300zxtt Transmission

Post by **mgp87zxt** » Sat Sep 27, 2003 2:40 pm

I have heard that the 300zxTT transmission will bolt up so I am assumeing that the bellhousing bolt patterns are the same?

also others have said that the transmission is much shorter and the shifter would not line up.

How much shorter are we talking about here?

Is there enuf room to move the rb engine "without cutting the car" back to where the 300zxtt box will line up with the s13 shifter hole?

If anyone has had the transmissions side by side please let me know.

Post by **hurddawg** » Sat Sep 27, 2003 2:40 pm

why don't use just use the RB transmission?

either case you'll have to fab a driveshaft (unless its a RB20, then stock 5-spd driveshaft is ok)...

Post by **mgp87zxt** » Sat Sep 27, 2003 2:40 pm

And if I get a clip with the rb25det with a manual trust me Ill use it.

Post by **Nameless EJ6** » Sat Sep 27, 2003 2:40 pm

It's quite a bit different.. I don't think it would work. The bellhousings are different.. but you can swap it with an RB.

Here's a pic of the shifter so you have an idea of what you'd be dealing with.

This particular one has an RB bellhousing..

Post by **hurddawg** » Sat Sep 27, 2003 2:40 pm

i know someone tried to mod a z32 transmission in their KA-T s14. But i dunno what happened. That about 2 yrs ago.

Post by **davehoos** » Sat Sep 27, 2003 2:40 pm

good to show the picture.shows how most nissan boxes are similar.old 71 and newer 81 mm box.you can see that the engine mount are around 1 inch on most models..as the front mounts on nissan products nissan vary about the samethe short main shaft is shorter by about the same as the L6 TO L4/V6 engine length difference.4.5 to 5.5 inch. .the tail shafts come in a few different dia splined shafts.but as you cut shut to suit not an issue.the diameter of the box can be a problem,the FS5W71C box comes in most of the different lenghts and a few strange gearstick combinations but all have the small splined shaft.the 81mm box has a larger spline like the auto and is very round so often the tunnel requires reshaping.the holden RB30ET has spacer fitted to the rear crossmember to get it in.

later gear boxes are doing away with speedo drive so this can be a issue fo older cars.

Post by **Nameless EJ6** » Sat Sep 27, 2003 2:40 pm

I didn't really understand alot of what you just said. Have yo been drinking?

I'd like to hear more about them..

Post by **davehoos** » Sat Sep 27, 2003 2:40 pm

there are two main nissan gearboxes that have been around since the 1980's.then there is the borg warner and the newer 6 speeds.

the common 71 mm box[distance between the shafts]FS5W71C [FS5W71B before 1985] has a small output shaft.

and the 81 mm box.FS5R30A [Z32 RS5R30A] has a larger type the same as the auto.these can be very wide and wont fit in some models.

due to the fact that most nissan are basicaly the same platforms,the transmissions are similar lengths.long or short.the short transmission is about the same amount shorter as is the 4 cyl and 6 cyl engine.the idea is they use the long box on the 4 cyl to get the stick in the same spot.4 cyl nissans that have the long box when sold with a optional longer engine will have a longer nose and wheelbase.due to a few differnt clutch setups some have 1 inch longer front housings and some nissan products the front engine mounts maybe 1-1.5 inch different so the gear box mount may be moved a little.

lots of differences inside the box to get the many ratios needed.but most are intechangable as gear sets.also there are remote shifts like the Z32 and steer columb shift models.

Post by **Nameless EJ6** » Sat Sep 27, 2003 2:40 pm

Cool thanks. Do you happen to know what 300tt transmission I would want to get if I was to swap out the gearsets into an RB25DET gearbox?

I haven't found anyone who has done this yet.. just people saying it is possible.

Post by **hurddawg** » Sat Sep 27, 2003 2:40 pm

90-96 as the older 300Zs has the 71C, which is the same as the 240, I believe

Post by **davehoos** » Sat Sep 27, 2003 2:40 pm

R33 RB25DET use the larger 81 mm box as per the Z32 tt.so the front housing is different to suit the engine,and the main[output] shaft and shift linkages will be different.On all nissan boxes the constant mesh gears are matched.these [imput gears]can be different numbers of teeth to give wide/close ratios..the only ones i have listed 22/32[3.325 1st] and 20/33 [4.061 1st] there will be others in between.RB25DE use the 71C so the gear sets from way back to the 71B can be fitted,[bearings are larger on the 71C]

Post by **Nameless EJ6** » Sat Sep 27, 2003 2:40 pm

I know the bellhousing is different, and I know how gear ratios work.. what I'm wondering is what year of Z32tt transmission I'd need to buy to swap the gears and synchros over to the RB25DET box.

Post by **PROJECTRB240SX** » Sat Sep 27, 2003 2:40 pm

OK NOW WHAT ABOUT THE RB20DET? CAN I USE S13/14 GEARS, 300ZX PRE 90 GEARS, ETC.? WELL I WANT TO BUILD A CUSTOM GEAR SET FOR MY transmission WHEN I DO THE REBUILD.

