Differential Gear Oil & Transmission Oil

[umangu]

Hi People,

What do you recommend for my 66 Mustang for:

1. Gear oil for 8.75" differential
2. Transmission fluid for C4 (3 speed automatic)

I'm most comfortable with Penrite.

Thanks!

[Chris66pny]

I used the below, has been great so far. Curious to see what others are using also.

https://www.sparesbox.com.au/part/penrite-gear-oil-80w-90-2-5l-go80900025?gclid=CjwKCAjwnef6BRAgEiwAgv8mQTR01Qv3AR6VsEYUlEJszH8BGvwciAa1TLVmxcYaprfE5HtZTxdB-BoCgwYQAvD_BwE

https://www.sparesbox.com.au/part/castrol-transmax-type-f-automatic-transmission-fluid-4l-3371519?gclid=CjwKCAjwnef6BRAgEiwAgv8mQcXBBqolRwwV0UXmulLsb6R3QBVrXBp1MuL6F8oVwjXqHsj0ke3gsRoCcc0QAvD_BwE

[AussiePhil]

Hey Umang,
You don't mention if it's a limited slip diff, makes a big difference but Penrite very popular!
With the C4 just Dextron lll, you can't get the original Dextron ll anymore! I used Shell Dextron lll even though I have a T5 manual transmission. Nulon are also good and they have a squeeze container for easy filling!
But I've found Penrite OK in my Diff and Engine.
Cheers Phil.

[pgold]

If I remember correctly type F for ford C4, FMX and power steering. DEX 11 & 111 is a GM formula I think??? But happy to be corrected.

[GLENN 70]

Std open diff 80w90 mineral base oil  . LSD diff LS90 . Transmission , penrite AFT 33 type F is best .

[AussiePhil]

Hi all,
Sorry, seems that I'm wrong about using dextron lll in a C4 transmission.
You should use type F transmission fluid.
Penrite do a type F.
Cheers Phil.

[cap70]

Std open diff 80w90 mineral base oil  . LSD diff LS90 . Transmission , penrite AFT 33 type F is best .

this is what i use in mine. and both penrite brand oils

[umangu]

I don't know if I have a limited slip diff. Is there any way to find out?

[scedd1]

foot on brake, rev to 4000 rpm, release brake, test result in mirror   

[umangu]

 

OK, I googled it! When I jack up my rear next....

[GEOFF289]

Jack it up, turn a wheel. If the other wheel turns the same way you have an LSD, if it turns the other way or stays still, you don't.

[AussiePhil]

foot on brake, rev to 4000 rpm, release brake, test result in mirror   
[/q3uote]

It il be a onesy or a twosy!

Cheers Phil.

[Glen Mach 1]

Hi all,

Just did a search on this topic to understand what best to use for a similar situation:
1969 Mustang 351
9 inch diff
c4 trans auto

Is the advice in earlier posts still valid for the best product to use?

I'm looking to remove the plate and give it a good clean - what is best to use for the gasket between the plate and diff?

Thanks

Glen

[FB.65.68.70]

Glen
go to the Penrite oil webpage
https://penriteoil.com.au

use the 'product selector' then select vehicle type
then chose your car and it will tell you 'all' the oils to use in your car, engine, trans, diff etc.
if your still unsure there is a 'chat' that you can ask questions of one of their techs.

worth the time
regards
Mark