ATTN DTP: You won't believe it... (Z Tranny ?s)

[Kirden]

Ok so yea, this should have probably been a private message, but this is a two part question. First and formost I need to know how to identify which ZX transmission I have. See back in February our resident ZX bro, DTP, sold me a transmission and shipped it all the way from Oregon to Georgia. I had every intention of installing this transmission at the time, but the truck ran and I had no other ride. Plus the whole flywheel, clutch, clutch fork compatability thing kinda confused me. Well now I am building my LZ and I would like to overhaul the tranny and prep it for install, but I forgot which tranny I bought... I'm almost certain it was from a '79, maybe. I do remember DTP saying I would have a long first gear.

 

I figure my noobishness might actually help someone else because I remember someone mentioning that you can identify your trans by marking your output shaft and turning your input shaft so many times. Then check your output. Who ever had this information please point me in the right direction.

 

Second question is can someone point me to a dummy proof version of gear ratio explanations? Once I figure out which trans I have I want to figure out which rear end I need to have decent highway drivability. Not asking to be completely spoon fed, but please show me the way to the kitchen. Thanks and hope you guys have a great holiday season.

 

 

[I'm BLUE]

Kirden ,

 

ATTN Kirden: --- you and I have long winded replys .. :lol: ;) :D ( the way it should be right ? lol )

indeed you ended up with the 79' 280zx tranny (out of the lower miler 2+2 that was being restored  ;) ).

Your clutch stuff ... for transfer .. keep your existing clutch fork , clutch collar w/throwout bearing , pressure plate , and disc as a matched set and just simply transfer it all over to the new zx tranny. Done :cool: .. don't over think it .. I always over-think things lolol.

The later 80-83' zx 5spds have the longer (higher) numerically lower number 1st gear :)

 

Cobratransmission.com ... may or may not have a cheapo rebuild kit with bearings/synchro's/retainers. (check the shipping first before purchasing)

Don't forget to check your shift fork roll pins and the cavity's they go in :)

Use approved GL-4 fluid in the trans or there the wrong fluid will eat the "yellow metal" as time progresses.

make sure your kit has at least the input shaft pocket bearing.

You can somewhat measure the synchro wear before tearing the transmission down as you know :).

Rebuilding a trans really isn't too bad , but make sure you have a press of some kind and bearing seperators/pullers :cool:

Take pictures of everything and a dedicated space essential bro (Ima pig lol).

 

 

The gear ratios are as follows for 77-79 z-car 5spds. (including yours yo ! )

1    3.321     2    2.077  3    1.308     4    1.000     5    0.864

Here is a list of gear ratios to sift through and bookmark (scroll down) ---> http://www.zhome.com/ZCMnL/tech/GearRatios.html

It's all pretty decently accurate and easy to sift through :D ... one of my favorites !

 

Also if you're asking how gear ratios work easy to remember

High numerical number (low gearing .. because lower speed in the end of the rpm powerband ranger) = Higher rpms

Low numerical number (high gearing ... because higher speed in the end of the rpm  powerband range .. think "SALT FLATS") = Lower rpms

 

 

 

Boiled down you have the "shorter" 1st and 5th gear in your transmission :) .

 

Here's some pictures for a quick identify ... shifter ear height ... fil plug location (passengers/drivers) ... exhaust hangar/casting ears number (2 is earlier , only 1 is later) ... speedo cog bolt position :)

 

 

Hope that helps ya Kirden , and hope you + yours have a great holiday season as well :cool:

Hopefully this post isn't too confusing.

 

DTP

[Kirden]

Holy cow DTP, that's awesome. You just answered it all in one swoop! This is why I wish to set up a tent on your lawn...

 

Thank you for the confirmation on the trans. That will help greatly. I still may have some questions as to which rear end I should run, but with me having the "short" first and fifth, I think I'll try my current rear end and make changes as needed. I was worried I had the long gears so I had decided on building a standard LZ for a torquey street monster but maybe I could get away with the long rod build. Time for contemplation

[I'm BLUE]

No problem Kirden ! hahaha ... I have industrial bunk-beds that you can just put a car-cover over... instead of tent ... unless you wanna run it into a giant $#$%ing bbq that's cool too ................. :rofl:

 

 

Well you'll be able to figure out the gearing fair enough really. If it were me.. ? I would just look at your power-band (or normal driving habits) ... geography and roads driven ... then use a transmission calculator to calculate out each rpm/mph/rpm drop between gears .... write out all out for both your existing rear diff , and potential diff ratios as well. Also noting your cars habits ... pretty much cuz Datsun habits ... and many times you just have to drive the dang things in order to really find out (wow what a neat concept right ? ;) )

 

A lot of these other members might be able to tell you what they like better for diffs in a 620 :cool:

 

A great example is I have a very low 1st gear in my v8 project ... like 3.53:1 ... but my rear diff that I'll be using is 2.73 .... it has plenty of torque and some to pull the light z-car right along...... that is if I ever finish it ... :rolleyes: :lol:

 

What's your current rear gearing ?

