RB25dET Tranny

[Modern]

Hey guys i was doing some searching and i stumbled on a thread saying that the rb20 and rb25 tranny would bolt up to each other. But i also looked at another post saying that the rb25deT tranny is not the same as the rb25de tranny. So to get to the point i ordered a rb26dett motor with rb25det tranny. Now i have never seen a rb25 tranny before but it looks like a sr/ka tranny and it has a cable speed sensor on it. And in the post i was reading the rb25deT tranny can handel more hp. so i ask you does all of this matter? should i call the guys i got my tranny from and have them send me the right tranny? If you have pictures side by side of the rb25det and rb20 it would help me alot.
thank you

[HitAndRunCrew]

I got alittle confused by what you were writing, but I will tell you what I know. If you want to use a RB26 then you need the RB25DET tranny. I don't think there is a big difference in the RB25DE and DET mainly because they didn't make too many non turbo 5spd RB25DE's. The RB25 tranny is head and shouders above any other 5 spd nissan tranny, including RB20, and SR20. They can handle huge horsepower compared to the others. If you send me a pic I can tell you what you have...Let me know if you need anyting else...Dave

[HitAndRunCrew]

Also, I could be way off on this, but from personal experience, I found that a RB20 tranny bolted up to a RB25 engine, and a RB25 tranny bolted up to RB26 engine, but a RB20 tranny didn't bolt up to a RB26...Don't ask me why, and I am not asking why, (don't care) just letting you know what I found out...

[TheSnail]

I don't think there is a big difference in the RB25DE and DET mainly because they didn't make too many non turbo 5spd RB25DE's.


That is wrong. There is a very big difference. Rb25de tranny is identical to a rb20det tranny. Rb25det tranny holds 2X more than the rb25de tranny. The only cool thing about having a rb25de tranny on a rb26, is that when it brakes, you just disconnect the tranny from the bell housing and use a ka, sr, Ca, or rb20 tranny. Another fun fact, is that if you are putting a rb26 in a 240, by using a rb25de tranny, then you use the stock drive shaft, just as a rb20 swapped 240. :)

PS: 26 bell + 300zxtt tranny, but that is a secret

[HitAndRunCrew]

That is wrong. There is a very big difference. Rb25de tranny is identical to a rb20det tranny. Rb25det tranny holds 2X more than the rb25de tranny. The only cool thing about having a rb25de tranny on a rb26, is that when it brakes, you just disconnect the tranny from the bell housing and use a ka, sr, Ca, or rb20 tranny. Another fun fact, is that if you are putting a rb26 in a 240, by using a rb25de tranny, then you use the stock drive shaft, just as a rb20 swapped 240. :)

PS: 26 bell + 300zxtt tranny, but that is a secret

Like I said, I wasn't sure...but that is some good info. I guess I never noticed a RB25DE tranny because you said they are the same as RB20's. So I just assumed they were RB20 trannies...you know what I mean?

Anyhow if he has a RB25DET tranny he should be fine...that was the point...

[Modern]

K this is what i have learned sofar.
rb20 is the same as the sr/ka/ca and rb25de
rb25det has the (some of) same internals as a 300zx.

i have the one on the right wich is the rb20. notice the size difference. and i wish i would have know about the driveshaft cause i already had one made for the rb25det. so i need to call the people who sent me the tranny and get the right one. thank you for the help guys. also for some more info i hear that if you have the rb26dett bell housing then you can put it on the supra six speed.

[HitAndRunCrew]

Just for your info don't expect them to just give you a RB25DET tranny because they are alot more expensive and harder to find then all of the others...

As per your info about the 6 speed swaps with different bellhousings...The same compnay makes most of the 6 speeds in Toyota and Nissan, so alot of the internals of the trannies are the same or similar (Supra 6 speed, R34 GTR 6 Speed etc...) so using different bellhousings ususally can be made to work with little or no modification...

[Modern]

Just for your info don't expect them to just give you a RB25DET tranny because they are alot more expensive and harder to find then all of the others...

As per your info about the 6 speed swaps with different bellhousings...The same compnay makes most of the 6 speeds in Toyota and Nissan, so alot of the internals of the trannies are the same or similar (Supra 6 speed, R34 GTR 6 Speed etc...) so using different bellhousings ususally can be made to work with little or no modification...

No offense guy but 1. we said the supra six speed would work with the gtr bell housing. 2nd i paid for a rb25det tranny. so they will give it to me.

