Model 20 and Dana 30

[Germy]

Is there anything to watch out for when changing fluids? I know the past owner and owner before him did not. Are there problems resealing, leaking? While in there can I find out the gear ratio?

 

[Incommando]

Make sure the sealing surfaces are clean before re-attaching the covers. The ring gear may have the gear ratio stamped into it. For example: 41-10 would be 4.10 gears. M-20 also has a code stamped on the outside to tell you:

Narrow Track AMC20 :

Code Gear Ratio Diff Type
AA 2.73 Open
DD 2.73 Trac-Lok
BB 3.31 Open
CC 3.31 Trac-Lok
A 3.54 Open
N 3.54 Trac-Lok
GG 3.73 Open
Q 3.73 Trac-Lok
L 4.10 Open
M 4.10 Trac-Lok

Wide Track AMC20 :

Code Gear Ratio Diff Type
D 2.73 Open
DD 2.73 Trac-Lok
B 3.31 Open
BB 3.31 Trac-Lok
A 3.54 Open
AA 3.54 Trac-Lok
H 3.73 Open
HH 3.73 Trac-Lok
C 4.10 Open
CC 4.10 Trac-Lok

As the gears inside may have been changed the best way to be 100% sure is to count the ring gear teeth and divide by the # of teeth on the pinion gears. Don't be alarmed if the front and rear are slightly different, say 3.54 & 3.55, as this matters not at all unless you get over about a .07 difference.

 

[Germy]

How tight on the bolts? Impact?

 

[Old Dog]

I just snug them with a ratchet.

 

[Germy]

Thanks for the info guys!

 

[Purple77CJ7]

Just pay a little extra attention on the gasket for the AMC20 . Sometimes they can be a pain to keep in place while installing the cover. Some just use RTV and no gasket. The Dana 30 is easy to do.

 

[Germy]

Here is an important question. What fluid goes in and what make is recommended.

 

[Germy]

View attachment 11562View attachment 11563

20 and 30 right

 

[Incommando]

Yep... 20 & 30.

85w-90 gear oil. Plain ol' dino oil or synthetic, your choice.

If you are going off-road a lot and may get into water I would not spring for synthetic as you need to change it often to avoid failure due to contamination.

 

[Germy]

Thanks for the info!

 

[Old Dog]

Yep... 20 & 30.

85w-90 gear oil. Plain ol' dino oil or synthetic, your choice.

If you are going off-road a lot and may get into water I would not spring for synthetic as you need to change it often to avoid failure due to contamination.

^^what he said^^

 

[Germy]

One more question, how much fluid? To the fill whole?

 

[Purple77CJ7]

Yes fill to the fill plug. The 30 I think takes around a quart. The 20 a little more than a quart, maybe 1 1/2.

 

[Germy]

Thanks, napa has the gaskets

 

[Germy]

Ummmmmm...... I counted gears. 43 ring, 14 pinion. 3.07 gear ratio. This may explain why the clutch was so bad, there are 35's on this thing. I should be at least 4.11 even on 33's right?

 

[CJim7]

Ummmmmm...... I counted gears. 43 ring, 14 pinion. 3.07 gear ratio. This may explain why the clutch was so bad, there are 35's on this thing. I should be at least 4.11 even on 33's right?

Correct..you are a little high geared for 35's

 

[Germy]

Will I damage anything by running em for a while. I understand the clutch, but motor wise.

 

[CJim7]

Will I damage anything by running em for a while. I understand the clutch, but motor wise.

No. You're powerband will be less then desireable, but that's about it.

 

[Germy]

Does 900 installed sound right for front 30 new carrier and superiors and superiors in the model 20. Mini and master kit

 

[mtnwhlr]

That sounds pretty good for parts and labor. What kind of warranty does it come with?