Post by **hurddawg** » Sat Sep 27, 2003 2:40 pm

Nameless EJ6 wrote:I know the bellhousing is different, and I know how gear ratios work.. what I'm wondering is what year of Z32tt transmission I'd need to buy to swap the gears and synchros over to the RB25DET box.

He and I told you 90-96 300ZX TwinTurbo (Z32) the trannies are the same through that period.

Post by **davehoos** » Sat Sep 27, 2003 2:40 pm

All rb20 use the 71C long box.[not certiain about Z31 200ZR]

the DET has more ribs in the casing to reduce beaming.also has different gear sets but they look the same and same number of teeth ect..

the SOHC RB20 have wider ratio. 1st gear.3.5:1

Some 71B boxes have 71C bits.speed drives and bearings are different on some boxes.also there are about 3 different synchro setups.

Post by **PROJECTRB240SX** » Sat Sep 27, 2003 2:40 pm

SO IF I WAS BUILDING A CUSTOM GEAR SET I WOULD FIND ANY GEARS FROM A 71C STYLE TRANSMISSION?

ALSO FOR SYNCHROS AND OTHER TRANSMISSION PARTS WHAT WOULD I CROSSREFERNCE TO SO I CAN STRENGTHEN THE transmission.

Post by **davehoos** » Sat Sep 27, 2003 2:40 pm

the constant mesh gears[imput] are a set.the overdrive is a set.reverse is a set.the other gears,1,2and 3 are a complete set as the cluster is one piece.so there is not much you can strengthen.nismo have sold gear sets inc straitght cut gears.i looked at a trust set and cheeper to buy new cars.

i replace the allot front cover with a cast one of comercial vehicles.

Post by **PROJECTRB240SX** » Sat Sep 27, 2003 2:40 pm

WELL I WANT TO PUT OUT MORE POWER THROUGH MY RB20 AND I KNOW ITS GOING TO NEED A transmission JOB PLUS I WANT TO CHANGE GEAR RATIOS.

Post by **Nameless EJ6** » Sat Sep 27, 2003 2:40 pm

hurddawg wrote:He and I told you 90-96 300ZX TwinTurbo (Z32) the trannies are the same through that period.

I saw your post. You said I "believe".... so you really didn't know for sure.

I want to find someone who KNOWS this ****, not believes it or has heard it through the grapevine.

Davehoos, can you elaborate on this?

"and the main[output] shaft and shift linkages will be different"

What do you mean by "shift linkages"? Are you saying the shift forks inside the transmission? Or the shifter linkage on the outside of the box?

And you are saying the output shaft is different? Is that going to give me problems or something?

thanks

Post by **hurddawg** » Sat Sep 27, 2003 2:40 pm

dude I got that from davehoo's post... the Z32 is only from 90-96. No other TwinTurbos or any other Z32s 300ZXs. So far he hasn't said anything to say I am wrong has he? He has posted a couple times since my post.

P.S. the "I believe" was refering to older 300Z having the 71C as the gearbox

. That is what I wasn't sure of.

Post by **Nameless EJ6** » Sat Sep 27, 2003 2:40 pm

but so far no one can give any information as to what EXACTLY can be swapped between the gearboxes.

What gears? What shafts? What synchros? What hubs? Etc? Know what I mean? Or entire gear clusters?

Post by **davehoos** » Sat Sep 27, 2003 2:40 pm

the out put shafts are different in some boxes.but the Z32 TT is a short box so the output shaft is short.Z32 is a remote shift box but can be converted back to a floor shift but in most situaton the stick would be in the radio..

you need to change the output shaft to suit the rear housing.

if you ever see a nissan manual over hauled you will see that they consist of the front casing,middle bearing plate,and the rear casing.if you split the front and rear all the gears and selector forks stay with the middle plate untill you pull it all apart.From the gear stick inside and out side the box is a shift rail.this fits into the three selector rails that are part of the middle box.the rear selector mechanism is different from box to box to suit the aplication.

Post by **Nameless EJ6** » Sat Sep 27, 2003 2:40 pm

Please make this easy to understand..

I want to use the internals from a Z32TT transmission and put them into an RB25DET transmission.

Can you tell me what problems I might encounter?

I don't even want the z32 case.. I just want the internals. GEARS, SYNCHROS, SLEEVES, HUBS, SHAFTS, ETC..

Any problems with that? You say SOME output shafts are different? Do you happen to know which ones?

Post by **hurddawg** » Sat Sep 27, 2003 2:40 pm

Nameless EJ6 wrote:but so far no one can give any information as to what EXACTLY can be swapped between the gearboxes.

What gears? What shafts? What synchros? What hubs? Etc? Know what I mean? Or entire gear clusters?

ok I understand what you are talking about now. It all makes sense now.

Post by **JCAP_Tuning** » Sat Sep 27, 2003 2:40 pm

That being the case, the KA gearbox would more than likely work bolted up to a RB bellhousing, probably would be a better fit.

300zxtt Transmission

300zxtt Transmission

got lots of z parts

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