[HitAndRunCrew]

No offense guy but 1. we said the supra six speed would work with the gtr bell housing. 2nd i paid for a rb25det tranny. so they will give it to me.


okay 1. I wasn't taking credit for the info... the guy that posted before me knows his shit. I was just saying that the same company makes most of those trannies that is why they work together.

2. I was just assuming they were trying to send you the cheaper tranny...

I'll make sure not to try and help you out in the future...dick

[TheSnail]

No offense guy but 1. we said the supra six speed would work with the gtr bell housing. 2nd i paid for a rb25det tranny. so they will give it to me.


We? I was talking about a Vg30dett tranny, not a Getrag 2j tranny. VG, Just extend the shift linkage, and you will have a tranny more durable then the rb25det. And it will cost you like 3-400$ rather then 8-1200$. You will be able to use your "custom" drive shaft you had made for the 25-t, since the yoke is the same between the 25-t and vg-tt.

[deep in silvia]

bump bump bump

[HitAndRunCrew]

We? I was talking about a Vg30dett tranny, not a Getrag 2j tranny. VG, Just extend the shift linkage, and you will have a tranny more durable then the rb25det. And it will cost you like 3-400$ rather then 8-1200$. You will be able to use your "custom" drive shaft you had made for the 25-t, since the yoke is the same between the 25-t and vg-tt.

That is some good info...RB25DET trannys are getting very expensive over here, but the 5spd 300zxTT are even more rare. I am sure they are little easier to find in the states. I am curious though, what do you mean " extend the shift linkage"? I know you said it straight forward, I just can't picture a shift linkage in my head. Also the 300zx tranny bolts right up to the RB26 bellhousing? And,.. if I were to install the RB26 with RB25DET or 300zx TT tranny into a S14 chassis what stock driveshaft (if any) can I use that is the same length? Thanks for the help in advance Mr.Snail...

[TheSnail]

Here in the states 300zxtt trannys are 400ish dollars. I picked 2 up last month for 500$, and can get them for cheap if any one is interested. As for the shift linkage, the 300zx tranny is shorter then a sr, rb , ka etc.. tranny. So when installed in a 240, The shifter is located 2" in front of the hole where the shifter goes into the car. The cool thing is, unlike the other trannys where the shifter goes directly into the tranny, a 300zx uses a shift linkage. Extend the shift linkage 2-4" and the shifter will be in the same location as a normal tranny's shifter. I’m not too sure about the drive shaft interchange with out modification, since the 300zxtt tranny is shorter then the rb25det tranny. If its 1" off then you could get away with it, but other then that you would have to extend the rb25 ds. They both use the same yoke, so you can make the ds with either yoke. you can not use the stock ds s13-s14 since the yoke for a ka sr rb20 is a smaller diameter. Yet another cool thing is, if you want to use the stock 2 piece ds and have the 300/rb25 yoke welded on, you would have a near stock ds for $50. I have not looked at the diameter of a 300zx/rb25 ds so it might be weird for the ds shop to weld the two parts together if they are different diameters. Though, looking in my garage I see that a s15 drive shaft is the same diameter as a s13 or 14 ds. The s15's (6spd) drive shaft has a 300zx/rb25 yoke on it, so if a 300zx/rb25 ds is too big of a diameter to have welded to a s13-14 ds, then use a s15 ds. Another thing I have been pondering about is that you can use the s15 ds when doing a s15 sr swap in a s14, since the s15 ds is a s14 ds with a larger yoke. I have a s13 so I can not use it but, since the yoke is the same as a rb25det or 300zx. I bet you can use a stock s15 ds on a rb25det/rb26-rb25t swapped s14, with out any modification to the s15 ds. There is a rb25/s14 swap going on at the shop right now so I will go up there and see if s15 ds can be used. I have a good feeling that it will. If so, s15 ds's price will sky rocket if enough s14 owners know about it. I will go check it out for you s14 guys:) Thanks for your interest HitAndRunCrew, you gave me something to do:)

[HitAndRunCrew]

Thanks Mr. snail for all of the great info...I will also check here on my end about the S15 DS length, I am super interested in doing the RB26 swap into my S14...Dave

[Modern]

okay 1. I wasn't taking credit for the info... the guy that posted before me knows his shit. I was just saying that the same company makes most of those trannies that is why they work together.

2. I was just assuming they were trying to send you the cheaper tranny...

I'll make sure not to try and help you out in the future...dick

errr like i said i didnt mean to sound like a dick but take it how you want.