mixing vr4 rs trans and original trans

pj91gsx · 06-28-2008, 02:20 PM

I want to use my jdm transmission so I am going to swap parts. So far I am going to swap the first gear and center differential to change the gear ratio. I was wondering what else I should change. Is the 5th gear in the jdm or my original transmission better for daily driving?

twicks69 · 06-28-2008, 03:22 PM

Why don't you just install the JDM GVR4 transmission instead?

The 1st gear may have a longer gear ratio, but it is weaker than the stock gear. As well, your 1G AWD shares the same 5th gear ratio with a GVR4, so it would be a waste of time.

So, the only benefit you would have is a slightly longer, but weaker 1st gear. You pick.

pj91gsx · 06-28-2008, 04:11 PM

The gear ratio is different so I cant install it without changing the center differential so I thought I might as well change 1st gear too. I want to use it because the transmission has low mileage and is in better condition then original.

Cesar · 06-28-2008, 11:08 PM

you'll have to press bearings out to swap gear ratios, no?

twicks69 · 06-29-2008, 02:23 PM

Yes, you would have to press off the tapered roller bearing on the intermediate shaft and swap the 1st gear, along with replacing the input shaft with the JDM input shaft, new tapered roller bearings and new bearing races installed, along with swapping center differentials with new tapered roller bearings and races.

It isn't a 5-minute job to say the least.

If you end up doing it, I would reccomend knowing what you are getting into before dissassembly. Also, if you are going to be pulling off the 1st gear, you will want to replace the tapered roller bearings on the input shaft, intermediate shaft, and center differential, along with the output shaft, bearing races, snap rings, etc. As well, it is worth doing new synchros and inspecting the 1/2 and 3/4 hub and sliders. The parts aren't always interchangable, so if you are going to just toss them into the other transmission, you may be having more problems than you are expecting.

On top of all that, then the transmission will need to be properly re-shimmed since you are replacing tapered roller bearings.

pj91gsx · 06-29-2008, 04:23 PM

Would I have to buy any parts to do this conversion? How is reshimming done?

twicks69 · 06-29-2008, 08:23 PM

Quote:

Originally Posted by pj91gsx

Would I have to buy any parts to do this conversion? How is reshimming done?

You should read up on here, along with checking out:
1G Transmission Rebuild
2G Transmission Rebuild
Center Diff Swap
Gearset Identification based on vehicle year

These links will hopefully give you a little more insight on what is necessary to do for transmission rebuilding/swap work. I would suggest letting a professional do it for you.

pj91gsx · 06-29-2008, 08:35 PM

Quote:

Originally Posted by twicks69

You should read up on here, along with checking out:
1G Transmission Rebuild
2G Transmission Rebuild
Center Diff Swap
Gearset Identification based on vehicle year

These links will hopefully give you a little more insight on what is necessary to do for transmission rebuilding/swap work. I would suggest letting a professional do it for you.

Thanks, I want to learn to work with transmission so Ill figure it out. The 1st gear in the vr4 rs transmission is weaker right? If I put my 1st gear in the vr4 transmission will it be strange going from the 1st gear to the 2nd gear jdm gear. In other words, If I shifted at 3,000 in first gear would the 2nd gear be geared so different that it would start up at a low rpm like 1500?