1G 3000gt vr4 rear diff swap progress

[SasaniFab]

So I finally decided to take the plunge and do the swap. For a auto car you need a 6 speed diff, the cups and stock rear axles. The axles need to be shortened , dss offers a set of bars made out of 300m.The 1g driveshaft flange needs to be drilled into the 3000gt pinion flange. The subframe then needs to be chopped down to accommodate for the larger pumpkin. The only thing left for me to do it box in the subframe and weld in the mounts and mustache bar I fabricated.

 

[bastarddsm]

You have to be very careful how you mount that diff, or you will break the rear cover if you have any power.

 

[SasaniFab]

You have to be very careful how you mount that diff, or you will break the rear cover if you have any power.

I will be reinforcing the crap out of the subframe and mounts...

The mounts will be 1/4 inch plate , I know there are a lot of forcing being applied that I need to account for

 

[SasaniFab]

She’s mounted, now I understand why nobody has any tutorials,it’s a lot of work getting the diff to fit. I’m happy overall..

 

[SasaniFab]

Diff is installed and mustache bar is 90% completed. Almost ready for testing

 

[SasaniFab]

Mustache bar is finished , just need to get the car back together

More

 

[bastarddsm]

Not to be a dick, but first time that car leaves hard it is very likely the diff is going to leave the car.

 

[SasaniFab]

Not to be a dick, but first time that car leaves hard it is very likely the diff is going to leave the car.

Guess we’ll find out
Care to elaborate?

 

[bastarddsm]

How many fasteners holding it in the subframe?

 

[SasaniFab]

How many fasteners holding it in the subframe?

Total including mustache bar..... 9, 3 on each side and 3 on front of diff cover. I can’t take the diff out without dropping the subframe , installing the bolts is difficult as I added a lot of bracing to the mount

 

[bastarddsm]

It's a good start, but it's likely going to rip em loose and kink your mustache brace, or break the rear cover. Seen that happen to several.

 

[ist dwa]

They can be ripped out, but you need lots o power to do so and launching heavily regularly.

 

[SasaniFab]

I don’t know how it would be possible for the diff to move. The diff mounts I made are welded to the control arm brackets with box steel .Its a very tight fit. Where the bolts go through I welded grade 8 washers to the steel , it’s very thick. I then went around and added reinforcement to the end of the mounts to stop flexing.

I was thinking of doing something like this with the diff cover to add some structural integrity

 

[b00stedtalon2]

This looks like a catastrophe waiting to happen. The mustache bar looks good but I would not trust those side supports.

 

[SasaniFab]

This looks like a catastrophe waiting to happen. The mustache bar looks good but I would not trust those side supports.

Guys I assure you , it’s not going anywhere....it’s solid, it’s not pretty.... but it’s solid. The car has been launched several times.... nothing has moved. I’m adding a brace to the diff cover as well. This shit isn’t going anywere

 

[SasaniFab]

I decided to tie the mounts internally, by the time I’m
Done it will be 10x stronger than Oem

Cont

 

[SasaniFab]

Ready for business

 

[bastarddsm]

What in the 7 day meth binge is that all about?

 

[SasaniFab]

What in the 7 day meth binge is that all about?

I opened up the subframe and made a structure internally to stop flexing at the top of the mounts. Then I made a brace that bolts to the control arm mounts which in my case also connects to the bottom of the diff mount.

 

[SasaniFab]

took the car on a long ride, been launching it hard..... so far so good

 

[Josh_JDTRacing_com]

More power to you for finding a way to make it work for you. How is it holding up? Still no issues?

 

[Joewy Rodriguez]

An update ? How it’s doing ?

 

[awdmonster1904]

This is very interesting. I should do this

 

[The 4ce]

Any update on how everything is running? Also...

For a auto car you need a 6 speed diff, the cups and stock rear axles. The axles need to be shortened , dss offers a set of bars made out of 300m.

Sorry to resurrect the thread. I am looking to do this same mod for my build. Can you clarify the shaft components to mate the 3kgt pumpkin to the 1g spindle? Does my following understanding of your process sound about right?

1. Swap out 1g pumpkin for 3kgt pumpkin by hacking/reinforcing rear subframe
2. Modify 3kgt pinion shaft flange to accept 1g driveshaft bolt pattern
3. Fab out new mustache bar for 3kgt rear pumpkin bolts
4. Modify 3kgt axle shaft assembly by replacing shaft with shorter DSS 300m shaft and reusing both oem 3kgt inner and outer CV joint/housings (in other words, no 1g rear axle shaft, splines, joints, housings, components etc?)
5. Swap out 1g inner axle cup (attached to spindle) with 3kgt cup to accept the wider 3kgt 4-bolt pattern

I'm mostly interested in the axle shaft mods necessary to tie the 3kgt pumpkin back to the 1g rear spindles. Where does 3kgt parts stop and 1g parts begin again?

Thanks in advance.