 

here is a transmission calculator ( as you know they all don't calculate the same ) ---> http://teammfactory.com/gear-calculator

 

I.. also another note ... facility's ... you can pee/shat in the neighbors bushes .... specifically the old lady that doesn't like any of my Datsun ,... trust me she's totally cool with it .... the deal is she doesn't want to see you do it ... if she does she'll call the cops ... don't be seen ! 

[07FlyingWagon]

This is a pretty epic thread! Love the responses!

 

Excuse my noobness - I assume that by LZ you mean a Z24 build, which is different than a KA 24 build? Am I right on that one, and this why you are sticking with an older trans instead of the 5'er that the KA motor uses?

 

Thanks!!!!! :)

~Marty~

[flatcat19]

This is a pretty epic thread! Love the responses!

 

Excuse my noobness - I assume that by LZ you mean a Z24 build, which is different than a KA 24 build? Am I right on that one, and this why you are sticking with an older trans instead of the 5'er that the KA motor uses?

 

Thanks!!!!! :)

~Marty~

 

No. Not quite. 

 

LZ build would mean taking a Z block and putting an L head on it. 

Normally most people use the Z22 block. 

 

Kirden...do you have a Z bellhousing already to use? Start hunting if you don't. 

[wayno]

This is a pretty epic thread! Love the responses!

 

Excuse my noobness - I assume that by LZ you mean a Z24 build, which is different than a KA 24 build? Am I right on that one, and this why you are sticking with an older trans instead of the 5'er that the KA motor uses?

 

Thanks!!!!! :)

~Marty~

 

What they mean by a LZ build is that they use a Z22 block out of a 81/82 720, and put a "L" head with all the L hardware such as the timing chain cover, oil pan for the vehicle it is going into, ect, ect, Using a Z24 block has been done also, but it is a lot more complicated.

The "Z" block has to have water cooling holes drilled in it to match the "L" head, as the "Z" head has different passages.

When you make say an LZ23 like I did, you put the "L" block mounts onto the "Z" block, so it tilts like the "L" block, so you have to use the "L" block transmission, as it is now basically an "L" block, a bigger "L" block.

I suspect that the "5'er you mentioned could be tilted incorrectly for an "L" block, that could be why they are not using it.

[Kirden]

Well technically I'm not building a LZ. I'm taking a standard l20b, boring it to 87mm, using a z22 crank, and milled 87mm vg30 pistons. So more like an l20 stroker I guess.

[Kirden]

Alright, currently I have 4.375 in the tear. I'm gonna test it with these gear because based on that calculator, this seems to fit what I want. 4.11 is another option or I could look into changing out the innerds with something lower, but I kinda doubt that's needed.

 

Oh and don't worry about the old lady DTP. I shit like a ninja

[datzenmike]

Well technically I'm not building a LZ. I'm taking a standard l20b, boring it to 87mm, using a z22 crank, and milled 87mm vg30 pistons. So more like an l20 stroker I guess.

The Z20 block is almost identical to the L20B and even runs that crank. The Z22 block is (again) almost identical to the L20B but is cast with larger bores for the 87mm pistons. The oil filter boss is different but otherwise the blocks are the same and anything from an L20B will fit it.

 

I'm building an LZ23 (probably similar to Wayno's) using a Z22 bored to 89mm and fitted with KA pistons. The Z22 and L20B rods are the same.

[Kirden]

Yea, I know, just using what I have to work with :P These are parts I sourced a while back and finding a PnP Z22 for less than $300 isn't possible around here. Found a guy with a Z22 short block, he wanted $500 for it... Got the L20B short block for $52 thanks to MM47 :)

[hosestop@msn.com]

Make Z20 with 89mm will rev, long rod less angle. I have 90mm pistons put away maybe use in a kade later.