BlackBeaut Posted September 28, 2005 Share Posted September 28, 2005 Hey All, For my sins I've been planning to swap in a T5 box from an early Z31 Turbo - before you say things like "are you mad" etc. Yes, is the simple answer Being UK based we never got the 280ZX Turbo. I also know that the Z31 T5 box is not the worlds greatest but it should be OK for what I need, for a while at least. Anyway, I got hold of a box with only 40k on it, turns nicely and gear selection is fine. I managed to get hold of a 280ZXT bell housing, which conveniently had the input shaft with it, in near new condition, which is pretty handy as the Z31 input shaft is about 6cm longer then the 280ZX. So today I took the tranny to the local shop so they could swap them over and do all the fiddly stuff with bearing preload shims. Anyway, he pulls the Z31 shaft and it's got 23 teeth on the lay gear. The 280ZXT only has 22. The shaft and gear are one piece. Rats. So I'm a bit stumped now as to what I can do to get this box to work. One suggestion has been to machine the gear down on the 280ZXT shaft, machine the Z31 gear off, and cunningly combine the two again, maybe spline where the gear mates to the shaft. Another would be to cut 6cm out of the Z31 shaft and weld back together. Neither of which strike me as being the strongest options. Anyway, I'm a bit bummed to have got so close to fitting the gearbox to be shotdown at the last minute, so has anyone got any cunning ideas for a work around here? Cheers, Rob Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 28, 2005 Share Posted September 28, 2005 Why can't you just have the end of the long shaft cut down and new pilot and splines machined onto it? I've heard of people resplining axles for shortened housings on tubbed drag cars, this doesn't seem fundamentally any different. Quote Link to comment Share on other sites More sharing options...
BlackBeaut Posted September 28, 2005 Author Share Posted September 28, 2005 Alas, the shaft narrows down after the splined section but about 1mm in diameter. A guy has suggested having the shaft built up on an automatic welder (unfortunately I don't have one in my shed) as a possibility to allow resplining though. Presuambly the shafts are hardened and would require re-hardening after machining? Cheers, Rob Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 28, 2005 Share Posted September 28, 2005 Could you get a custom clutch disk with a different spline setup? I seem to remember someone here doing that to use a different transmission with a stock flywheel. 10,000 rpm clutch maybe? I'm a little fuzzy on it, but you might search and find something. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 28, 2005 Share Posted September 28, 2005 Another thought: Could you put a thick spacer between the bell housing and the input shaft to get the appropriate spacing? Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted September 29, 2005 Share Posted September 29, 2005 Another thought: Could you put a thick spacer between the bell housing and the input shaft to get the appropriate spacing? Wow genious i would of never thought of that. Quote Link to comment Share on other sites More sharing options...
BlackBeaut Posted September 29, 2005 Author Share Posted September 29, 2005 Well not much progress on this today. I've got a tranny company having a think about it, who may or may not come up with a plan. Not toooo keen on the idea of a 6cm spacer to be honest. Apart from being a PITA to have made up, it will shift the lever back, possibly too far. I'm wondering if it would be possible to fit a shaft from a WC box in to a NWC. Looking at the 23 Tooth/10 Spline 9 1/4" Input Shaft Part# 1352-085-025 these guys list: http://www.astroperformance.com/products/79-95/T5_parts/t5_parts.htm If the 9 1/4" is the overall length then that's about 1/4" shorter than the 280ZXT shaft, the tooth count on the lay gear is correct, so you'd kinda hope it would mesh with the counter shaft. Obviously the shaft is a larger diameter, think Ford 10 spline is 1 1/8"? Big question is would the brass synchro ring from the NWC fit on the end, and would the loose roller bearings fit inside it. If it did all work then I'd have to option of sticking with the larger shaft and sourcing a friction disc to suit, or presumably I could get the shaft ground and re-splined to Nissan specs. Anyone got a clue as to what the difference between the 1352-085-025 shaft and the 1352-085-050 & 1352-085-055 shafts are further down the page? As in what's the pocket bearing about and why doesn't the 1352-085-025 have it? PITA*100!! The 200/240SX gearbox swap is starting to look more reasonable, but having everything else with the T5 box in place, it would be just soo good to get it to work. Plus it's stupidly light, if I can lug it around then it's gotta be light!! The 5 speed I pulled from the car was much heavier. PITA*1000!!!! Cheers, Rob Quote Link to comment Share on other sites More sharing options...
