Profile
Supercharged

Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)Supercharged (1.4K reputation)

Group: Forum Members
Last Active: Last Week
Posts: 650, Visits: 96.3K
57RancheroJim (1/14/2021)
I'm thinking they must have newer seal materials that can handle synthetic. The old seals don't like it. When I took my 9" in to have new gears, bearings etc I was told there was no problem using it. This was by Hoopers who build tons of rear ends. So this was the first time I used synthetic and I'm reaching the 10,000 mile mark with no leaks.
My 57 is my daily driver. I've made several runs at 95mph across the desert. 95 is about my limit with 3.89 gears and OD and a small 390 cfm carb. I do lots of hiway trips running 65-75 for hundreds of miles. I only used it because I got it for free from a friend. If you have old seals I wouldn't recommend it

charliemccraney
Posted Last Week
View Quick Profile
Supercharged

Supercharged (9.1K reputation)Supercharged (9.1K reputation)Supercharged (9.1K reputation)Supercharged (9.1K reputation)Supercharged (9.1K reputation)Supercharged (9.1K reputation)Supercharged (9.1K reputation)Supercharged (9.1K reputation)Supercharged (9.1K reputation)

Group: Moderators
Last Active: 5 hours ago
Posts: 5.8K, Visits: 97.2K
The differential manufacturer may specify mineral oil.  You'd have to ask them for  the precise reason why.

Non synthetic is strongly recommended by the manufacturer of the differential in my truck.  It is a geared differential rather than clutch and it apparently works best with non synthetic and without friction modifier.


Lawrenceville, GA
slumlord444
Posted Last Week
View Quick Profile
Supercharged

Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)Supercharged (2.0K reputation)

Group: Forum Members
Last Active: 6 hours ago
Posts: 1.1K, Visits: 110.5K
Want to use synthetic because it's supposed to be better. 
KULTULZ
Posted Last Week
View Quick Profile
Supercharged

Supercharged (2.6K reputation)Supercharged (2.6K reputation)Supercharged (2.6K reputation)Supercharged (2.6K reputation)Supercharged (2.6K reputation)Supercharged (2.6K reputation)Supercharged (2.6K reputation)Supercharged (2.6K reputation)Supercharged (2.6K reputation)

Group: Forum Members
Last Active: Yesterday
Posts: 1.0K, Visits: 197.8K
We get asked this question almost every day, and the answer is straight up, you should only run 85W-140, API GL-6 rated conventional (non-synthetic) gear oil in a Currie axle assembly. You may hear about how synthetic gear oil provides reduced friction and wear; however, it may not be optimal for your setup – especially if you have a Ford 9-inch rearend. Hear us out.


SOURCE - https://www.currieenterprises.com/why-run-conventional-gear-oil

CURRIE is stating to use non-syn in their assembles only.

If using a SYN in non-CURRIE application(s), you would follow the manufacturers recommendation and/or the refiners recommendations.


W (BY GOD) V - EASTERN PANHANDLE
____________________________
http://forums.y-blocksforever.com/uploads/images/263cb1eb-8476-41ea-8345-eb66.gif







Reading This Topic


Site Meter