Best/easiest replacement for quadratrac amc 20

[tthstrm179]

I know that this question has probably been asked before, but I did not find an answer yet.

I have a 78 CJ7 with the AMC 304 and QuadraTrac with low range. The Jeep is mostly stock and I want to upgrade the one piece rear end. The Dana 20 is the QuadraTrac rear end with the passenger side drop.

Which rear end would be a drop in replacement? I want to stay with the Dana 44 line, so I'm looking for a make/model of a donor vehicle.

The other option would be to put in a Dana 20 from a wagoneer donor vehicle that will bolt up to the GM Turbo 400 . I'm hesitant on doing this due to the overall cost of the project when replacing drivelines and misc. work.

Any thoughts or experience with this?
Thanks in advance guys.

 

[Petescj]

There is no drop in replacement for the Off set AMC20 rear axle.

 

[lutry]

What is your expectation for the upgrade?
Sorry, I did not get your point here, why you want to upgrade, maybe
due to my different mother tongue.
One piece axles are available, but I am not sure, if this is what you mean.

 

[tthstrm179]

The reason for the upgrade is that the cost of 1 piece axles is about equivalent to the cost of many used Dana 44 's that already have a locker installed.

As for my second option, if it were required in order to change the rear end, I would get rid of the QuadraTrac -mostly because I am not entirely familiar with it.

Thanks

 

[Petescj]

I thought you meant complete axle replacement , housing and all. If you just want to upgrade the shafts to 1 piece that you can do:



http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=13&cad=rja&ved=0CGgQFjAM&url=http%3A%2F%2Fwww.4wheelparts.com%2FDrivetrain-Differentials%2FAMC-20-Quadratrac-CJ-Rear-One-Piece-Axle-Kit.aspx%3Ft_c%3D12%26t_s%3D237%26t_pt%3D5564%26t_pn%3DG%252F296-2025-2&ei=95z2UvbvCMTD0gHN5oHIBw&usg=AFQjCNEm5AbIWDApKZUz-OqrmpFxgLO7kAhttp://www.4wd.com/ProdDetail.aspx?partNo=G/296-2025-2

 

[rufus1138]

if your going to get rid of the QuadraTrac i would go with a T-18 , atlas 4sp Transfer Case if money isnt a problem or a good ol Dana 20 if you're on a budget and have that spin Dana 44 front and Dana 30 rear, basically the stock manual driveline you would have found on the lot in 79.

 

[Saddle Tramp]

As Petecj stated there is no drop in offset Dana 44 available from a donor vehicle. If the mission is to not put any money into an AMC20 it is going to cost more.

The only passenger side offset Dana 44 rear worth anything is from a 1971 CJ. The width is the same as your 1978 CJ axle at 50.5” but the spring hanger location are not the same and would need to be moved. (There may be other issues too as I don’t claim to be an axle expert.) The 1971 Dana 44 rear has 30 spline one piece shafts but most likely the gearing will need to be change to match your front. The other option mentioned was to go with a FSJ Dana 20 Transfer Case bolted to the GM Turbo 400 you have but the QudraTrac version has about a 12” output shaft and the two boxes will not marry without an adaptor and new output shaft. The parts alone would cost $600-$700 so if you want to go that way it would be better to get the Transmission and Transfer Case from the FSJ donor vehicle. (Then is the donor tranny OK or need to be rebuilt?) Of couse with a centered Transfer Case then the rear axle needs to be changed too. For a 1978 CJ one option is a 1972-1975 CJ Dana 44 axle, 30 spline one piece shafts but like the 1971 version the spring hangers would need to be moved; the width is the same. (Again there may other issues same as the 1971 axle that I am not aware.) The best Dana 44 centered differential swap for a 1978 CJ the rear end out of 1972-1973 Commando; 30 spline one piece shaft and a direct bolt in. With any axle swap gearing usually isn’t the same and that costs needs to be figured in.

Petecj is a big fan of beefing up the AMC20 and if the piggy bank is short then that just may be the best answer.

 

[Petescj]

Petecj is a big fan of beefing up the AMC20 and if the piggy bank is short then that just may be the best answer.

I am mainly for that reason. Im even more of a fan for it if he wants to keep the QuadraTrac .

 

[Saddle Tramp]

I am mainly for that reason. Im even more of a fan for it if he wants to keep the QuadraTrac .

Agreed.

 

[Red River Mafia]

I'm doing a similar project with a 79. I was able to find a project CJ with the right setup for less that what I would have spend on the conversion parts and labor.


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