BlackBeaut Posted October 1, 2005 Author Share Posted October 1, 2005 Well I got to look at a World Class input shaft today. Unfortuantely the WC synchro/baulk ring has a smaller internal diameter, so that route is a no go. Would've been nice if Astro Performance had answered my email about this though, although I'll give them a few more days, maybe they''ve got stuck in their shop basement looking for the perfect shaft for me I think tomorrow (barring rain) I'll stick the 300ZX shaft back in the box and mate the box - minus bell housing - up to the car to see how bad a fit it is, see where the shifter would end up. I've actually got a short shift kit so I could maybe work around the shifter being a little too far back by assembling the stick in a different way. Course then I'd have to come up with that spacer thing for the bell housing. This would be why you guys just stick V8s in right? Cheers, Rob Quote Link to comment Share on other sites More sharing options...
BlackBeaut Posted October 2, 2005 Author Share Posted October 2, 2005 Well with the 300ZX shaft I couldn't even get the box in position to raise it fully up to the clutch, so that's that. I'll see if I ever hear back from the various tranny shops I've contacted, otherwise it's time to check out the 200SX gearboxes. Cheers, Rob Quote Link to comment Share on other sites More sharing options...
zmech Posted May 29, 2008 Share Posted May 29, 2008 I put a WC T5Z trans into a Z31 before. The shafts are way different and I was in a similar predicament. However Liberty Gear came to my rescue. They took both shafts and cut them under the bearing and then combined the gear and front part of the shaft. It came out perfect and is still working for me 4 years later. I recommend them for your predicament. http://www.libertysgears.com/services.htm Quote Link to comment Share on other sites More sharing options...
evildky Posted May 30, 2008 Share Posted May 30, 2008 Could you get a custom clutch disk with a different spline setup? I seem to remember someone here doing that to use a different transmission with a stock flywheel. 10,000 rpm clutch maybe? I'm a little fuzzy on it, but you might search and find something. I know your next responce was more on point but just wanted to point about that all 70-96 Z's use the same imput shaft splining, I guess I can't confirm all, but 70,78,83T 85na, 87T, and 91TT are allt he same, so I assume all the others are as well, oh and the 240sx Quote Link to comment Share on other sites More sharing options...
Mike C Posted May 31, 2008 Share Posted May 31, 2008 Is it no longer possible to get the countershaft gear cluster? The labor is expensive compared to the parts. I think the Nissan T5 for the L6 has the same gear ratios as the Ford SVO trans. How do the rest of the Z31 gear ratios compare to the L6 trans? Was it just in Japan that the Z31 had an L6 in it? I thought the Euro cars were L6 as well and not V6? Quote Link to comment Share on other sites More sharing options...
zmech Posted May 31, 2008 Share Posted May 31, 2008 Is it no longer possible to get the countershaft gear cluster? The labor is expensive compared to the parts. I think the Nissan T5 for the L6 has the same gear ratios as the Ford SVO trans. How do the rest of the Z31 gear ratios compare to the L6 trans? Was it just in Japan that the Z31 had an L6 in it? I thought the Euro cars were L6 as well and not V6? No L6 engines in the Z31. Quote Link to comment Share on other sites More sharing options...
Mike C Posted June 2, 2008 Share Posted June 2, 2008 My mistake. I remember reading that the bump in the hood was to clear an L series motor, but none were installed as you noted. But it was designed to clear an inline 6: you could get an RB20DET in the '85 Fairlady Z. Called the Fairlady 200ZR. This is from the Wikipedia 300ZX page: On the home market, the Z31 also came with a 2.0 liter motor. The 200Z, 200ZG, and 200ZS used the VG20ET motor while the 200ZR had the RB20DET. My memory has only partially failed me! Quote Link to comment Share on other sites More sharing options...
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